Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
  • B60T17/18—Safety devices; Monitoring
  • B60T17/22—Devices for monitoring or checking brake systems; Signal devices
  • B60T17/221—Procedure or apparatus for checking or keeping in a correct functioning condition of brake systems
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M15/00—Testing of engines

Definitions

• the invention relates generally to the robot driving of a powertrain mounted on a test bench. More particularly, the invention relates to a method for driving a vehicle powertrain by robot, with optimization of the take-off and stop functions. The invention also relates to a driving robot implementing the aforementioned method.
• WLTP certification test procedure provides in particular for the measurement of fuel consumption, electrical range and C02 and pollutant emissions.
• Driving robots must be autonomous and non-intrusive to maintain the vehicle or powertrain in operating conditions close to real conditions. These driving robots are required, in particular, to ensure high accuracy of speed setpoint tracking, good repeatability for test correlation and so-called “human” driving quality.
• driving robots comprising actuators capable of mechanically controlling the steering components of a vehicle, such as the brake pedal, the accelerator pedal and the gearshift lever.
• these driving robots with actuators of the prior art have various drawbacks which are, among other things, a high cost, consequent durations of installation in the vehicle and of implementation, as well as the need for parameterization. specific for different types of vehicles.
• the applicant proposed a robot for driving an electrified vehicle powertrain mounted on a GMP test bench, which does not require actuators mechanically coupled to the organs steering the vehicle.
• the robot control computer communicates with a development engine control computer installed in the vehicle and with control means of the GMP test bench, through data communication links.
• the robot's computer is permanently informed of the vehicle's driving speed by the vehicle's computer and controls the acceleration and braking of the vehicle via instructions transmitted to the vehicle's computer and to the control means of the GMP test bench.
• the braking phases include a regenerative braking component managed by the driving robot so as to have a good representativeness of the contribution to braking of the energy recovery strategy on board the vehicle.
• the inventive entity has observed a lack of precision in the tracking of the speed setpoint carried out by the driving robot during the phases of take-off and shutdown phases of the powerplant.
• the "crawling” function is present in vehicles equipped with an automatic gearbox, called “BVA”, or a controlled or robotized gearbox, called “BVMP” or “BVP”, as well as in electric vehicles .
• BVA automatic gearbox
• BVMP controlled or robotized gearbox
• the "crawling” function causes the vehicle to travel at very low speed without pressing the accelerator pedal, in forward gear when the gear lever is in position “D” or reverse gear when the gear lever is in position “R from the moment the driver releases the brake pedal.
• the "crawling” function generates an acceleration of the vehicle and causes its driving speed to converge at a stabilized speed of the order of 7 km/h while the speed setpoint is zero or less than 7 km/h. h.
• This function meets a need for progressiveness at very low speed, in particular for driving pleasure during manoeuvres.
• the “crawl” function introduces a non-linearity in the response of the powertrain to an acceleration/braking command from the driving robot occurring in the take-off and stop life phases. This non-linearity generates significant deviations in the tracking of the speed setpoint during these life phases, which affect the high precision sought, in particular for regulatory approval tests.
• Figs.1 and 2 were recorded in the context of tests carried out with a driving robot such as that mentioned above by the applicant described in the unpublished French patent application FR2102391 filed on March 11, 2021.
• significant differences ED and EA appear between the measured taxiing speed VM and the speed setpoint CV in a zone ZD and a zone ZA corresponding to a take-off phase and a shutdown phase of the powertrain , respectively.
• the changes over time (t), in seconds (s), of the measured speed VM and of the speed setpoint CV are represented in Figs. 1 and 2, according to an acceleration/braking command CAF of the robot of driving, more precisely, of a cruise control included in the driving robot.
• the speeds VM and CV are in kilometer/hour (km/h) and the acceleration/braking command CAF is in % of a maximum acceleration (% positive) or a maximum braking (% negative) allowed by the vehicle. It is desirable to propose a method and a vehicle powertrain driving robot not having the aforementioned drawback of the prior art, which provides optimization of the following of the speed setpoint during the take-off and stopping phases of the powertrain.
