CN114572179A - Method, device and equipment for detecting abrasion of automatic friction plate of vehicle and storage medium - Google Patents

Method, device and equipment for detecting abrasion of automatic friction plate of vehicle and storage medium Download PDF

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Publication number
CN114572179A
CN114572179A CN202210134795.XA CN202210134795A CN114572179A CN 114572179 A CN114572179 A CN 114572179A CN 202210134795 A CN202210134795 A CN 202210134795A CN 114572179 A CN114572179 A CN 114572179A
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friction plate
wear
friction
preset
current
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刘武
付斌
翟润国
刘滨
裴金顺
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Lantu Automobile Technology Co Ltd
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Lantu Automobile Technology Co Ltd
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    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D66/00—Arrangements for monitoring working conditions, e.g. wear, temperature
    • F16D66/02—Apparatus for indicating wear
    • F16D66/021—Apparatus for indicating wear using electrical detection or indication means

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Braking Arrangements (AREA)
  • Regulating Braking Force (AREA)

Abstract

The invention discloses a method, a device, equipment and a storage medium for detecting the abrasion of an automatic friction plate of a vehicle, wherein the method comprises the steps of obtaining the abrasion loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate; judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result; the judgment result is that the current wear degree exceeds the preset threshold value, a wear alarm signal is generated, the judgment result is that the current wear degree does not exceed the preset threshold value, a wear state signal is generated, and human-computer interaction is performed according to the wear alarm signal or the wear state signal, so that the detection cost can be reduced, the functional diversity of the vehicle and the controller is enhanced, the product competitiveness is improved, the speed and the efficiency of wear detection of the automatic friction plate of the vehicle are improved, and the safety of vehicle running is improved.

Description

Method, device and equipment for detecting abrasion of automatic friction plate of vehicle and storage medium
Technical Field
The invention relates to the technical field of automobiles, in particular to a method, a device, equipment and a storage medium for detecting abrasion of an automatic friction plate of a vehicle.
Background
Currently, the intelligent technology of automobiles is better and better developed, the requirements of users on automobiles are changed from the aspects of traditional power, economy and the like to the aspects of intellectualization, vehicle-machine interaction and the like, and users increasingly pay attention to the perception and experience brought by the aspects of intellectualization and vehicle-machine interaction, such as remote control of automobiles by mobile phones or one-key preview of concerned whole automobile information and the like, wherein the information comprises basic information such as driving mileage, tire pressure monitoring and the like; host computer factories hope to develop more functions in the aspect of vehicle-machine interaction to meet the requirements of users, a braking system is one of systems which are particularly concerned by users as an important safety system of a whole vehicle, wherein a friction plate is used as a wearing part in the braking system, whether the friction plate needs to be replaced is mainly determined by regularly checking at present, and the situation of abrasion of the friction plate of the vehicle can be transmitted to a driver in real time when no vehicle exists in the market.
At present, methods such as calculation and the like are mainly carried out on the abrasion detection and alarm of the friction plate by adding mechanical hardware, circuits and sensors or referring to an electronic parking caliper, and in conclusion, the abrasion detection of the friction plate mainly has four schemes:
1. traditional mechanical alarm: the metal patch is arranged on the back plate of the friction plate, and when the friction material of the friction plate is abraded, the metal patch is contacted with the brake disc to rub, so that a sharp sound is emitted to prompt a driver that the friction plate needs to be replaced; however, the scheme cannot calculate and display the thickness of the friction plate in real time, a driver is only prompted when the friction plate is worn to a limit state, and a metal patch needs to be added on the friction plate, so that the cost is increased.
2. The traditional electronic alarm: a lead is embedded in the friction plate and used as an alarm signal line for abrasion of the friction plate, when the friction plate is abraded to a limit position, the built-in lead is abraded off or is in contact with a brake disc to form an open circuit or a passage, an alarm device is triggered, and a driver is informed that the current friction plate is abraded to a limit state by sending an alarm sound or lightening an instrument, so that the friction plate needs to be replaced; however, the scheme cannot be another implementation manner of the traditional mechanical alarm, the abrasion condition of the friction plate cannot be determined and displayed in real time, a driver can only be prompted when the abrasion condition reaches a limit state, and compared with the mechanical alarm, a circuit and components are added, the cost is increased, and meanwhile, as the temperature of the friction plate rises after braking, and partial conductive materials exist in the material of the friction plate, the electronic alarm may fail or false alarm may occur.
3. The sensor is additionally added: (1) a magnetic sensor, a resistance sensor and a controller are embedded in a back plate of the friction plate, when the abrasion loss of the friction plate changes, the induced current value generated by the sensor changes, the controller monitors the abrasion loss of the friction plate in real time according to the received current value, and triggers an alarm device to remind a driver to replace the friction plate after a certain range is reached; (2) the displacement sensor is additionally arranged between a caliper body and a caliper support of the brake caliper and is connected with the vehicle body controller, in the braking process, the displacement sensor CAN measure the moving length of the caliper support, the thickness of a friction plate CAN be obtained through calculation, the current abrasion loss is determined, and the vehicle body controller CAN display the abrasion condition and alarm information of the friction plate on an instrument through a CAN bus and provide the abrasion condition and the alarm information for a driver; however, in the two modes, the current or displacement signal is acquired by adding a sensor on the friction plate or the brake caliper, so that the abrasion loss of the friction plate is calculated, parts are added, and the cost change is high.
4. The method adopting parking caliper calculation comprises the following steps: (1) the electronic parking brake caliper is braked, the friction plate is clamped by the actuating mechanism, the controller detects and controls the voltage, current and time variation in the clamping process of the actuating mechanism, and the abrasion loss of the friction plate is calculated through a formula; (2) judging the difference between the rotation stroke and a preset target stroke through the rotation stroke of a motor of the electronic caliper, and comparing the difference with a set threshold value so as to judge whether the friction plate needs to be replaced; the above two modes all adopt existing parts on the current vehicle to detect the abrasion of the friction plate, but the abrasion condition of the friction plate of the rear brake caliper can only be detected, the abrasion loss of the friction plate of the front brake caliper cannot be detected, and if the front friction plate is abraded to a limit position and the rear friction plate is not in a limit state, the method cannot effectively remind and warn a driver.
Disclosure of Invention
The invention mainly aims to provide a method, a device, equipment and a storage medium for detecting the abrasion of an automatic friction plate of a vehicle, and aims to solve the technical problems that in the prior art, a metal patch is added on the friction plate, the cost is higher, an electronic alarm is easy to fail or give false alarm, the cost change of an additionally added sensor is higher, the abrasion loss of the friction plate of a front brake caliper cannot be detected by adopting a parking caliper, and a driver cannot be effectively reminded and warned.
In a first aspect, the present invention provides a method for detecting wear of an automatic friction plate of a vehicle, including the steps of:
acquiring the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate;
judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result;
and generating a wear alarm signal when the current wear degree exceeds the preset threshold value according to the judgment result, generating a wear state signal when the current wear degree does not exceed the preset threshold value according to the judgment result, and performing man-machine interaction according to the wear alarm signal or the wear state signal.
Optionally, the obtaining of the wear loss of the friction plate, the remaining thickness of the friction plate, and the estimated mileage for replacing the friction plate includes:
acquiring friction plate pressure, wheel angular speed, a preset friction plate temperature function and a preset friction fitting function of a target vehicle;
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function;
acquiring the total thickness of friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates;
and acquiring the current vehicle mileage of the target vehicle, the current abrasion loss and the current residual thickness of the friction plate with the maximum abrasion loss, and determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness.
