A composite brake antilock control system and method

Abstract

The application discloses a kind of composite brake anti-lock control system and method, belong to the technical field of automobile brake anti-lock system, a kind of composite brake anti-lock control system, including sensor unit, wheel slip rate deviation calculation unit, electronic mechanical brake ideal braking torque calculation unit, power motor controller assembly and anti-lock braking system assembly;The power motor controller assembly is connected with four power motors, each the power motor is connected with corresponding electronic mechanical brake, anti-lock braking system assembly includes fuzzy PID controller, composite braking system and torque distribution unit.The application detects when wheel slip rate has the tendency of lock, first macroscopically adjusts electronic mechanical braking force to the vicinity of road adhesion limit, while using fuzzy self-tuning PID control to adjust small range to regenerative braking torque, wheel speed fluctuation is very small in whole braking process, and vehicle has good braking smoothness.

Description

TECHNICAL FIELD

[0001] The present application mainly relates to the technical field of automobile anti-lock braking system, and particularly to a composite anti-lock braking control system and method. BACKGROUND

[0002] Anti-lock braking technology is one of the representatives of modern automobile active safety technology. In the prior art, when the anti-lock braking system is triggered, braking is performed by an electronic mechanical brake. In this way, the feedback braking characteristics of the power motor are not fully utilized, and energy cannot be effectively recovered during braking, resulting in waste of energy consumption. In addition, in order to ensure charging safety, many feedback braking systems currently do not consider operation in a high state of charge, and the starting threshold value of the feedback braking function is usually limited to below 85% of the battery SOC value of the whole vehicle. Although this approach ensures charging safety during feedback braking, it causes the braking energy in a high state of charge to be wasted.

[0003] In modern control theory, relatively traditional controls such as PID control, optimal control, and sliding mode control are widely used in ABS. Intelligent control theory includes intelligent control algorithms such as neural networks, fuzzy control, and genetic algorithms. The anti-lock braking process has characteristics such as a large amount of nonlinear, time-varying, and braking actuator hysteresis uncertain information. In most anti-lock braking controls, due to the complexity of the road surface during actual vehicle driving, and the fact that different road surfaces correspond to different peak adhesion coefficients corresponding to anti-lock torques, the wheel speed often fluctuates greatly, and the difference between the ideal anti-lock braking torque and the braking torque generated by the actual braking actuator is large, so the best braking effect cannot be achieved. SUMMARY

[0004] The technical solution of the present application provides a significantly different solution from the prior art to solve the technical problem of the prior art solution being too single, and mainly provides a composite anti-lock braking control system and method to solve the technical problem of poor vehicle braking effect in the background technology.

[0005] The technical solution adopted by the present application to solve the above technical problem is as follows:

[0006] A composite anti-lock braking control system, comprising:

[0007] A sensor unit, including a wheel speed sensor for measuring wheel speed, a vehicle speed sensor for measuring vehicle speed, an acceleration sensor for measuring braking deceleration, a torque sensor for measuring braking disc braking friction torque and power motor output torque, a current sensor for measuring current at both ends of the power motor, and a SOC sensor for measuring battery state of charge;

[0008] Wheel slip ratio deviation calculation unit, which calculates wheel slip ratio deviation and slip ratio deviation change rate according to wheel speed and vehicle speed measured by the sensor unit;

[0009] Electronic mechanical brake ideal brake torque calculation unit, which calculates ideal brake torque according to brake deceleration measured by the sensor unit;

[0010] Power motor controller assembly, which is connected with four power motors, each of which is connected with a corresponding electronic mechanical brake, and controls power motor to form actual regenerative braking torque and controls electronic mechanical brake to form actual brake braking torque;

[0011] Anti-lock braking system assembly, which includes fuzzy PID controller, composite braking system and torque distribution unit, inputs slip ratio deviation and slip ratio deviation change rate to fuzzy PID controller, which outputs ideal regenerative braking torque to composite braking system based on fuzzy adaptive setting PID control principle, inputs ideal brake braking torque to composite braking system, and torque distribution unit distributes anti-lock braking torque to composite braking system based on comprehensive braking control strategy, and torque distribution unit controls power motor controller assembly to make dynamic adjustment through electric signal.