• the invention relates to a method of driving by robot a powertrain of a vehicle, the powertrain being mounted on a test bench, the robot having a control computer in data communication with a supervising computer of the powertrain and of the control means of the test bench, the method ensuring monitoring of a speed setpoint by means of an acceleration/braking command.
• the method comprises steps of a) detection of a take-off phase or of a shutdown phase of the powertrain in the speed setpoint tracking, and b) correction of the acceleration command /braking by modifying the integral component thereof when the take-off phase or the stopping phase is detected.
• the take-off phase and the stopping phase are detected by means of a state automaton.
• a configurable initialization is applied to the integral component when the take-off phase is detected.
• the configurable initialization is calculated according to a gradient of the speed setpoint.
• the integral component is modified as a function of a loop deviation between the speed setpoint and a rolling speed measured when the stopping phase is detected.
• the invention also relates to a robot for driving a vehicle powertrain comprising a control computer having a memory in which are stored program instructions for implementing the method as described briefly below. below.
• the invention also relates to an assembly comprising a vehicle powertrain mounted on a test bench and the driving robot indicated above.
• Fig.1 shows, by way of example, speed setpoint monitoring curves recorded during the take-off phase of a power unit in the context of a test carried out with a driving robot of the prior art
• FIG.2 shows, by way of example, speed setpoint tracking curves recorded during the stopping phase of the same powertrain in the context of another test carried out with a driving robot. the prior art;
• FIG.3 Fig.3 is a general block diagram schematically showing the functional architecture of a particular embodiment of the driving robot according to the invention;
• Fig.4 is a sequential diagram of a state automaton implemented by a software module used for the implementation of a particular embodiment of the method according to the invention
• Fig.5 is a flowchart of correction processing carried out in the method according to the invention according to the life phases of the powertrain detected by the state automaton of Fig.4;
• Fig.6 shows, by way of example, speed setpoint monitoring curves recorded during the take-off phase of a powertrain as part of a test carried out with a driving robot according to the invention.
• Fig.7 shows, by way of example, speed setpoint tracking curves recorded during the stopping phase of the same powertrain in the context of another test carried out with a driving robot according to the invention.
• the general architecture and operation of a particular embodiment 1 of a driving robot according to the invention is described below, in the context of tests by a group vehicle powertrain mounted on a powertrain test bench, hereinafter simply referred to as "GMP test bench".
• the powertrain of a vehicle 2 is considered in the form of a vehicle having a traction chain with the “crawling” function.
• Driving robot 1 is connected to vehicle 2 for testing on a GMP 3 test bench.
• the powertrain of vehicle 2 is mounted on the GMP 3 test bench typically for one or more test cycles.
• the driving robot 1 controls the powertrain so as to cause it to follow a speed instruction which is specific to the test cycle.
• the driving robot 1 essentially comprises a control computer 10 hosting a driving robot software system ROB.
• the control computer 10 is here connected to a supervising computer 20 of the powertrain of the vehicle 2 by a data communication link LV established through the data communication network of the vehicle 2.
• the control computer 10 is also connected to control means 30 of the GMP test bench 3 by another data communication link LB.
• the supervising computer 20 manages the different traction chain control strategies.
• the supervising computer 20 is a so-called “development” computer which equips the vehicle 2 for the needs of the test cycle.
• the supervising computer 20 carries out identically all the functions fulfilled by the normal computer of the vehicle, but in addition hosts software interfaces (not represented) authorizing data processing and transfers to allow dialogue with the control computer 10 of the driving robot 1 .
• the software system ROB is located in a memory MEM of the control computer 10 and essentially comprises a regulation software module REG and a correction software module COR.
• An acceleration/braking control function FCAF is also realized by the ROB software system and is shown in Fig.3.
• the regulation module REG is responsible for monitoring the speed setpoint CV of the test cycle. This CV speed setpoint typically comes from a speed template file which determines the speed profile to be followed during the test cycle.
• the regulation module REG creates a speed regulation loop and calculates an acceleration/braking command CAFi.
