Composite system optimization and coordinated control method, device and storage medium

Abstract

The present invention relates to a composite system optimization and coordinated control method, device and storage medium, wherein the method comprises: obtaining the amplitude and change rate of a braking command; obtaining the actual value of a motor regenerative braking torque and the observed value of a hydraulic braking torque and their respective change rates; combining the amplitude and change rate of the braking command to obtain a state coordinate; calculating the distance between the state coordinate and the boundary of an attraction domain of a motor regenerative braking system as a first distance m 1, and the distance between the state coordinates and the boundary of the attraction domain of the hydraulic brake system as the second distance m 2; If at least one of the first distance and the second distance is less than the first threshold distance d 1, the first braking mode is executed; if both the first distance and the second distance are greater than the second threshold distance d 2, the second braking mode is executed. Compared with the prior art, the present invention improves the kinetic energy recovery rate and comfort while ensuring the following of the braking command signal.

Description

Technical Field

[0001] The present invention relates to the technical field of braking force distribution of new energy vehicles, and in particular to a composite system optimization and coordinated control method, device and storage medium. Background Art

[0002] As one of the most important components of a vehicle, the braking system has always been an important direction of vehicle research because it is directly related to the safety of passengers.

[0003] With the development of electric vehicles and self-driving cars driven by electricity, new challenges have been posed to the braking system. Not only are there higher requirements for response speed and braking accuracy, but also new requirements for the energy utilization rate of the braking system. Motor regenerative braking is one of the key technologies for automobile energy conservation and emission reduction. The motor regenerative braking system (RBS) refers to the ability of a moving car to convert part of the mechanical energy of the car into electrical energy and store it through the RBS when it is decelerating or braking, and to convert it into the kinetic energy required for the vehicle to run again. Electric vehicles can recover part of the braking energy through motor regenerative braking to improve energy utilization and thus increase the cruising range. Studies have shown that the energy consumed by vehicles running in urban areas during their braking process usually accounts for 30%-50% of the total energy consumption of the vehicle. Another study showed that the braking energy recovery system can help electric vehicles increase their cruising range by 8%-25%. In addition, due to the fast response speed of the motor regenerative braking system, it can improve the vehicle's energy utilization efficiency while improving the vehicle's braking performance. However, the braking torque that the motor can provide is much smaller than the braking torque that the hydraulic brake system or the electronic hydraulic brake system (EHB) can provide. The braking torque provided by the motor alone cannot meet the braking torque requirements of the vehicle under all braking conditions. Therefore, in order to ensure braking safety, electric vehicles are usually equipped with two braking systems, the motor regenerative braking system and the hydraulic braking system, that is, the composite braking system. The hydraulic braking system not only improves the energy utilization efficiency of the vehicle due to the intervention of the motor regenerative braking system, but also greatly improves the ride comfort and braking safety of the whole vehicle. However, the dynamic response characteristics of the motor regenerative braking system and the hydraulic braking system are inconsistent. The motor regenerative braking system responds quickly, while the hydraulic braking system responds slowly, resulting in a large braking impact (i.e., the derivative of the braking deceleration) of the composite braking system under transition conditions, and the smoothness and comfort of braking are deteriorated.

[0004] The current composite braking system braking torque optimization distribution and coordinated control strategies, superposition and coordination, have different focuses. The superposition focuses on the distribution of braking torque, while the coordination focuses on the coordinated control between sub-brake systems with different dynamic characteristics. Most studies divide the composite braking system braking torque optimization distribution and coordinated control into the upper braking torque distribution layer and the lower coordinated control layer, and design them separately. However, there are few studies that deeply integrate the braking torque distribution and coordinated control, which makes it difficult for the composite braking system to balance the braking accuracy, braking smoothness and braking energy. Summary of the invention

[0005] The purpose of the present invention is to provide a composite system optimization and coordinated control method, device and storage medium.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A composite system optimization and coordinated control method, comprising:

[0008] Acquire a brake pedal signal, and obtain an amplitude and a change rate of a brake command based on the brake pedal signal;

[0009] Obtaining the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque;

[0010] Based on the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque, respectively obtaining the change rates of the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque;

[0011] Based on the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque and its change rate, combined with the amplitude and change rate of the braking command, the state coordinates are obtained;

[0012] Calculate the distance between the state coordinates and the boundary of the attraction domain of the motor regenerative braking system as the first distance μ 1 , and the distance between the state coordinates and the boundary of the attraction domain of the hydraulic brake system as the second distance μ 2 ;

[0013] If at least one of the first distance and the second distance is less than the first threshold distance d 1 , then the first braking mode is executed, wherein the first braking mode is a correction mode of a dual closed-loop hydraulic braking system;

[0014] If both the first distance and the second distance are greater than the second threshold distance d 2 , then execute the second braking mode, wherein the second braking mode is a dual closed-loop motor regenerative braking system correction mode.

[0015] The magnitude and change rate of the braking command are obtained based on a tracking differentiator.

[0016] The observed value of the hydraulic braking torque is obtained based on an extended state observer, and the extended state observer is obtained based on the wheel speed and the first sub-braking command.

[0017] The process of obtaining the observed value of the hydraulic braking torque includes:

[0018] Get the braking mode of the previous braking state;

[0019] Obtaining a first sub-braking instruction based on a braking mode of a previous braking state;

[0020] Based on the extended state observer, an observed value of the hydraulic braking torque is obtained according to the wheel speed and the first sub-braking command.

