A method and system for controlling temperature of an electromechanical brake

Abstract

The application relates to a brake temperature control method and system of an electromechanical brake. The brake temperature control method of the electromechanical brake provided by the application obtains an intermediate temperature based on the temperature obtained by a thermistor installed on a stator winding, generates a brake temperature control scheme based on the relationship between the intermediate temperature and a preset temperature, controls the heat generation of an EMB driving motor, effectively improves the working environment of the driving motor in the EMB under a conventional temperature control strategy, guarantees the braking efficiency of the EMB, and effectively controls the working temperature of the driving motor through a brake force redistribution strategy under the high-temperature abnormal working state of the driving motor in the EMB, thereby avoiding the brake failure caused by the overheating of the motor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile component temperature control, in particular to a brake temperature control method and system of an electromechanical brake. BACKGROUND

[0002] The electromechanical braking system (EMB) is a new type of braking mechanism driven by an electric motor, and its working principle is that the driving motor generates stable braking force through locking. If the EMB driving motor does not have good heat dissipation, in the continuous braking process, on the one hand, the continuous locking of the motor is prone to overheating, and after the temperature of the stator winding continuously rises, the internal resistance of the motor will also increase, resulting in the decline of the motor efficiency and output torque; on the other hand, the heat generated in the process of mutual extrusion and contact between the friction block and the brake disc will also be transferred to the driving motor. When in extremely severe braking conditions, the overheat of the EMB driving motor caused by multiple factors may cause the coil winding to burn out and the brake to fail.

[0003] At present, there is no effective technical solution to solve the heating problem of the EMB driving motor in the existing disclosed technology. Therefore, it is necessary to make technical innovation from the EMB mechanism design and temperature control strategy. SUMMARY

[0004] The purpose of the present application is to provide a brake temperature control method and system of an electromechanical brake, which can effectively improve the working environment of the driving motor in the EMB under the conventional temperature control strategy, and ensure the braking efficiency of the EMB system; under the high-temperature abnormal working state of the driving motor, the working temperature of the driving motor can be effectively controlled through the brake force redistribution strategy, and the brake failure caused by motor overheating can be avoided.

[0005] To achieve the above purpose, the present application provides the following scheme:

[0006] A brake temperature control method of an electromechanical brake is applied to a vehicle in which each wheel is installed with an electromechanical brake; the electromechanical brake comprises a stator winding, a thermistor, a fan, a ventilation fin and a thermoelectric semiconductor refrigeration sheet; the thermistor is arranged at a first position and a second position of the stator winding; the first position and the second position are symmetrical; a fan is arranged between the thermoelectric semiconductor refrigeration sheet and the stator winding.

[0007] The brake temperature control method of the electromechanical brake comprises:

[0008] The thermistor is used to obtain the temperature of the stator winding in the electromechanical brake; the temperature of the stator winding comprises a first position temperature and a second position temperature;

[0009] determining an intermediate temperature based on the first location temperature and the second location temperature;

[0010] obtaining a preset temperature; the preset temperature includes: a first preset temperature, a second preset temperature, a third preset temperature and a fourth preset temperature;

[0011] generating a brake temperature control scheme based on the relationship between the intermediate temperature and the preset temperature.

[0012] Preferably, the generation of the brake temperature control scheme based on the relationship between the intermediate temperature and the preset temperature specifically includes:

[0013] when the intermediate temperature is less than the first preset temperature, no processing is performed;

[0014] when the intermediate temperature is greater than or equal to the first preset temperature and less than the second preset temperature, the thermoelectric semiconductor refrigeration piece is powered on, the current value of the thermoelectric semiconductor refrigeration piece is controlled to be a first current value, the fan is started, and the rotating speed of the fan is controlled to be a first rotating speed;

[0015] when the intermediate temperature is greater than or equal to the second preset temperature and less than the third preset temperature, the current value of the thermoelectric semiconductor refrigeration piece is controlled to be a second current value, and the rotating speed of the fan is controlled to be a second rotating speed; the second current value is greater than the first current value; the second rotating speed is greater than the first rotating speed;

[0016] when the intermediate temperature is greater than or equal to the third preset temperature and less than the fourth preset temperature, the current value of the thermoelectric semiconductor refrigeration piece is controlled to be a third current value, and the rotating speed of the fan is controlled to be a third rotating speed; the third current value is greater than the second current value; the third rotating speed is greater than the second rotating speed;

[0017] when the intermediate temperature is greater than or equal to the fourth preset temperature, a high-temperature early warning is generated, the current value of the thermoelectric semiconductor refrigeration piece is reduced, and a brake force distribution strategy is adopted to complete wheel braking.

