Temperature calculation method and system for brake disc of vehicle, and device and storage medium

Abstract

Provided in the embodiments of the present application are a temperature calculation method and system for a brake disc of a vehicle, and a device and a storage medium. The method comprises: obtaining a brake torque and an actual regenerative torque on the basis of the current speed and a target speed, obtaining wheel friction power on the basis of a wheel brake torque, the actual regenerative torque and a wheel rotation speed, and obtaining a brake-disc temperature rise rate on the basis of the wheel friction power; obtaining convective heat-exchange cooling power on the basis of a brake-disc cooling coefficient, a brake-disc heat dissipation area, a brake-disc temperature and an ambient temperature, and obtaining a brake-disc temperature drop rate on the basis of the convective heat-exchange cooling power and heat-radiative cooling power; and obtaining a brake-disc temperature the on the basis of the brake-disc temperature rise rate and the brake-disc temperature drop rate.

Description

Vehicle brake disc temperature calculation method, system, device and storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202410065288.4 and application date January 17, 2024, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present invention relates to the field of automobile technology, and in particular to a method, system, device and storage medium for calculating the temperature of a vehicle brake disc. Background Art

[0004] Vehicles encounter continuous braking during driving. To ensure vehicle stability during braking, the vehicle must exhibit high braking performance consistency, known as thermal fade resistance. Before production, braking simulations are performed on the vehicle model to verify the vehicle's thermal fade resistance.

[0005] Electric vehicles utilize both friction braking and energy recovery during braking. Regenerative braking converts some of the vehicle's kinetic energy into electrical energy and stores it in the battery, resulting in a lower brake disc temperature rise compared to friction braking alone. Therefore, braking simulation for electric vehicles differs from that for gasoline vehicles and requires consideration of energy recovery models.

[0006] Conventional brake disc temperature simulations are performed using a 3D digital model of the brake disc using finite element analysis software. This requires meshing based on the 3D digital models of components such as the brake disc and friction pad, followed by post-processing simulation. This results in lengthy simulation cycles and fails to account for brake energy recovery. Furthermore, at the outset of the project, only component weight targets were defined to meet the high range requirements of electric vehicles. Brake disc calibration and a 3D digital model were not finalized, making it impossible to use finite element analysis software to simulate brake disc temperature for electric vehicles.

[0007] Summary of the Invention

[0008] The present application provides a vehicle brake disc temperature calculation method, system, device and storage medium to achieve brake disc temperature simulation calculation without relying on the three-dimensional digital and analog data of the brake disc and improve the accuracy of the simulation calculation.

[0009] An embodiment of the first aspect of the present application provides a method for calculating the temperature of a vehicle brake disc, comprising:

[0010] Obtain the brake disc temperature, brake disc cooling area, wheel speed, current speed, and target speed of the vehicle model;

[0011] Calculating the output torque according to the current speed and the target speed to obtain the braking torque;

[0012] Performing energy recovery calculation according to the current speed to obtain an actual energy recovery torque;

[0013] distributing the braking torque to a plurality of wheels to obtain wheel braking torque, obtaining wheel friction power according to the wheel braking torque, the actual energy recovery torque, and the wheel speed, and obtaining a brake disc heating rate according to the wheel friction power;

[0014] obtaining a wheel brake disc cooling coefficient according to the current speed, obtaining a convection heat transfer cooling power according to the brake disc cooling coefficient, the brake disc heat dissipation area, the brake disc temperature, and a preset ambient temperature, obtaining a thermal radiation cooling power according to the brake disc heat dissipation area, the brake disc temperature, and a preset ambient temperature, and obtaining a brake disc cooling rate according to the convection heat transfer cooling power and the thermal radiation cooling power;

[0015] The brake disc temperature is obtained according to the brake disc heating rate and the brake disc cooling rate.

[0016] An embodiment of a second aspect of the present application provides a vehicle brake disc temperature calculation system, comprising:

[0017] a vehicle model, wherein the vehicle model is provided with an energy recovery unit, and the energy recovery unit is configured to obtain an actual energy recovery torque according to a current speed of the vehicle model;

[0018] a torque controller, the torque controller acquiring a brake disc temperature, a brake disc heat dissipation area, a wheel speed, and a current speed from the vehicle model, and receiving a target vehicle speed, the torque controller being configured to calculate an output torque based on the current speed and the target speed to obtain a braking torque, so that the vehicle model distributes the braking torque to a plurality of wheels to obtain wheel braking torque, and to obtain wheel friction power based on the wheel braking torque, the actual energy recovery torque, and the wheel speed;

[0019] A brake disc temperature model, the brake disc temperature model includes a brake disc heating model and a brake disc cooling model, the brake disc temperature model obtains the wheel friction power, current speed, brake disc heat dissipation area and brake disc temperature from the vehicle model, the brake disc heating model is used to obtain the brake disc heating rate according to the wheel friction power, the brake disc cooling model is used to obtain the wheel brake disc cooling coefficient according to the current speed, obtain the convection heat transfer cooling power according to the brake disc cooling coefficient, the brake disc heat dissipation area, the brake disc temperature and the preset ambient temperature, obtain the thermal radiation cooling power according to the brake disc heat dissipation area, the brake disc temperature and the preset ambient temperature, obtain the brake disc cooling rate according to the convection heat transfer cooling power and the thermal radiation cooling power, and the brake disc temperature model is used to obtain the brake disc temperature according to the brake disc heating rate and the brake disc cooling rate.

[0020] An embodiment of the third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the vehicle brake disc temperature calculation method as described above when executing the computer program.

