WO2011128565A1 - Method for indicating slip of a coupler for distributing torque between two axles of a motorised vehicle, respective distribution control method, and vehicle comprising a system operating according to such a method - Google Patents

Method for indicating slip of a coupler for distributing torque between two axles of a motorised vehicle, respective distribution control method, and vehicle comprising a system operating according to such a method Download PDF

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Publication number
WO2011128565A1
WO2011128565A1 PCT/FR2011/050822 FR2011050822W WO2011128565A1 WO 2011128565 A1 WO2011128565 A1 WO 2011128565A1 FR 2011050822 W FR2011050822 W FR 2011050822W WO 2011128565 A1 WO2011128565 A1 WO 2011128565A1
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WO
WIPO (PCT)
Prior art keywords
slip
vehicle
threshold
coupler
axles
Prior art date
Application number
PCT/FR2011/050822
Other languages
French (fr)
Inventor
François FOUSSARD
Alessandro Monti
Nicolas Romani
Original Assignee
Renault S.A.S.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Renault S.A.S. filed Critical Renault S.A.S.
Publication of WO2011128565A1 publication Critical patent/WO2011128565A1/en

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
    • B60K17/344—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear
    • B60K17/346—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear
    • B60K17/3462—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having a transfer gear the transfer gear being a differential gear with means for changing distribution of torque between front and rear wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K17/00—Arrangement or mounting of transmissions in vehicles
    • B60K17/34—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles
    • B60K17/348—Arrangement or mounting of transmissions in vehicles for driving both front and rear wheels, e.g. four wheel drive vehicles having differential means for driving one set of wheels, e.g. the front, at one speed and the other set, e.g. the rear, at a different speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K23/00—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for
    • B60K23/08—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for for changing number of driven wheels, for switching from driving one axle to driving two or more axles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
    • B60K23/00—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for
    • B60K23/08—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for for changing number of driven wheels, for switching from driving one axle to driving two or more axles
    • B60K23/0808—Arrangement or mounting of control devices for vehicle transmissions, or parts thereof, not otherwise provided for for changing number of driven wheels, for switching from driving one axle to driving two or more axles for varying torque distribution between driven axles, e.g. by transfer clutch
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/18—Propelling the vehicle
    • B60W30/184—Preventing damage resulting from overload or excessive wear of the driveline
    • B60W30/186—Preventing damage resulting from overload or excessive wear of the driveline excessive wear or burn out of friction elements, e.g. clutches
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W50/04—Monitoring the functioning of the control system
    • B60W50/045—Monitoring control system parameters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W50/08—Interaction between the driver and the control system
    • B60W50/14—Means for informing the driver, warning the driver or prompting a driver intervention
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2250/00—Driver interactions
    • B60L2250/10—Driver interactions by alarm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2250/00—Driver interactions
    • B60L2250/16—Driver interactions by display
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/12—Conjoint control of vehicle sub-units of different type or different function including control of differentials
    • B60W10/14—Central differentials for dividing torque between front and rear axles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W50/08—Interaction between the driver and the control system
    • B60W50/14—Means for informing the driver, warning the driver or prompting a driver intervention
    • B60W2050/143—Alarm means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W50/08—Interaction between the driver and the control system
    • B60W50/14—Means for informing the driver, warning the driver or prompting a driver intervention
    • B60W2050/146—Display means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2300/00—Indexing codes relating to the type of vehicle
    • B60W2300/18—Four-wheel drive vehicles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2510/00—Input parameters relating to a particular sub-units
    • B60W2510/02—Clutches
    • B60W2510/0241—Clutch slip, i.e. difference between input and output speeds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2510/00—Input parameters relating to a particular sub-units
    • B60W2510/02—Clutches
    • B60W2510/0241—Clutch slip, i.e. difference between input and output speeds
    • B60W2510/025—Slip change rate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/26—Wheel slip
    • B60W2520/263—Slip values between front and rear axle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2710/00—Output or target parameters relating to a particular sub-units
    • B60W2710/12—Differentials