[0018] Preferably, the brake force distribution strategy includes:

[0019] the clamping force output by the electromechanical brake generating the high-temperature early warning is reduced to 80% of the original clamping force, and the clamping force output by the electromechanical brake at other wheels in the vehicle is adjusted to meet a regulation criterion; the regulation criterion includes: a brake intensity maintenance criterion, a vehicle stability criterion and a maximum clamping force criterion.

[0020] Preferably, the brake intensity maintenance criterion is used to keep the original target brake intensity of the vehicle unchanged.

[0021] Preferably, the vehicle stability criterion is used to keep the moment of the longitudinal force and the lateral force of the vehicle on the vehicle center of mass to be 0.

[0022] Preferably, the maximum clamping force criterion is used to minimize the clamping force of the output of all the electronic mechanical brakes in the vehicle, and each does not exceed the maximum clamping force of each electronic mechanical brake.

[0023] Preferably, the intermediate temperature is T real :

[0024] T real =max{T r1 , T r2}, wherein T r1 is the first position temperature, T r2 is the second position temperature, and max{} is the maximum value assignment function.

[0025] According to the specific embodiments provided by the application, the following technical effects are disclosed:

[0026] The brake temperature control method of the electronic mechanical brake provided by the application obtains an intermediate temperature based on the temperature obtained by the thermistor installed on the stator winding, generates a brake temperature control scheme based on the relationship between the intermediate temperature and the preset temperature, and controls the heating of the EMB driving motor, so that the working environment of the driving motor in the EMB can be effectively improved under the conventional temperature control strategy, the braking efficiency of the EMB is ensured, and the working temperature of the driving motor can be effectively controlled through the brake force redistribution strategy in the abnormal working state of the driving motor in the EMB, so that the brake failure caused by overheating of the motor is avoided.

[0027] In addition, the application also provides a brake temperature control system of an electronic mechanical brake, which is applied to a vehicle in which each wheel is provided with an electronic mechanical brake; the electronic mechanical brake comprises a stator winding, a thermistor, a fan, a ventilation fin and a thermoelectric semiconductor refrigeration sheet; the thermistor is arranged at a first position and a second position of the stator winding; the first position and the second position are symmetrical; the thermoelectric semiconductor refrigeration sheet and the stator winding are provided with a fan therebetween.

[0028] The brake temperature control system of the electronic mechanical brake comprises:

[0029] A temperature acquisition module is configured to acquire the temperature of the stator winding of the electronic mechanical brake by using the thermistor; the temperature of the stator winding comprises a first position temperature and a second position temperature.

[0030] A temperature determination module is configured to determine an intermediate temperature based on the first position temperature and the second position temperature.

[0031] The preset temperature acquisition module is configured to acquire a preset temperature, wherein the preset temperature comprises a first preset temperature, a second preset temperature, a third preset temperature and a fourth preset temperature.

[0032] The temperature control scheme generation module is configured to generate a brake temperature control scheme based on the relationship between the intermediate temperature and the preset temperature.