[0021] An embodiment of the fourth aspect of the present application provides a computer storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the vehicle brake disc temperature calculation method as described above.

[0022] This application has the following beneficial effects: using a model that integrates friction braking and energy recovery braking to simulate brake disc temperature, it can accurately simulate the brake temperature change process during continuous braking of an electric vehicle without relying on the three-dimensional digital and analog data of the brake disc. The model has good real-time calculation effect, can meet the requirements of front and rear brake disc temperature estimation, is conducive to determining performance parameters such as brake disc thermal mass, improves the pass rate of brake disc products, and shortens the electric vehicle project development cycle and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG1 is a schematic structural diagram of a vehicle brake disc temperature calculation system provided in an embodiment of the present application;

[0024] FIG2 is a step diagram of a vehicle brake temperature calculation method provided in an embodiment of the present application;

[0025] FIG3 is a diagram showing steps for obtaining an actual energy recovery torque according to the current speed of a vehicle model provided by an embodiment of the present application;

[0026] FIG4 is a diagram showing the steps of distributing braking torque to multiple wheels to obtain wheel braking torque according to an embodiment of the present application;

[0027] FIG5 is a diagram showing steps for calculating the heating rate of the front wheel brake disc provided in an embodiment of the present application;

[0028] FIG6 is a diagram showing steps for calculating the heating rate of the rear wheel brake disc provided in an embodiment of the present application;

[0029] FIG7 is a diagram showing the steps for calculating the convective heat transfer cooling power of the front wheel brake disc provided by an embodiment of the present application;

[0030] FIG8 is a diagram showing the steps for calculating the convective heat transfer cooling power of the rear wheel brake disc provided by an embodiment of the present application;

[0031] FIG9 is a step diagram of an electronic device provided in an embodiment of the present application;

[0032] FIG10 is a schematic diagram of the output results of the vehicle brake temperature calculation system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0034] It should be noted that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and the like in the specification, claims, or accompanying drawings are used to distinguish similar items and are not necessarily used to describe a specific sequence or precedence.

[0035] The embodiments of the present application are further described below with reference to the accompanying drawings.

[0036] An embodiment of the present application provides a vehicle brake disc temperature calculation system.

[0037] 1 , the vehicle brake disc temperature calculation system includes a vehicle model 100 , a torque controller 300 , and a brake disc temperature model 400 .

[0038] Among them, the vehicle model 100 is provided with an energy recovery unit 200, and the energy recovery unit 200 is configured to obtain the actual energy recovery torque according to the current speed of the vehicle model 100; the torque controller 300 obtains the brake disc temperature, the brake disc heat dissipation area, the wheel speed and the current speed from the vehicle model 100, and receives the target vehicle speed. The torque controller 300 is configured to obtain the braking torque according to the current speed and the target speed, so that the vehicle model 100 distributes the braking torque to multiple wheels to obtain the wheel braking torque, and obtains the wheel friction power according to the wheel braking torque, the actual energy recovery torque and the wheel speed; the brake disc temperature model 400 includes a brake disc heating model 410 and a brake disc cooling model 420, and the brake disc temperature Model 400 obtains the wheel friction power, current speed, brake disc heat dissipation area and brake disc temperature from the vehicle model 100. The brake disc heating model 410 is used to obtain the brake disc heating rate according to the wheel friction power. The brake disc cooling model 420 is used to obtain the wheel brake disc cooling coefficient according to the current speed, obtain the convection heat transfer cooling power according to the brake disc cooling coefficient, the brake disc heat dissipation area, the brake disc temperature and the preset ambient temperature, obtain the thermal radiation cooling power according to the brake disc heat dissipation area, the brake disc temperature and the preset ambient temperature, obtain the brake disc cooling rate according to the convection heat transfer cooling power and the thermal radiation cooling power, and the brake disc temperature model 400 is used to obtain the brake disc temperature according to the brake disc heating rate and the brake disc cooling rate.

[0039] The vehicle brake disc temperature calculation system is a vehicle simulation system. The vehicle model 100 is a vehicle simulation model, specifically a three-degree-of-freedom vehicle model, which can simulate the vehicle operation.

[0040] The input to the vehicle brake disc temperature calculation system is the target vehicle speed. The vehicle model 100 simulates the target vehicle speed. During this simulation, the vehicle model 100 operates under a continuous braking condition. The vehicle model 100 undergoes acceleration and deceleration, resulting in a cyclical triangular wave curve in the vehicle speed.

[0041] During the simulation operation of the vehicle model 100 , the vehicle brake disc temperature calculation system executes the following vehicle brake disc temperature calculation method to calculate the vehicle brake disc temperature.

[0042] 2 , the method for calculating the vehicle brake disc temperature includes but is not limited to the following steps:

[0043] Step S100, obtaining the brake disc temperature, brake disc heat dissipation area, wheel speed, current speed and target speed of the vehicle model;

[0044] Step S200, calculating the output torque according to the current speed and the target speed to obtain the braking torque;

[0045] Step S300, performing energy recovery calculation according to the current speed to obtain actual energy recovery torque;

[0046] Step S400: Distributing braking torque to multiple wheels to obtain wheel braking torque, obtaining wheel friction power based on the wheel braking torque, actual energy recovery torque, and wheel speed, and obtaining a brake disc heating rate based on the wheel friction power;

[0047] Step S500: obtaining a wheel brake disc cooling coefficient based on the current speed, obtaining a convection heat transfer cooling power based on the brake disc cooling coefficient, the brake disc heat dissipation area, the brake disc temperature, and a preset ambient temperature, obtaining a thermal radiation cooling power based on the brake disc heat dissipation area, the brake disc temperature, and the preset ambient temperature, and obtaining a brake disc cooling rate based on the convection heat transfer cooling power and the thermal radiation cooling power;

[0048] Step S600: obtaining the brake disc temperature according to the brake disc heating rate and the brake disc cooling rate.