[0012] Preferably, the sensor unit is connected with wheel slip ratio deviation calculation unit, electronic mechanical brake ideal brake torque calculation unit and anti-lock braking system assembly respectively, the wheel slip ratio deviation calculation unit and the electronic mechanical brake ideal brake torque calculation unit are connected with the anti-lock braking system assembly, and the anti-lock braking system assembly is connected with the power motor controller assembly.

[0013] Preferably, each electronic mechanical brake includes a brake disc, a brake friction plate, a caliper housing, a speed reduction mechanism, a pressure plate and a high-voltage brake motor, and the electronic mechanical brake is connected with the power motor through high-voltage brake motor input / output current at both ends.

[0014] Preferably, the algorithm design of the anti-lock braking system assembly includes:

[0015] S1, fuzzy PID controller design based on slip ratio control:

[0016] (1) Fuzzy quantization: the obtained slip ratio error and slip ratio error change rate are taken as fuzzy control input, and membership function fuzzy quantization is used to obtain corresponding fuzzy input;

[0017] The fuzzy language values of the slip ratio error e and the slip ratio error change rate ec are {NB, NM, NS, ZO, PS, PM, PB}, wherein NB represents negative big, NM represents negative medium, NS represents negative small, ZO represents zero, PS represents positive small, PM represents negative medium, and PB represents positive big.

[0018] The membership functions of the slip ratio error e and the slip ratio error change rate ec are TRIMF functions.

[0019] The fuzzy domain and the membership function are designed, the fuzzy input quantity obtained by the slip ratio error e is E, and the fuzzy input quantity obtained by the slip ratio error change rate ec is EC.

[0020] (2) Fuzzy reasoning: the fuzzy input quantity obtained in (1) is subjected to fuzzy reasoning according to the fuzzy control rule, so as to obtain a corresponding fuzzy output quantity.

[0021] The fuzzy rule table based on the fuzzy input quantity E of the slip ratio error e and the fuzzy input quantity EC of the slip ratio error change rate ec is designed, and the fuzzy output quantity obtained thereby is ΔK p , ΔK i , and ΔK d .

[0022] (3) Fuzzy decision: the fuzzy output quantity in (2) is subjected to fuzzy decision, and the decision result is input into the PID controller, so as to adjust the actual parameters of the PID controller.

[0023] The fuzzy language values of the fuzzy control output quantity ΔK p , ΔK i , and ΔK d are {NB, NM, NS, ZO, PS, PM, PB}, wherein NB represents negative big, NM represents negative medium, NS represents negative small, ZO represents zero, PS represents positive small, PM represents negative medium, and PB represents positive big. The membership functions of ΔK p , ΔK i , and ΔK d are TRIMF functions.

[0024] The fuzzy domain and the membership function are designed.

[0025] The actual parameters of the PID controller are obtained by self-adjustment on the basis of the initial values of the PID controller, that is:

[0026] K p = K p0 + ΔK p

[0027] K i = K i0 + ΔK i

[0028] K d =K d0 +ΔK d

[0029] In the formula, K p0 , K i0 , K d0 are initial parameter values of the PID controller;

[0030] S2, brake anti-lock torque distribution based on the comprehensive brake control strategy:

[0031] (1) output ideal regenerative braking torque and ideal brake braking torque to the composite brake system;

[0032] (2) the torque distribution unit calculates the actual regenerative braking torque and actual brake braking torque based on the comprehensive brake control strategy;

[0033] S3, feedback control based on slip rate deviation:

[0034] The torque distribution unit outputs the actual regenerative braking torque and actual brake braking torque to the vehicle model, and then the vehicle model feeds back the real-time slip rate to the wheel slip rate deviation calculation unit and calculates the slip rate deviation, if the slip rate deviation is not 0, the result is re-input to the PID controller and the braking torque is dynamically adjusted until the slip rate deviation is 0.