Optionally, the obtaining of the friction plate pressure, the wheel angular speed, the preset friction plate temperature function, and the preset friction fitting function of the target vehicle includes:
obtaining the pressure of four brake wheel cylinders acting on the friction plates according to the pressure sensor of the target vehicle, and taking the pressure acting on the friction plates as the pressure of the friction plates;
acquiring angular velocities of four wheels according to a wheel speed sensor of the target vehicle, and taking the angular velocities of the four wheels as wheel angular velocities;
obtaining a preset friction plate temperature function through the following formula:
Figure BDA0003504042480000031
wherein, FTFor presetting a function of temperature of the friction disk, T0The initial temperature at the current time; r is the effective braking radius; omega is the angular velocity of the wheel,
Figure BDA0003504042480000032
the central angle is corresponding to the friction plate; r0And R1Respectively the radius of the inner edge and the radius of the outer edge of the friction plate; mu is the friction coefficient of the disc; p is the pressure acting on the friction plate; ρ is a unit of a gradientdiscAnd ρpadThe densities of the brake disc and the friction plate are respectively; cdiscAnd CpadThe specific heat capacities of the brake disc and the friction plate are respectively; kdiscAnd KpadThe heat conductivity coefficients of the brake disc and the friction plate are respectively; r is friction plate radius, rdr is pair R0And R1D θ is a pair
Figure BDA0003504042480000033
Integral of (d), dt is the derivative mark, CpadIs the specific heat capacity of the friction plate, mpad(t) is the mass of the friction plate, and is a function of the temperature of the friction plate over time;
and fitting the abrasion loss data of unit distance at different temperatures and different brake pressures to obtain a preset friction fitting function.
Optionally, the determining a friction plate wear amount according to the friction plate pressure, the wheel angular velocity, the preset friction plate temperature function, and the preset friction fitting function includes:
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function through the following formula:
Δh＝F(P,ω,FT,FP)
wherein Δ h is a friction plate wear amount, P is the friction plate pressure, ω is the wheel angular velocity, FTFor said predetermined friction lining temperature function, FPFitting a function to the preset friction.
Optionally, the obtaining a total thickness of friction plates of the target vehicle, and determining a remaining thickness of the friction plates according to the total thickness of the friction plates and the wear amount of the friction plates includes:
acquiring the total thickness of friction plates of the target vehicle, and determining the remaining thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates by the following formula:
h＝l-Δh
wherein h is the residual thickness of the friction plate, l is the total thickness of the friction plate, and delta h is the abrasion loss of the friction plate.
Optionally, the determining an estimated driving mileage for friction plate replacement according to the current vehicle mileage, the current wear amount, and the current remaining thickness includes:
determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness by the following formula:
Figure BDA0003504042480000041
wherein S is the estimated mileage0Is the current vehicle mileage, Δ hmaxFor the current amount of wear, hminIs the current remaining thickness.
Optionally, the determining, according to the wear amount of the friction plate, the remaining thickness of the friction plate, and the estimated mileage, whether the current wear degree exceeds a preset threshold value, and generating a determination result includes:
comparing the wear loss of the friction plate with a preset wear loss threshold value, comparing the residual thickness of the friction plate with a preset thickness threshold value, and comparing the estimated driving mileage with a preset mileage threshold value;
when the wear loss of the friction plate is larger than the preset wear loss threshold, and/or the residual thickness of the friction plate is larger than the preset thickness threshold, and/or the estimated driving mileage is larger than the preset mileage threshold, generating a judgment result that the current wear degree is judged to exceed the preset threshold;
and when the wear loss of the friction plate is not more than the preset wear loss threshold, the residual thickness of the friction plate is not more than the preset thickness threshold, and the estimated driving mileage is not more than the preset mileage threshold, generating the judgment result as that the current wear degree does not exceed the preset threshold.
In a second aspect, to achieve the above object, the present invention further provides a vehicle automatic friction plate wear detection device, including:
the data acquisition module is used for acquiring the abrasion loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate;
the judging module is used for judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage and generating a judging result;
and the abrasion detection module is used for generating an abrasion alarm signal when the judgment result shows that the current abrasion degree exceeds the preset threshold value, generating an abrasion state signal when the judgment result shows that the current abrasion degree does not exceed the preset threshold value, and carrying out man-machine interaction according to the abrasion alarm signal or the abrasion state signal.
In a third aspect, to achieve the above object, the present invention also provides a vehicle automatic friction plate wear detection apparatus including: a memory, a processor and a vehicle automatic friction plate wear detection program stored on the memory and operable on the processor, the vehicle automatic friction plate wear detection program configured to implement the steps of the vehicle automatic friction plate wear detection method as described above.
In a fourth aspect, to achieve the above object, the present invention further provides a storage medium, on which a vehicle automatic friction plate wear detection program is stored, which when executed by a processor implements the steps of the vehicle automatic friction plate wear detection method as described above.
The invention provides an automatic wear detection method for a friction plate of a vehicle, which comprises the steps of obtaining the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate; judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result; the automatic abrasion detection device comprises a controller, a judging result and a wear state signal generation unit, wherein the judging result is that an abrasion alarm signal is generated when the current abrasion degree exceeds a preset threshold value, the judging result is that an abrasion state signal is generated when the current abrasion degree does not exceed the preset threshold value, man-machine interaction is carried out according to the abrasion alarm signal or the abrasion state signal, the abrasion condition of the friction plates of four wheels of the current vehicle can be calculated in real time, no extra hardware equipment is needed to be added, the detection cost is reduced, the abrasion state of the friction plates can be presented to a driver in a data mode, the functional diversity of the vehicle and the controller is enhanced, the product competitiveness is improved, the problem that the detection failure probability is increased due to the addition of a sensor is avoided, the speed and the efficiency of automatic abrasion detection of the vehicle are improved, and the safety of vehicle running is improved.
Drawings
FIG. 1 is a schematic diagram of an apparatus architecture of a hardware operating environment according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart illustrating a first embodiment of an automatic friction plate wear detection method for a vehicle according to the present invention;
FIG. 3 is a schematic flow chart illustrating a method for detecting wear of an automatic friction plate of a vehicle according to a second embodiment of the present invention;
FIG. 4 is a schematic flow chart illustrating a method for detecting wear of an automatic friction plate of a vehicle according to a third embodiment of the present invention;
FIG. 5 is a functional block diagram of a first embodiment of an automatic friction plate wear detection apparatus for a vehicle according to the present invention;
FIG. 6 is a schematic flow chart of the automatic friction plate wear detection system of the vehicle according to the present invention.
The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The solution of the embodiment of the invention is mainly as follows: estimating the driving mileage by acquiring the abrasion loss of the friction plate, the residual thickness of the friction plate and the replacement of the friction plate; judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result; when the judgment result is that the current wear degree exceeds the preset threshold value, a wear state signal is generated, man-machine interaction is carried out according to the wear state signal or the wear state signal, the wear condition of the friction plates of four wheels of the current vehicle can be calculated in real time without adding extra hardware equipment, the detection cost is reduced, the wear state of the friction plates can be presented to a driver in a data form, the functional diversity of the vehicle and the controller is enhanced, the product competitiveness is improved, the problem that the detection failure probability is increased due to the addition of a sensor is avoided, the speed and the efficiency of the wear detection of the automatic friction plates of the vehicle are improved, the safety of the vehicle running is improved, and the problem that a metal patch is added on the friction plate in the prior art is solved, the cost is higher, and electronic type alarm appears inefficacy easily or the wrong report is alert, and it is higher to additionally increase sensor cost and change, and adopts the wearing and tearing volume of braking calliper friction disc before the unable detection of parking calliper, can't effectively remind and warn driver's technical problem.