[0049] In step S100, while the vehicle model 100 is simulating, the calculation unit, including the torque controller 300 and the brake disc temperature model 400, can obtain the brake disc temperature, brake disc heat dissipation area, wheel speed, and current speed of the vehicle model 100 from the vehicle model 100. The target speed is typically input into the vehicle brake disc temperature calculation system by a user via an external input device, and the calculation unit can directly obtain the target speed.

[0050] In step S200 , the torque controller 300 obtains the braking torque according to the current speed and the target speed.

[0051] Specifically, the torque controller 300 is a PID controller.

[0052] The PID controller obtains the target vehicle speed input from the outside, and reads the current speed of the vehicle model 100 during the simulation operation from the vehicle model 100 .

[0053] The PID controller obtains the braking torque according to the current speed and the target speed, including but not limited to the following steps:

[0054] Obtain a proportional coefficient, an integral coefficient, and a differential coefficient; multiply the difference between the target speed and the current speed by the proportional coefficient to obtain a target proportional value; multiply the integral value of the difference between the target speed and the current speed by the integral coefficient to obtain a target integral value; multiply the differential value of the difference between the target speed and the current speed by the differential coefficient to obtain a target differential value; and obtain a braking torque based on the target proportional value, the target integral value, and the target differential value.

[0055] When the target speed is lower than the current speed, the vehicle model 100 needs to brake the wheels to decelerate to the target speed, and the PID controller outputs a negative braking torque; when the target speed is higher than the current speed, the vehicle model 100 needs to drive the wheels to accelerate to the target speed, and the PID controller outputs a positive driving torque.

[0056] The PID controller can obtain the braking torque based on the current speed and target speed through the following formula: T brake =T m T m <0;T drive =T m T m >0.

[0057] Where K p is the proportionality coefficient, K i is the integral coefficient, K d is the differential coefficient, V target is the target speed, V is the current speed, T brake is the braking torque, T drive is the driving torque, T m is the torque output by the PID controller, t is the current time, t start is the start time.

[0058] The proportional coefficient, integral coefficient and differential coefficient are set according to actual production requirements and are usually adjusted according to calibration parameters.

[0059] In this embodiment, the torque required for driving or braking the vehicle is calculated based on the closed-loop PID control of the target vehicle speed and the actual vehicle speed under continuous braking conditions, and then the torque is applied to the four wheels of the vehicle model 100 .

[0060] In step S300 , the vehicle model 100 is a vehicle model 100 corresponding to an electric vehicle. The vehicle model 100 is provided with an energy recovery unit 200 . The energy recovery unit 200 obtains an actual energy recovery torque according to a current speed of the vehicle model 100 .

[0061] Electric vehicles utilize the energy recovery unit 200 to recover excess energy during deceleration / braking. While ensuring braking efficiency, the drive motor is controlled to operate as a generator. An energy conversion device connected to the drive shaft converts a portion of the vehicle's mechanical energy into electrical energy, which is stored in the energy storage device and utilized for subsequent acceleration. This energy can be quickly released upon use, achieving the goal of recovering braking energy. This results in a lower brake disc temperature rise than with simple friction braking.

[0062] 3 , specifically, the energy recovery unit 200 obtains the actual energy recovery torque according to the current speed of the vehicle model 100 , including but not limited to the following steps:

[0063] Step S310, obtaining a target energy recovery torque based on a preset vehicle speed and energy recovery torque calibration map and the current speed;

[0064] Step S320: Delay processing is performed on the target energy recovery torque to obtain the actual energy recovery torque.

[0065] In this embodiment, the target regenerative torque is obtained by interpolating the current speed V onto a preset calibration map of vehicle speed and regenerative torque. The target regenerative torque is then delayed to obtain the actual regenerative torque. Furthermore, the regenerative unit 200 applies the actual regenerative torque to the front or rear wheels based on the vehicle's drive mode and type.

[0066] The driving forms of a car include acceleration driving and deceleration braking; the driving types of a car include front-wheel drive, rear-wheel drive and two-wheel drive.

[0067] In step S400, braking torque is distributed to multiple wheels to obtain wheel braking torque, wheel friction power is obtained according to the wheel braking torque, actual energy recovery torque and wheel speed, and brake disc heating rate is obtained according to the wheel friction power.

[0068] The vehicle model 100 performs secondary distribution based on the braking torque output by the PID controller, and distributes the braking torque according to the braking force distribution coefficient.

[0069] 4 , specifically, distributing the braking torque to multiple wheels to obtain wheel braking torque includes but is not limited to the following steps:

[0070] Step S411, obtaining the ratio of the front wheel braking torque to the front wheel pressure, the ratio of the rear wheel braking torque to the rear wheel pressure, the candidate rear wheel pressure, and the rear wheel brake locking pressure;

[0071] Step S412, obtaining the front wheel pressure according to the braking torque, the ratio of the front wheel braking torque to the front wheel pressure, and the ratio of the rear wheel braking torque to the rear wheel pressure;

[0072] Step S413, taking the smaller of the candidate rear wheel pressure and the rear wheel brake lock pressure to obtain the rear wheel pressure;

[0073] Step S414, obtaining the front wheel braking torque according to the ratio of the front wheel braking torque to the front wheel pressure and the front wheel pressure;

[0074] Step S415 , obtaining the rear wheel braking torque according to the ratio of the rear wheel braking torque to the rear wheel pressure and the rear wheel pressure.