[0035] A composite brake anti-lock control method, using the above-mentioned composite brake anti-lock control system, comprising the following steps:

[0036] S1, signal acquisition: using a vehicle speed sensor and a wheel speed sensor to obtain vehicle speed signals and wheel speed signals during braking, and the wheel slip rate deviation calculation unit calculates the real-time slip rate, slip rate error, and slip rate error rate during braking after receiving the signals;

[0037] S2, determine whether to start the brake anti-lock function:

[0038] (1) if the slip rate error corresponding to each wheel is 0, the anti-lock brake system assembly does not participate in work, and the conventional braking mode is performed until the vehicle stops;

[0039] (2) If the slip rate error corresponding to each wheel is not zero, the anti-lock braking system assembly will start working and use the acceleration sensor to obtain the braking deceleration of the electric vehicle. After receiving the signal, the compound braking system calculates the required braking torque during the vehicle braking process according to the signal. The wheel slip rate deviation calculation unit outputs the slip rate deviation and the slip rate deviation change rate to the fuzzy PID controller. The fuzzy PID controller outputs the ideal regenerative braking torque T based on the fuzzy adaptive PID control principle. Reg0 To the compound brake system, at the same time the ideal braking torque calculation unit of the electronic mechanical brake outputs the ideal brake torque T EMB0 to the compound braking system, and then the torque distribution unit distributes the anti-lock braking torque to the compound braking system based on the comprehensive braking control strategy;

[0040] S3, controlling the electromechanical brake to form the brake torque through an electrical signal, and controlling the regenerative braking system to form the regenerative braking torque, and dynamically adjusting the regenerative braking torque based on the change in wheel slip rate until the anti-lock braking system is deactivated.

[0041] Preferably, in S2, the comprehensive braking control strategy adopted by the anti-lock braking system assembly includes:

[0042] (1) If the battery state of charge (SOC) satisfies SOC≤85% under low-intensity braking conditions, the braking torque T EMB , regenerative braking torque T Reg Satisfy the following formula:

[0043] T EMB =T EMB0 =0

[0044] T Reg =T Reg0

[0045] (2) If the battery state of charge (SOC) satisfies SOC>85% under low-intensity braking conditions, the power motor controller assembly obtains the target charging current and motor target braking torque T according to the current SOC value and power motor current. Reg * ,

[0046] If T Reg * >T Reg0 , brake torque T EMB , regenerative braking torque T Reg Satisfy the following formula:

[0047] T EMB =T EMB0 =0

[0048] T Reg = T Reg0

[0049] If T Reg * ≤ T Reg0 , the brake torque T EMB and the regenerative braking torque T Reg satisfy the following formula:

[0050] T Reg = T Reg *

[0051] T EMB = T db - T Reg *

[0052] (3) If in the medium-high intensity braking condition, the battery state of charge SOC satisfies SOC≤85%, the brake torque T EMB and the regenerative braking torque T Reg satisfy the following formula:

[0053] T EMB = T EMB0 = 0

[0054] T Reg = T Reg0

[0055] (4) If in the medium-high intensity braking condition, the battery state of charge SOC satisfies SOC>85%, the electric energy output by the motor is directly supplied to the EMB motor, and the braking torque generated by the EMB motor is T REMB .

[0056] If T REMB > T EMB0 , the brake torque T EMB and the regenerative braking torque T Reg satisfy the following formula:

[0057] T Reg = T Reg0

[0058] T REMB = T EMB0

[0059] That is, if the electric energy output by the motor exceeds the requirement of the EMB system, the excess part is transferred to the battery;

[0060] If T REMB ≤ T EMB0 , the brake torque T EMB and the regenerative braking torque T Regsatisfies the following formula:

[0061] T Reg = T Reg0

[0062] T EMB = T REMB + T BEMB

[0063] wherein T BEMB is the braking torque generated when the battery replenishes the energy of the EMB motor;

[0064] T BEMB = T EMB -T REMB .

[0065] Compared with the prior art, the present application has the following beneficial effects:

[0066] 1. The composite braking anti-lock control proposed in the present application is not a control mode of regulating the oil pressure of the conventional hydraulic braking system, but is applied to a vehicle equipped with EMB. In the braking process, the ABS control is performed by using the macroscopic regulation of the electronic mechanical braking and the microscopic regulation of the regenerative braking. When the wheel slip rate is detected to have a tendency of locking, the electronic mechanical braking force is firstly macroscopically regulated to the vicinity of the road adhesion limit, and at the same time, the regenerative braking torque is adjusted in a small range by using the fuzzy self-tuning PID control. In the whole braking process, the wheel speed fluctuation is very small, and the vehicle has good braking smoothness.

[0067] 2. The present application details the intervention and withdrawal of the regenerative braking under the high battery state of charge. In the low-intensity high-charge braking state, the motor controller assembly calculates the motor target braking torque, and the braking process energy recovery efficiency is improved by expanding the feedback braking threshold. In the medium-high intensity high-charge braking state, the generator output power directly supplies the EMB mechanism to perform braking, and the kinetic energy is converted in real time without static energy storage, which can solve the problems of low energy recovery efficiency, small power and difficult large-scale recovery.