Referring to fig. 1, fig. 1 is a schematic device structure diagram of a hardware operating environment according to an embodiment of the present invention.
As shown in fig. 1, the apparatus may include: a processor 1001, such as a CPU, a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Wherein a communication bus 1002 is used to enable connective communication between these components. The user interface 1003 may include a Display screen (Display), an input unit such as a Keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface, a wireless interface. The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., a Wi-Fi interface). The Memory 1005 may be a high-speed RAM Memory or a Non-Volatile Memory (Non-Volatile Memory), such as a disk Memory. The memory 1005 may alternatively be a storage device separate from the processor 1001.
Those skilled in the art will appreciate that the configuration of the apparatus shown in fig. 1 is not intended to be limiting of the apparatus and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components.
As shown in fig. 1, a memory 1005, which is a storage medium, may include therein an operating device, a network communication module, a user interface module, and a vehicle automatic friction plate wear detection program.
The apparatus of the present invention calls, through the processor 1001, the vehicle automatic friction plate wear detection program stored in the memory 1005, and performs the following operations:
acquiring the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate;
judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result;
and generating a wear alarm signal when the current wear degree exceeds the preset threshold value according to the judgment result, generating a wear state signal when the current wear degree does not exceed the preset threshold value according to the judgment result, and performing man-machine interaction according to the wear alarm signal or the wear state signal.
The apparatus of the present invention calls, by the processor 1001, the vehicle automatic friction plate wear detection program stored in the memory 1005, and also performs the following operations:
acquiring friction plate pressure, wheel angular speed, a preset friction plate temperature function and a preset friction fitting function of a target vehicle;
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function;
acquiring the total thickness of friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates;
and acquiring the current vehicle mileage of the target vehicle, the current abrasion loss and the current residual thickness of the friction plate with the maximum abrasion loss, and determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness.
The apparatus of the present invention calls a vehicle automatic friction plate wear detection program stored in the memory 1005 by the processor 1001, and also performs the following operations:
obtaining the pressure of four brake wheel cylinders acting on the friction plates according to the pressure sensor of the target vehicle, and taking the pressure acting on the friction plates as the pressure of the friction plates;
acquiring angular velocities of four wheels according to a wheel speed sensor of the target vehicle, and taking the angular velocities of the four wheels as wheel angular velocities;
obtaining a preset friction plate temperature function through the following formula:
Figure BDA0003504042480000081
wherein, FTFor said predetermined friction lining temperature function, T0The initial temperature at the current time; r is the effective braking radius; omega is the angular velocity of the wheel,
Figure BDA0003504042480000082
the central angle is corresponding to the friction plate; r is0And R1Respectively the radius of the inner edge and the radius of the outer edge of the friction plate; mu is the friction coefficient of the disc; p is the pressure acting on the friction plate; rhodiscAnd ρpadThe densities of the brake disc and the friction plate are respectively; cdiscAnd CpadThe specific heat capacities of the brake disc and the friction plate are respectively; kdiscAnd KpadThe heat conductivity coefficients of the brake disc and the friction plate are respectively; r is friction plate radius, rdr is pair R0And R1D θ is in
Figure BDA0003504042480000083
Integral of (d), dt is the derivative mark, CpadIs the specific heat capacity of the friction plate, mpad(t) is the mass of the friction plate, and is a function of the temperature of the friction plate over time;
and fitting the abrasion loss data of unit distance at different temperatures and different brake pressures to obtain a preset friction fitting function.
The apparatus of the present invention calls, by the processor 1001, the vehicle automatic friction plate wear detection program stored in the memory 1005, and also performs the following operations:
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function through the following formula:
Δh＝F(P,ω,FT,FP)
wherein Δ h is a friction plate wear amount, P is the friction plate pressure, ω is the wheel angular velocity, FTFor said predetermined friction lining temperature function, FPFitting a function to the preset friction.
The apparatus of the present invention calls, by the processor 1001, the vehicle automatic friction plate wear detection program stored in the memory 1005, and also performs the following operations:
acquiring the total thickness of friction plates of the target vehicle, and determining the remaining thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates by the following formula:
h＝l-Δh
wherein h is the residual thickness of the friction plate, l is the total thickness of the friction plate, and delta h is the abrasion loss of the friction plate.
The apparatus of the present invention calls, by the processor 1001, the vehicle automatic friction plate wear detection program stored in the memory 1005, and also performs the following operations:
determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness by the following formula:
Figure BDA0003504042480000091
wherein S is the estimated mileage0Is the current vehicle mileage, Δ hmaxFor the current amount of wear, hminIs the current remaining thickness.
The apparatus of the present invention calls, by the processor 1001, the vehicle automatic friction plate wear detection program stored in the memory 1005, and also performs the following operations:
comparing the wear loss of the friction plate with a preset wear loss threshold value, comparing the residual thickness of the friction plate with a preset thickness threshold value, and comparing the estimated driving mileage with a preset mileage threshold value;
when the wear loss of the friction plate is larger than the preset wear loss threshold, and/or the residual thickness of the friction plate is larger than the preset thickness threshold, and/or the estimated driving mileage is larger than the preset mileage threshold, generating a judgment result that the current wear degree is judged to exceed the preset threshold;
and when the wear loss of the friction plate is not more than the preset wear loss threshold, the residual thickness of the friction plate is not more than the preset thickness threshold, and the estimated driving mileage is not more than the preset mileage threshold, generating the judgment result as that the current wear degree does not exceed the preset threshold.
According to the scheme, the estimated driving mileage of the friction plate is obtained by acquiring the abrasion loss of the friction plate, the residual thickness of the friction plate and the replacement of the friction plate; judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result; the wear detection method comprises the steps that a wear alarm signal is generated when the current wear degree exceeds a preset threshold value according to a judgment result, a wear state signal is generated when the current wear degree does not exceed the preset threshold value according to the judgment result, man-machine interaction is carried out according to the wear alarm signal or the wear state signal, the wear condition of the friction plates of four wheels of the current vehicle can be calculated in real time, extra hardware equipment is not needed, the detection cost is reduced, the wear state of the friction plates can be presented to a driver in a data mode, the functional diversity of the vehicle and the controller is enhanced, the competitiveness of the product is improved, the problem that the detection failure probability is increased due to the fact that a sensor is added is avoided, the speed and the efficiency of wear detection of the automatic friction plates of the vehicle are improved, and the safety of vehicle running is improved.
Based on the hardware structure, the embodiment of the method for detecting the abrasion of the automatic friction plate of the vehicle is provided.
Referring to fig. 2, fig. 2 is a schematic flow chart of a first embodiment of a method for detecting wear of an automatic friction plate of a vehicle according to the present invention.
In a first embodiment, the automatic friction plate wear detection method for a vehicle includes the steps of:
and step S10, acquiring the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate.
It should be noted that the wear loss of the friction plate is the wear loss generated when the friction plate contacts the brake disc and is worn, the remaining thickness of the friction plate is the current remaining thickness of the wheel friction plate, and the estimated driving distance for replacing the friction plate is the estimated value of the driving distance for replacing the friction plate.
And step S20, judging whether the current wear degree exceeds a preset threshold value according to the wear amount of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result.