[0075] According to the braking torque, the ratio of the front wheel braking torque to the front wheel pressure, and the ratio of the rear wheel braking torque to the rear wheel pressure, the front wheel pressure can be expressed by the following formula: The rear wheel pressure can be expressed by the following formula by taking the smaller of the candidate rear wheel pressure and the rear wheel brake lock pressure: R =min(P R , P locking_R The front wheel braking torque can be expressed by the following formula based on the ratio of the front wheel braking torque to the front wheel pressure and the front wheel pressure: brake_F =C p1 *P F The rear wheel braking torque can be expressed by the following formula based on the ratio of the rear wheel braking torque to the rear wheel pressure and the rear wheel pressure: brake_R =C p2 *P R .

[0076] Where C p1 is the ratio of the front wheel braking torque to the front wheel pressure, C p2 is the ratio of rear wheel braking torque to rear wheel pressure, P F is the front wheel pressure, P R is the rear wheel pressure, P locking_R is the rear wheel brake locking pressure, T brake_F is the front wheel braking torque, T brake_R is the rear wheel braking torque.

[0077] Among them, the wheel friction power is obtained according to the wheel braking torque, the actual energy recovery torque and the wheel speed, and the brake disc heating rate is obtained according to the wheel friction power, which includes calculating the front wheel brake disc heating rate and the rear wheel brake disc heating rate.

[0078] 5 , the brake heating model calculates the front wheel brake disc heating rate, including but not limited to the following steps:

[0079] Step S421, obtaining the front wheel friction braking torque according to the front wheel braking torque and the actual energy recovery torque;

[0080] Step S422, obtaining the front wheel friction power according to the front wheel friction braking torque and the front wheel speed;

[0081] Step S423 , obtaining a front wheel brake disc heating rate according to the front wheel friction power, the mass of the front wheel brake disc friction ring, and the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc.

[0082] The front wheel friction braking torque is equal to the difference between the front wheel braking torque and the actual energy recovery torque obtained by front wheel distribution. It can be understood that the actual energy recovery torque is distributed to the front or rear wheels according to the driving mode, and the actual energy recovery torque obtained by the front wheel distribution may be 0. The front wheel friction power can be expressed by the following formula based on the front wheel friction braking torque and the front wheel speed: W F =T brake_F *w F According to the front wheel friction power, the mass of the front wheel brake disc friction ring and the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc, the front wheel brake disc heating rate can be expressed by the following formula: Where w F is the front wheel speed, m disc_F is the mass of the front wheel brake disc friction ring.

[0083] The specific heat capacity calculation formula C is obtained based on the polynomial fitting of the experimental data. v =C v0 *(1+cpt*(T-T0)+cpt2*(T-T0) 2 ), C v is the specific heat capacity of the material at the current temperature, C v0 is the specific heat capacity of the material at the initial temperature, T is the current temperature, T0 is the initial temperature, cpt is the linear coefficient of the polynomial fitting, and cpt2 is the quadratic coefficient of the polynomial fitting; the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc is obtained based on the initial temperature of the front wheel brake disc, the current temperature of the front wheel brake disc and the specific heat capacity of the front wheel brake disc material at the initial temperature of the front wheel brake disc.

[0084] 6 , the brake heating model calculates the rear wheel brake disc heating rate, including but not limited to the following steps:

[0085] Step S431, obtaining the rear wheel friction braking torque according to the rear wheel braking torque and the actual energy recovery torque;

[0086] Step S432, obtaining rear wheel friction power according to the rear wheel friction braking torque and the rear wheel speed;

[0087] Step S433 , obtaining a rear wheel brake disc heating rate according to the rear wheel friction power, the mass of the rear wheel brake disc friction ring, and the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc.

[0088] The rear wheel friction braking torque is equal to the difference between the rear wheel braking torque and the actual energy recovery torque obtained by the rear wheel distribution. It can be understood that the actual energy recovery torque is distributed to the front or rear wheels according to the driving mode, and the actual energy recovery torque obtained by the rear wheel distribution may be 0. The rear wheel friction power can be expressed by the following formula based on the rear wheel friction braking torque and the rear wheel speed: W R =T brake_R *w R Based on the rear wheel friction power, the mass of the rear wheel brake disc friction ring and the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc, the rear wheel brake disc heating rate can be expressed by the following formula: Where w R is the rear wheel speed, is the mass of the rear wheel brake disc friction ring.

[0089] For step S500, the brake cooling model is based on convection heat transfer and thermal radiation. It obtains the wheel brake disc cooling coefficient according to the current speed, obtains the convection heat transfer cooling power according to the brake disc cooling coefficient, the brake disc heat dissipation area, the brake disc temperature and the preset ambient temperature, obtains the thermal radiation cooling power according to the brake disc heat dissipation area, the brake disc temperature and the preset ambient temperature, and obtains the brake disc cooling speed according to the convection heat transfer cooling power and the thermal radiation cooling power, which includes calculating the front wheel brake disc cooling speed and the rear wheel brake disc cooling speed.

[0090] The wheel brake disc cooling coefficient is obtained by interpolating the current speed into the brake disc cooling coefficient fitting curve; the wheel brake disc cooling coefficient includes the front wheel brake disc cooling coefficient and the rear wheel brake disc cooling coefficient.

[0091] Starting from the brake disc's initial temperature, T0, and cooling at a steady speed, V (km / h), a curve is plotted with time t on the horizontal axis and ln(T - T0) on the vertical axis. The slope of the line is then read. This slope is then used to determine the cooling coefficient. This coefficient is then fitted to experimental data on the cooling coefficient at different vehicle speeds. The fitting coefficient for the formula is then obtained from this fitting curve. The cooling coefficient at different vehicle speeds can be determined using the cooling coefficient fitting curves.