[0033] The technical effects achieved by the brake temperature control system of the electronic mechanical brake provided by the present application are the same as those of the brake temperature control method of the electronic mechanical brake provided by the present application, and thus will not be described here again. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0035] Figure 1 The flowchart of the brake temperature control method of the electronic mechanical brake provided by the present application;

[0036] Figure 2 The cross-sectional view of the heat dissipation mechanism of the electronic mechanical brake provided by the embodiment of the present application;

[0037] Figure 3 The single wheel brake state force schematic diagram provided by the embodiment of the present application;

[0038] Figure 4 The whole vehicle brake state force schematic diagram provided by the embodiment of the present application;

[0039] Figure 5 The four-wheel and whole vehicle brake state force schematic diagram provided by the embodiment of the present application;

[0040] Figure 6 The structure schematic diagram of the temperature control system of the electronic mechanical brake provided by the embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0042] The application aims to provide a braking temperature control method and system of an electromechanical brake, which can effectively improve the working environment of a driving motor in the EMB and ensure the braking efficiency of the EMB system under a conventional temperature control strategy, and can effectively control the working temperature of the driving motor through a braking force redistribution strategy to avoid braking failure caused by motor overheating under the high-temperature abnormal working state of the driving motor.

[0043] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the application will be further described in detail below with reference to the drawings and specific embodiments.

[0044] The braking temperature control method of the electromechanical brake provided by the application is mainly applied to a vehicle in which an electromechanical brake is installed on each wheel. Figure 2 As shown in the figure, the electromechanical brake comprises a stator winding 13, a thermistor, a fan 3, a ventilation fin 2, a thermoelectric semiconductor refrigeration sheet 16, a heat pipe base plate 17, a gravity heat pipe 18, a high-thermal-conductivity insulating silica gel sheet 19 and an outer shell 6. The thermistor is arranged at a first position and a second position of the stator winding 13, for example, the thermistor is respectively embedded at the top and bottom of the stator winding 13. The first position and the second position are symmetrical. The fan 3 is arranged between the thermoelectric semiconductor refrigeration sheet 16 and the stator winding 13.

[0045] As shown in the figure, the braking temperature control method of the electromechanical brake comprises: Figure 1

[0046] Step 100: obtaining the temperature of the stator winding in the electromechanical brake by using the thermistor. The temperature of the stator winding 13 comprises a first position temperature and a second position temperature. For example, the voltage change signal of the thermistor is transmitted to four independent brake control units (BCU, Brake Control Unite) after being processed by amplification and digital-to-analog conversion, and then the resistance value of the thermistor is calculated based on Ohm's law to obtain the accurate temperature of the two positions in the coil (i.e. the first position temperature and the second position temperature), which are respectively denoted as T r1 and T r2 .

[0047] Step 101: determining the intermediate temperature based on the first position temperature and the second position temperature. Specifically, the first position temperature T r1 and the second position temperature T r2 are compared, and the larger value is assigned to the intermediate temperature T real , i.e. T real =max{T r1 , T r2}.

[0048] ​Step 102: Obtain preset temperature. The preset temperature includes: first preset temperature, second preset temperature, third preset temperature and fourth preset temperature.

[0049] Step 103: Generate brake temperature control scheme based on the relationship between intermediate temperature and preset temperature. This step specifically includes:

[0050] Step 1031: When the intermediate temperature is less than the first preset temperature (i.e. T real <T1), at this time, it is considered that the stator winding 13 of the driving motor in the EMB is heat-conducted to the outer shell 6 of the motor through the gravity heat pipe 18, and under the natural convection heat exchange condition of the outer shell 6, the temperature of the stator winding 13 of the driving motor in the EMB meets the working requirements.

[0051] Step 1032: When the intermediate temperature is greater than or equal to the first preset temperature and less than the second preset temperature (i.e. T1≤T real <T2), the thermoelectric semiconductor refrigeration sheet 16 is powered on, and the current value of the thermoelectric semiconductor refrigeration sheet 16 is controlled to be the first current value I1, the fan 3 is started, and the rotating speed of the fan 3 is controlled to be the first rotating speed n1.

[0052] Step 1033: When the intermediate temperature is greater than or equal to the second preset temperature and less than the third preset temperature (i.e. T2≤T real <T3), the current value of the thermoelectric semiconductor refrigeration sheet 16 is controlled to be the second current value I2, and the rotating speed of the fan 3 is controlled to be the second rotating speed n2. The second current value I2 is greater than the first current value I1. The second rotating speed n2 is greater than the first rotating speed n1.