It can be understood that whether the current wear degree exceeds a preset threshold value can be judged through the wear amount of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and the wear amount of the friction plate, the residual thickness of the friction plate and the estimated driving mileage can be analyzed through an intelligent integrated brake control unit generally, so that the current wear degree is determined, and a corresponding judgment result is generated.
And step S30, generating a wear alarm signal when the judgment result is that the current wear degree exceeds the preset threshold, generating a wear state signal when the judgment result is that the current wear degree does not exceed the preset threshold, and performing man-machine interaction according to the wear alarm signal or the wear state signal.
It should be understood that when the current wear degree exceeds a preset threshold value, a wear warning signal of the friction plate may be generated, and when the current wear degree does not exceed the preset threshold value, a wear state signal of the friction plate may be generated, so that human-computer interaction may be performed according to the wear warning signal or the wear state signal.
In the specific implementation, when the abrasion loss of the friction plate calculated by the intelligent integrated brake control unit exceeds a certain threshold value, an alarm signal zone bit CAN be sent to a CAN bus, a vehicle-mounted information entertainment system displays a brake fault lamp on an instrument and CAN prompt a driver to replace the friction plate in a text mode, meanwhile, a low-power-consumption Bluetooth module pushes a message of replacing the friction plate to a mobile terminal after receiving the alarm signal zone bit to prompt the driver to replace the friction plate and CAN also transmit the message to a mobile terminal (such as a mobile phone) of a user through Bluetooth, and the user CAN display the abrasion loss of the friction plate of four wheels, the thickness of the residual friction plate, estimate the state information of the friction plate replacing travel mileage and the like in real time through the mobile terminal, so that man-machine interaction is realized.
According to the scheme, the estimated driving mileage of the friction plate is obtained by acquiring the abrasion loss of the friction plate, the residual thickness of the friction plate and the replacement of the friction plate; judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result; the automatic abrasion detection device comprises a controller, a judging result and a wear state signal generation unit, wherein the judging result is that an abrasion alarm signal is generated when the current abrasion degree exceeds a preset threshold value, the judging result is that an abrasion state signal is generated when the current abrasion degree does not exceed the preset threshold value, man-machine interaction is carried out according to the abrasion alarm signal or the abrasion state signal, the abrasion condition of the friction plates of four wheels of the current vehicle can be calculated in real time, no extra hardware equipment is needed to be added, the detection cost is reduced, the abrasion state of the friction plates can be presented to a driver in a data mode, the functional diversity of the vehicle and the controller is enhanced, the product competitiveness is improved, the problem that the detection failure probability is increased due to the addition of a sensor is avoided, the speed and the efficiency of automatic abrasion detection of the vehicle are improved, and the safety of vehicle running is improved.
Further, fig. 3 is a schematic flow chart of a second embodiment of the method for detecting wear of the automatic friction plate of the vehicle according to the present invention, and as shown in fig. 3, the second embodiment of the method for detecting wear of the automatic friction plate of the vehicle according to the present invention is proposed based on the first embodiment, and in this embodiment, the step S10 specifically includes the following steps:
and step S11, acquiring friction plate pressure, wheel angular speed, a preset friction plate temperature function and a preset friction fitting function of the target vehicle.
It should be noted that the pressure of the friction plate is the braking pressure when the friction plate brakes, the angular velocity of the wheel is the angular velocity of the wheel when the wheel rotates, the preset friction plate temperature function is a function of the friction plate corresponding to different wear conditions under different temperature conditions, and the preset friction fitting function is a fitting function of the wear amount per unit distance of the friction plate under different temperatures and different braking pressures.
Further, the step S11 specifically includes the following steps:
obtaining the pressure of four brake wheel cylinders acting on the friction plates according to the pressure sensor of the target vehicle, and taking the pressure acting on the friction plates as the pressure of the friction plates;
acquiring angular velocities of four wheels according to a wheel speed sensor of the target vehicle, and taking the angular velocities of the four wheels as wheel angular velocities;
obtaining a preset friction plate temperature function through the following formula:
Figure BDA0003504042480000121
wherein, FTFor said predetermined friction lining temperature function, T0The initial temperature at the current time; r is the effective braking radius; omega is the angular velocity of the wheel,
Figure BDA0003504042480000122
the central angle is corresponding to the friction plate; r0And R1Respectively the radius of the inner edge and the radius of the outer edge of the friction plate; mu is the friction coefficient of the disc; p is the pressure acting on the friction plate; rhodiscAnd ρpadThe densities of the brake disc and the friction plate are respectively; cdiscAnd CpadThe specific heat capacities of the brake disc and the friction plate are respectively; kdiscAnd KpadThe heat conductivity coefficients of the brake disc and the friction plate are respectively; r is friction plate radius, rdr is pair R0And R1D θ is in
Figure BDA0003504042480000123
Integral of (d), dt is the derivative mark, CpadAs friction discsSpecific heat capacity of (b), mpad(t) is the mass of the friction plate, and is a function of the temperature of the friction plate over time;
and fitting the abrasion loss data of unit distance at different temperatures and different brake pressures to obtain a preset friction fitting function.
It will be appreciated that since the friction plates wear differently at different temperatures, the calculation of the temperature of the friction plates is the basis for calculating the amount of wear. When the vehicle brakes, the friction between the friction plate and the brake disc realizes the deceleration of the vehicle, part of the kinetic energy of the vehicle is converted into the heat energy of the friction plate and the brake disc, so that the temperature of the friction plate and the brake disc is increased, and the calculation formula for the temperature increase of the friction plate can be confirmed by adopting an energy conservation and thermodynamic formula.
Correspondingly, when the vehicle is not braked, the friction plate and the brake disc begin to radiate heat, the temperature begins to decrease, and the calculation formula for confirming the temperature decrease of the friction plate according to the thermodynamic formula is as follows:
Figure BDA0003504042480000131
wherein: t is0The initial temperature at the current time; t iseIs ambient temperature; re is Reynolds coefficient, related to wheel speed; pr is a Plantago number; gamma is the coefficient of thermal conductivity; l is a characteristic length; a is the friction plate area.
In the concrete implementation, the material characteristics of the friction plate are also important factors for determining the friction plate abrasion in the braking process, different abrasion can be generated under the same braking working condition due to different friction plate material formulas and compression ratios, the material characteristic module of the friction plate is set as a calibratable module, when the type selection of the vehicle friction plate is completed, namely the material of the friction plate and key parameters such as the compression ratio are locked, the abrasion loss of the friction plate in unit distance under different temperatures and different braking pressures can be determined through calibration test and fitting, and the formula is as follows:
FP＝F(P,T)
wherein, FPFor a predetermined friction fit function, P is different brakingThe pressure, T, is the different temperatures.
And step S12, determining the friction plate abrasion loss according to the friction plate pressure, the wheel angular speed, the preset friction plate temperature function and the preset friction fitting function.
It is understood that the wear amount of the wheel friction plates may be determined based on the friction plate pressure, the wheel angular velocity, the preset friction plate temperature function, and the preset friction fitting function.
Further, the step S12 specifically includes the following steps:
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function through the following formula:
Δh＝F(P,ω,FT,FP)
wherein Δ h is a friction plate wear amount, P is the friction plate pressure, ω is the wheel angular velocity, FTFor said predetermined friction lining temperature function, FPFitting a function to the preset friction.
It should be understood that the wear of the friction plate is related to the characteristics of the brake pressure, wheel speed, temperature and friction material at the time of braking, and the friction plate wear calculation may be expressed as the above-described functional expression related to the brake pressure, wheel speed, temperature and friction material.