[0092] The front wheel brake disc cooling coefficient is obtained based on the preset front wheel brake disc cooling coefficient fitting curve and the current speed, which can be expressed by the following formula: CF F =CF 0_F +K F *V 0.8 .

[0093] The rear wheel brake disc cooling coefficient is obtained based on the preset rear wheel brake disc cooling coefficient fitting curve and the current speed, which can be expressed by the following formula: CF R =CF0_R +K R *V 0.8 .

[0094] Where, CF F is the cooling coefficient of the front wheel brake disc; CF 0_F and K F CF is the fitting coefficient of the front wheel brake disc cooling coefficient fitting curve; R is the cooling coefficient of the rear wheel brake disc; CF 0_R and K R is the fitting coefficient of the rear wheel brake disc cooling coefficient fitting curve.

[0095] Calculating the cooling rate of the front wheel brake disc includes but is not limited to the following steps: adding the front wheel brake disc convection heat transfer cooling power and the front wheel brake disc heat radiation cooling power to obtain the total cooling power of the front wheel brake disc; according to the formula The cooling rate of the front wheel brake disc is obtained based on the total cooling power of the front wheel brake disc, the mass of the front wheel brake disc friction ring and the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc. total_cooling_F Total cooling power for the front wheel brake discs.

[0096] 7 , the calculation steps for the front wheel brake disc convective heat transfer cooling power include:

[0097] Step S511, obtaining a heat transfer coefficient of the front wheel brake disc according to the cooling coefficient of the front wheel brake disc, the mass of the friction ring of the front wheel brake disc, the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc, and the heat dissipation area of ​​the front wheel brake disc;

[0098] Step S512: obtaining the front wheel brake disc convective heat transfer cooling power according to the front wheel brake disc cooling coefficient, the front wheel brake disc heat dissipation area, the front wheel brake disc temperature and the preset ambient temperature.

[0099] The heat transfer coefficient of the front wheel brake disc can be expressed by the following formula based on the cooling coefficient of the front wheel brake disc, the mass of the front wheel brake disc friction ring, the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc, and the heat dissipation area of ​​the front wheel brake disc:

[0100] According to the front wheel brake disc cooling coefficient, the front wheel brake disc heat dissipation area, the front wheel brake disc temperature and the preset ambient temperature, the front wheel brake disc convection heat transfer cooling power can be expressed by the following formula:

[0101] Where h F is the heat transfer coefficient of the front wheel brake disc, A disc_F is the heat dissipation area of ​​the front wheel brake disc, T ambientis the ambient temperature, T F is the front wheel brake disc temperature, W cooling_F It is the convection heat transfer cooling power of the front wheel brake disc.

[0102] The front wheel brake disc heat radiation cooling power is obtained according to the front wheel brake disc heat dissipation area, the front wheel brake disc temperature and the preset ambient temperature.

[0103] Calculating the cooling rate of the rear wheel brake disc includes but is not limited to the following steps: adding the convective heat transfer cooling power of the rear wheel brake disc and the thermal radiation cooling power of the rear wheel brake disc to obtain the total cooling power of the rear wheel brake disc; according to the formula The cooling rate of the rear wheel brake disc is obtained based on the total cooling power of the rear wheel brake disc, the mass of the rear wheel brake disc friction ring, the mass of the rear wheel brake disc friction ring, and the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc. total_cooling_F Total cooling power for rear brake discs.

[0104] 8 , the calculation steps for the rear wheel brake disc convective heat transfer cooling power include:

[0105] Step S521, obtaining a heat transfer coefficient of the rear wheel brake disc according to the cooling coefficient of the rear wheel brake disc, the mass of the rear wheel brake disc friction ring, the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc, and the heat dissipation area of ​​the rear wheel brake disc;

[0106] Step S522 , obtaining the rear wheel brake disc convective heat transfer cooling power according to the rear wheel brake disc cooling coefficient, the rear wheel brake disc heat dissipation area, the rear wheel brake disc temperature and the preset ambient temperature.

[0107] The heat transfer coefficient of the rear wheel brake disc can be expressed by the following formula based on the cooling coefficient of the rear wheel brake disc, the mass of the rear wheel brake disc friction ring, the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc, and the heat dissipation area of ​​the rear wheel brake disc:

[0108] According to the rear wheel brake disc cooling coefficient, the rear wheel brake disc heat dissipation area, the rear wheel brake disc temperature and the preset ambient temperature, the rear wheel brake disc convection heat transfer cooling power can be expressed by the following formula: W cooling_R =h R *A disR *(T ambient -T R ).

[0109] Where h R is the heat transfer coefficient of the rear wheel brake disc, A disc_R is the heat dissipation area of ​​the rear wheel brake disc, T R is the rear wheel brake disc temperature, W cooling_RProvides convection heat transfer cooling power for the rear wheel brake disc.

[0110] The heat radiation cooling power of the rear wheel brake disc is obtained according to the heat dissipation area of ​​the rear wheel brake disc, the temperature of the rear wheel brake disc and the preset ambient temperature.

[0111] In step S600 , the brake disc temperature is obtained according to the brake disc heating rate and the brake disc cooling rate.