Definitions

  • the present invention relates, in a general manner, to four-wheel drive vehicles equipped with a system for controlling the distribution of engine torque between a first axle and a second axle capable furthermore of driving a coupler mounted between the two axles.
  • the first axle and the second axle the sum of the torques transmitted to the two axles being constant.
  • the first axle is connected to a transfer shaft which is secured to the second axle by means of said coupler. Only the first axle permanently receives a torque, the second axle is more or less secured by the coupler controlled by
  • the dispatch control system thus, the torque level transmitted on each of the axles can be adjusted by the control system as a function, for example, of a vehicle operating mode.
  • a first mode of operation the engine torque is fully transmitted to the first axle and no torque is transmitted to the second axle.
  • a second mode of operation a first fixed portion of the engine torque is transmitted to the first axle and a second fixed portion of the engine torque is transmitted to the second axle.
  • the torques transmitted to the two axles are constantly adjusted according to the driving conditions of the vehicle.
  • slip In four-wheel drive vehicles can further occur a slip phenomenon.
  • the slip corresponds to a difference in rotational speed between the front and rear axles. Sliding can be a normal phenomenon, in the case for example of a change of speed. It may also be the consequence of a difference in rolling radius, in the case for example of a bad tire mounts or a puncture. Slip is then permanent and it may cause warming and / or deterioration of the coupler.
  • the coupler is a mechanical transmission system which may, as an exemplary embodiment, be composed of several oil-bathed discs secured to a shaft connected to the second axle and the others to the transfer shaft.
  • the discs shear the oil whose temperature increases and then expands and thickens .
  • the pressure on the discs increases and they end up training each other.
  • the speed difference between the two shafts decreases and the temperature of the oil and the coupler decreases.
  • the discs continue to shear the oil which heats up until a possible deterioration of the coupler.
  • Patent application JP4103433 discloses a control system of the torque distribution in a four-wheel drive vehicle.
  • This system includes a torque distribution clutch, as well as slip detection means, vehicle speed and the difference in tire diameter of the four-wheel drive.
  • the system makes it possible to reduce slippage by using the torque distribution clutch while taking into account, if necessary, a difference in tire diameter.
  • Patent Application JP61275028 describes a system for increasing the maneuverability of a four-wheel drive vehicle whose wheels do not have exactly the same diameter.
  • This system is equipped with front and rear wheel speed sensors, a front and rear wheel drive force distribution device, a subtraction system and a compensating device. It is thus possible to determine a rotation speed difference between the front and rear wheels taking into account a compensation factor relating to a difference in diameter. The ratio between the torque transmitted on the front and rear axle is then controlled from the difference in speed of rotation.
  • These systems use a control of the distribution of the torque to reduce the slip but nothing is planned to protect the coupler effectively in the case of a permanent slip. They also do not allow to overcome slippage resulting from specific driving conditions. They do not propose a control system for the torque distribution integrated in the four-wheel drive management system which makes it possible to alert the user of the vehicle of permanent sliding of the coupler.
  • the present invention relates to a torque distribution control method for a motorized four-wheel drive vehicle that is capable of effectively protecting the coupler in the case of permanent sliding and in particular, to preserve the coupling of a heating due to a permanent slip.
  • the present invention also aims to protect the coupler in the case of permanent slip caused by improper mounting, a difference in wheel diameter, a slow puncture, over or under inflation.
  • the object of the invention is to detect a permanent slip and to discriminate it from a normal slip or slip related to specific driving conditions.
  • the present invention also aims to protect the coupler without unnecessarily stopping the operation of the "four-wheel drive” mode according to a compromise between the protection of the coupler and the availability of the mode "four-wheel drive” optimum and adjustable.
  • the invention further relates to a four-wheel drive vehicle provided with a computer and a coupler controlled so that it is protected in the case of a permanent slip.
  • a slip warning method of a coupler capable of distributing a torque between two axles of a motorized four-wheel drive vehicle mounted on the two axles.
  • the slip representing the difference in speed of the two axles is determined. only when certain driving conditions are fulfilled for a configurable duration.
  • an alert is sent to a user of the vehicle when the counter reaches a first configurable threshold MaxCounter.
  • it raises the alert when the counter becomes less than or equal to a second parameterizable threshold Mincounter.
  • it raises the alert when the counter is reset at start of the vehicle.
  • the counter is incremented if the two tests are checked.
  • the counter is decremented only when the average value of the slip is less than the fifth threshold and the magnitude of the slip variation Gmax-Gmin during said configurable duration MinTime is less than a fourth threshold.
  • the decrementation is only triggered in the case where the slip is in a stabilized phase, below the value of the second threshold. This avoids a decrement related to a situation particular driving behavior or the presence of measurement noise. In the case of an oscillating permanent sliding, a succession of incrementation and decrementation phases is avoided which would make the detection of oscillating sliding impossible.
  • a counter is incremented or decremented as a function of the determined slip and any transfer of torque to one or the other of the axles is suppressed when the average value of the sliding during said MinTime duration exceeds one threshold and when said counter 36 reaches a first threshold MaxCounter.
  • a four-wheel drive motor vehicle mounted on two axles comprising a transfer shaft connected to the first axle and a controlled coupler capable of transferring a portion of the torque from the transfer shaft to the second axle , means for determining the respective speeds of the two axles and a torque distribution control system capable of determining a slip value representing the difference in speed between the two axles and driving the coupler
  • the torque distribution control system is configured to inform the user by warning according to the slip warning method of a coupler of the invention.
  • Figure 1 schematically shows a motorized four-wheel drive vehicle
  • Figure 2 schematically shows the main elements of the control system of the operation of the vehicle
  • Figure 3 schematically shows the main aspects of a software implanted in the vehicle computer and allowing the protection of the coupler.
  • Figure 1 are schematically illustrated the main elements of a motorized vehicle Ve four-wheel drive with a permanent transmission of the engine torque on the front axle 2AV.
  • This type of vehicle was chosen as an example.
  • the vehicle engine may be a heat engine 3, an electric motor or a hybrid combination. Permanent transmission of the engine torque could also be exerted on the 2AR rear axle.
  • the vehicle comprises four wheels 1 a, 1 b, 1 e, 1 d respectively mounted on a front axle 2AV and a rear axle 2AR.
  • the vehicle also comprises a steering wheel 4 connected to a steering column 5.
  • the vehicle further comprises a gearbox 6 transmitting the torque of the engine 3 to the front axle 2AV and to a front transfer case 7.
  • a transfer shaft 8, driven by the transfer box 7 is connected by a coupler 9 to a rear axle transfer box 10 so as to transfer torque from the gearbox 6 to the rear axle 2AR.
  • the vehicle also comprises a computer 1 1 capable in particular of controlling the coupler 9, a mode control device 12 and a control unit 13 of the engine 3 capable of controlling the operation of the engine 3 (in particular to determine the torque exerted by the engine and to estimate the gear ratio engaged).
  • the vehicle also includes four wheel speed sensors 14a, 14b, 14c, 14d, one on each of the wheels l a, lb, l e, ld.
  • the computer 1 1 is connected to each of the wheel speed sensors 14a ... 14d by connections 16a ... 16d allowing the exchange of information.
  • the computer 1 1 is also connected to the mode control device 12 by a connection 16e, the engine control unit 1 3 by a connection 16f and the coupler 9 by a connection 16g.
  • the electrical connection 16g also allows the circulation of a control current to close the controlled coupler 9.
  • a display unit of the control panel 15 is also connected by a connection 16h to the computer 1 1 in order to display to the driver of the vehicle including the four-wheel drive mode used.
  • the four-wheel drive vehicle can, in fact, operate in three different types of operating mode.
  • a first mode of operation the gearbox 6 drives the front axle 2AV, the coupler 9 is open and does not transfer any torque to the rear axle transfer box 10.
  • This mode is called “4x2" mode, only the two wheels la and lb of the front axle being driven.
  • the gearbox 6 drives the front axle 2AV and the transfer shaft 8 drives the coupler 9 which is kept completely closed.
  • the coupler 9 therefore drives the rear axle transfer box 10 so that a maximum portion of the engine torque is transferred to the rear axle 2AR.
  • This mode is called “four wheel drive all terrain”.
  • the gearbox 6 drives the front axle 2AV and the transfer shaft 8 drives the coupler 9 which is driven by the current of the computer 1 1 so as to be more or less closed depending on the torque requested by each of the axles.
  • This mode is called “automatic four-wheel drive”.
  • the different operating modes depend on the state of the coupler 9.
  • the closing of the punctured pi coupler 9 is controlled by the computer 1 1 via the connection 16g.
  • the torque level transmitted from the transfer shaft 8 to the transfer box of the rear axle 1 0 is controlled by the computer 1 1.
  • the computer 1 1 receives information concerning:
  • the mode control device 1 2 which can be actuated by the driver.
  • This information is transmitted to the computer 1 1 via the link 1 6e; and the rotational speed of the four wheels 1a, 1d determined by the four wheel speed sensors 14a ... 14d.
  • This information is transmitted to the computer 1 1 via the four links 16a ... 16d.
  • the computer 1 1 is able to choose the appropriate operating mode.
  • the computer 1 1 is also capable of communicating to the driver of the vehicle information concerning the active mode of operation via the display unit of the control panel 1 5 and the link 1 6h.
  • the computer 1 1 is able to determine the appropriate clamping to be applied to the coupler 9.
  • the links 16a ... 16g to which reference has been made can, by way of example of realization, be branches of a bus type CAN (Controller Area Network according to an Anglo-Saxon term well known to those skilled in the art).
  • the computer 1 1 can further transmit according to the received information, a control signal to fully open the coupler 9 so as to avoid heating and or excessive wear of the coupler 9 in case of permanent slip.
  • FIG. 2 shows the computer 1 1 connected by the connection 16g to the coupler 9 and the mode control device 12 connected to the computer 1 1;
  • the connection bus 16 makes it possible to ensure the connections between the computer 1 1, the control unit 13 of the engine 3 and the rest of the control and control elements of the vehicle represented in the form of a single block 20.
  • these bodies include, for example, an AB S braking system and an AYC (Active Yaw Control) trajectory control system according to an Anglo-Saxon term well known to those skilled in the art.
  • the computer 1 1 can receive from the block 20, information relating to the driving conditions:
  • ABS braking system ABS braking system
  • parking brake brake pedal
  • the computer 1 1 can then for example send an opening control signal to the coupler via the electrical connection 16g depending on the driving conditions, the driver's wishes and the condition of the coupler.
  • FIG. 3 diagrammatically illustrates in block form the subfunctions of an opening decision software of the coupler 9.
  • the program can be integrated into the computer 1 1.
  • a first processing unit 31 receives input variables relating to the operation of the vehicle.
  • the processing block 3 1 notably receives:
  • ACF variables noted ACF. They are related to the condition of the driving assistants and braking.
  • the ACF variables can be transmitted by one or more brake management programs and driver assistance located for example in the computer 1 1.
  • brake management programs and driver assistance located for example in the computer 1 1.
  • ABS Anti-Blocking System
  • the processing block 3 1 determines whether at the same time no driving assistant (AYC, MSR, ASR), no braking assistance system (AB S) and no braking is active. If this is the case, it returns to a detection block 32 the binary value ACF OK with the value 1.
  • the processing block 31 also receives variables V, G, Cm relating respectively to the speed of the vehicle, to the slippage between the two axles and to the torque supplied by the engine to both axles.
  • the variables V and G are provided by the four wheel speed sensors 14a, 14b, 14c, 14d while the variable Cm is provided by the control unit 13 of the engine 3.
  • the speed V of the vehicle Ve is estimated from the average speeds provided by the two rear wheel speed sensors 14c and 14d.
  • the slip between the two axles is estimated from the difference between two speeds of rotation, that of the front axle 2AV and that of the rear axle 2AR.
  • the speed of rotation of the front axle may, as an exemplary embodiment, be determined by averaging the speeds provided by the two front wheel sensors 14a, 14b.
  • the rotational speed of the rear axle can be determined by averaging the speeds provided by the two rear wheel sensors 14c and 14d.
  • the engine torque Cm is estimated by the control unit 13 of the engine 3.
  • the control unit 1 3 also returns an estimate of the gear ratio engaged.
  • the processing block 31 calculates the slip expressed as a percentage with respect to the speed of the vehicle% G, it then transmits this value to a calculation block 33. From the variable Cm and from the estimate of the gear ratio engaged, the processing block 31 determines the torque exerted by the engine on the front axle Cm AV, it then transmits this value to the detection block 32.
  • the processing block 31 also receives DISP variables relating to the availability and the validity of the input information, they are used for the detection of sensor faults or input information.
  • DISP variables there are, for example, the following variables:
  • ASR traction control detection
  • the processing block 31 also determines whether the speed sensors 14a, 14b, 14c, 14d are in working order and whether the information they transmit is in working order.
  • processing block 31 determines whether all sensors are working and all required variables are available and valid. If necessary, it transmits to an activation block 35 a binary value, DISP OK, relating to the availability of the information.
  • the detection block 32 receives, in addition to the variables transmitted by the processing block 31, ACF_OK and Cm AV, variables V, POS and BV.
  • the variable V corresponds to the variable V at the input of processing block 31.
  • the variable POS is a decimal variable whose value expresses the position of the accelerator pedal. This information is, for example, provided by the control unit 13 of the engine 3.
  • the variable BV is a binary variable which takes the value 1 if the gear ratio is indeed engaged in the gearbox 6. This information is, for example, provided by the control unit 13 of the engine 3.
  • the detection block 32 is configured to detect whether the rolling conditions for calculating a permanent slip are satisfied. If the conditions are not satisfied then the calculation block 33 is not activated. This makes it possible to perform slip detection only when the driving conditions are satisfied. Thus, for the detection of permanent slip, normal slips are not taken into account due to particular circumstances such as: the passage of a gear ratio, the driving during a turn, the braking, the operation a driving assistant, lifting the foot of the accelerator pedal, the vehicle in full acceleration.
  • the detection block 32 transmits to the calculation block 33 a variable C rolling equal to 1.
  • a variable C rolling equal to 1.
  • variable ACF OK is equal to 1, which makes it possible to prevent the calculation of permanent slip from occurring in the case where the vehicle is braking or while a driving or braking assistant is active.
  • variable V is greater than a first threshold, which makes it possible to prevent the calculation of permanent slip from occurring in the case where the vehicle is in a turn.
  • variable Pos is greater than a second threshold: this makes it possible to avoid the calculation of permanent slip if the driver's foot lifts intervene.
  • variable BV is equal to 1: this prevents the calculation of permanent slip occurs while the vehicle is changing speed.
  • variable Cm_AV is less than a third threshold: this makes it possible to prevent the calculation of permanent slip from occurring while the vehicle is in full acceleration.
  • the three thresholds to which reference is made are configurable. This makes it possible to adapt the conditions for the detection of a permanent slip according to the driving of the driver or of the rolling ground. For example, the minimum speed from which slip detection is provided can be escalated in the case of sporty driving.
  • the activation block 35 receives, in addition to the variable DISP OK, a security variable Sec and a commissioning variable ON.
  • the variable Sec is binary, it is 1 if no fault from other computers or programs is detected.
  • the variable ON is also binary it is 1 if the permanent slip alert function is activated. From this information, the block activation 35 refers to the calculation block 33 an activation variable State 35. This variable is 1 if the variables DISP_OK, Sec and ON have the value 1.
  • the activation block 35 may receive a value from the mode control device 12. In this case, it returns a state value equal to 1 only when the automatic four-wheel drive mode is selected by the driver of the vehicle .
  • the calculation block 33 receives, in addition to the variables C rolling,% G and state 35, a variable V.
  • the variable V corresponds to the speed V at the input of the processing block 31.
  • the calculation block 33 calculates speed variables Vmin, Vmax, Vmoy and slip Gmin, Gmax, Gmoy of the vehicle.
  • the values Gmin, Gmax, Gmoy respectively correspond to the minimum, maximum and average slip value during a configurable duration MinTime.
  • the values Vmin, Vmax, Vmoy correspond to the minimum, maximum and average vehicle speeds during the MinTime time, respectively.
  • the calculation block 33 also calculates a binary value Fav relating to the fulfillment of the required conditions.
  • the value of Fav goes to 1 if the rolling conditions C_roulage are checked during the MinTime time.
  • the calculation block 33 also calculates a binary value State 33 on 2 bits corresponding to the state on a flow diagram of the sub-function of the calculation block 33.
  • the subfunction of the block 33 can indeed be represented in the form of a 4-state diagram:
  • the state - 1 corresponds to the default state of block 33.
  • state 0 corresponds to an initialization state.
  • the speed and slip variables to be calculated are initialized to 0.
  • the state 2 is active if the rolling value C is equal to 1 during a configurable minimum duration, the binary variable Fav then passes from 0 to 1. It is at the instant of activation of this state 2 that the speed and slip variables and the variable Fav are sent to a counting block 34.
  • the counting block 34 filters these variables to control if necessary the triggering of a permanent slip alert via the binary variable Alert.
  • the Alert variable goes to 1
  • the permanent slip alert is triggered. It is this alert that triggers the opening of the controlled coupler 9 by the computer 1 1 via the connection 1 6g.
  • the counting block 34 performs both the permanent slip detection, the counting of the occurrences of permanent slip, and the generation of the alert.
  • the counting block 34 cooperates with a counter 36.
  • the counter 36 is controlled by the counting block 34 to be incremented (plus) at each occurrence of permanent slip detected.
  • counter 36 reaches a configurable threshold MaxCounter, the value of the variable Alert goes to 1.
  • the incrementation (plus) occurs when the variable Fav is equal to 1, the amplitude of the slip variation (Graax-Gmin) during a MinTime time is less than another configurable threshold (MaxDeltaSlip) and that during the MinTime time the average Gmoy slip is greater than a configurable MinWheelSlip threshold value.
  • the counter can also be decremented (minus) when the variable Fav is equal to 1, the amplitude of the slip variation (Gmax-Gmin) is less than MaxDeltaSlip during the MinTime duration and the average slip is less than a threshold equal to said second threshold minus a constant MinWheelSlip- Constant.
  • the constant (Constant) can advantageously be chosen with a value relating to the hysteresis (WheelSlipHyst).
  • the permanent slip alert is raised when the variable
  • This variable goes to 0 when the counter 36 goes to a value less than or equal to a configurable threshold MinCounter.
  • MinCounter a configurable threshold
  • This passage can take place after a sufficient number of successive decrements or when the counter 36 undergoes a forced resetting by a particular event related to the use of the vehicle. It can be done to reset the counter 36 at each start (or alternatively at each stop) of the vehicle, so that the user is not interrupted from the start by an alert message on the dashboard following the passage the Alert variable at 1 or the coupler is not forced into an open state at each startup. Indeed, the user was able to perform an intervention to correct (changing tires, puncture repair etc ..) Permanent slip before restarting it.
  • the counting block 34 receives as input (or directly the counter 36 with which it cooperates), an Ignit variable passing to 1 when the vehicle start event is detected.
  • the offset value estimation block 37 estimates a permanent slip value over time, in order to make a correction of the slip value used in the coupler control strategies.
  • the block 37 for estimating an offset value receives, on a first input, a variable representing the average slip Gmoy during the configurable duration MinTime as calculated by the calculation block 33.
  • Block 37 also receives on a second input, the variable
  • the block 37 further comprises storage means forming a buffer whose size is parameterizable according to the value taken by a variable T_B.
  • the buffer memory receives average slip values Gmoy, since the variable D is equal to 1, and the amplitude of the variation between two immediately consecutive average slip values Gmoy is less than a parameterizable threshold (MaxDeltaGmoySlip).
  • MaxDeltaGmoySlip a parameterizable threshold
  • MaxCounterGmoySlip an arithmetic mean of these stored average Gmoy slip values is computed. The result of this calculation is then sent to the output G Offset to communicate the offset value of the permanent slip.
  • the value applied on the output GOffset is equal to the current value plus the threshold value MaxGOffsetVar.
  • the difference between the new calculated value and the current value is less than a configurable threshold MaxGOffsetVar then the value applied to the output GOffset is equal to the new calculated value.
  • the output G Offset takes values representative of the offset of the permanent slip G Offset only when the output activation variable SActivate takes the value 1. This is particularly useful in the case of troubleshooting, but also when it is desired to inhibit the function.
  • the offset value of the permanent slip is stored in nonvolatile memory accessed by the calculator 1 1.
  • the saved offset value is immediately resumed and applied to the output G Offset the next time the vehicle is started, well before the vehicle moves and the block 37 calculates a new value. This improves the overall responsiveness of the system, especially when the filtering of the variation of the offset value is operational.
  • the invention as described allows efficient coupler protection without consuming a lot of memory resources or generating unnecessary 4x4 operation interruptions.
  • the invention for detecting permanent slip can also be applied to the revelation of a problem that creates such a permanent slip. Thus, it is possible to detect tire wear, improper inflation pressure, or excessive load of the vehicle.
  • the values of the thresholds which trigger favorable driving conditions are parameterizable, it is therefore possible to privilege the non-interruption of the four-wheel drive mode on the protection of the coupler or to do the opposite. For example, one can in the calculation block 33 lower the minimum speed or increase the configurable time MinTime to promote the protection of the coupler. It is thus possible to adjust the compromise protection of the coupler / availability of the four-wheel drive mode.
  • a dual objective of informing and protecting the coupler is achieved.
  • the user can be warned of the presence of abnormal sliding by an alert signal on the one hand, in order to incite him to remedy the problem detected and on the other hand, when the Abnormal slip remains in a range of values that does not affect the reliability of the coupler in the short term, to take into account this abnormal slip "bearable" in order to correct the control strategies of the coupler.