[0068] The present application will be explained in detail below in combination with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0069] Fig. 1 It is a principle block diagram of the composite braking anti-lock control system.

[0070] Fig. 2 It is a flow chart of the composite braking anti-lock control system.

[0071] Fig. 3 It is a principle diagram of the anti-lock braking system assembly. DETAILED DESCRIPTION

[0072] For the purpose of facilitating the understanding of the present application, a more comprehensive description will be made below with reference to the relevant drawings, which show several embodiments of the present application. However, the present application can be realized in different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0073] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can be a middle element, and when an element is referred to as being "connected to" another element, it can be directly connected to the other element or there can be a middle element. The terms "vertical", "horizontal", "left", "right", and the like used herein are for illustrative purposes only.

[0074] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0075] Please refer to the drawings carefully Figs. 1-3 The present application provides a technical solution: a composite brake anti-lock control system, comprising:

[0076] A sensor unit, comprising a wheel speed sensor for measuring wheel speed, a vehicle speed sensor for measuring vehicle speed, an acceleration sensor for measuring braking deceleration, a torque sensor for measuring braking disc braking friction torque and power motor output torque, a current sensor for measuring current at both ends of the power motor, and a SOC sensor for measuring battery state of charge;

[0077] A wheel slip ratio deviation calculation unit for calculating wheel slip ratio deviation and slip ratio deviation change rate according to wheel speed and vehicle speed measured by the sensor unit;

[0078] An electronic mechanical brake ideal braking torque calculation unit for calculating ideal brake braking torque according to braking deceleration measured by the sensor unit;

[0079] The power motor controller assembly is connected with four power motors, each of which is connected with a corresponding electronic mechanical brake, the power motor controller assembly controls the power motor to form an actual regenerative braking torque and controls the electronic mechanical brake to form an actual brake braking torque, each of the electronic mechanical brakes comprises a brake disc, a brake friction plate, a caliper shell, a speed reduction mechanism, a pressure plate and a high-voltage brake motor, and the electronic mechanical brake is connected with the power motor through the input / output current at both ends of the high-voltage brake motor.

[0080] The anti-lock braking system assembly comprises a fuzzy PID controller, a composite braking system and a torque distribution unit, the slip ratio deviation and the slip ratio deviation change rate are input to the fuzzy PID controller, the fuzzy PID controller outputs an ideal regenerative braking torque to the composite braking system based on the fuzzy adaptive setting PID control principle, the ideal brake braking torque is input to the composite braking system, the torque distribution unit distributes the anti-lock braking torque of the composite braking system based on the comprehensive braking control strategy, and the torque distribution unit controls the power motor controller assembly to be dynamically adjusted through an electric signal.

[0081] The sensor unit is connected with a wheel slip ratio deviation calculation unit, an electronic mechanical brake ideal braking torque calculation unit and an anti-lock braking system assembly respectively, the wheel slip ratio deviation calculation unit and the electronic mechanical brake ideal braking torque calculation unit are connected with the anti-lock braking system assembly, and the anti-lock braking system assembly is connected with a power motor controller assembly.

[0082] The algorithm design of the anti-lock braking system assembly comprises the following steps.

[0083] S1, fuzzy PID controller design based on slip ratio control:

[0084] (1) Fuzzy quantization: the obtained slip ratio error and slip ratio error change rate are taken as fuzzy control input quantities, and membership function fuzzy quantization is used to obtain corresponding fuzzy input quantities;

[0085] The fuzzy language values of the slip ratio error e and the slip ratio error change rate ec are {NB, NM, NS, ZO, PS, PM, PB}, wherein NB represents negative big, NM represents negative medium, NS represents negative small, ZO represents zero, PS represents positive small, PM represents negative medium, and PB represents positive big.

[0086] The membership functions of the slip ratio error e and the slip ratio error change rate ec are TRIMF functions.

[0087] The fuzzy domain and the membership function are designed, the fuzzy input quantity obtained by the slip ratio error e is E, and the fuzzy input quantity obtained by the slip ratio error change rate ec is EC.