• the acceleration/braking command CAFi is calculated by the regulation module REG from an error between the speed setpoint CV of the test cycle and the measured driving speed VM of the vehicle 2.
• the measured speed VM is supplied by the supervising computer 20 to the control computer 10 via the data communication link LV.
• the acceleration/braking command CAFi is corrected in the regulation module REG by a correction function FCOR in association with the correction module COR.
• a corrected acceleration/braking command CAFc is provided by the correction function FCOR.
• the correction module COR is responsible for determining the correction to be applied to the acceleration/braking command CAFi to obtain the corrected acceleration/braking command CAFc, so as to mitigate the effects of the "ramping" function.
• the corrected acceleration/braking command CAFc is processed by the acceleration/braking command function FCAF so as to calculate an acceleration command ACC and a braking command DEC which respectively command the increase and the reduction of the speed of vehicle 2.
• the acceleration command ACC is transmitted to the supervising computer 20 via the data communication link LV and the braking command DEC is transmitted to the control means 30 of the GMP test bench 3 via the link of data communication LB.
• the acceleration command ACC modifies the content of at least one calibration parameter of the vehicle 2 which represents the physical position of the accelerator pedal of the powertrain of the vehicle 2, or an engine torque setpoint for the powertrain of the vehicle 2.
• the presence of the data communication link LV through which the dialogue between the computer 10 of the robot and the computer 20 of the vehicle 2 takes place, authorizes the control described above of the acceleration without the need for an actuator coupled to the vehicle's powertrain accelerator pedal 2.
• the deceleration of the powertrain of the vehicle 2, controlled by the braking control DEC is obtained by application on the traction chain of a braking torque per slope to the road.
• the road gradient braking torque is applied to the traction chain by an electric generator from the GMP 3 test bench which is coupled to the wheel.
• the road slope function is a function used in GMP test benches and here makes it possible to apply a braking torque to the vehicle without actuating the brake pedal, and therefore, without the need for an actuator acting on this one.
• the correction module COR notably comprises two functional software modules MOD1 and MOD2 which cooperate with each other and with other functions of the regulation module REG.
• the method according to the invention is implemented essentially by the execution of program code instructions of the correction module COR by a processor (not shown) of the control computer 10.
• the function of the MOD1 module is to follow the transitions between the different life phases of the powertrain, so as to detect the take-off and stop life phases for which corrections are necessary.
• the MOD1 module is made using a sequential state automaton shown schematically in Fig.4.
• This state automaton comprises six functional states designated E1 to E6.
• the states E1 to E6 correspond respectively to a so-called plating state, a so-called exit state from the plating, a so-called take-off state, a so-called ramping state, a so-called off-crawling zone state and a so-called stop state. Transitions between states are detected using velocity conditions.
• various configurable speed thresholds are defined to detect transitions T1 to T5.
• the state of clamping E1 corresponds to the end of the regulation.
• the transition T1 to the state E1 from the stop state E6 is detected when the speed setpoint CV becomes equal to or less than a first configurable threshold CP, called “plating setpoint”, equal for example to 0 km /h, and that the measured speed VM becomes less than a second parameterizable threshold VP, called “plating speed”, equal for example to 3 km/h.
• the regulation module REG delivers a fixed command called “plating command” which corresponds to a fixed braking command DEC, for example equal to -30%, which "plates" at 0 km/h the speed VM of the vehicle.
• the transition T2 from the state E1 to the state E2 is detected when the speed setpoint CV becomes greater than a third parameterizable threshold STP, known as the "plating top threshold", equal for example to 0.5 km/h.
• STP third parameterizable threshold
• An analysis of the speed setpoint CV with an anticipation time, for example of the order of 100 ms, can also be carried out to detect the state of the clamping output E2.
• the plating output state E2 is followed automatically by the take-off state E3 and then the ramping state E4, the successive switchings from E2 to E3 and from E3 to E4 occurring on successive steps of the automaton. state.
• the speed of approximately 0.5 km/h assigned to the STP top plating threshold is the speed at which it is generally considered that the power unit has taken off and entered the crawling phase.