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Abstract

The invention relates to a method for indicating the slip of a coupler for distributing torque between two axles (2AV, 2AR) of a motorised vehicle having four driving wheels (la, lb, le, l d) mounted on the two axles, said method being characterised in that the slip representing the difference in speed between the two axles is only determined when certain running conditions (C running) are met during a parameterable period (MinTime).

Description

PROCEDE D'ALERTE DE GLISSEMENT D'UN COUPLEUR APTE A REPARTIR UN COUPLE ENTRE DEUX ESSIEUX D'UN VEHICULE MOTORISE, PROCEDE DE COMANDE DE REPARTION RESPECTIF ET VEHICULE AVEC UN SYSTEME FONCTIONNANT SELON UN TEL PROCEDE  METHOD OF ALLOYING A COUPLER SLIDING TO DISTRIBUTE A TORQUE BETWEEN TWO AXLES OF A MOTORIZED VEHICLE, METHOD OF RESPECTIVE REPARTION CONTROL AND VEHICLE WITH A SYSTEM OPERATING IN SUCH A METHOD
La présente invention concerne, d'une manière générale, les 5 véhicules à quatre roues motrices équipés d'un système de commande de répartition du couple moteur entre un premier essieu et un deuxième essieu capable en outre d'assurer le pilotage d'un coupleur monté entre les deux essieux. The present invention relates, in a general manner, to four-wheel drive vehicles equipped with a system for controlling the distribution of engine torque between a first axle and a second axle capable furthermore of driving a coupler mounted between the two axles.
Dans ces véhicules, le couple moteur est réparti entre le In these vehicles, the engine torque is distributed between the
10 premier essieu et le deuxième essieu, la somme des couples transmis aux deux essieux étant constante. Le premier essieu est relié à un arbre de transfert auquel est solidarisé le deuxième essieu au moyen dudit coupleur. Seul le premier essieu reçoit en permanence un couple, le deuxième essieu est plus ou moins solidarisé par le coupleur piloté parThe first axle and the second axle, the sum of the torques transmitted to the two axles being constant. The first axle is connected to a transfer shaft which is secured to the second axle by means of said coupler. Only the first axle permanently receives a torque, the second axle is more or less secured by the coupler controlled by
15 le système de commande de répartition. Ainsi, le niveau de couple transmis sur chacun des essieux peut être ajusté par le système de commande en fonction, par exemple, d'un mode de fonctionnement du véhicule. The dispatch control system. Thus, the torque level transmitted on each of the axles can be adjusted by the control system as a function, for example, of a vehicle operating mode.
Dans un premier mode de fonctionnement, le couple moteur est 20 intégralement transmis au premier essieu et aucun couple n'est transmis au deuxième essieu. Dans un deuxième mode de fonctionnement, une première partie fixe du couple moteur est transmise au premier essieu et une deuxième partie fixe du couple moteur est transmise au deuxième essieu . Dans un troisième mode de 25 fonctionnement les couples transmis aux deux essieux sont constamment ajustés en fonction des conditions de roulage du véhicule.  In a first mode of operation, the engine torque is fully transmitted to the first axle and no torque is transmitted to the second axle. In a second mode of operation, a first fixed portion of the engine torque is transmitted to the first axle and a second fixed portion of the engine torque is transmitted to the second axle. In a third mode of operation the torques transmitted to the two axles are constantly adjusted according to the driving conditions of the vehicle.
Dans les véhicules à quatre roues motrices peut en outre survenir un phénomène de glissement. Le glissement correspond à une 30 différence de vitesse de rotation entre les essieux avant et arrière. Le glissement peut être un phénomène normal, dans le cas par exemple d'un changement de vitesse. Il peut être aussi la conséquence d'une différence de rayon de roulement, dans le cas par exemple d'une mauvaise monte pneumatique ou d'une crevaison. Le glissement est alors permanent et il peut entraîner réchauffement et/ou la détérioration du coupleur. In four-wheel drive vehicles can further occur a slip phenomenon. The slip corresponds to a difference in rotational speed between the front and rear axles. Sliding can be a normal phenomenon, in the case for example of a change of speed. It may also be the consequence of a difference in rolling radius, in the case for example of a bad tire mounts or a puncture. Slip is then permanent and it may cause warming and / or deterioration of the coupler.
En effet, le coupleur est un système de transmission mécanique qui peut à titre d'exemple de réalisation être composé de plusieurs disques baignant dans de l'huile les uns solidarisés à un arbre relié au deuxième essieu les autres à l'arbre de transfert. Dans le cas d'un fonctionnement normal, lorsqu'il y a une différence de vitesse entre l'arbre de transfert et l'arbre relié au deuxième essieu, les disques cisaillent l'huile dont la température augmente puis se dilate et s'épaissit. La pression sur les disques augmente et ils finissent par s'entraîner mutuellement. Ainsi, la différence de vitesse entre les deux arbres décroît et la température de l'huile et du coupleur diminue. Par contre, en présence d'un glissement permanent, les disques continuent de cisailler l'huile qui s'échauffe jusqu'à une possible détérioration du coupleur.  Indeed, the coupler is a mechanical transmission system which may, as an exemplary embodiment, be composed of several oil-bathed discs secured to a shaft connected to the second axle and the others to the transfer shaft. In the case of normal operation, when there is a difference in speed between the transfer shaft and the shaft connected to the second axle, the discs shear the oil whose temperature increases and then expands and thickens . The pressure on the discs increases and they end up training each other. Thus, the speed difference between the two shafts decreases and the temperature of the oil and the coupler decreases. On the other hand, in the presence of a permanent slip, the discs continue to shear the oil which heats up until a possible deterioration of the coupler.
La demande de brevet JP4103433 décrit un système de commande de la distribution de couple dans un véhicule à quatre roues motrices. Ce système comprend un embrayage de répartition de couple, ainsi que des moyens de détection de glissement, de la vitesse du véhicule et de la différence de diamètre des pneus des quatre roues motrices. Le système permet de diminuer le glissement en utilisant l'embrayage de répartition de couple tout en tenant compte, le cas échéant, d'une différence de diamètre des pneus.  Patent application JP4103433 discloses a control system of the torque distribution in a four-wheel drive vehicle. This system includes a torque distribution clutch, as well as slip detection means, vehicle speed and the difference in tire diameter of the four-wheel drive. The system makes it possible to reduce slippage by using the torque distribution clutch while taking into account, if necessary, a difference in tire diameter.
La demande de brevet JP61275028 décrit un système permettant d'augmenter la manœuvrabilité d'un véhicule à quatre roues motrices dont les roues n'ont pas exactement le même diamètre. Ce système est muni de détecteurs de vitesse des roues avant et arrière, d'un dispositif de répartition des forces d'entraînement des roues avant et arrière, d'un système de soustraction et d'un dispositif compensateur. Il est ainsi possible de déterminer une différence de vitesse de rotation entre les roues avant et arrière en tenant compte d'un facteur de compensation relatif à une différence de diamètre. Le ratio entre les couples transmis sur l'essieu avant et arrière est alors contrôlé à partir de la différence de vitesse de rotation. Ces systèmes utilisent une commande de la répartition du couple pour diminuer le glissement mais rien n'est prévu pour protéger le coupleur efficacement dans le cas d'un glissement permanent. Ils ne permettent pas non plus de s'affranchir des glissements résultant de conditions de roulage spécifiques. Ils ne proposent pas de système de commande de la répartition du couple intégré dans le système de gestion des quatre roues motrices qui permette d'alerter l'utilisateur du véhicule d'un glissement permanent du coupleur. Patent Application JP61275028 describes a system for increasing the maneuverability of a four-wheel drive vehicle whose wheels do not have exactly the same diameter. This system is equipped with front and rear wheel speed sensors, a front and rear wheel drive force distribution device, a subtraction system and a compensating device. It is thus possible to determine a rotation speed difference between the front and rear wheels taking into account a compensation factor relating to a difference in diameter. The ratio between the torque transmitted on the front and rear axle is then controlled from the difference in speed of rotation. These systems use a control of the distribution of the torque to reduce the slip but nothing is planned to protect the coupler effectively in the case of a permanent slip. They also do not allow to overcome slippage resulting from specific driving conditions. They do not propose a control system for the torque distribution integrated in the four-wheel drive management system which makes it possible to alert the user of the vehicle of permanent sliding of the coupler.
La présente invention a pour objet un procédé de commande de répartition de couple pour un véhicule motorisé à quatre roues motrices qui soit capable de protéger efficacement le coupleur dans le cas d'un glissement permanent et en particulier, de préserver le coupleur d'un échauffement dû à un glissement permanent.  The present invention relates to a torque distribution control method for a motorized four-wheel drive vehicle that is capable of effectively protecting the coupler in the case of permanent sliding and in particular, to preserve the coupling of a heating due to a permanent slip.
La présente invention a également pour objet de protéger le coupleur dans le cas d'un glissement permanent provoqué par une mauvaise monte, par une différence de diamètre des roues, une crevaison lente, un sur ou sous gonflage.  The present invention also aims to protect the coupler in the case of permanent slip caused by improper mounting, a difference in wheel diameter, a slow puncture, over or under inflation.
L'invention a pour objet de détecter un glissement permanent et de le discriminer d'un glissement normal ou d'un glissement lié à des conditions de roulage spécifiques.  The object of the invention is to detect a permanent slip and to discriminate it from a normal slip or slip related to specific driving conditions.
La présente invention a également pour objet de protéger le coupleur sans inutilement arrêter le fonctionnement du mode "quatre roues motrices" suivant un compromis entre la protection du coupleur et la disponibilité du mode "quatre roues motrices" optimum et réglable.  The present invention also aims to protect the coupler without unnecessarily stopping the operation of the "four-wheel drive" mode according to a compromise between the protection of the coupler and the availability of the mode "four-wheel drive" optimum and adjustable.
L'invention a encore pour objet un véhicule à quatre roues motrices muni d'un calculateur et d'un coupleur piloté de tel sorte qu'il soit protégé dans le cas d'un glissement permanent.  The invention further relates to a four-wheel drive vehicle provided with a computer and a coupler controlled so that it is protected in the case of a permanent slip.
Selon un premier aspect, il est proposé un procédé d'alerte de glissement d'un coupleur apte à répartir un couple entre deux essieux d'un véhicule motorisé à quatre roues motrices montées sur les deux essieux.  According to a first aspect, there is provided a slip warning method of a coupler capable of distributing a torque between two axles of a motorized four-wheel drive vehicle mounted on the two axles.
Selon une caractéristique générale de ce procédé, on détermine le glissement représentant la différence de vitesse des deux essieux uniquement lorsque certaines conditions de roulage sont réalisées pendant une durée paramétrable. According to a general characteristic of this method, the slip representing the difference in speed of the two axles is determined. only when certain driving conditions are fulfilled for a configurable duration.
Selon un autre mode de mise en œuvre également préféré, on incrémente un compteur à chaque occurrence de glissement détecté.  According to another embodiment also preferred, increments a counter at each occurrence of slip detected.
Selon une autre mise en œuvre, on adresse une alerte à un utilisateur du véhicule lorsque le compteur atteint un premier seuil paramétrable MaxCounter.  According to another implementation, an alert is sent to a user of the vehicle when the counter reaches a first configurable threshold MaxCounter.
Selon une autre mise en œuvre, on lève l 'alerte lorsque le compteur devient inférieur ou égal à un deuxième seuil paramétrable Mincounter.  According to another implementation, it raises the alert when the counter becomes less than or equal to a second parameterizable threshold Mincounter.
Selon encore une autre mise en œuvre, on lève l 'alerte lorsque le compteur est remis à zéro au démarrage du véhicule.  According to yet another implementation, it raises the alert when the counter is reset at start of the vehicle.