And step S13, acquiring the total thickness of the friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates.
It should be understood that the total thickness of the friction plates of the target vehicle is obtained, and the remaining thickness of the friction plates can be obtained by calculating the difference between the total thickness of the friction plates and the amount of wear of the friction plates.
Further, the step S13 specifically includes the following steps:
acquiring the total thickness of friction plates of the target vehicle, and determining the remaining thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates by the following formula:
h＝l-Δh
wherein h is the residual thickness of the friction plate, l is the total thickness of the friction plate, and delta h is the abrasion loss of the friction plate.
It is understood that the remaining thickness of the friction plate can be calculated by subtracting the total thickness of the friction plate and the wear amount of the friction plate, and the wear amount of the friction plate can also be obtained by the following formula:
Figure BDA0003504042480000141
and S14, acquiring the current vehicle mileage of the target vehicle, the current wear amount and the current remaining thickness of the friction plate with the largest wear amount, and determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current wear amount and the current remaining thickness.
It can be understood that after the vehicle mileage of the current vehicle, the wear loss and the residual thickness of the friction plate with the maximum wear loss are obtained, the estimated driving mileage needing to replace the friction plate can be obtained through calculation.
Further, the step S14 includes the following steps:
determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness by the following formula:
Figure BDA0003504042480000142
wherein S is the estimated mileage0Is the current vehicle mileage, Δ hmaxFor the current amount of wear, hminIs the current remaining thickness.
It should be understood that the wheel speeds ω of the four wheels will be adjustedFL(left front wheel angular velocity), ωFR(angular velocity of right front wheel), ωRL(angular velocity of left rear wheel), ωRR(rear right wheel angular velocity) and corresponding wheel cylinder pressure PFL(left front wheel friction plate pressure), PFR(Right front wheel Friction platePressure), PRL(left rear wheel friction plate pressure), PRRRespectively substituting the pressure of the right rear wheel friction plate into a formula to obtain the abrasion loss delta h of the current friction plateFL、ΔhFR、ΔhRL、ΔhRRAnd the remaining thickness h of the friction plateFL、hFR、hRL、hRR(ii) a When the abrasion loss of any one friction plate exceeds a threshold value, the alarm is given to a driver, so that the estimated driving mileage for replacing the friction plate is calculated by adopting the friction plate with the largest abrasion loss, and the residual thickness is the smallest.
According to the scheme, the pressure of the friction plate of the target vehicle, the angular speed of the wheel, the temperature function of the preset friction plate and the preset friction fitting function are obtained; determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function; acquiring the total thickness of friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates; the current vehicle mileage of the target vehicle, the current wear extent and the current remaining thickness of the friction plate with the largest wear extent are obtained, the estimated driving mileage for replacing the friction plate is determined according to the current vehicle mileage, the current wear extent and the current remaining thickness, the wear extent of the friction plate, the remaining thickness of the friction plate and the estimated driving mileage for replacing the friction plate can be accurately obtained in detail, and the speed and the efficiency of automatic wear detection of the friction plate of the vehicle are improved.
Further, fig. 4 is a schematic flow chart of a third embodiment of the method for detecting wear of the automatic friction plate of the vehicle according to the present invention, and as shown in fig. 4, the third embodiment of the method for detecting wear of the automatic friction plate of the vehicle according to the present invention is proposed based on the first embodiment, and in this embodiment, the step S20 specifically includes the following steps:
step S21, the wear loss of the friction plate is compared with a preset wear loss threshold value, the residual thickness of the friction plate is compared with a preset thickness threshold value, and the estimated driving mileage is compared with a preset mileage threshold value.
It should be noted that the wear loss of the friction plate, the remaining thickness of the friction plate, and the estimated mileage may be compared according to different preset thresholds, so as to generate corresponding comparison results.
And step S22, when the wear loss of the friction plate is larger than the preset wear loss threshold, and/or the residual thickness of the friction plate is larger than the preset thickness threshold, and/or the estimated mileage is larger than the preset mileage threshold, generating a judgment result that the current wear degree is judged to exceed the preset threshold.
It can be understood that when the wear amount of the friction plate is greater than the preset wear amount threshold, and/or the remaining thickness of the friction plate is greater than the preset thickness threshold, and/or the estimated mileage is greater than the preset mileage threshold, a corresponding determination result may be generated, that is, it may be determined that the current wear degree exceeds the preset threshold.
Step S23, when the wear loss of the friction plate is not larger than the preset wear loss threshold, the residual thickness of the friction plate is not larger than the preset thickness threshold, and the estimated driving mileage is not larger than the preset mileage threshold, generating the judgment result as that the current wear degree does not exceed the preset threshold.
It should be understood that, when the wear amount of the friction plate is not greater than the preset wear amount threshold, the remaining thickness of the friction plate is not greater than the preset thickness threshold, and the estimated mileage is not greater than the preset mileage threshold, a corresponding determination result may be generated, that is, it may be determined that the current wear degree does not exceed the preset threshold.
According to the scheme, the wear loss of the friction plate is compared with a preset wear loss threshold value, the residual thickness of the friction plate is compared with a preset thickness threshold value, and the estimated driving mileage is compared with a preset mileage threshold value; when the wear loss of the friction plate is larger than the preset wear loss threshold, and/or the residual thickness of the friction plate is larger than the preset thickness threshold, and/or the estimated driving mileage is larger than the preset mileage threshold, generating a judgment result that the current wear degree is judged to exceed the preset threshold; when the wear loss of the friction plate is not more than the preset wear loss threshold, the residual thickness of the friction plate is not more than the preset thickness threshold, and the estimated driving mileage is not more than the preset mileage threshold, generating the judgment result as that the current wear degree does not exceed the preset threshold; the abrasion condition of the friction plate can be accurately acquired, so that the abrasion detection speed and efficiency of the automatic friction plate of the vehicle are improved, and the running safety of the vehicle is improved.
Correspondingly, the invention further provides an automatic friction plate wear detection device for the vehicle.
Referring to fig. 5, fig. 5 is a functional block diagram of a first embodiment of an automatic friction plate wear detecting device for a vehicle according to the present invention.
In a first embodiment of the apparatus for detecting wear of an automatic friction plate for a vehicle according to the present invention, the apparatus includes:
and the data acquisition module 10 is used for acquiring the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate.
And the judging module 20 is configured to judge whether the current wear degree exceeds a preset threshold according to the wear amount of the friction plate, the remaining thickness of the friction plate, and the estimated driving mileage, and generate a judgment result.
And the wear detection module 30 is configured to generate a wear alarm signal when the current wear degree exceeds the preset threshold according to the determination result, generate a wear state signal when the current wear degree does not exceed the preset threshold according to the determination result, and perform human-computer interaction according to the wear alarm signal or the wear state signal.
The data acquisition module 10 is further configured to acquire a friction plate pressure, a wheel angular velocity, a preset friction plate temperature function and a preset friction fitting function of the target vehicle; determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function; acquiring the total thickness of friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates; and acquiring the current vehicle mileage of the target vehicle, the current abrasion loss and the current residual thickness of the friction plate with the maximum abrasion loss, and determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness.