[0088] (2) Fuzzy Inference: fuzzy inference is performed on the fuzzy input quantity obtained in (1) according to fuzzy control rules to obtain corresponding fuzzy output quantity;

[0089] A fuzzy rule table of the fuzzy input quantity E based on the slip rate error e and the fuzzy input quantity EC of the slip rate error change rate ec is designed, and the fuzzy output quantity obtained is ΔK p , ΔK i , ΔK d ;

[0090] (3) Fuzzy Decision: fuzzy decision is performed on the fuzzy output quantity in (2), and the decision result is input into the PID controller to adjust the actual parameters of the PID controller;

[0091] The fuzzy language values of the fuzzy control output quantity ΔK p , ΔK i , ΔK d are {NB, NM, NS, ZO, PS, PM, PB}, wherein NB represents negative big, NM represents negative medium, NS represents negative small, ZO represents zero, PS represents positive small, PM represents negative medium, and PB represents positive big. The membership functions of ΔK p , ΔK i , ΔK d all adopt TRIMF functions.

[0092] The fuzzy domain and the membership function are designed.

[0093] The actual parameters of the PID controller are obtained by self-adjustment on the basis of the initial values, that is:

[0094] K p = K p0 + ΔK p

[0095] K i = K i0 + ΔK i

[0096] K d = K d0 + ΔK d

[0097] In the formula, K p0 , K i0 , K d0 are the initial parameter values of the PID controller;

[0098] S2, brake anti-lock torque distribution based on comprehensive braking control strategy:

[0099] (1) output ideal regenerative braking torque and ideal brake braking torque to the composite brake system;

[0100] (2) The torque distribution unit calculates the actual regenerative braking torque and the actual brake braking torque based on the comprehensive braking control strategy;

[0101] S3, feedback control based on slip rate deviation:

[0102] The torque distribution unit outputs the actual regenerative braking torque and the actual brake braking torque to the vehicle model, and then the vehicle model feeds back the real-time slip rate to the wheel slip rate deviation calculation unit and calculates the slip rate deviation. If the slip rate deviation is not 0, the result is re-input to the PID controller and the braking torque is dynamically adjusted until the slip rate deviation is 0.

[0103] A composite brake anti-lock control method, comprising the following steps:

[0104] S1, signal acquisition: using a vehicle speed sensor and a wheel speed sensor to obtain vehicle speed signals and wheel speed signals during braking, and a wheel slip rate deviation calculation unit calculates real-time slip rate, slip rate error, and slip rate error rate during braking;

[0105] Let: v be the center speed of the wheel, ω be the angular speed of the wheel, r be the rolling radius of the wheel, and s be the slip rate. The slip rate calculation formula of the wheel during braking is:

[0106] s = (v - rω) / v

[0107] Let: the optimal slip rate on the road be s0 (empirical value), the slip rate error of the wheel during braking be e, and the slip rate error rate be ec, then:

[0108] e = s - s0

[0109] ec = de / dt

[0110] S2, determine whether to start the anti-lock braking function:

[0111] (1) If the slip rate error corresponding to each wheel is 0, the anti-lock braking system assembly does not participate in work, and the normal braking mode is performed until the vehicle stops;

[0112] (2) If the slip rate error corresponding to each wheel is not 0, the anti-lock braking system assembly participates in work, an acceleration sensor is used to obtain the braking deceleration of the electric vehicle, and the composite braking system receives the signal, calculates the required braking torque during braking of the vehicle according to the signal, and outputs the slip rate deviation and the slip rate deviation rate to the fuzzy PID controller. The fuzzy PID controller outputs the ideal regenerative braking torque T based on the fuzzy self-adaptive PID control principle. Reg0to the composite braking system, and an electronic mechanical brake ideal brake torque calculation unit outputs an ideal brake brake torque T EMB0 to the composite braking system, and then a torque distribution unit distributes the brake anti-lock torque to the composite braking system based on a comprehensive braking control strategy;

[0113] S3, the electronic mechanical brake is controlled by an electrical signal to form the brake brake torque, and the regenerative braking system is controlled to form the regenerative brake torque, and the regenerative brake torque is dynamically adjusted until the anti-lock braking system is turned off, with the change of the wheel slip ratio as the reference.