Selon une autre mise en œuvre, on teste si la valeur moyenne du glissement Gmoy au cours de ladite durée paramétrable MinTime est supérieure à un troisième seuil MinWheelSlip et si l'amplitude de la variation du glissement Gmax-Gmin au cours de ladite durée paramétrable MinTime est inférieure à un quatrième seuil MaxDeltaSlip, on incrémente le compteur si les deux tests sont vérifiés.  According to another implementation, it is tested whether the average value of the slip Gmoy during said configurable duration MinTime is greater than a third threshold MinWheelSlip and if the amplitude of the variation of the slip Gmax-Gmin during said configurable duration MinTime is less than a fourth threshold MaxDeltaSlip, the counter is incremented if the two tests are checked.
Ainsi il n'est pas tenu compte d'aléas entraînant une variation importante de glissement; seul le glissement stabilisé lié à un dimensionnement mécanique problématique tel qu'une différence de rayon de roulement entre les roues avant et arrière est détecté.  Thus, it is not taken into account hazards causing a significant variation in slip; only the stabilized sliding linked to a problematic mechanical dimensioning such as a difference in rolling radius between the front and rear wheels is detected.
Selon une mise en œuvre, on teste si la valeur moyenne du glissement Gmoy au cours de ladite durée paramétrable MinTime est inférieure à un cinquième seuil égal audit troisième seuil moins une constante MinWheelSlip-Constant, et on décrémente le compteur uniquement lorsque la valeur moyenne du glissement est inférieure au cinquième seuil et l'amplitude de la variation du glissement Gmax- Gmin au cours de ladite durée paramétrable MinTime est inférieure à un quatrième seuil.  According to one implementation, it is tested whether the average value of the slip Gmoy during said configurable duration MinTime is less than a fifth threshold equal to said third threshold minus a constant MinWheelSlip-Constant, and the counter is decremented only when the average value of the slip is less than the fifth threshold and the magnitude of the slip variation Gmax-Gmin during said configurable duration MinTime is less than a fourth threshold.
Ainsi, on ne déclenche la décrémentation que dans le cas où le glissement est dans une phase stabilisée, en deçà de la valeur du deuxième seuil. On évite ainsi une décrémentation liée à une situation de conduite particulière ou à la présence de bruits de mesure . Dans le cas d'un glissement permanent oscillant, on évite une succession de phases d'incrémentation et de décrémentation qui rendrait la détection du glissement oscillant impossible. Thus, the decrementation is only triggered in the case where the slip is in a stabilized phase, below the value of the second threshold. This avoids a decrement related to a situation particular driving behavior or the presence of measurement noise. In the case of an oscillating permanent sliding, a succession of incrementation and decrementation phases is avoided which would make the detection of oscillating sliding impossible.
Selon encore un autre aspect du procédé, on incrémente ou on décrémente un compteur en fonction du glissement déterminé et on supprime tout transfert de couple vers l 'un ou l 'autre des essieux lorsque la valeur moyenne du glissement au cours deladite durée MinTime dépasse un seuil et lorsque ledit compteur 36, atteint un premier seuil MaxCounter.  According to yet another aspect of the method, a counter is incremented or decremented as a function of the determined slip and any transfer of torque to one or the other of the axles is suppressed when the average value of the sliding during said MinTime duration exceeds one threshold and when said counter 36 reaches a first threshold MaxCounter.
Selon un autre obj et, il est proposé un véhicule motorisé à quatre roues motrices montées sur deux essieux comprenant un arbre de transfert relié au premier essieu et un coupleur piloté capable de transférer une partie du couple depuis l'arbre de transfert vers le deuxième essieu, des moyens de détermination des vitesses respectives des deux essieux et un système de commande de répartition du couple capable de déterminer une valeur de glissement représentant la différence de vitesse entre les deux essieux et de piloter le coupleur According to another obj and, it is proposed a four-wheel drive motor vehicle mounted on two axles comprising a transfer shaft connected to the first axle and a controlled coupler capable of transferring a portion of the torque from the transfer shaft to the second axle , means for determining the respective speeds of the two axles and a torque distribution control system capable of determining a slip value representing the difference in speed between the two axles and driving the coupler
Selon une caractéristique générale de ce mode de réalisation, le système de commande de répartition de couple est configuré pour informer l'utilisateur par alerte selon le procédé d 'alerte de glissement d'un coupleur de l 'invention. According to a general characteristic of this embodiment, the torque distribution control system is configured to inform the user by warning according to the slip warning method of a coupler of the invention.
L'invention sera mieux comprise à l'étude de la description détaillée d'un mode de réalisation pris à titre d'exemple non limitatif et illustré par les dessins annexés sur lesquels :  The invention will be better understood on studying the detailed description of an embodiment taken by way of nonlimiting example and illustrated by the appended drawings in which:
la figure 1 représente schématiquement un véhicule motorisé à quatre roues motrices;  Figure 1 schematically shows a motorized four-wheel drive vehicle;
la figure 2 représente schématiquement les principaux éléments du système de commande du fonctionnement du véhicule;  Figure 2 schematically shows the main elements of the control system of the operation of the vehicle;
la figure 3 représente schématiquement les principaux aspects d'un logiciel implanté dans le calculateur du véhicule et permettant la protection du coupleur.  Figure 3 schematically shows the main aspects of a software implanted in the vehicle computer and allowing the protection of the coupler.
Sur la figure 1 sont illustrés schématiquement les principaux éléments d'un véhicule motorisé Ve à quatre roues motrices avec une transmission permanente du couple moteur sur l'essieu avant 2AV. Ce type de véhicule a été choisi à titre d'exemple. Le moteur du véhicule peut être un moteur thermique 3, un moteur électrique ou une combinaison hybride. La transmission permanente du couple moteur pourrait également être exercée sur l'essieu arrière 2AR. In Figure 1 are schematically illustrated the main elements of a motorized vehicle Ve four-wheel drive with a permanent transmission of the engine torque on the front axle 2AV. This type of vehicle was chosen as an example. The vehicle engine may be a heat engine 3, an electric motor or a hybrid combination. Permanent transmission of the engine torque could also be exerted on the 2AR rear axle.
Le véhicule comprend quatre roues l a, l b, l e, l d, montées respectivement sur un essieu avant 2AV et un essieu arrière 2AR. Le véhicule comporte également un volant de direction 4 relié à une colonne de direction 5. Le véhicule comprend, en outre, une boîte de vitesses 6 transmettant le couple du moteur 3 à l'essieu avant 2AV et à une boîte de transfert avant 7. Un arbre de transfert 8, entraîné par la boite de transfert 7 est relié par un coupleur 9 à une boîte de transfert de pont arrière 10 de façon à transférer un couple en provenance de la boite de vitesse 6 à l'essieu arrière 2AR.  The vehicle comprises four wheels 1 a, 1 b, 1 e, 1 d respectively mounted on a front axle 2AV and a rear axle 2AR. The vehicle also comprises a steering wheel 4 connected to a steering column 5. The vehicle further comprises a gearbox 6 transmitting the torque of the engine 3 to the front axle 2AV and to a front transfer case 7. A transfer shaft 8, driven by the transfer box 7 is connected by a coupler 9 to a rear axle transfer box 10 so as to transfer torque from the gearbox 6 to the rear axle 2AR.
Le véhicule comprend également un calculateur 1 1 capable notamment de piloter le coupleur 9, un dispositif de commande de mode 12 et une unité 13 de contrôle du moteur 3 capable de contrôler le fonctionnement du moteur 3 (notamment pour déterminer le couple exercé par le moteur et pour estimer le rapport de vitesse engagé) . Le véhicule comprend également quatre capteurs de vitesse de roues 14a, 14b, 14c, 14d, un sur chacune des roues l a, lb, l e, ld.  The vehicle also comprises a computer 1 1 capable in particular of controlling the coupler 9, a mode control device 12 and a control unit 13 of the engine 3 capable of controlling the operation of the engine 3 (in particular to determine the torque exerted by the engine and to estimate the gear ratio engaged). The vehicle also includes four wheel speed sensors 14a, 14b, 14c, 14d, one on each of the wheels l a, lb, l e, ld.
Le calculateur 1 1 est relié à chacun des capteurs de vitesse de roues 14a... 14d par des connexions 16a... 16d permettant l'échange d'informations. Le calculateur 1 1 est également relié au dispositif de commande de mode 12 par une connexion 16e, à l'unité de contrôle moteur 1 3 par une connexion 16f et au coupleur 9 par une connexion 16g. La connexion électrique 16g permet également la circulation d'un courant de commande pour fermer le coupleur piloté 9. Une unité d'affichage du tableau de bord 15 est également reliée par une connexion 16h au calculateur 1 1 afin d'afficher au conducteur du véhicule notamment le mode de fonctionnement quatre roues motrices utilisé.  The computer 1 1 is connected to each of the wheel speed sensors 14a ... 14d by connections 16a ... 16d allowing the exchange of information. The computer 1 1 is also connected to the mode control device 12 by a connection 16e, the engine control unit 1 3 by a connection 16f and the coupler 9 by a connection 16g. The electrical connection 16g also allows the circulation of a control current to close the controlled coupler 9. A display unit of the control panel 15 is also connected by a connection 16h to the computer 1 1 in order to display to the driver of the vehicle including the four-wheel drive mode used.
Le véhicule à quatre roues motrices peut, en effet, fonctionner selon trois types de mode de fonctionnement distincts. Dans un premier mode de fonctionnement, la boîte de vitesses 6 entraîne l'essieu avant 2AV, le coupleur 9 est ouvert et ne transfère aucun couple à la boîte de transfert de pont arrière 10. Ce mode est dit mode "4x2", seules les deux roues l a et l b de l'essieu avant étant entraînées. The four-wheel drive vehicle can, in fact, operate in three different types of operating mode. In a first mode of operation, the gearbox 6 drives the front axle 2AV, the coupler 9 is open and does not transfer any torque to the rear axle transfer box 10. This mode is called "4x2" mode, only the two wheels la and lb of the front axle being driven.
Dans un deuxième mode de fonctionnement, la boîte de vitesses 6 entraîne l'essieu avant 2AV et l'arbre de transfert 8 entraîne le coupleur 9 qui est maintenu totalement fermé. Le coupleur 9 entraîne donc la boîte de transfert de pont arrière 10 de telle sorte qu'une partie maximale du couple moteur est transférée à l'essieu arrière 2AR. Ce mode, est dit " quatre roues motrices tout terrain" .  In a second mode of operation, the gearbox 6 drives the front axle 2AV and the transfer shaft 8 drives the coupler 9 which is kept completely closed. The coupler 9 therefore drives the rear axle transfer box 10 so that a maximum portion of the engine torque is transferred to the rear axle 2AR. This mode is called "four wheel drive all terrain".
Dans un troisième mode de fonctionnement, la boîte de vitesses 6 entraîne l'essieu avant 2AV et l'arbre de transfert 8 entraîne le coupleur 9 qui est piloté par le courant du calculateur 1 1 de façon à être plus ou moins fermé en fonction du couple demandé par chacun des essieux. Ainsi une partie variable du couple moteur est transférée à l'essieu arrière 2AR. Ce mode est dit " quatre roues motrices automatique".  In a third mode of operation, the gearbox 6 drives the front axle 2AV and the transfer shaft 8 drives the coupler 9 which is driven by the current of the computer 1 1 so as to be more or less closed depending on the torque requested by each of the axles. Thus a variable portion of the engine torque is transferred to the rear axle 2AR. This mode is called "automatic four-wheel drive".
Les différents modes de fonctionnement dépendent de l'état du coupleur 9. La fermeture du coupleur pi loté 9 est commandée par le calculateur 1 1 via la connexion 16g. Ainsi, le niveau de couple transmis depuis l'arbre de transfert 8 vers la boîte de transfert du pont arrière 1 0 est commandé par le calculateur 1 1 . A cet effet, le calculateur 1 1 reçoit des informations concernant:  The different operating modes depend on the state of the coupler 9. The closing of the punctured pi coupler 9 is controlled by the computer 1 1 via the connection 16g. Thus, the torque level transmitted from the transfer shaft 8 to the transfer box of the rear axle 1 0 is controlled by the computer 1 1. For this purpose, the computer 1 1 receives information concerning:
-le fonctionnement du moteur 3 par l'unité de contrôle moteur the operation of the engine 3 by the engine control unit
1 3 via la liaison 16f; 1 3 via the link 16f;