The data acquisition module 10 is further configured to obtain pressures acting on the friction plates by the four brake wheel cylinders according to the pressure sensor of the target vehicle, and use the pressures acting on the friction plates as friction plate pressures; acquiring angular velocities of four wheels according to a wheel speed sensor of the target vehicle, and taking the angular velocities of the four wheels as wheel angular velocities; obtaining a preset friction plate temperature function through the following formula:
Figure BDA0003504042480000171
wherein, FTFor presetting a function of temperature of the friction disk, T0The initial temperature at the current time; r is the effective braking radius; omega is the angular velocity of the wheel,
Figure BDA0003504042480000172
the central angle is corresponding to the friction plate; r is0And R1Respectively the radius of the inner edge and the radius of the outer edge of the friction plate; mu is the friction coefficient of the disc; p is the pressure acting on the friction plate; rhodiscAnd ρpadThe densities of the brake disc and the friction plate are respectively; cdiscAnd CpadThe specific heat capacities of the brake disc and the friction plate are respectively; kdiscAnd KpadThe heat conductivity coefficients of the brake disc and the friction plate are respectively; r is friction plate radius, rdr is pair R0And R1D θ is in
Figure BDA0003504042480000173
Integral of (d), dt is the derivative mark, CpadIs the specific heat capacity of the friction plate, mpad(t) is the mass of the friction plate, and is a function of the temperature of the friction plate over time;
and fitting the abrasion loss data of unit distance at different temperatures and different brake pressures to obtain a preset friction fitting function.
The data obtaining module 10 is further configured to determine a wear loss of the friction plate according to the friction plate pressure, the wheel angular velocity, the preset friction plate temperature function, and the preset friction fitting function by using the following formula:
Δh＝F(P,ω,FT,FP)
wherein Δ h is a friction plate wear loss, P is the friction plate pressure, ω is the wheel angular velocity, FTFor said predetermined friction lining temperature function, FPFitting a function to the preset friction.
The data obtaining module 10 is further configured to obtain a total thickness of friction plates of the target vehicle, and determine a remaining thickness of the friction plates according to the total thickness of the friction plates and the wear amount of the friction plates by the following formula:
h＝l-Δh
wherein h is the residual thickness of the friction plate, l is the total thickness of the friction plate, and delta h is the abrasion loss of the friction plate.
The data obtaining module 10 is further configured to determine an estimated driving distance for replacing a friction plate according to the current vehicle mileage, the current wear amount, and the current remaining thickness by using the following formula:
Figure BDA0003504042480000181
wherein S is the estimated mileage0Is the current vehicle mileage, Δ hmaxFor the current amount of wear, hminIs the current remaining thickness.
The judging module 20 is further configured to compare the wear loss of the friction plate with a preset wear loss threshold, compare the remaining thickness of the friction plate with a preset thickness threshold, and compare the estimated driving mileage with a preset mileage threshold; when the wear loss of the friction plate is larger than the preset wear loss threshold, and/or the residual thickness of the friction plate is larger than the preset thickness threshold, and/or the estimated driving mileage is larger than the preset mileage threshold, generating a judgment result that the current wear degree is judged to exceed the preset threshold; and when the wear loss of the friction plate is not more than the preset wear loss threshold, the residual thickness of the friction plate is not more than the preset thickness threshold, and the estimated driving mileage is not more than the preset mileage threshold, generating the judgment result as that the current wear degree does not exceed the preset threshold.
The steps implemented by each functional module of the automatic friction plate wear detection device for the vehicle can refer to each embodiment of the automatic friction plate wear detection method for the vehicle of the invention, and are not described herein again.
In a specific implementation, referring to fig. 6, fig. 6 is a schematic flow chart of the automatic friction plate wear detection system of the vehicle according to the present invention; as shown in fig. 6, the automatic friction plate wear detection system for a vehicle includes an IPB (intelligent integrated brake control unit), an IVI (vehicle infotainment system), a BLE (bluetooth low energy module), a wheel speed sensor, a brake caliper, a hydraulic brake pipe, a CAN bus, and a mobile terminal.
IPB, IVI and BLE link to each other through the CAN bus and carry out signal interaction, IPB links to each other with four braking pincers through the hydraulic brake pipe, establish brake pressure through hydraulic pressure and promote the calliper piston and remove, promote the friction disc and press from both sides tight brake disc, thereby realize the speed reduction braking to the vehicle, IPB links to each other with the fast sensor of wheel and CAN acquires the real-time fast pulse of wheel, CAN be used to calculate the rotational speed of wheel, IVI CAN show relevant vehicle information and carry out human-computer interaction with the driver through the instrument, and send signals such as current vehicle mileage and ambient temperature for IPB through the CAN bus, BLE carries out information interaction through the bluetooth with mobile terminal connection, BLE CAN be with showing for the driver on sending the mobile terminal from CAN bus received relevant information.
The system work flow is as follows: when the intelligent integrated brake control unit receives the input of the brake pedal stepped by the driver or the brake request sent by other controllers, the automobile starts to brake and decelerate, and the intelligent integrated brake control unit pushes the caliper piston to move by building pressure to drive the friction plate to clamp the brake disc, so that the brake is realized. In the process, the friction plate is in contact with the brake disc and generates abrasion, the intelligent integrated brake control unit receives a current vehicle driving mileage signal and an environment temperature signal which are sent by a vehicle-mounted information entertainment system, the abrasion condition of the friction plate of four wheels of a current vehicle is calculated in real time to obtain the abrasion loss of the friction plate, the thickness of the residual friction plate and the estimated driving mileage for replacing the friction plate, the signals obtained by calculation are sent to a CAN bus, the low-power-consumption Bluetooth module receives the signals and sends the signals to a mobile terminal (such as a mobile phone and a PAD) of a user through Bluetooth, the user CAN display the abrasion loss of the friction plate of the four wheels, the thickness of the residual friction plate, the estimated driving mileage for replacing the friction plate and other state information in real time through the mobile terminal, and when the abrasion loss of the friction plate calculated by the intelligent integrated brake control unit exceeds a certain threshold value, an alarm signal is sent to the CAN bus, the vehicle-mounted information entertainment system displays a brake fault lamp on the instrument, prompts a driver to replace a friction plate in a text mode, and meanwhile, the low-power-consumption Bluetooth module receives a message of replacing the friction plate after receiving the alarm signal zone bit and pushes the message of replacing the friction plate to the mobile terminal, and prompts the driver to replace the friction plate.
In a specific implementation, a calculation module of the wear condition of a friction plate in the IPB comprises a brake pressure module, a wheel speed module, a friction plate temperature module and a friction plate material characteristic module;
wherein the brake pressure module: the pressure sensor is arranged in the IPB, so that the master cylinder pressure can be obtained, and the pressures acting on the four brake wheel cylinders, namely the pressures acting on the friction plates, which are respectively P, can be obtained after internal calculationFL(left front wheel friction plate pressure), PFR(Right front wheel friction plate pressure), PRL(left rear wheel friction plate pressure), PRR(right rear wheel friction plate pressure).
Wheel speed module function: the wheel speed sensor is connected with the IPB through a wire harness, when the wheel rotates, the wheel speed sensor acquires wheel speed pulses, and the IPB receives the wheel speed pulses and then can obtain the angular speed omega of the current four wheelsFL(left front wheel angular velocity), ωFR(angular velocity of right front wheel), ωRL(angular velocity of left rear wheel), ωRR(right rear wheel angular velocity).
Friction disc temperature module: because the friction plates have different wear conditions under different temperature conditions, the calculation of the temperature of the friction plates is the basis for calculating the wear loss; when the vehicle brakes, the friction between the friction plate and the brake disc realizes the deceleration of the vehicle, part of the kinetic energy of the vehicle is converted into the heat energy of the friction plate and the brake disc, so that the temperature of the friction plate and the brake disc is increased, and the temperature increase of the friction plate can be confirmed by adopting an energy conservation and thermodynamic formula.