[0114] In S2, the comprehensive braking control strategy adopted by the anti-lock braking system assembly includes:

[0115] (1) If the battery state of charge SOC satisfies SOC≤85% under low-intensity braking conditions, the brake brake torque T EMB , the regenerative brake torque T Reg satisfies the following formula:

[0116] T EMB =T EMB0 =0

[0117] T Reg =T Reg0

[0118] (2) If the battery state of charge SOC satisfies SOC>85% under low-intensity braking conditions, the power motor controller assembly obtains the target charging current and the motor target brake torque T Reg * ,

[0119] If T Reg * >T Reg0 , the brake brake torque T EMB , the regenerative brake torque T Reg satisfies the following formula:

[0120] T EMB =T EMB0 =0

[0121] T Reg =T Reg0

[0122] If T Reg * ≤T Reg0 , the brake brake torque T EMB , the regenerative brake torque T Reg satisfies the following formula:

[0123] TReg = T Reg *

[0124] T EMB = T db - T Reg *

[0125] (3) If in the medium-high intensity braking condition, the battery state of charge SOC satisfies SOC≤85%, the brake torque T EMB , the regenerative braking torque T Reg satisfy the following formula:

[0126] T EMB = T EMB0 = 0

[0127] T Reg = T Reg0

[0128] (4) If in the medium-high intensity braking condition, the battery state of charge SOC satisfies SOC>85%, the electric energy output by the motor is directly supplied to the EMB motor, and the braking torque generated by the motor is T REMB ,

[0129] If T REMB > T EMB0 , the brake torque T EMB , the regenerative braking torque T Reg satisfy the following formula:

[0130] T Reg = T Reg0

[0131] T REMB = T EMB0

[0132] That is, if the electric energy output by the motor exceeds the needs of the EMB system, the excess part is transferred to the battery;

[0133] If T REMB ≤ T EMB0 , the brake torque T EMB , the regenerative braking torque T Reg satisfy the following formula:

[0134] T Reg = T Reg0

[0135] T EMB = T REMB + T BEMB

[0136] Wherein, T BEMBBraking torque generated when the battery supplies energy to the EMB motor;

[0137] T BEMB = T EMB -T REMB .

[0138] The application has been described above by way of example with reference to the accompanying drawings without limitation to the described embodiments. Any modifications of the described embodiments that employ the inventive concept and the technical solution of the application, or direct application of the inventive concept and the technical solution of the application to other occasions without modification, all fall within the scope of the application.

Claims

1. A composite brake antilock control system characterized by comprising: The application relates to an electronic mechanical brake system, which comprises the following parts: a sensor unit, which comprises a wheel speed sensor for measuring wheel speed, a vehicle speed sensor for measuring vehicle speed, an acceleration sensor for measuring braking deceleration, a torque sensor for measuring braking disc braking friction torque and motor output torque, a current sensor for measuring current at both ends of a motor, and an SOC sensor for measuring battery state of charge; a wheel slip ratio deviation calculation unit for calculating wheel slip ratio deviation and slip ratio deviation change rate according to wheel speed and vehicle speed measured by the sensor unit; an electronic mechanical brake ideal braking torque calculation unit for calculating ideal brake braking torque according to braking deceleration measured by the sensor unit; a motor controller assembly, which is connected with four motors, each of which is connected with a corresponding electronic mechanical brake; the motor controller assembly controls the motors to form actual regenerative braking torque and controls the electronic mechanical brakes to form actual brake braking torque; an anti-lock braking system assembly, which comprises a fuzzy PID controller, a composite braking system and a torque distribution unit; slip ratio deviation and slip ratio deviation change rate are input into the fuzzy PID controller; the fuzzy PID controller outputs ideal regenerative braking torque to the composite braking system based on fuzzy adaptive setting PID control principle; ideal brake braking torque is input into the composite braking system; the torque distribution unit distributes anti-lock braking torque to the composite braking system based on a comprehensive braking control strategy, and the torque distribution unit controls the motor controller assembly to be dynamically adjusted through electric signals; the comprehensive braking control strategy comprises the following steps: (1) If in the low-intensity braking condition, the battery state of charge SOC satisfies SOC≤85%, the brake torque T EMB , the regenerative brake torque T Reg , the ideal brake torque T EMB0 , and the ideal regenerative brake torque T Reg0 satisfy the following formula: T EMB =T EMB0 =0 T Reg =T Reg0 (2) If in the low-intensity braking working condition, the battery state of charge SOC satisfies SOC > 85%, the motor controller assembly obtains the target charging current and the motor target braking torque T according to the current SOC value and the motor current Reg * , If T Reg * T Reg0 , the brake torque T EMB , the regenerative brake torque T Reg satisfies the following equation: T EMB =T EMB0 =0 T Reg =T Reg0 If T Reg * ≤ T Reg0 , then the brake torque T EMB , the regenerative brake torque T Reg , and the demand brake torque T db satisfy the following equation: T Reg =T Reg * T EMB =T db -T Reg * (3) If the battery state of charge (SOC) satisfies SOC≤85% under medium-to-high-intensity braking conditions, the braking torque T EMB , regenerative braking torque T Reg Satisfy the following formula: T EMB =T EMB0 T Reg =T Reg0 (4) If under the medium-high intensity braking condition, the battery state of charge SOC satisfies SOC>85%, the electric energy output by the motor is directly supplied to the EMB motor, so that the braking torque generated by the EMB motor is T REMB , If T REMB > T EMB0 , the brake torque T EMB , the regenerative brake torque T Reg satisfies the following equation: T Reg =T Reg0 T EMB =T EMB0 if the electric energy generated by the motor exceeds the requirement of the EMB system, the excess part is transferred to the battery; If T REMB ≤ T EMB0 , then the brake torque T EMB , the regenerative brake torque T Reg satisfies the following equation: T Reg =T Reg0 T EMB =T REMB +T BEMB where T BEMB is the braking torque generated by the battery when it is supplying energy to the EMB motor. T BEMB =T EMB -T REMB .