[0112] Brake disc temperatures include front and rear brake disc temperatures. The front brake disc temperature is obtained by integrating the front brake disc temperature rise rate and the front brake disc temperature fall rate. A plot of the front brake disc temperature versus time is generated by plotting the front brake disc temperature rise rate and the front brake disc temperature fall rate with time as the horizontal axis and the front brake disc temperature as the vertical axis. The rear brake disc temperature is obtained by integrating the rear brake disc temperature rise rate and the rear brake disc temperature fall rate. A plot of the rear brake disc temperature versus time is generated by plotting the rear brake disc temperature rise rate and the rear brake disc temperature fall rate with time as the horizontal axis and the rear brake disc temperature as the vertical axis. Referring to Figure 10 , the front and rear brake disc temperature versus time graphs constitute the output of the vehicle brake temperature calculation system. The rising segment of the curve is derived from the brake temperature rise model 410 , while the falling segment is derived from the brake temperature fall model 420 .

[0113] In this embodiment, a model integrating friction braking and energy recovery braking is used to simulate the brake disc temperature. This can accurately simulate the brake temperature change process during continuous braking of an electric vehicle without relying on the three-dimensional digital and analog data of the brake disc. The model has good real-time calculation effect, can meet the requirements for estimating the front and rear brake disc temperatures, is conducive to determining performance parameters such as the thermal mass of the brake disc, improves the pass rate of brake disc products, shortens the development cycle and cost of electric vehicle projects, and meets the forward development requirements of the thermal stability performance target decomposition of the brake system.

[0114] 9 , an embodiment of the present application provides an electronic device comprising a memory 20 , a processor 10 , and a computer program stored in the memory 20 and executable on the processor 10 , wherein the processor 10 implements the vehicle brake disc temperature calculation method described above when executing the computer program.

[0115] The electronic device may be any intelligent terminal including a computer.

[0116] In general, for the hardware structure of the electronic device, the processor 10 can be implemented using a general-purpose CPU (Central Processing Unit, central processing unit, microprocessor, application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), or one or more integrated circuits, etc., to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0117] The memory 20 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 20 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 20 and is called by the processor 10 to execute the methods of the embodiments of this application.

[0118] The input / output interface is used to realize information input and output.

[0119] The communication interface is used to realize the communication interaction between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0120] The bus 30 transmits information between the various components of the device (such as the processor 10, memory 20, input / output interface, and communication interface). The processor 10, memory 20, input / output interface, and communication interface are connected to each other through the bus 30 within the device.

[0121] An embodiment of the present application provides a computer storage medium storing computer-executable instructions for executing the vehicle brake disc temperature calculation method described above.

[0122] Those skilled in the art will appreciate that all or some of the steps and systems in the method disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, and the computer-readable medium can include computer storage media (or non-transitory media) and communication media (or temporary media). As known to those skilled in the art, the term computer storage media is included in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data) and is volatile and non-volatile, removable, and non-removable. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory, or other memory technology, CD-ROM, digital versatile disks (DVD), or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage, or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media generally contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transmission mechanism, and may include any information delivery medium. In the above description of this specification, the reference terms "one embodiment / example", "another embodiment / example" or "certain embodiments / examples" and the like are intended to mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0123] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0124] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0125] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0126] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes multiple instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: various media that can store programs, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0127] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. Although the embodiments of the present application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and purpose of the present application, and the scope of the present application is defined by the claims and their equivalents.

[0128] The above is a specific description of several implementations of the present application, but the present application is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present application, and these equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A method for calculating the temperature of a vehicle brake disc, comprising: Obtaining the brake disc temperature, brake disc heat dissipation area, wheel rotation speed, current speed, and target speed of a vehicle model; Calculating the braking torque by performing output torque calculation based on the current speed and the target speed; Calculating the actual energy recovery torque by performing energy recovery calculation based on the current speed; Allocating the braking torque to multiple wheels to obtain the wheel braking torque, obtaining the wheel friction power based on the wheel braking torque, the actual energy recovery torque, and the wheel rotation speed, and obtaining the brake disc temperature rise rate based on the wheel friction power; Obtaining the wheel brake disc cooling coefficient based on the current speed, obtaining the convective heat transfer cooling power based on the brake disc cooling coefficient, the brake disc heat dissipation area, the brake disc temperature, and a preset ambient temperature, obtaining the thermal radiation cooling power based on the brake disc heat dissipation area, the brake disc temperature, and the preset ambient temperature, and obtaining the brake disc temperature drop rate based on the convective heat transfer cooling power and the thermal radiation cooling power; Obtaining the brake disc temperature based on the brake disc temperature rise rate and the brake disc temperature drop rate.

2. The vehicle brake disc temperature calculation method according to claim 1, wherein, The calculating the braking torque by performing output torque calculation based on the current speed and the target speed includes: Obtaining a proportional coefficient, an integral coefficient, and a differential coefficient; Multiplying the difference between the target speed and the current speed by the proportional coefficient to obtain a target proportional value; Multiplying the integral value of the difference between the target speed and the current speed by the integral coefficient to obtain a target integral value; Multiplying the differential value of the difference between the target speed and the current speed by the differential coefficient to obtain a target differential value; Obtaining the braking torque based on the target proportional value, the target integral value, and the target differential value.

3. The vehicle brake disc temperature calculation method according to claim 1, wherein, The calculating the actual energy recovery torque by performing energy recovery calculation based on the current speed includes: Obtaining the target energy recovery torque based on a calibration graph of vehicle speed and energy recovery torque and the current speed; Performing a time delay process on the target energy recovery torque to obtain the actual energy recovery torque.