-la volonté du conducteur du véhicule par le dispositif de commande de mode 1 2 qui peut être actionné par le conducteur. Ces informations sont transmises au calculateur 1 1 via la liaison 1 6e; et -la vitesse de rotation des quatre roues l a ... l d déterminée par les quatre capteurs de vitesse de roues 14a ... 14d. Ces informations sont transmises au calculateur 1 1 via les quatre liaisons 16a ... 16d.  the will of the driver of the vehicle by the mode control device 1 2 which can be actuated by the driver. This information is transmitted to the computer 1 1 via the link 1 6e; and the rotational speed of the four wheels 1a, 1d determined by the four wheel speed sensors 14a ... 14d. This information is transmitted to the computer 1 1 via the four links 16a ... 16d.
En fonction de toutes ces informations, le calculateur 1 1 est capable de choisir le mode de fonctionnement approprié. Le calculateur 1 1 est également capable de communiquer au conducteur du véhicule des informations concernant le mode de fonctionnement actif via l'unité d'affichage du tableau de bord 1 5 et la liaison 1 6h. Dans le cas où le mode sélectionné est le mode automatique, le calculateur 1 1 est capable de déterminer le serrage approprié à appliquer au coupleur 9. Les liaisons 16a... 16g auxquelles il a été fait référence peuvent, à titre d'exemple de réalisation, être des branches d'un bus de type CAN (Controller Area Network selon un terme anglo- saxon bien connu de l'homme du métier). According to all this information, the computer 1 1 is able to choose the appropriate operating mode. The The computer 1 1 is also capable of communicating to the driver of the vehicle information concerning the active mode of operation via the display unit of the control panel 1 5 and the link 1 6h. In the case where the selected mode is the automatic mode, the computer 1 1 is able to determine the appropriate clamping to be applied to the coupler 9. The links 16a ... 16g to which reference has been made can, by way of example of realization, be branches of a bus type CAN (Controller Area Network according to an Anglo-Saxon term well known to those skilled in the art).
Selon l'invention, le calculateur 1 1 peut en outre émettre en fonction des informations reçues, un signal de commande pour complètement ouvrir le coupleur 9 de façon à éviter un échauffement et ou une usure excessive du coupleur 9 en cas de glissement permanent.  According to the invention, the computer 1 1 can further transmit according to the received information, a control signal to fully open the coupler 9 so as to avoid heating and or excessive wear of the coupler 9 in case of permanent slip.
Sur la figure 2, sont illustrés schématiquement les principaux éléments du système de commande du fonctionnement du véhicule. Les éléments déjà illustrés sur la figure 1 portent les mêmes références.  In Figure 2, are schematically illustrated the main elements of the control system of the operation of the vehicle. The elements already illustrated in FIG. 1 bear the same references.
On retrouve sur la figure 2 le calculateur 1 1 relié par la connexion 16g au coupleur 9 et le dispositif de commande de mode 12 relié au calculateur 1 1 ; Le bus de connexion 16 permet d'assurer les liaison entre le calculateur 1 1 , l'unité de contrôle 13 du moteur 3 et le reste des organes de contrôle et de commande du véhicule représenté sous la forme d'un unique bloc 20. On compte parmi ces organes, par exemple, un système de freinage AB S et un système de contrôle de trajectoire AYC (Active Yaw Control selon un terme anglo-saxon bien connu de l'homme du métier).  FIG. 2 shows the computer 1 1 connected by the connection 16g to the coupler 9 and the mode control device 12 connected to the computer 1 1; The connection bus 16 makes it possible to ensure the connections between the computer 1 1, the control unit 13 of the engine 3 and the rest of the control and control elements of the vehicle represented in the form of a single block 20. these bodies include, for example, an AB S braking system and an AYC (Active Yaw Control) trajectory control system according to an Anglo-Saxon term well known to those skilled in the art.
Le calculateur 1 1 peut recevoir du bloc 20, des informations relatives aux conditions de roulage:  The computer 1 1 can receive from the block 20, information relating to the driving conditions:
-des informations relatives au freinage du véhicule: Système de freinage ABS, frein de stationnement, pédale de frein.  - information relating to the braking of the vehicle: ABS braking system, parking brake, brake pedal.
-des informations relatives au fonctionnement du système de contrôle de trajectoire AYC .  information relating to the operation of the AYC trajectory control system.
Le calculateur 1 1 peut ensuite par exemple envoyer un signal de commande d'ouverture au coupleur via la connexion électrique 16g en fonction des conditions de roulage, de la volonté du conducteur et de l'état du coupleur. The computer 1 1 can then for example send an opening control signal to the coupler via the electrical connection 16g depending on the driving conditions, the driver's wishes and the condition of the coupler.
Sur la figure 3 , sont illustrées schématiquement sous forme de bloc les sous fonctions d'un logiciel de décision d'ouv.erture du coupleur 9. Le programme peut être intégré dans le calculateur 1 1 . Dans l'exemple illustré, un premier bloc de traitement 3 1 reçoit en entrée des variables relatives au fonctionnement du véhicule. Le bloc de traitement 3 1 reçoit notamment:  FIG. 3 diagrammatically illustrates in block form the subfunctions of an opening decision software of the coupler 9. The program can be integrated into the computer 1 1. In the illustrated example, a first processing unit 31 receives input variables relating to the operation of the vehicle. The processing block 3 1 notably receives:
-des variables notées ACF. Elles sont relatives à l'état des assistants de conduite et de freinage. Les variables ACF peuvent être transmises par un ou plusieurs programmes de gestion du freinage et d'assistance à la conduite situés par exemple au sein du calculateur 1 1 . Parmi les variables ACF, on peut compter:  variables noted ACF. They are related to the condition of the driving assistants and braking. The ACF variables can be transmitted by one or more brake management programs and driver assistance located for example in the computer 1 1. Among the ACF variables, we can count:
-une variable binaire signalant l'utilisation de l'ABS (Anti Blocage Système);  a binary variable signaling the use of ABS (Anti-Blocking System);
-une variable binaire signalant l'utilisation du contrôle de trajectoire AYC;  a binary variable signaling the use of the AYC trajectory control;
-une variable binaire signalant l'utilisation de l'antipatinage (ASR Accelaration Slip Régulation selon un terme anglo-saxon bien connu de l'homme du métier);  a binary variable signaling the use of traction control (ASR Accelaration Slip Regulation according to an Anglo-Saxon term well known to those skilled in the art);
-une variable binaire signalant l'utilisation de la régulation du couple d'inertie du moteur (MSR MotorSchleppmomentRegler selon un terme allemand bien connu de l'homme du métier); et  a binary variable signaling the use of the regulation of the engine inertia torque (MSR MotorSchleppmomentRegler according to a German term well known to those skilled in the art); and
-une variable signalant l'utilisation du freinage par le conducteur que ce soit par la pédale ou par le frein parking (frein à main).  a variable indicating the use of braking by the driver whether by the pedal or by the parking brake (hand brake).
A partir des variables ACF, le bloc de traitement 3 1 détermine si à la fois aucun assistant de conduite (AYC, MSR, ASR), aucun système d'assistance au freinage (AB S) et aucun freinage n'est actif. Si c'est le cas il renvoie à un bloc de détection 32 la valeur binaire ACF OK avec la valeur 1 .  From the ACF variables, the processing block 3 1 determines whether at the same time no driving assistant (AYC, MSR, ASR), no braking assistance system (AB S) and no braking is active. If this is the case, it returns to a detection block 32 the binary value ACF OK with the value 1.
Le bloc de traitement 3 1 reçoit également des variables V, G, Cm relatives respectivement à la vitesse du véhicule, au glissement entre les deux essieux et au couple fourni par le moteur aux deux essieux. Les variables V et G sont fournies par les quatre capteurs de vitesse de roues 14a, 14b, 14c, 14d tandis que la variable Cm est fournie par l'unité de contrôle 13 du moteur 3. The processing block 31 also receives variables V, G, Cm relating respectively to the speed of the vehicle, to the slippage between the two axles and to the torque supplied by the engine to both axles. The variables V and G are provided by the four wheel speed sensors 14a, 14b, 14c, 14d while the variable Cm is provided by the control unit 13 of the engine 3.
Plus précisément, la vitesse V du véhicule Ve est estimée à partir de la moyenne des vitesses fournies par les deux capteurs de vitesse de roue arrière 14c et 14d. Le glissement entre les deux essieux est estimé à partir de la différence entre deux vitesses de rotation, celle de l'essieu avant 2AV et celle de l'essieu arrière 2AR. La vitesse de rotation de l'essieu avant peut, à titre d'un exemple de réalisation, être déterminée en faisant la moyenne des vitesses fournies par les deux capteurs de roues avant 14a, 14b. De manière similaire, la vitesse de rotation de l'essieu arrière peut être déterminée en faisant la moyenne des vitesses fournies par les deux capteurs de roues arrière 14c et 14d. Enfin, le couple moteur Cm est estimé par l'unité de contrôle 13 du moteur 3. L'unité de contrôle 1 3 renvoie également une estimation du rapport de vitesse engagé.  More specifically, the speed V of the vehicle Ve is estimated from the average speeds provided by the two rear wheel speed sensors 14c and 14d. The slip between the two axles is estimated from the difference between two speeds of rotation, that of the front axle 2AV and that of the rear axle 2AR. The speed of rotation of the front axle may, as an exemplary embodiment, be determined by averaging the speeds provided by the two front wheel sensors 14a, 14b. Similarly, the rotational speed of the rear axle can be determined by averaging the speeds provided by the two rear wheel sensors 14c and 14d. Finally, the engine torque Cm is estimated by the control unit 13 of the engine 3. The control unit 1 3 also returns an estimate of the gear ratio engaged.
A partir des variables V et G, le bloc de traitement 3 1 calcule le glissement exprimé en pourcentage par rapport à la vitesse du véhicule %G, il transmet alors cette valeur à un bloc de calcul 33. À partir de la variable Cm et de l'estimation du rapport de vitesse engagée, le bloc de traitement 3 1 détermine le couple exercé par le moteur sur l'essieu avant Cm AV, il transmet alors cette valeur au bloc de détection 32.  From the variables V and G, the processing block 31 calculates the slip expressed as a percentage with respect to the speed of the vehicle% G, it then transmits this value to a calculation block 33. From the variable Cm and from the estimate of the gear ratio engaged, the processing block 31 determines the torque exerted by the engine on the front axle Cm AV, it then transmits this value to the detection block 32.
Le bloc de traitement 3 1 reçoit aussi des variables DISP relatives à la disponibilité et la validité des informations d'entrée, elles sont utilisées pour la détection de défauts des capteurs ou des informations d'entrée. Parmi les variables DISP, on compte par exemple, les variables suivantes :  The processing block 31 also receives DISP variables relating to the availability and the validity of the input information, they are used for the detection of sensor faults or input information. Among the DISP variables, there are, for example, the following variables:
-une variable binaire d'état de la détermination du couple moteur;  a binary state variable of the determination of the engine torque;
-une variable binaire d'état de la détection de l'engagement d'une vitesse;  a binary state variable of the detection of the commitment of a speed;
-une variable binaire d'état de la détection de la position de la pédale d'accélération; -une variable binaire d'état de la détection de l'ABS; a binary state variable of the detection of the position of the accelerator pedal; a binary state variable of the detection of the ABS;
-une variable binaire d'état de la détection du contrôle de trajectoire (AYC);  a binary state variable of the detection of the trajectory control (AYC);
-une variable binaire d'état de la détection de l'antipatinage (ASR);  a binary state variable of the traction control detection (ASR);
-une variable binaire d'état de la détection de la régulation du couple d'inertie du moteur (MSR).  a binary state variable of the detection of the regulation of the motor inertia torque (MSR).
Le bloc de traitement 31 détermine également si les capteurs de vitesse 14a, 14b, 14c, 14d sont en état de marche et si les informations qu'ils transmettent sont en état de marche.  The processing block 31 also determines whether the speed sensors 14a, 14b, 14c, 14d are in working order and whether the information they transmit is in working order.
A partir de ces variables et de ces informations, le bloc de traitement 31 détermine si tous les capteurs fonctionnent et toutes les variables requises sont disponibles et valides. Le cas échéant, il transmet à un bloc d'activation 35 une valeur binaire, DISP OK, relative à la disponibilité des informations.  From these variables and information, processing block 31 determines whether all sensors are working and all required variables are available and valid. If necessary, it transmits to an activation block 35 a binary value, DISP OK, relating to the availability of the information.