2. A composite brake antilock control system according to claim 1, characterized in that: the sensor unit is connected with the wheel slip ratio deviation calculation unit, the electronic mechanical brake ideal braking torque calculation unit and the anti-lock braking system assembly; the wheel slip ratio deviation calculation unit and the electronic mechanical brake ideal braking torque calculation unit are connected with the anti-lock braking system assembly; and the anti-lock braking system assembly is connected with the motor controller assembly.

3. The combined brake and antilock control system according to claim 1, wherein: Each of the electronic mechanical brakes comprises a brake disc, a brake friction plate, a caliper shell, a speed reduction mechanism, a pressure plate and a high-voltage brake motor; the electronic mechanical brake is connected with the motor through current input / output at both ends of the high-voltage brake motor.

4. The combined brake and antilock control system of claim 1 wherein: The algorithm design of the anti-lock braking system assembly comprises the following steps: S1, fuzzy PID controller design based on slip ratio control: (1) fuzzy quantization: the obtained slip ratio error and slip ratio error change rate are taken as fuzzy control input quantities, and membership function fuzzy quantization is utilized to obtain corresponding fuzzy input quantities; the fuzzy language values of the slip ratio error e and the slip ratio error change rate ec are {NB, NM, NS, ZO, PS, PM, PB}, wherein NB represents negative big, NM represents negative medium, NS represents negative small, ZO represents zero, PS represents positive small, PM represents negative medium, and PB represents positive big; the membership functions of the slip ratio error e and the slip ratio error change rate ec are both TRIMF functions. Design fuzzy domain and membership function, set the fuzzy input quantity of slip rate error e is E, set the fuzzy input quantity of slip rate error change rate ec is EC; (2) Fuzzy reasoning: according to the fuzzy control rule, the fuzzy input quantity obtained in (1) is subjected to fuzzy reasoning to obtain the corresponding fuzzy output quantity; A fuzzy rule table is designed based on the fuzzy input E of the slip ratio error e and the fuzzy input EC of the slip ratio error change rate ec, and the fuzzy output obtained is ΔK p , ΔK i , ΔK d ; (3) Fuzzy decision: the fuzzy output quantity in (2) is subjected to fuzzy decision, and the decision result is input into the PID controller to adjust the actual parameters of the PID controller; fuzzy control output ΔK p , ΔK i , ΔK d The fuzzy language values of ΔK p , ΔK i , ΔK d The membership functions of ΔK Design fuzzy domain and membership function; The actual parameters of the PID controller are obtained by self-adjusting on the basis of its initial value, that is: K p =K p0 +ΔK p K i =K i0 +ΔK i K d =K d0 +ΔK d where K p0 , K i0 , K d0 are initial parameter values of the PID controller; S2, brake anti-lock torque distribution based on comprehensive brake control strategy: (1) output ideal regenerative braking torque, ideal brake actuator braking torque to composite brake system; (2) torque distribution unit calculates actual regenerative braking torque, actual brake actuator braking torque based on the comprehensive brake control strategy; S3, feedback control based on slip rate deviation: The torque distribution unit outputs the actual regenerative braking torque and the actual brake actuator braking torque to the vehicle model, and then the vehicle model feeds back the real-time slip rate to the wheel slip rate deviation calculation unit and obtains the slip rate deviation by calculation. If the slip rate deviation is not 0, the result is re-input into the PID controller and the braking torque is dynamically adjusted until the slip rate deviation is 0.