Friction plate material characteristic module: the material characteristics of the friction plate are also important factors for determining the abrasion of the friction plate in the braking process, different abrasion can be generated under the same braking working condition due to different friction plate material formulas and compression ratios, the material characteristic module of the friction plate is set as a calibratable module, when the type selection of the vehicle friction plate is completed, namely the material, the compression ratio and other key parameters of the friction plate are locked, and the abrasion amount of the friction plate in unit distance under different temperatures and different braking pressures can be determined through calibration tests and fitting.
It should be understood that the wheel speed module in the IPB processes the signal of the wheel speed sensor in real time, and converts the signal into a wheel speed signal for other modules to call and process; the brake pressure module calculates the pressure acting on each friction plate in real time; the friction plate temperature module calculates the current temperature of the friction plate in real time; after the friction plate parameters are locked, the friction plate material characteristic module can determine a relation table of the unit abrasion loss of the friction plate and the pressure and the temperature through calibration and fitting, and other modules can obtain corresponding abrasion values through a table look-up method; when the IPB receives the input of a driver stepping on a brake pedal or a braking request sent by other controllers, the automobile starts to brake and decelerate, and the IPB pushes the caliper piston to move by building pressure to drive the friction plate to clamp the brake disc, so that braking is realized. In the process, the friction plate is contacted with the brake disc and generates abrasion, the intelligent integrated brake control unit receives a current vehicle traveling mileage signal and an environment temperature signal sent by the vehicle-mounted infotainment system, calculates the abrasion condition of the friction plate of four wheels of the current vehicle in real time to obtain the abrasion loss of the friction plate, the thickness of the residual friction plate and the estimated replacement traveling mileage of the friction plate, sends the signals obtained by calculation to the CAN bus, the low-power-consumption Bluetooth module receives the signals and sends the signals to a mobile terminal (such as a mobile phone) of a user through Bluetooth, the user CAN display the abrasion loss of the friction plate of the four wheels, the thickness of the residual friction plate, the estimated replacement traveling mileage of the friction plate and other state information in real time through the mobile terminal, and when the abrasion loss of the friction plate calculated by the intelligent integrated brake control unit exceeds a certain threshold value, an alarm signal mark is sent to the CAN bus, the vehicle-mounted information entertainment system displays a brake fault lamp on the instrument, prompts a driver to replace a friction plate in a text mode, and meanwhile, the low-power-consumption Bluetooth module receives a message of replacing the friction plate after receiving the alarm signal zone bit and pushes the message of replacing the friction plate to the mobile terminal, and prompts the driver to replace the friction plate.
In addition, an embodiment of the present invention further provides a storage medium, where a vehicle automatic friction plate wear detection program is stored on the storage medium, and when executed by a processor, the vehicle automatic friction plate wear detection program implements the following operations:
acquiring the abrasion loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate;
judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result;
and generating a wear alarm signal when the current wear degree exceeds the preset threshold value according to the judgment result, generating a wear state signal when the current wear degree does not exceed the preset threshold value according to the judgment result, and performing man-machine interaction according to the wear alarm signal or the wear state signal.
Further, the automatic friction plate wear detection program of the vehicle is executed by the processor to realize the following operations:
acquiring friction plate pressure, wheel angular speed, a preset friction plate temperature function and a preset friction fitting function of a target vehicle;
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function;
acquiring the total thickness of friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates;
and acquiring the current vehicle mileage of the target vehicle, the current abrasion loss and the current residual thickness of the friction plate with the maximum abrasion loss, and determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness.
Further, the automatic friction plate wear detection program of the vehicle is executed by the processor to realize the following operations:
obtaining the pressure of four brake wheel cylinders acting on the friction plates according to the pressure sensor of the target vehicle, and taking the pressure acting on the friction plates as the pressure of the friction plates;
acquiring angular velocities of four wheels according to a wheel speed sensor of the target vehicle, and taking the angular velocities of the four wheels as wheel angular velocities;
obtaining a preset friction plate temperature function through the following formula:
Figure BDA0003504042480000211
wherein, FTFor presetting a function of temperature of the friction disk, T0The initial temperature at the current time; r is effective braking radius; omega is the angular velocity of the wheel,
Figure BDA0003504042480000212
the central angle is corresponding to the friction plate; r is0And R1Respectively the radius of the inner edge and the radius of the outer edge of the friction plate; mu is the friction coefficient of the disc; p is the pressure acting on the friction plate; ρ is a unit of a gradientdiscAnd ρpadThe densities of the brake disc and the friction plate are respectively; cdiscAnd CpadThe specific heat capacities of the brake disc and the friction plate are respectively; kdiscAnd KpadThe heat conductivity coefficients of the brake disc and the friction plate are respectively; r is friction plate radius, rdr is pair R0And R1D θ is in
Figure BDA0003504042480000213
Integral of (d), dt is the derivative mark, CpadIs the specific heat capacity of the friction plate, mpad(t) is the mass of the friction plate, and is a function of the temperature of the friction plate over time;
and fitting the abrasion loss data of unit distance at different temperatures and different brake pressures to obtain a preset friction fitting function.
Further, the automatic friction plate wear detection program of the vehicle is executed by the processor to realize the following operations:
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function through the following formula:
Δh＝F(P,ω,FT,FP)
wherein Δ h is a friction plate wear loss, P is the friction plate pressure, ω is the wheel angular velocity, FTFor said predetermined friction lining temperature function, FPFitting a function to the preset friction.
Further, the automatic friction plate wear detection program of the vehicle is executed by the processor to realize the following operations:
acquiring the total thickness of friction plates of the target vehicle, and determining the remaining thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates by the following formula:
h＝l-Δh
wherein h is the residual thickness of the friction plate, l is the total thickness of the friction plate, and delta h is the abrasion loss of the friction plate.
Further, the automatic friction plate wear detection program of the vehicle is executed by the processor to realize the following operations:
determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness by the following formula:
Figure BDA0003504042480000221
wherein S is the estimated mileage0Is the current vehicle mileage, Δ hmaxFor the current amount of wear, hminIs the current remaining thickness.
Further, the automatic friction plate wear detection program of the vehicle is executed by the processor to realize the following operations:
comparing the wear loss of the friction plate with a preset wear loss threshold, comparing the residual thickness of the friction plate with a preset thickness threshold, and comparing the estimated driving mileage with a preset mileage threshold;
when the wear loss of the friction plate is larger than the preset wear loss threshold, and/or the residual thickness of the friction plate is larger than the preset thickness threshold, and/or the estimated driving mileage is larger than the preset mileage threshold, generating a judgment result that the current wear degree is judged to exceed the preset threshold;
and when the wear loss of the friction plate is not more than the preset wear loss threshold, the residual thickness of the friction plate is not more than the preset thickness threshold, and the estimated driving mileage is not more than the preset mileage threshold, generating the judgment result as that the current wear degree does not exceed the preset threshold.