Le bloc de détection 32 reçoit, outre les variables transmi ses par le bloc de traitement 31 , ACF_OK et Cm AV, des variables V, POS et BV. La variable V correspond à la variable V en entrée du bloc de traitement 31. La variable POS est une variable décimale dont la valeur exprime la position de la pédale d'accélération. Cette information est, par exemple, fournie par l'unité de contrôle 13 du moteur 3. La variable BV est une variable binaire qui prend la valeur 1 si le rapport de vitesse est bien enclenché dans la boîte de vitesse 6. Cette information est, par exemple, fournie par l'unité de contrôle 13 du moteur 3.  The detection block 32 receives, in addition to the variables transmitted by the processing block 31, ACF_OK and Cm AV, variables V, POS and BV. The variable V corresponds to the variable V at the input of processing block 31. The variable POS is a decimal variable whose value expresses the position of the accelerator pedal. This information is, for example, provided by the control unit 13 of the engine 3. The variable BV is a binary variable which takes the value 1 if the gear ratio is indeed engaged in the gearbox 6. This information is, for example, provided by the control unit 13 of the engine 3.
A partir des variables reçues, le bloc de détection 32 est configuré pour détecter si les conditions de roulage pour calculer un glissement permanent sont satisfaites. Si les conditions ne sont pas satisfaites alors le bloc de calcul 33 n'est pas activé. Cela permet de ne réaliser la détection de glissement que lorsque les conditions de roulage sont satisfaites. Ainsi, ne sont pas pris en compte pour la détection du glissement permanent, des glissements normaux dus à des circonstances particulières telles que: le passage d'un rapport de vitesse, la conduite lors d'un virage, le freinage, le fonctionnement d'un assistant de conduite, le lever de pied de la pédale d'accélérateur, le véhicule en pleine accélération. From the received variables, the detection block 32 is configured to detect whether the rolling conditions for calculating a permanent slip are satisfied. If the conditions are not satisfied then the calculation block 33 is not activated. This makes it possible to perform slip detection only when the driving conditions are satisfied. Thus, for the detection of permanent slip, normal slips are not taken into account due to particular circumstances such as: the passage of a gear ratio, the driving during a turn, the braking, the operation a driving assistant, lifting the foot of the accelerator pedal, the vehicle in full acceleration.
Le cas échéant le bloc de détection 32 transmet au bloc de calcul 33 une variable C roulage égale à 1. Pour que le bloc de détection 32 émette une variable C roulage il faut que toutes les conditions ci-dessous soient respectées :  If necessary, the detection block 32 transmits to the calculation block 33 a variable C rolling equal to 1. In order for the detection block 32 to transmit a variable C rolling, all the conditions below must be observed:
- la variable ACF OK soit égale à 1 , cela permet d'éviter que le calcul de glissement permanent intervienne dans le cas où le véhicule est en freinage ou alors qu'un assistant de conduite ou de freinage est actif.  the variable ACF OK is equal to 1, which makes it possible to prevent the calculation of permanent slip from occurring in the case where the vehicle is braking or while a driving or braking assistant is active.
- la variable V soit supérieure à un premier seuil, cela permet d'éviter que le calcul de glissement permanent intervienne dans le cas où le véhicule est en virage.  the variable V is greater than a first threshold, which makes it possible to prevent the calculation of permanent slip from occurring in the case where the vehicle is in a turn.
- la variable Pos soit supérieure à un deuxième seuil: cela permet d'éviter le calcul de glissement permanent si des levers de pied du conducteur interviennent.  the variable Pos is greater than a second threshold: this makes it possible to avoid the calculation of permanent slip if the driver's foot lifts intervene.
- la variable BV soit égale à 1 : cela permet d'éviter que le calcul de glissement permanent intervienne alors que le véhicule est en train de changer de vitesse .  - The variable BV is equal to 1: this prevents the calculation of permanent slip occurs while the vehicle is changing speed.
- la variable Cm_AV soit inférieure à un troisième seuil : cela permet d'éviter que le calcul de glissement permanent intervienne alors que le véhicule est en pleine accélération.  the variable Cm_AV is less than a third threshold: this makes it possible to prevent the calculation of permanent slip from occurring while the vehicle is in full acceleration.
Les trois seuils auxquels il est fait référence sont paramétrables. Cela permet d'adapter les conditions pour la détection d'un glissement permanent en fonction de la conduite du conducteur ou du terrain de roulage. Par exemple, la vitesse minimum à partir de laquelle il est prévu une détection de glissement peut être remontée dans le cas d'une conduite sportive.  The three thresholds to which reference is made are configurable. This makes it possible to adapt the conditions for the detection of a permanent slip according to the driving of the driver or of the rolling ground. For example, the minimum speed from which slip detection is provided can be escalated in the case of sporty driving.
Le bloc d'activation 35 reçoit, outre la variable DISP OK, une variable de sécurité Sec et une variable de mise en service ON. La variable Sec est binaire, elle vaut 1 si aucun défaut de la part d'autres calculateurs ou programmes n'est détecté. La variable ON est également binaire elle vaut 1 si la fonction d'alerte de glissement permanent est mise en service. A partir de ces informations, le bloc d'activation 35 renvoie au bloc de calcul 33 une variable d'activation Etat 35. Cette variable vaut 1 si les variables DISP_OK, Sec et ON ont la valeur 1 . A titre optionnel, le bloc d'activation 35 peut recevoir une valeur du dispositif de commande de mode 12. Le cas échéant, il renvoie une valeur Etat 35 égale à 1 uniquement lorsque le mode quatre roues motrices automatique est sélectionné par le conducteur du véhicule. The activation block 35 receives, in addition to the variable DISP OK, a security variable Sec and a commissioning variable ON. The variable Sec is binary, it is 1 if no fault from other computers or programs is detected. The variable ON is also binary it is 1 if the permanent slip alert function is activated. From this information, the block activation 35 refers to the calculation block 33 an activation variable State 35. This variable is 1 if the variables DISP_OK, Sec and ON have the value 1. Optionally, the activation block 35 may receive a value from the mode control device 12. In this case, it returns a state value equal to 1 only when the automatic four-wheel drive mode is selected by the driver of the vehicle .
Le bloc de calcul 33 reçoit, outre les variables C roulage, %G et Etat 35 , une variable V. La variable V correspond à la vitesse V en entrée du bloc de traitement 31 . A partir de la variable %G et de la vitesse V, le bloc de calcul 33 calcule des variables de vitesse Vmin, Vmax, Vmoy et de glissement Gmin, Gmax, Gmoy du véhicule. Les valeurs Gmin, Gmax, Gmoy correspondent respectivement à la valeur de glissement minimum, maximum et moyen pendant une durée paramétrable MinTime. Les valeurs Vmin, Vmax, Vmoy correspondent respectivement à la vitesse du véhicule minimum, maximum et moyenne au cours de la durée MinTime. Ces calculs sont réalisés par le bloc de calcul 33 uniquement lorsque les valeurs binaires C roulage et Etat 35 sont égales à 1 .  The calculation block 33 receives, in addition to the variables C rolling,% G and state 35, a variable V. The variable V corresponds to the speed V at the input of the processing block 31. From the variable% G and the speed V, the calculation block 33 calculates speed variables Vmin, Vmax, Vmoy and slip Gmin, Gmax, Gmoy of the vehicle. The values Gmin, Gmax, Gmoy respectively correspond to the minimum, maximum and average slip value during a configurable duration MinTime. The values Vmin, Vmax, Vmoy correspond to the minimum, maximum and average vehicle speeds during the MinTime time, respectively. These calculations are carried out by the calculation block 33 only when the binary values C rolling and state 35 are equal to 1.
Le bloc de calcul 33 calcule également une valeur binaire Fav relative à la réalisation de conditions requises. La valeur de Fav passe à 1 si les conditions de roulage C_roulage sont vérifiées au cours de la durée MinTime. Le bloc de calcul 33 calcule aussi une valeur binaire Etat 33 sur 2 bits correspondant à l'état sur un diagramme de flux de la sous fonction du bloc de calcul 33. La sous fonction du bloc 33 peut en effet être représentée sous la forme d'un diagramme à 4 états :  The calculation block 33 also calculates a binary value Fav relating to the fulfillment of the required conditions. The value of Fav goes to 1 if the rolling conditions C_roulage are checked during the MinTime time. The calculation block 33 also calculates a binary value State 33 on 2 bits corresponding to the state on a flow diagram of the sub-function of the calculation block 33. The subfunction of the block 33 can indeed be represented in the form of a 4-state diagram:
-l'état - 1 correspond à l'état par défaut du bloc 33.  the state - 1 corresponds to the default state of block 33.
-l 'état 0 correspond à un état d'initialisation. Les variables de vitesse et de glissement à calculer sont initialisées à 0.  state 0 corresponds to an initialization state. The speed and slip variables to be calculated are initialized to 0.
-l 'état 1 est actif dès que la variable binaire C roulage passe à the state 1 is active as soon as the binary variable C rolling passes to
1 , et est inactif dès que celle-ci repasse à 0. Tant que C_roulage reste égal à 1 , on calcule les variables de vitesse et de glissement. 1, and is inactive as soon as it returns to 0. As C_roulage remains equal to 1, the speed and slip variables are calculated.
- l'état 2 est actif si la valeur C roulage est égale 1 pendant une durée minimum paramétrable, la variable binaire Fav passe alors de la valeur 0 à 1 . C'est à l'instant d'activation de cet état 2 que sont envoyées les variables de vitesse et de glissement ainsi que la variable Fav vers un bloc de comptage 34. the state 2 is active if the rolling value C is equal to 1 during a configurable minimum duration, the binary variable Fav then passes from 0 to 1. It is at the instant of activation of this state 2 that the speed and slip variables and the variable Fav are sent to a counting block 34.
Le bloc de comptage 34 filtre ces variables pour commander s'il y a lieu le déclenchement d'une alerte de glissement permanent via la variable binaire Alerte. Quand la variable Alerte passe à 1 , l'alerte de glissement permanent est enclenchée. C'est cette alerte qui déclenche l'ouverture du coupleur piloté 9 par le calculateur 1 1 via la connexion 1 6g. Plus précisément, le bloc de comptage 34 réalise à la fois la détection de glissement permanent, le comptage des occurrences de glissement permanent, et la génération de l'alerte. Pour cela, le bloc de comptage 34 coopère avec un compteur 36. Le compteur 36 est contrôlé par le bloc de comptage 34 pour être incrémenté (plus) à chaque occurrence de glissement permanent détectée. Quand le compteur 36 atteint un seuil paramétrable MaxCounter, la valeur de la variable Alerte passe à 1 .  The counting block 34 filters these variables to control if necessary the triggering of a permanent slip alert via the binary variable Alert. When the Alert variable goes to 1, the permanent slip alert is triggered. It is this alert that triggers the opening of the controlled coupler 9 by the computer 1 1 via the connection 1 6g. More specifically, the counting block 34 performs both the permanent slip detection, the counting of the occurrences of permanent slip, and the generation of the alert. For this, the counting block 34 cooperates with a counter 36. The counter 36 is controlled by the counting block 34 to be incremented (plus) at each occurrence of permanent slip detected. When counter 36 reaches a configurable threshold MaxCounter, the value of the variable Alert goes to 1.
L'incrémentation (plus) intervient dès lors que la variable Fav est égale à 1 , que l'amplitude de la variation de glissement (Graax- Gmin) au cours d'une durée MinTime est inférieure à un autre seuil paramétrable (MaxDeltaSlip) et qu'au cours de la durée MinTime le glissement moyen Gmoy est supérieur à une valeur de seuil MinWheelSlip paramétrable. Le compteur peut également être décrémenté (moins) lorsque la variable Fav est égale à 1 , l'amplitude de la variation de glissement (Gmax-Gmin) est inférieure à MaxDeltaSlip au cours de la durée MinTime et le glissement moyen est inférieur à un seuil égal audit deuxième seuil moins une constante MinWheelSlip- Constant. La constante (Constant) peut avantageusement être choisie avec une valeur relative à l'hystérésis (WheelSlipHyst).  The incrementation (plus) occurs when the variable Fav is equal to 1, the amplitude of the slip variation (Graax-Gmin) during a MinTime time is less than another configurable threshold (MaxDeltaSlip) and that during the MinTime time the average Gmoy slip is greater than a configurable MinWheelSlip threshold value. The counter can also be decremented (minus) when the variable Fav is equal to 1, the amplitude of the slip variation (Gmax-Gmin) is less than MaxDeltaSlip during the MinTime duration and the average slip is less than a threshold equal to said second threshold minus a constant MinWheelSlip- Constant. The constant (Constant) can advantageously be chosen with a value relating to the hysteresis (WheelSlipHyst).