5. A compound brake antilock control method, characterized by, Use the composite brake anti-lock control system of any one of claims 1-4, comprising the following steps: S1, signal acquisition: use vehicle speed sensor and wheel speed sensor to obtain vehicle speed signal and wheel speed signal during braking process, and wheel slip rate deviation calculation unit calculates real-time slip rate, slip rate error and slip rate error change rate during braking process after receiving the signal; S2, judge whether to start the brake anti-lock function: (1) if the slip rate error of each wheel is 0, the anti-lock brake system assembly does not participate in work, and the normal braking mode is carried out until the vehicle stops; (2) If the slip ratio error corresponding to each wheel is not 0, the anti-lock braking system assembly participates in the work, the braking deceleration of the electric vehicle is obtained by using an acceleration sensor, the composite braking system receives the signal, calculates the required braking torque in the braking process of the vehicle according to the signal, the slip ratio deviation calculation unit outputs the slip ratio deviation and the slip ratio deviation change rate to the fuzzy PID controller, and the fuzzy PID controller outputs the ideal regenerative braking torque T Reg0 to the composite braking system based on the fuzzy adaptive setting PID control principle, and the ideal brake torque T EMB0 of the electromechanical brake is output to the composite braking system, and then the torque distribution unit distributes the anti-lock braking torque to the composite braking system based on the comprehensive braking control strategy. S3, control the brake actuator to form the brake actuator braking torque and control the regenerative braking system to form the regenerative braking torque, and dynamically adjust the regenerative braking torque with the change of wheel slip rate as reference until the anti-lock system exits.

6. The method of claim 5, wherein: In S2, the comprehensive brake control strategy adopted by the anti-lock brake system assembly includes: (1) If in the low-intensity braking condition, the battery state of charge SOC satisfies SOC≤85%, the brake torque T EMB , the regenerative brake torque T Reg , the ideal brake torque T EMB0 , and the ideal regenerative brake torque T Reg0 satisfy the following formula: T EMB =T EMB0 =0 T Reg =T Reg0 (2) If in the low-intensity braking working condition, the battery state of charge SOC satisfies SOC > 85%, the motor controller assembly obtains the target charging current and the motor target braking torque T according to the current SOC value and the motor current Reg * , If T Reg * T Reg0 , the brake torque T EMB , the regenerative brake torque T Reg satisfies the following equation: T EMB =T EMB0 =0 T Reg =T Reg0 If T Reg * ≤ T Reg0 , then the brake torque T EMB , the regenerative brake torque T Reg , and the demand brake torque T db satisfy the following equation: T Reg =T Reg * T EMB =T db -T Reg * (3) If the battery state of charge (SOC) satisfies SOC≤85% under medium-to-high-intensity braking conditions, the braking torque T EMB , regenerative braking torque T Reg Satisfy the following formula: T EMB =T EMB0 T Reg =T Reg0 (4) If under the medium-high intensity braking condition, the battery state of charge SOC satisfies SOC>85%, the electric energy output by the motor is directly supplied to the EMB motor, so that the braking torque generated by the EMB motor is T REMB , If T REMB > T EMB0 , then the brake torque T EMB , the regenerative brake torque T Reg satisfies the following equation: T Reg =T Reg0 T EMB =T EMB0 That is, if the power motor generates more electric energy than the EMB system needs, the excess part will be transferred to the storage battery; If T REMB ≤ T EMB0 , then the brake torque T EMB , the regenerative brake torque T Reg satisfies the following equation: T Reg =T Reg0 T EMB =T REMB +T BEMB where T BEMB is the braking torque generated by the battery when it is recharging the EMB motor. T BEMB =T EMB -T REMB .

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