[0053] Step 1034: When the intermediate temperature is greater than or equal to the third preset temperature and less than the fourth preset temperature (i.e. T3≤T real <T4), the current value of the thermoelectric semiconductor refrigeration sheet 16 is controlled to be the third current value I3, and the rotating speed of the fan 3 is controlled to be the third rotating speed. The third current value I3 is greater than the second current value I2. The third rotating speed n3 is greater than the second rotating speed n2.

[0054] Step 1035: When the intermediate temperature is greater than or equal to the fourth preset temperature (T real ≥T4), a high temperature warning is generated, the current value of the thermoelectric semiconductor refrigeration sheet 16 is reduced, and a brake force distribution strategy is adopted to complete the wheel braking. Specifically, when the intermediate temperature is greater than or equal to the fourth preset temperature (T realWhen the temperature reaches ≥T4, the BCU determines that the temperature of the stator winding 13 in the EMB drive motor is too high. The BCU sends the abnormal motor status information to the vehicle control unit (ECU) and displays a high temperature warning for the EMB motor on the vehicle display screen to prevent the complete failure of the brakes caused by the burnout of the stator winding 13 in the EMB drive motor. Specifically, when the driver applies the brakes, the ECU receives signals such as the pedal speed and position, determines the braking intensity of the four wheels through a specific algorithm, and transmits the signals to the four BCUs respectively.

[0055] At this time, on the one hand, the current flowing through the thermoelectric semiconductor cooling chip 16 is maintained at I3, and the fan speed 3 is maintained at n3. On the other hand, due to the clamping force F output by the EMB... 夹 With stator winding 13 current I coil A positive correlation can be established by F. 夹 =F(k)·I coil This indicates that F(k) is a positive correlation function.

[0056] Therefore, by reducing the current in stator winding 13, the EMB output clamping force is reduced to the target braking clamping force F. 夹 It reduces the heating of the winding coil by 80% and intervenes in the braking force distribution control strategy.

[0057] The specific implementation process of the braking force distribution control strategy is explained below.

[0058] First, the forces acting on the wheels and the entire vehicle during braking are analyzed and explained:

[0059] For example, when analyzing a single wheel, during wheel braking, such as Figure 3 As shown, the frictional force μ generated by the electromechanical brake clamping the brake disc... 夹 F 夹 The vertical support force F exerted by the ground on the tire N The frictional force (longitudinal braking force) exerted by the ground on the tires μ x F N And the inertial torque M of the tire r Establish the torque balance equation for a single wheel:

[0060] M r +μ x F N R-μ 夹 F 夹 r = 0 (1-1)

[0061] Where, μ 夹Let R be the coefficient of friction, R be the radius of the wheel, r be the distance from the brake pad to the center of wheel rolling, and M be the torque of inertia of the tire. r It can be represented by the tire's moment of inertia J and angular acceleration dω / dt:

[0062]

[0063] The angular velocity ω can be obtained from the wheel speed sensor at the wheel.

[0064] Therefore, the expression for the frictional force of a single tire is:

[0065]

[0066] Taking the whole vehicle as the analysis object, such as Figure 4 As shown, the weight of the entire vehicle is mg. During vehicle braking, assuming the vehicle is symmetrical from left to right, the vertical support forces exerted by the ground on the front and rear wheels are F and F, respectively. N-f (Front wheel), F N-r (Rear wheel). The distances from the front and rear axles to the center of gravity are a and b respectively, the vehicle's center of gravity is h above the ground, and the braking deceleration is v' (obtained from the vehicle's deceleration sensor). Therefore, the overall vehicle mechanics model is:

[0067] 2F N-f (a+b)=mgb-mv′h (1-4)

[0068] 2F N-r (a+b)=mga+mv′h (1-5)

[0069] Therefore, the expressions for the vertical support forces of the front and rear wheels are as follows:

[0070]