L 'alerte de glissement permanent est levée lorsque la variable The permanent slip alert is raised when the variable
Alerte passe à 0. Cette variable passe à 0 lorsque le compteur 36 passe à une valeur inférieure ou égale à un seuil paramétrable MinCounter. Ce passage peut intervenir après un nombre suffisant de décrémentations successives ou bien lorsque le compteur 36 subit une remise à zéro forcée par un événement particulier lié à l 'utilisation du véhicule. On peut faire en sorte de remettre à zéro le compteur 36 à chaque démarrage (ou alternativement à chaque arrêt) du véhicule, pour que l 'utilisateur ne soit pas interrompu dès le démarrage par un message d'alerte au tableau de bord consécutif au passage de la variable Alerte à 1 ou que le coupleur ne soit pas forcé dans un état ouvert à chaque démarrage. En effet, l 'utilisateur a pu réaliser une intervention pour corriger (changement de pneus, réparation de crevaison etc .. ) le glissement permanent avant le redémarrage de celui-ci. A cette fin, le bloc de comptage 34 reçoit en entrée (ou directement le compteur 36 avec lequel il coopère), une variable Ignit passant à 1 lorsque l 'événement démarrage du véhicule, est détecté. Alert goes to 0. This variable goes to 0 when the counter 36 goes to a value less than or equal to a configurable threshold MinCounter. This passage can take place after a sufficient number of successive decrements or when the counter 36 undergoes a forced resetting by a particular event related to the use of the vehicle. It can be done to reset the counter 36 at each start (or alternatively at each stop) of the vehicle, so that the user is not interrupted from the start by an alert message on the dashboard following the passage the Alert variable at 1 or the coupler is not forced into an open state at each startup. Indeed, the user was able to perform an intervention to correct (changing tires, puncture repair etc ..) Permanent slip before restarting it. For this purpose, the counting block 34 receives as input (or directly the counter 36 with which it cooperates), an Ignit variable passing to 1 when the vehicle start event is detected.
La présence d 'une telle alerte de glissement permanent propose un système de détection à la fois robuste et réactif, et propose une information à l'utilisateur avec un degré d'intrusion réduit. La possibilité d 'ajustement de la taille du compteur, de la durée de moyennage du glissement, de la valeur de glissement maximum autorisé et de l 'hystérésis - tous paramétrables - permettent une mise au point très précise de la stratégie d 'alerte de l 'utilisateur tout en assurant une durabilité et une protection du coupleur élevées .  The presence of such a permanent slip alert provides a robust and responsive detection system, and provides information to the user with a reduced degree of intrusion. The possibility of adjusting the counter size, the sliding averaging time, the maximum allowable slip value and the hysteresis - all of which can be set - allow a very precise fine tuning of the warning strategy. while ensuring high durability and coupler protection.
Le bloc 37 d ' estimation d 'une valeur de décalage estime une valeur de glissement permanent dans le temps, afin de procéder à une correction de la valeur de glissement utilisée dans les stratégies de contrôle du coupleur. The offset value estimation block 37 estimates a permanent slip value over time, in order to make a correction of the slip value used in the coupler control strategies.
Le bloc 37 d 'estimation d 'une valeur de décalage reçoit, sur une première entrée, une variable représentant le glissement moyen Gmoy pendant la durée paramétrable MinTime tel que calculé par le bloc de calcul 33.  The block 37 for estimating an offset value receives, on a first input, a variable representing the average slip Gmoy during the configurable duration MinTime as calculated by the calculation block 33.
Le bloc 37 reçoit en outre sur une deuxième entrée, la variable Block 37 also receives on a second input, the variable
D prenant la valeur de la sortie d' une porte OU logique dont les entrées sont respectivement une variable Rev Calc représentant l ' état de réveil du calculateur et la variable Fav émise par le bloc de calcul 33. Les opérations d' estimation de la valeur de décalage sont conditionnées à la valeur prise par cette variable D de sorte que les opérations réalisées par le bloc 37 sont réalisées lorsque la variable D prend la valeur 1 . D taking the value of the output of a logic OR gate whose inputs are respectively a variable Rev Calc representing the wakeup state of the computer and the variable Fav emitted by the calculation block 33. The operations of estimation of the value shift are conditioned by the value taken by this variable D so that the operations performed by the block 37 are performed when the variable D takes the value 1.
Le bloc 37 comporte en outre des moyens de mémorisation formant une mémoire tampon dont la taille est paramétrable en fonction de la valeur prise par une variable T_B . La mémoire tampon reçoit des valeurs de glissement moyen Gmoy, dès lors que la variable D est égale à 1 , et que l 'amplitude de la variation entre deux valeurs immédiatement consécutives de glissement moyen Gmoy est inférieure à un seuil paramétrable (MaxDeltaGmoySlip). Lorsque le nombre de valeurs stockées dans la mémoire tampon atteint un seuil paramétrable MaxCounterGmoySlip, alors une moyenne arithmétique de ces valeurs de glissement moyen Gmoy stockées est calculée. Le résultat de ce calcul est alors envoyé sur la sortie G Offset pour communiquer la valeur de décalage du glissement permanent.  The block 37 further comprises storage means forming a buffer whose size is parameterizable according to the value taken by a variable T_B. The buffer memory receives average slip values Gmoy, since the variable D is equal to 1, and the amplitude of the variation between two immediately consecutive average slip values Gmoy is less than a parameterizable threshold (MaxDeltaGmoySlip). When the number of values stored in the buffer reaches a configurable threshold MaxCounterGmoySlip, then an arithmetic mean of these stored average Gmoy slip values is computed. The result of this calculation is then sent to the output G Offset to communicate the offset value of the permanent slip.
Avantageusement, on peut ne pas reporter directement le résultat du calcul sur la sortie GOffset, et limiter les variations entre la valeur courante présente sur la sortie GOffset et la nouvelle valeur calculée. Dans le cas où la différence entre la nouvelle valeur calculée et la valeur courante est supérieure à un seuil paramétrable MaxGOffsetVar, alors la valeur appliquée sur la sortie GOffset est égale à la valeur courante plus la valeur de seuil MaxGOffsetVar. Dans le cas où la différence entre la nouvelle valeur calculée et la valeur courante est inférieure à un seuil paramétrable MaxGOffsetVar alors la valeur appliquée sur la sortie GOffset est égale à la nouvelle valeur calculée. On obtient ainsi un filtrage des valeurs de décalage du glissement permanent G Offset, permettant de limiter les changements de comportement du véhicule produits et/ou d 'éventuels à-coups au niveau du coupleur (dus à des perturbations de boucles de régulation du coupleur). En outre, le lissage permet d' augmenter le seuil paramétrable MaxCounterGmoySlip des valeurs stockées, sans toutefois augmenter les variations des valeurs appliquées sur la sortie G Offset. La sortie G Offset ne prend des valeurs représentatives du décalage du glissement permanent G Offset seulement lorsque la variable d'activation de sortie SActivate prend la valeur 1 . Ceci se révèle particulièrement utile dans le cas de la recherche de pannes, mais aussi lorsque l ' on souhaite inhiber la fonction. Advantageously, one can not directly report the result of the calculation on the output GOffset, and limit the variations between the current value present on the GOffset output and the new calculated value. In the case where the difference between the new calculated value and the current value is greater than a configurable threshold MaxGOffsetVar, then the value applied on the output GOffset is equal to the current value plus the threshold value MaxGOffsetVar. In the case where the difference between the new calculated value and the current value is less than a configurable threshold MaxGOffsetVar then the value applied to the output GOffset is equal to the new calculated value. This results in a filtering of the offset values of the permanent slip G Offset, making it possible to limit the changes in vehicle behavior produced and / or possible jerks at the coupler (due to disturbances of the coupler control loops). . In addition, the smoothing makes it possible to increase the parameterizable threshold MaxCounterGmoySlip of the stored values, without however increasing the variations of the values applied on the output G Offset. The output G Offset takes values representative of the offset of the permanent slip G Offset only when the output activation variable SActivate takes the value 1. This is particularly useful in the case of troubleshooting, but also when it is desired to inhibit the function.
De plus, lorsqu 'un événement d 'arrêt du véhicule (moteur inclus) est détecté, par exemple par l ' activation de la variable Ignit à une valeur 0, la valeur de décalage du glissement permanent est enregistrée dans une mémoire non volatile accessible par le calculateur 1 1 . Ainsi, la valeur de décalage sauvegardée est immédiatement reprise et appliquée à la sortie G Offset lors du prochain démarrage du véhicule, bien avant que le véhicule ne se déplace et que le bloc 37 ne calcule une nouvelle valeur. Ceci améliore la réactivité globale du système notamment lorsque le filtrage de la variation de la valeur de décalage est opérationnel. In addition, when a vehicle stop event (including engine) is detected, for example by setting the Ignit variable to a value of 0, the offset value of the permanent slip is stored in nonvolatile memory accessed by the calculator 1 1. Thus, the saved offset value is immediately resumed and applied to the output G Offset the next time the vehicle is started, well before the vehicle moves and the block 37 calculates a new value. This improves the overall responsiveness of the system, especially when the filtering of the variation of the offset value is operational.
L'invention telle qu'elle a été décrite permet une protection du coupleur efficace sans consommer beaucoup de ressources mémoire ni générer des interruptions de fonctionnement du mode 4x4 inutiles. L'invention permettant de détecter le glissement permanent peut aussi être appliquée à la révélation d'un problème qui crée un tel glissement permanent. Ainsi, il est possible de détecter une usure de pneus, une pression de gonflage inadaptée, ou une charge trop importante du véhicule. The invention as described allows efficient coupler protection without consuming a lot of memory resources or generating unnecessary 4x4 operation interruptions. The invention for detecting permanent slip can also be applied to the revelation of a problem that creates such a permanent slip. Thus, it is possible to detect tire wear, improper inflation pressure, or excessive load of the vehicle.
Les valeurs des seuils qui enclenchent des conditions de roulage favorables sont paramétrables, il est donc possible de privilégier la non interruption du mode quatre roues motrices sur la protection du coupleur ou de faire l'inverse. Par exemple, on peut dans le bloc de calcul 33 baisser la vitesse minimum ou augmenter la durée paramétrable MinTime pour favoriser la protection du coupleur. Il est ainsi possible d'ajuster le compromis protection du coupleur/disponibilité du mode quatre roues motrices. De plus selon l 'invention, un double obj ectif d' information et de protection du coupleur est atteint. En effet, d'une part l 'utilisateur peut être averti de la présence d 'un glissement anormal par un signal d 'alerte d 'une part, afin de l 'inciter à remédier au problème détecté et d' autre part, lorsque le glissement anormal subsiste dans une plage de valeurs qui ne nuit pas à court terme à la fiabilité du coupleur, de prendre en compte ce glissement anormal « supportable » afin de corriger les stratégies de contrôle du coupleur. The values of the thresholds which trigger favorable driving conditions are parameterizable, it is therefore possible to privilege the non-interruption of the four-wheel drive mode on the protection of the coupler or to do the opposite. For example, one can in the calculation block 33 lower the minimum speed or increase the configurable time MinTime to promote the protection of the coupler. It is thus possible to adjust the compromise protection of the coupler / availability of the four-wheel drive mode. In addition, according to the invention, a dual objective of informing and protecting the coupler is achieved. Indeed, on the one hand the user can be warned of the presence of abnormal sliding by an alert signal on the one hand, in order to incite him to remedy the problem detected and on the other hand, when the Abnormal slip remains in a range of values that does not affect the reliability of the coupler in the short term, to take into account this abnormal slip "bearable" in order to correct the control strategies of the coupler.