4. A method for calculating the temperature of a vehicle brake disc according to claim 1, wherein, The wheel braking torque includes a front wheel braking torque and a rear wheel braking torque. The allocating the braking torque to multiple wheels to obtain the wheel braking torque includes: Obtaining the ratio of the front wheel braking torque to the front wheel pressure, the ratio of the rear wheel braking torque to the rear wheel pressure, a candidate rear wheel pressure, and a rear wheel braking lock pressure; Obtaining the front wheel pressure based on the braking torque, the ratio of the front wheel braking torque to the front wheel pressure, and the ratio of the rear wheel braking torque to the rear wheel pressure; Taking the minimum of the candidate rear wheel pressure and the rear wheel braking lock pressure to obtain the rear wheel pressure; Obtaining the front wheel braking torque based on the ratio of the front wheel braking torque to the front wheel pressure and the front wheel pressure; Obtaining the rear wheel braking torque based on the ratio of the rear wheel braking torque to the rear wheel pressure and the rear wheel pressure.

5. A method for calculating the temperature of a vehicle brake disc according to claim 4, wherein, The wheel rotation speed includes the front wheel rotation speed, the brake disc heat dissipation area includes the front wheel brake disc heat dissipation area, and the brake disc temperature rise rate includes the front wheel brake disc temperature rise rate; The wheel friction power is obtained based on the wheel braking torque, the actual energy recovery torque, and the wheel speed, and the brake disc temperature rise rate is obtained based on the wheel friction power, including: Obtain the mass of the front wheel brake disc friction ring, the initial temperature of the front wheel brake disc, the current temperature of the front wheel brake disc, and the specific heat capacity of the front wheel brake disc material at the initial temperature of the front wheel brake disc; Obtain the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc based on the initial temperature of the front wheel brake disc, the current temperature of the front wheel brake disc, and the specific heat capacity of the front wheel brake disc material at the initial temperature of the front wheel brake disc; Obtain the front wheel friction braking torque based on the front wheel braking torque and the actual energy recovery torque; Obtain the front wheel friction power based on the front wheel friction braking torque and the front wheel speed; Obtain the front wheel brake disc temperature rise rate based on the front wheel friction power, the mass of the front wheel brake disc friction ring, and the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc.

6. A method for calculating the temperature of a vehicle brake disc according to claim 4, wherein, The wheel speed includes the front wheel speed, the brake disc heat dissipation area includes the front wheel brake disc heat dissipation area, and the brake disc temperature rise rate includes the front wheel brake disc temperature rise rate; The wheel friction power is obtained based on the wheel braking torque, the actual energy recovery torque, and the wheel speed, and the brake disc temperature rise rate is obtained based on the wheel friction power, including: Obtain the mass of the rear wheel brake disc friction ring, the initial temperature of the rear wheel brake disc, the current temperature of the rear wheel brake disc, and the specific heat capacity of the rear wheel brake disc material at the initial temperature of the rear wheel brake disc; Obtain the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc based on the initial temperature of the rear wheel brake disc, the current temperature of the rear wheel brake disc, and the specific heat capacity of the rear wheel brake disc material at the initial temperature of the rear wheel brake disc; Obtain the rear wheel friction braking torque based on the rear wheel braking torque and the actual energy recovery torque; Obtain the rear wheel friction power based on the rear wheel friction braking torque and the rear wheel speed; Obtain the rear wheel brake disc temperature rise rate based on the rear wheel friction power, the mass of the rear wheel brake disc friction ring, and the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc.

7. A method for calculating the temperature of a vehicle brake disc according to claim 1, wherein, The wheel brake disc cooling coefficient includes the front wheel brake disc cooling coefficient, and obtaining the wheel brake disc cooling coefficient according to the current speed includes: Obtain the front wheel brake disc cooling coefficient based on a preset front wheel brake disc cooling coefficient fitting curve and the current speed.

8. A method for calculating the temperature of a vehicle brake disc according to claim 7, wherein, The brake disc heat dissipation area includes the front wheel brake disc heat dissipation area, the brake disc temperature includes the front wheel brake disc temperature, the convective heat transfer cooling power includes the front wheel brake disc convective heat transfer cooling power, and obtaining the convective heat transfer cooling power according to the brake disc cooling coefficient, the brake disc heat dissipation area, the brake disc temperature, and a preset ambient temperature includes: Obtain the mass of the front wheel brake disc friction ring, the initial temperature of the front wheel brake disc, the current temperature of the front wheel brake disc, and the specific heat capacity of the front wheel brake disc material at the initial temperature of the front wheel brake disc; Obtain the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc based on the initial temperature of the front wheel brake disc, the current temperature of the front wheel brake disc, and the specific heat capacity of the front wheel brake disc material at the initial temperature of the front wheel brake disc; Obtain the heat transfer coefficient of the front wheel brake disc based on the front wheel brake disc cooling coefficient, the mass of the front wheel brake disc friction ring, the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc, and the heat dissipation area of the front wheel brake disc; Obtain the convective heat transfer cooling power of the front wheel brake disc based on the front wheel brake disc cooling coefficient, the heat dissipation area of the front wheel brake disc, the temperature of the front wheel brake disc, and the preset ambient temperature.

9. The method for calculating the temperature of a vehicle brake disc according to claim 8, wherein, The thermal radiation cooling power includes the thermal radiation cooling power of the front wheel brake disc. Obtaining the thermal radiation cooling power based on the heat dissipation area of the brake disc, the temperature of the brake disc, and the preset ambient temperature includes: Obtain the thermal radiation cooling power of the front wheel brake disc based on the heat dissipation area of the front wheel brake disc, the temperature of the front wheel brake disc, and the preset ambient temperature.