[0071] Taking the four tires and the entire vehicle as the analysis objects, the longitudinal frictional forces exerted by the ground on the four wheels in the local coordinate system are μ x-fl F N-f (Left front wheel), μ x-fr F N-f (Right front wheel), μ x-rl F N-r (Left rear wheel), μ x-rr F N-r (Right rear wheel), μ x-fl μ x-fr μ x-rl and μ x-rr The coefficients of friction for the left front wheel, right front wheel, left rear wheel, and right rear wheel are given. The lateral forces acting on them are F and F, respectively. y1 (Front left wheel), F y2 (Right front wheel), F y3(left rear wheel), F y4 (right rear wheel). The side slip angles (the angle between the x-axis of the tire coordinate system and the direction of the velocity vector of the wheel) of the four tires are α fl , α fr , α rl , and α rr , respectively. The steering angles of the front wheels are δ fl and δ fr , respectively. The longitudinal velocity, lateral velocity, and yaw rate of the vehicle are v, u, and ω r , respectively. c is the distance from the tire to the center of gravity of the vehicle. The side slip angle expressions of the four tires are as follows:

[0072]

[0073] The lateral force of the tire uses the semi-empirical tire model proposed by Pacejka, and the expression is as follows:

[0074] F y1，y2 = D sin{C arctan[Bα fl，fr -E(Bα fl，fr -arctanBα fl，fr )]} (1-10)

[0075] F y3，y4 = D sin{C arctan[Bα rl，rr -E(Bα rl，rr -arctanBα rl，rr )]} (1-11)

[0076] In the formula, D is a peak factor, B is a stiffness factor, E is a curvature factor, all of which are related to the vertical load of the tire and can be measured according to tire tests, and C is a shape factor of the tire. The forces of the four wheels and the vehicle in the braking state are shown in Figure 4 .

[0077] As shown in Figure 5 , by analyzing the dynamics of a single wheel and the whole vehicle, the relationship between the clamping force F 夹 output by the EMB and the parameters in the vehicle braking process is clarified. The following is a re-distribution of the braking force under the overheating state of the EMB motor, and then, based on the above analysis, the braking force distribution control strategy provided in the present application is as follows:

[0078] a) When the EMB motor at the left front wheel or the right front wheel is in high temperature warning (taking the right front wheel as an example):

[0079] i) Braking intensity maintenance criterion

[0080] According to formula (1-3), by changing the clamping force F 夹The longitudinal braking force of the wheels can be controlled. Since the clamping force output by the right front wheel EMB motor is reduced to 80% of the original clamping force, the clamping forces output by the other three EMB motors that are not heated need to be adjusted so that the longitudinal braking force of the vehicle should reach the original target longitudinal braking force, i.e., the braking intensity remains unchanged:

[0081] μ' x-fl F N-f cosδ fl +μ' x-fr F N-f cosδ fr +μ' x-rl F N-r +μ' x-rr F N-r = mv' (1-12)

[0082] wherein,

[0083]

[0084] ii) Vehicle stability criterion

[0085] The moment of the longitudinal force and the lateral force of the vehicle on the center of mass is 0, avoiding the lateral movement of the vehicle:

[0086]

[0087] iii) Maximum braking force criterion

[0088] The sum of the adjusted motor braking clamping forces should be taken as the minimum value, and each motor output should not exceed the maximum braking force:

[0089] ∑F 夹 = min (F' 夹-fl +F' 夹-rl +F' 夹-rr ) (1-18)

[0090] F' 夹-fl ≤ F 夹-fl-max (1-19)

[0091] F' 夹-rl ≤ F 夹-rl-max (1-20)

[0092] F' 夹-rr ≤ F 夹-rr-max (1-21)

[0093] wherein fl is the left front wheel, fr is the right front wheel, rl is the left rear wheel, rr is the right rear wheel, F' 夹-fl is the left front wheel EMB target braking clamping force (adjusted motor braking clamping force), F' 夹-rlF' is the EMB target braking clamping force for the left rear wheel 夹-rr F is the EMB target braking clamping force for the right rear wheel 夹-fl-max F is the maximum (rated) clamping force that the EMB can output for the left front wheel 夹-rl-max F is the maximum clamping force that the EMB can output for the left rear wheel 夹-rr-max F is the maximum clamping force that the EMB can output for the right rear wheel.

[0094] When the EMB motor output at a certain wheel reaches the maximum clamping force, the criteria ii) and iii) should be met in priority.