According to the scheme, the estimated driving mileage of the friction plate replacement, the residual thickness of the friction plate and the abrasion loss of the friction plate are obtained; judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result; the automatic abrasion detection device comprises a controller, a judging result and a wear state signal generation unit, wherein the judging result is that an abrasion alarm signal is generated when the current abrasion degree exceeds a preset threshold value, the judging result is that an abrasion state signal is generated when the current abrasion degree does not exceed the preset threshold value, man-machine interaction is carried out according to the abrasion alarm signal or the abrasion state signal, the abrasion condition of the friction plates of four wheels of the current vehicle can be calculated in real time, no extra hardware equipment is needed to be added, the detection cost is reduced, the abrasion state of the friction plates can be presented to a driver in a data mode, the functional diversity of the vehicle and the controller is enhanced, the product competitiveness is improved, the problem that the detection failure probability is increased due to the addition of a sensor is avoided, the speed and the efficiency of automatic abrasion detection of the vehicle are improved, and the safety of vehicle running is improved.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element identified by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or apparatus that comprises the element.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent structures or equivalent processes performed by the present invention or directly or indirectly applied to other related technical fields are also included in the scope of the present invention.

Claims (10)

1. A wear detection method for an automatic friction plate of a vehicle is characterized by comprising the following steps:
acquiring the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate;
judging whether the current wear degree exceeds a preset threshold value according to the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage, and generating a judgment result;
and generating a wear alarm signal when the current wear degree exceeds the preset threshold value according to the judgment result, generating a wear state signal when the current wear degree does not exceed the preset threshold value according to the judgment result, and performing man-machine interaction according to the wear alarm signal or the wear state signal.
2. The automatic friction plate wear detection method for a vehicle according to claim 1, wherein said obtaining the friction plate wear amount, the friction plate remaining thickness and the estimated driving mileage for friction plate replacement comprises:
acquiring the pressure of a friction plate, the angular speed of a wheel, a preset friction plate temperature function and a preset friction fitting function of a target vehicle;
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function;
acquiring the total thickness of friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates;
and acquiring the current vehicle mileage of the target vehicle, the current abrasion loss and the current residual thickness of the friction plate with the maximum abrasion loss, and determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness.
3. The method for automatic friction plate wear detection for vehicles according to claim 2, wherein said obtaining a friction plate pressure, a wheel angular velocity, a preset friction plate temperature function and a preset friction fitting function of a target vehicle comprises:
obtaining the pressure of four brake wheel cylinders acting on the friction plates according to the pressure sensor of the target vehicle, and taking the pressure acting on the friction plates as the pressure of the friction plates;
acquiring angular velocities of four wheels according to a wheel speed sensor of the target vehicle, and taking the angular velocities of the four wheels as wheel angular velocities;
obtaining a preset friction plate temperature function through the following formula:
Figure FDA0003504042470000021
wherein, FTFor presetting a temperature function, T, of the friction disk0The initial temperature at the current time; r is effective braking radius; omega is the angular velocity of the wheel,
Figure FDA0003504042470000022
the central angle is corresponding to the friction plate; r0And R1Respectively the radius of the inner edge and the radius of the outer edge of the friction plate; mu is the friction coefficient of the disc; p is the pressure acting on the friction plate; rhodiscAnd ρpadThe densities of the brake disc and the friction plate are respectively; cdiscAnd CpadThe specific heat capacities of the brake disc and the friction plate are respectively; kdiscAnd KpadThe heat conductivity coefficients of the brake disc and the friction plate are respectively; r is friction plate radius, rdr is pair R0And R1D θ is in
Figure FDA0003504042470000023
Integral of (d), dt is the derivative mark, CpadIs the specific heat capacity of the friction plate, mpad(t) is the mass of the friction plate, and is a function of the temperature of the friction plate over time;
and fitting the abrasion loss data of unit distance at different temperatures and different brake pressures to obtain a preset friction fitting function.
4. The method of automatic friction plate wear detection for a vehicle of claim 2 wherein said determining an amount of friction plate wear based on said friction plate pressure, said wheel angular velocity, said preset friction plate temperature function, and said preset friction fit function comprises:
determining the abrasion loss of the friction plate according to the pressure of the friction plate, the angular speed of the wheel, the preset friction plate temperature function and the preset friction fitting function through the following formula:
Δh＝F(P，ω，FT，FP)
wherein Δ h is a friction plate wear amount, P is the friction plate pressure, ω is the wheel angular velocity, FTFor said predetermined friction lining temperature function, FPFitting a function to the preset friction.
5. The automatic friction plate wear detection method for a vehicle according to claim 2, wherein said obtaining a total friction plate thickness of the target vehicle and determining a remaining friction plate thickness based on the total friction plate thickness and the friction plate wear amount comprises:
acquiring the total thickness of the friction plates of the target vehicle, and determining the residual thickness of the friction plates according to the total thickness of the friction plates and the abrasion loss of the friction plates through the following formula:
h＝l-Δh
wherein h is the residual thickness of the friction plate, l is the total thickness of the friction plate, and delta h is the abrasion loss of the friction plate.
6. The method of automatic friction plate wear detection for a vehicle of claim 2 wherein said determining an estimated driving range for friction plate replacement based on said current vehicle mileage, said current amount of wear, and said current remaining thickness comprises:
determining the estimated driving mileage for replacing the friction plate according to the current vehicle mileage, the current abrasion loss and the current residual thickness by the following formula:
Figure FDA0003504042470000031
wherein S is the estimated mileage0Is the current vehicle mileage, Δ hmaxFor the current amount of wear, hminIs the current remaining thickness.
7. The automatic friction plate wear detection method for vehicles according to claim 1, wherein said determining whether the current wear level exceeds a preset threshold value according to the friction plate wear amount, the friction plate remaining thickness and the estimated mileage and generating a determination result comprises:
comparing the wear loss of the friction plate with a preset wear loss threshold value, comparing the residual thickness of the friction plate with a preset thickness threshold value, and comparing the estimated driving mileage with a preset mileage threshold value;
when the wear loss of the friction plate is larger than the preset wear loss threshold, and/or the residual thickness of the friction plate is larger than the preset thickness threshold, and/or the estimated driving mileage is larger than the preset mileage threshold, generating a judgment result that the current wear degree is judged to exceed the preset threshold;
and when the wear loss of the friction plate is not more than the preset wear loss threshold, the residual thickness of the friction plate is not more than the preset thickness threshold, and the estimated driving mileage is not more than the preset mileage threshold, generating the judgment result as that the current wear degree does not exceed the preset threshold.
8. A vehicle automatic friction plate wear detection device characterized by comprising:
the data acquisition module is used for acquiring the wear loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage for replacing the friction plate;
the judging module is used for judging whether the current abrasion degree exceeds a preset threshold value or not according to the abrasion loss of the friction plate, the residual thickness of the friction plate and the estimated driving mileage and generating a judging result;
and the abrasion detection module is used for generating an abrasion alarm signal when the judgment result shows that the current abrasion degree exceeds the preset threshold value, generating an abrasion state signal when the judgment result shows that the current abrasion degree does not exceed the preset threshold value, and carrying out man-machine interaction according to the abrasion alarm signal or the abrasion state signal.
9. A vehicle automatic friction plate wear detection apparatus characterized by comprising: a memory, a processor and a vehicle automatic friction plate wear detection program stored on the memory and executable on the processor, the vehicle automatic friction plate wear detection program configured to implement the steps of the vehicle automatic friction plate wear detection method as recited in any one of claims 1 to 7.
10. A storage medium, characterized in that a vehicle automatic friction plate wear detection program is stored thereon, which when executed by a processor implements the steps of the vehicle automatic friction plate wear detection method according to any one of claims 1 to 7.
CN202210134795.XA 2022-02-14 2022-02-14 Method, device and equipment for detecting abrasion of automatic friction plate of vehicle and storage medium Pending CN114572179A (en)

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