Claims

REVENDICATIONS
1 . Procédé d'alerte de glissement d'un coupleur apte à répartir un couple entre deux essieux (2AV, 2AR) d'un véhicule motorisé à quatre roues motrices (l a, l b, l e, l d) montées sur les deux essieux caractérisé en ce que l 'on détermine le glissement représentant la différence de vitesse des deux essieux uniquement lorsque certaines conditions de roulage (C roulage) sont réalisées pendant une durée paramétrable (MinTime). 1. A slip warning method of a coupler capable of distributing a torque between two axles (2AV, 2AR) of a motorized four-wheel drive vehicle (la, lb, le, ld) mounted on the two axles characterized in that the slip representing the difference in speed of the two axles is determined only when certain driving conditions (C rolling) are carried out for a configurable duration (MinTime).
2. Procédé d 'alerte selon la revendication précédente caractérisé en ce que l 'on incrémente un compteur (36) à chaque occurrence de glissement détecté.  2. Alerting method according to the preceding claim characterized in that it increments a counter (36) at each occurrence of slip detected.
3. Procédé d'alerte selon la revendication précédente caractérisé en ce qu 'une alerte est adressée à un utilisateur du véhicule lorsque le compteur (36) atteint un premier seuil paramétrable (MaxCounter).  3. Alerting method according to the preceding claim characterized in that an alert is sent to a user of the vehicle when the counter (36) reaches a first configurable threshold (MaxCounter).
4. Procédé d'alerte selon la revendication 2 caractérisé en ce que l 'alerte est levée lorsque le compteur (36) devient inférieur ou égal à un deuxième seuil paramétrable (Mincounter).  4. Alerting method according to claim 2 characterized in that the alert is raised when the counter (36) becomes less than or equal to a second parameterizable threshold (Mincounter).
5. Procédé d 'alerte selon l'une quelconque des revendications revendication 2 ou 4 caractérisé en ce que l'alerte est levée lorsque le compteur (36) est remis à zéro au démarrage du véhicule.  5. Alerting method according to any one of claims 2 or 4 characterized in that the alert is raised when the counter (36) is reset at start of the vehicle.
6. Procédé d' alerte selon l'une quelconque des revendications 2 ou 3 dans lequel on teste si la valeur moyenne du glissement (Gmoy) au cours de ladite durée paramétrable (MinTime) est supérieure à un troisième seuil (MinWheelSlip) et si l'amplitude de la variation du glissement (Gmax-Gmin) au cours de ladite durée paramétrable (MinTime) est inférieure à un quatrième seuil (MaxDeltaSlip), on incrémente le compteur si les deux tests sont vérifiés.  6. The alerting method as claimed in claim 2, wherein it is tested whether the average value of the slip (Gmoy) during said configurable duration (MinTime) is greater than a third threshold (MinWheelSlip) and whether the amplitude of the slip variation (Gmax-Gmin) during said configurable duration (MinTime) is less than a fourth threshold (MaxDeltaSlip), the counter is incremented if the two tests are checked.
7. Procédé d'alerte selon la revendication 6 dans lequel on teste si la valeur moyenne du glissement (Gmoy) au cours de ladite durée paramétrable (MinTime) est inférieure à un cinquième seuil égal audit troisième seuil moins une constante (MinWheelSlip-Constant), et on décrémente le compteur uniquement lorsque la valeur moyenne du glissement est inférieure au cinquième seuil et l'amplitude de la variation du glissement (Gmax-Gmin) au cours de ladite durée paramétrable (MinTime) est inférieure à un quatrième seuil. 7. An alert method according to claim 6 wherein it is tested whether the average value of the slip (Gmoy) during said configurable duration (MinTime) is less than a fifth threshold equal to said third threshold minus a constant (MinWheelSlip-Constant) , and the counter is decremented only when the average value of the slip is less than the fifth threshold and the amplitude of the slip variation (Gmax-Gmin) during said configurable duration (MinTime) is less than a fourth threshold.
8. Procédé de commande de répartition du couple pour un véhicule selon la revendication 1 dans lequel on incrémente ou on décrémente un compteur (36) en fonction du glissement déterminé et en ce que l 'on supprime tout transfert de couple vers l 'un ou l'autre des essieux lorsque la valeur moyenne du glissement au cours deladite durée (MinTime) dépasse un seuil et lorsque ledit compteur (36) atteint un premier seuil (MaxCounter).  A torque distribution control method for a vehicle according to claim 1 in which a counter (36) is incremented or decremented according to the determined slip and in that any transfer of torque to one or the other of the axles when the average value of the slip during said duration (MinTime) exceeds a threshold and when said counter (36) reaches a first threshold (MaxCounter).
9. Véhicule motorisé (Ve) à quatre roues motrices ( l a, lb, le, l d) montées sur deux essieux (2AV, 2AR) comprenant un arbre de transfert (8) relié au premier essieu et un coupleur piloté (9) capable de transférer une partie du couple depuis l'arbre de transfert (8) vers le deuxième essieu, des moyens de détermination des vitesses respectives des deux essieux et un système de commande de répartition du couple (1 1 ) capable de déterminer une valeur de glissement représentant la différence de vitesse entre les deux essieux et de piloter le coupleur caractérisé en ce que le système de commande de répartition de couple (1 1 ) est configuré pour informer l'utilisateur par alerte selon le procédé d'alerte de glissement d'un coupleur selon l'une des revendications précédentes.  9. Four-wheel drive vehicle (Ve) (la, lb, le, ld) mounted on two axles (2AV, 2AR) comprising a transfer shaft (8) connected to the first axle and a controlled coupler (9) capable of transferring a part of the torque from the transfer shaft (8) to the second axle, means for determining the respective speeds of the two axles and a torque distribution control system (1 1) capable of determining a sliding value representing the speed difference between the two axles and driving the coupler, characterized in that the torque distribution control system (1 1) is configured to inform the user by warning according to the slip warning method of a coupler according to one of the preceding claims.
PCT/FR2011/050822 2010-04-12 2011-04-11 Method for indicating slip of a coupler for distributing torque between two axles of a motorised vehicle, respective distribution control method, and vehicle comprising a system operating according to such a method WO2011128565A1 (en)

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FR1001533A FR2958584B1 (en) 2010-04-12 2010-04-12 METHOD FOR ALLOYING A SLIDE OF A COUPLER.

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111332299A (en) * 2020-03-09 2020-06-26 北京理工大学 Driving anti-skid control method and system based on multi-method fusion

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102016223177B4 (en) * 2016-11-23 2021-06-17 Zf Friedrichshafen Ag Method for operating a vehicle drive train

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61275028A (en) 1985-05-01 1986-12-05 Nissan Motor Co Ltd Driving force distribution controller for four-wheel drive vehicle
DE3838709A1 (en) * 1987-11-23 1989-06-08 Steyr Daimler Puch Ag DRIVE ARRANGEMENT FOR A MOTOR VEHICLE
EP0336055A1 (en) * 1988-04-02 1989-10-11 Dr.Ing.h.c. F. Porsche Aktiengesellschaft System controlling power transmission to at least two axles of a motor vehicle
EP0438178A1 (en) * 1990-01-19 1991-07-24 Mazda Motor Corporation Differential control system for four-wheel drive vehicle
EP1538016A2 (en) * 2003-12-03 2005-06-08 Toyoda Koki Kabushiki Kaisha Drive power transmission control method and system for vehicle
US20050177294A1 (en) * 2004-02-09 2005-08-11 Hong Jiang Method and system for controlling a transfer case clutch to protect against excessive heat
JP4103433B2 (en) 2002-04-15 2008-06-18 松下電器産業株式会社 Dishwasher

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2646820B2 (en) * 1990-08-21 1997-08-27 日産自動車株式会社 Driving force distribution control device for four-wheel drive vehicle
US8095287B2 (en) * 2007-08-30 2012-01-10 Chrysler Group Llc Methods and systems for controlling an axle disconnect device for an all-wheel drive vehicle

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61275028A (en) 1985-05-01 1986-12-05 Nissan Motor Co Ltd Driving force distribution controller for four-wheel drive vehicle
DE3838709A1 (en) * 1987-11-23 1989-06-08 Steyr Daimler Puch Ag DRIVE ARRANGEMENT FOR A MOTOR VEHICLE
EP0336055A1 (en) * 1988-04-02 1989-10-11 Dr.Ing.h.c. F. Porsche Aktiengesellschaft System controlling power transmission to at least two axles of a motor vehicle
EP0438178A1 (en) * 1990-01-19 1991-07-24 Mazda Motor Corporation Differential control system for four-wheel drive vehicle
JP4103433B2 (en) 2002-04-15 2008-06-18 松下電器産業株式会社 Dishwasher
EP1538016A2 (en) * 2003-12-03 2005-06-08 Toyoda Koki Kabushiki Kaisha Drive power transmission control method and system for vehicle
US20050177294A1 (en) * 2004-02-09 2005-08-11 Hong Jiang Method and system for controlling a transfer case clutch to protect against excessive heat

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111332299A (en) * 2020-03-09 2020-06-26 北京理工大学 Driving anti-skid control method and system based on multi-method fusion

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