[0095] b) When the EMB stator winding 13 at multiple wheels is in a high temperature state, the EMB output clamping force is reduced to 80% of the target braking clamping force by reducing the current of the corresponding stator winding 13. The braking force distribution at the remaining wheels should meet the i) braking intensity maintenance criterion, ii) vehicle stability criterion and iii) maximum clamping force criterion. When the EMB motor output at a certain wheel reaches the maximum clamping force, the criteria ii) and iii) should be met in priority.

[0096] When the temperature T of the overheated EMB stator winding 13 real drops below T4, its output original target clamping force is restored, and the normal temperature control strategy is restored.

[0097] In most braking conditions, the heat of the EMB stator winding 13 can be completely dissipated by the passive heat dissipation system. In a small number of braking conditions, the active heat dissipation mode needs to be started. When the EMB high temperature warning occurs, the EMB is in an abnormal state, and the braking force redistribution control strategy is intervened. The purpose is to avoid the complete failure of the brake due to the burning of the stator winding 13 by sacrificing part of the braking intensity, and at the same time ensure the braking stability of the vehicle. When the vehicle is in a stopped state, the driver should arrange the maintenance or replacement of the EMB system in time.

[0098] Based on the above provided technical solutions, compared with the prior art, it has the following advantages:

[0099] 1) The present application uses a thermistor to monitor the temperature of the stator winding 13 of the EMB mechanism during braking in real time. The collected feedback signal is transmitted to the BCU. The BCU implements a multi-grade cooling rate temperature control strategy according to the heating condition of the stator winding 13, ensuring the stable operation of the EMB drive motor.

[0100] 2) When the drive motor of the EMB is in a high temperature abnormal state, the braking force redistribution control strategy is adopted, which effectively avoids the complete failure of the brake due to the burning of the stator winding 13, and at the same time takes into account the braking stability of the vehicle.

[0101] Furthermore, the application also provides a brake temperature control system of an electromechanical brake, which is applied to a vehicle with an electromechanical brake installed on each wheel. The electromechanical brake comprises a stator winding 13, a thermistor, a fan 3, a ventilation fin 2 and a thermoelectric semiconductor refrigeration sheet 16. The thermistor is arranged at a first position and a second position of the stator winding 13. The first position and the second position are symmetrical. The thermoelectric semiconductor refrigeration sheet 16 and the stator winding 13 are provided with the fan 3.

[0102] As shown in Figure 6 The application provides a brake temperature control system of an electromechanical brake, which comprises:

[0103] A temperature acquisition module 600 is configured to acquire the temperature of the stator winding 13 of the electromechanical brake by using the thermistor. The temperature of the stator winding 13 comprises a first position temperature and a second position temperature.

[0104] A temperature determination module 601 is configured to determine an intermediate temperature based on the first position temperature and the second position temperature.

[0105] A preset temperature acquisition module 602 is configured to acquire preset temperatures. The preset temperatures comprise a first preset temperature, a second preset temperature, a third preset temperature and a fourth preset temperature.

[0106] A temperature control scheme generation module 603 is configured to generate a brake temperature control scheme based on the relationship between the intermediate temperature and the preset temperatures.

[0107] In the description, each embodiment is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0108] The principles and implementation manners of the application are described by using specific examples. The above description of the embodiments is only used to help understand the method and the core idea of the application. For those skilled in the art, the specific implementation manners and application ranges can be changed according to the idea of the application. In conclusion, the content of the description should not be understood as a limitation of the application.