10. A method for calculating the temperature of a vehicle brake disc according to claim 9, wherein, The temperature reduction rate of the brake disc includes the temperature reduction rate of the front wheel brake disc. Obtaining the temperature reduction rate of the brake disc based on the convective heat transfer cooling power and the thermal radiation cooling power includes: Obtain the total cooling power of the front wheel brake disc based on the convective heat transfer cooling power of the front wheel brake disc and the thermal radiation cooling power of the front wheel brake disc; Obtain the temperature reduction rate of the front wheel brake disc based on the total cooling power of the front wheel brake disc, the mass of the front wheel brake disc friction ring, and the specific heat capacity of the front wheel brake disc material at the current temperature of the front wheel brake disc.

11. A method for calculating the temperature of a vehicle brake disc according to claim 1, wherein, The wheel brake disc cooling coefficient includes the rear wheel brake disc cooling coefficient. Obtaining the wheel brake disc cooling coefficient based on the current speed includes: Obtain the rear wheel brake disc cooling coefficient based on the preset rear wheel brake disc cooling coefficient fitting curve and the current speed.

12. The vehicle brake disc temperature calculation method according to claim 11, wherein, The heat dissipation area of the brake disc includes the heat dissipation area of the rear wheel brake disc, the temperature of the brake disc includes the temperature of the rear wheel brake disc, and the convective heat transfer cooling power includes the convective heat transfer cooling power of the rear wheel brake disc. Obtaining the convective heat transfer cooling power based on the brake disc cooling coefficient, the heat dissipation area of the brake disc, the temperature of the brake disc, and the preset ambient temperature includes: Obtain the mass of the rear wheel brake disc friction ring, the initial temperature of the rear wheel brake disc, the current temperature of the rear wheel brake disc, and the specific heat capacity of the rear wheel brake disc material at the initial temperature of the rear wheel brake disc; According to the initial temperature of the rear wheel brake disc, the current temperature of the rear wheel brake disc, and the specific heat capacity of the rear wheel brake disc material at the initial temperature of the rear wheel brake disc Obtain the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc; Obtain the heat transfer coefficient of the rear wheel brake disc based on the rear wheel brake disc cooling coefficient, the mass of the rear wheel brake disc friction ring, the specific heat capacity of the rear wheel brake disc material at the current temperature of the rear wheel brake disc, and the heat dissipation area of the rear wheel brake disc; Obtain the convective heat transfer cooling power of the rear wheel brake disc based on the rear wheel brake disc cooling coefficient, the heat dissipation area of the rear wheel brake disc, the temperature of the rear wheel brake disc, and the preset ambient temperature.

13. A method for calculating the temperature of a vehicle brake disc according to claim 12, wherein, The thermal radiation cooling power includes the thermal radiation cooling power of the rear wheel brake disc. Obtaining the thermal radiation cooling power based on the heat dissipation area of the brake disc, the temperature of the brake disc, and the preset ambient temperature includes: Obtain the thermal radiation cooling power of the rear wheel brake disc based on the heat dissipation area of the rear wheel brake disc, the temperature of the rear wheel brake disc, and the preset ambient temperature.

14. A method for calculating the temperature of a vehicle brake disc according to claim 13, wherein, The braking disc cooling rate includes the rear-wheel braking disc cooling rate. Obtaining the braking disc cooling rate based on the convective heat transfer cooling power and the thermal radiation cooling power includes: Obtaining the total cooling power of the rear-wheel braking disc based on the convective heat transfer cooling power of the rear-wheel braking disc and the thermal radiation cooling power of the rear-wheel braking disc; Obtaining the cooling rate of the rear-wheel braking disc based on the total cooling power of the rear-wheel braking disc, the mass of the friction ring of the rear-wheel braking disc, and the specific heat capacity of the rear-wheel braking disc material at the current temperature of the rear-wheel braking disc.

15. A vehicle braking disc temperature calculation system, comprising: A vehicle model, which is provided with an energy recovery unit, and the energy recovery unit is configured to obtain an actual energy recovery torque according to the current speed of the vehicle model; A torque controller, which obtains the braking disc temperature, the braking disc heat dissipation area, the wheel speed, and the current speed from the vehicle model and receives a target vehicle speed. The torque controller is configured to calculate an output torque based on the current speed and the target speed to obtain a braking torque, so that the vehicle model distributes the braking torque to multiple wheels to obtain a wheel braking torque, and obtain the wheel friction power according to the wheel braking torque, the actual energy recovery torque, and the wheel speed; A braking disc temperature model, which includes a braking disc temperature rise model and a braking disc temperature drop model. The braking disc temperature model obtains the wheel friction power, the current speed, the braking disc heat dissipation area, and the braking disc temperature from the vehicle model. The braking disc temperature rise model is used to obtain the braking disc temperature rise rate according to the wheel friction power. The braking disc temperature drop model is used to obtain the wheel braking disc cooling coefficient according to the current speed, and obtain the convective heat transfer cooling power according to the braking disc cooling coefficient, the braking disc heat dissipation area, the braking disc temperature, and a preset ambient temperature, obtain the thermal radiation cooling power according to the braking disc heat dissipation area, the braking disc temperature, and the preset ambient temperature, and obtain the braking disc cooling rate according to the convective heat transfer cooling power and The thermal radiation cooling power, and the braking disc temperature model is used to obtain the braking disc temperature according to the braking disc temperature rise rate and the braking disc cooling rate.

16. An electronic device, comprising: A memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the vehicle braking disc temperature calculation method according to any one of claims 1 to 14.

17. A computer storage medium stores computer-executable instructions, wherein, The computer-executable instructions are used to execute the vehicle braking disc temperature calculation method according to any one of claims 1 to 14.

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