• the transition T3 from the crawling state E4 to the off-crawling zone state E5 is detected when the measured speed VM becomes greater than a fourth configurable threshold VR, called “crawling speed", generally equal to approximately 7 km/h .
• the transition T4 from the off-crawling zone state E5 to the stop state E6 is detected when the speed setpoint CV becomes lower than the creeping speed, in other words the above-mentioned fourth configurable threshold VR of approximately 7 km/h .
• the speed setpoint CV can increase and return above the fourth configurable threshold VR. This case corresponds to the transition T5 from the stop state E6 to the non-ramping zone state E5 which is detected when the speed reference CV becomes greater than the fourth configurable threshold VR.
• the module MOD2 is responsible, depending on the state determined by the module MOD1, for controlling a modification of the behavior of the regulation module REG, via the correction function FCOR (cf. Fig3) of the latter, to counter the non -linearity of the powertrain induced by the rampage function.
• the flowchart of Fig.5 schematically shows the correction processing according to the invention carried out on the initial acceleration/braking command CAFi to obtain the corrected acceleration/braking command CAFc delivered as output by the regulation module REG and that depending on the functional state (E1 to E6) detected by module MOD1.
• an OK output delivered by one of the conditional blocks B1 to B6, corresponding respectively to the functional states E1 to E6, indicates detection of the corresponding functional state by the module MOD1.
• a NOK output delivered by one of the conditional blocks B1 to B6 indicates the absence of detection of the corresponding functional state by the module MOD1 and a loop on the block awaiting detection.
• effective correction processing is applied to the acceleration/braking control when the states E3 and E6 are detected, corresponding respectively to the take-off phase and to the shutdown phase of the powertrain.
• the corrected acceleration/braking command CAFc is obtained by correcting the integral component CI_CAFi of the initial acceleration/braking command CAFi.
• a configurable initialization OFS(GD_CV n+i ) is applied to the integral component CI_CAFi of the command CAFi to obtain the integral component CI_CAFc of the corrected command CAFc.
• the correction made in this state E3, corresponding to the take-off phase introduces an offset Z_OFS into the corrected command CAFc which delays stopping braking to counter the effect of the ramp and limit function thus an overshoot of the speed setpoint CV by the measured speed VM.
• the corrected acceleration/braking command CAFc is obtained by correcting the integral component CI_CAFi of the initial acceleration/braking command CAFi.
• the corrected CAFc command differs of the initial command CAFi by an integral component CI_CAFc which is obtained by modifying the integral component CI_CAFi of the initial command CAFi as a function of the loop deviation EV between the speed setpoint CV and the measured speed VM.
• the increase in the integral component due to an increase in loop deviation introduces an accelerated decrease Z_E V in the corrected command CAFc which increases the braking to counter the acceleration induced by the ramping function.
• the corrected acceleration/braking command CAFc therefore remains substantially identical to the initial acceleration/braking command CAFi, as indicated respectively in blocks B10, B20, B40 and B50 of Fig.5.
• the present invention it is possible to obtain optimal monitoring of the speed setpoint template regardless of the disturbances undergone by the powertrain during the take-off and stop phases.
• the automatic detection of the life phases ensured by the state automaton makes it possible to apply the necessary compensations and thus to eliminate the effect of non-linearities.
• the speed obtained is closer to the speed setpoint during the ramping phase, which also makes it possible to limit speed oscillations during the acceleration following the ramping phase.
• the invention is advantageous from an economic point of view, since it allows substantial time savings. It does not require any management of the diversity of settings depending on the powertrain under test. The absence of the need for parameterization favors a rapid implementation time of the driving robot.

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• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Control Of Driving Devices And Active Controlling Of Vehicle (AREA)
• Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=77711030

Family Applications (1)

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Family Cites Families (7)

• 2021
  • 2021-07-01 FR FR2107135A patent/FR3124779B1/fr active Active
• 2022
  • 2022-05-18 WO PCT/FR2022/050941 patent/WO2023275448A1/fr active Application Filing
  • 2022-05-18 EP EP22731269.1A patent/EP4363286A1/de active Pending

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