Claims

1. A brake temperature control method for an electromechanical brake, characterized by, The application is applied to a vehicle with an electromechanical brake installed on each wheel; The electromechanical brake comprises a stator winding, a thermistor, a fan, a ventilation fin and a thermoelectric semiconductor refrigeration sheet; the thermistor is arranged at a first position and a second position of the stator winding; the first position and the second position are symmetrical; the thermoelectric semiconductor refrigeration sheet and the stator winding are provided with a fan therebetween; The brake temperature control method of the electromechanical brake comprises: The temperature of the stator winding in the electromechanical brake is obtained by using the thermistor; the temperature of the stator winding comprises a first position temperature and a second position temperature; An intermediate temperature is determined based on the first position temperature and the second position temperature; A preset temperature is obtained; the preset temperature comprises a first preset temperature, a second preset temperature, a third preset temperature and a fourth preset temperature; A brake temperature control scheme is generated based on the relationship between the intermediate temperature and the preset temperature, comprising: When the intermediate temperature is less than the first preset temperature, no processing is performed; When the intermediate temperature is greater than or equal to the first preset temperature and less than the second preset temperature, the thermoelectric semiconductor refrigeration sheet is powered on, the current value of the thermoelectric semiconductor refrigeration sheet is controlled to be a first current value, the fan is started and the rotating speed of the fan is controlled to be a first rotating speed; When the intermediate temperature is greater than or equal to the second preset temperature and less than the third preset temperature, the current value of the thermoelectric semiconductor refrigeration sheet is controlled to be a second current value and the rotating speed of the fan is controlled to be a second rotating speed; the second current value is greater than the first current value; the second rotating speed is greater than the first rotating speed; When the intermediate temperature is greater than or equal to the third preset temperature and less than the fourth preset temperature, the current value of the thermoelectric semiconductor refrigeration sheet is controlled to be a third current value and the rotating speed of the fan is controlled to be a third rotating speed; the third current value is greater than the second current value; the third rotating speed is greater than the second rotating speed; When the intermediate temperature is greater than or equal to the fourth preset temperature, a high-temperature early warning is generated, the current value of the thermoelectric semiconductor refrigeration sheet is reduced, and a brake force distribution strategy is used to complete wheel braking.

2. The brake temperature control method of an electromechanical brake according to claim 1, characterized by, The brake force distribution strategy comprises: The clamping force output by the electromechanical brake generating the high-temperature early warning is reduced to 80% of the original clamping force, and the clamping force output by the electromechanical brake at other wheels in the vehicle is adjusted to meet a regulation criterion; the regulation criterion comprises a brake intensity maintenance criterion, a vehicle stability criterion and a maximum clamping force criterion.

3. The brake temperature control method of an electromechanical brake according to claim 2, characterized by, The brake intensity maintenance criterion is used to keep the original target brake intensity of the vehicle unchanged.

4. The brake temperature control method of an electromechanical brake according to claim 2, characterized by, The vehicle stability criterion is used to keep the moment generated by the longitudinal force and the lateral force of the vehicle on the vehicle center of mass to be 0.

5. The brake temperature control method of an electromechanical brake according to claim 2, wherein The maximum clamping force criterion is used to minimize the output clamping force of all the electromechanical brakes in the vehicle, and the output clamping force of each electromechanical brake does not exceed the maximum clamping force.

6. The brake temperature control method of an electromechanical brake according to claim 1, wherein The intermediate temperature is T real : T real = max{T r1 , T r2}, where T r1 is the first location temperature, T r2 is the second location temperature, and max{} is the maximum value assignment function.

7. A brake temperature control system for an electromechanical brake, characterized by, The application is applied to a vehicle with an electromechanical brake installed on each wheel; The electromechanical brake comprises a stator winding, a thermistor, a fan, a ventilation fin and a thermoelectric semiconductor refrigeration sheet; the thermistor is arranged at a first position and a second position of the stator winding; the first position and the second position are symmetrical; the thermoelectric semiconductor refrigeration sheet and the stator winding are arranged with the fan therebetween; The brake temperature control system of the electromechanical brake is used for implementing the brake temperature control method of the electromechanical brake according to any one of claims 1-6, comprising: A temperature acquisition module is used for acquiring the temperature of the stator winding in the electromechanical brake by using the thermistor; the temperature of the stator winding comprises a first position temperature and a second position temperature; A temperature determination module is used for determining an intermediate temperature based on the first position temperature and the second position temperature; A preset temperature acquisition module is used for acquiring a preset temperature; the preset temperature comprises a first preset temperature, a second preset temperature, a third preset temperature and a fourth preset temperature; A temperature control scheme generation module is used for generating a brake temperature control scheme based on the relationship between the intermediate temperature and the preset temperature.

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