[0021] The first sub-brake instruction is:

[0022] When the braking mode of the previous braking state is the first braking mode, the first sub-braking command T m,com The value is the reference value of the motor recovery brake system command signal T m,ref ;

[0023] When the braking mode of the previous braking state is the second braking mode, the first sub-braking command T m,com The values ​​are:

[0024] T m,com = T m,ref + T f,ref - T f *

[0025] in: T f,ref is the reference value of the hydraulic brake system command signal, T f * Compensation signal of hydraulic brake system.

[0026] The reference value of the motor recovery braking system command signal and the reference value of the hydraulic braking system command signal are obtained by a first model, wherein the first model is based on the input of the amplitude of the braking command and outputs the reference value of the motor recovery braking system command signal and the reference value of the hydraulic braking system command signal.

[0027] The first model is a hybrid model, and the objective function of the first model is:

[0028]

[0029] Where: J is the objective function, N p For the prediction time domain, T ref ( k + i │ k ) is the braking command k Always k + i Predictions of the moment, T ( k + i │ k ) is the total braking torque k Always k + prediction at time i, Q T is the first weight, Δ T ( k + i │ k ) is the total braking torque change value in k Always k + i Moment prediction, Q ΔT is the second weight, N C To control the time domain, T f,ref ( k + i │ k ) is the reference value of the hydraulic brake system command signal k Always k + i Prediction of the moment, Q Tf is the third weight, ||·|| 2 is the Euclidean distance.

[0030] The control process of the first braking mode includes:

[0031] The motor braking system compensation signal is obtained according to the reference value of the motor recovery braking system command signal T m *;

[0032] Subtract the motor brake system compensation signal from the sum of the reference value of the motor recovery brake system command signal and the reference value of the hydraulic brake system command signal T m *Get the second sub-braking command;

[0033] The second sub-braking instruction is respectively subtracted from the observed value of the pressing torque and the actual value of the motor regenerative braking torque to obtain a control signal acting on the hydraulic brake system.

[0034] The control process of the second braking mode includes:

[0035] The hydraulic brake system compensation signal is obtained according to the reference value of the hydraulic brake system command signal T f *;

[0036] Subtract the hydraulic brake system compensation signal from the sum of the reference value of the motor recovery brake system command signal and the reference value of the hydraulic brake system command signal T f *Get the first sub-brake command;

[0037] A control signal acting on the motor recovery braking system is generated based on the first sub-brake command and the actual value of the motor regenerative braking torque.

[0038] A control device based on brake force distribution of a composite brake system comprises a memory, a processor, and a program stored in the memory. When the processor executes the program, the method as described above is implemented.

[0039] A storage medium stores a program, which implements the above method when executed.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. Based on the actual value of the motor regenerative braking torque and the observed value and change rate of the hydraulic braking torque, the state coordinates are obtained in combination with the amplitude and change rate of the braking command, and the distance from the state coordinates to the boundary of the attraction domain of the two braking systems is used as the basis for selecting the braking mode. When the braking state is relatively stable, the dual closed-loop hydraulic braking system correction mode can be selected to maximize kinetic energy recovery and improve smoothness. Conversely, when it is unstable, the dual closed-loop motor regenerative braking system correction mode can be selected to ensure the braking effect and improve smoothness.

[0042] 2. Determine the first sub-brake command according to the brake mode of the previous brake state, so as to ensure the follow-up accuracy of the brake command signal at the beginning of braking.

[0043] 3. The first model is introduced to obtain the reference value of the motor recovery braking system command signal and the reference value of the hydraulic braking system command signal, thereby achieving braking energy recovery, braking smoothness and braking command signal following accuracy.

[0044] 4. The objective function takes into account braking stability, braking impact and braking energy recovery at the same time, and can achieve the goal of improving braking impact and enhancing braking energy recovery while ensuring braking stability in any braking mode of the compound braking system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic flow chart of the main steps of the method of the present invention;

[0046] Figure 2 It is a schematic diagram of the control principle of the present invention;

[0047] Figure 3 is a schematic diagram of the control principle of the first brake module;

[0048] Figure 4 Schematic diagram of the control principle of the second brake module. DETAILED DESCRIPTION

[0049] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0050] The general title frame of the compound brake system is as follows Figure 2 As shown, it consists of three parts: differential acquisition, optimal allocation and coordinated control.

[0051] Firstly, the controllers of each sub-brake system are designed and the attraction domain of each sub-brake system is estimated. The estimated attraction domain is the control boundary or reachable set of each sub-brake system, which can be used as the basis for the determination of coordinated control. Then, on the basis of obtaining the characteristics of the command signal, the hybrid model predictive control is used to realize the optimal distribution of braking torque and the selection of braking mode by combining the dynamic characteristics of each sub-brake system and the characteristics of the command signal. The present invention proposes a dual-mode dual-closed-loop coordinated control mode of a dual-closed-loop hydraulic brake system correction mode and a dual-closed-loop motor regenerative brake system correction mode. Finally, the coordinated control mode of the hybrid brake system is selected according to the estimated attraction domain and the allocated braking torque, and each sub-brake system is dynamically compensated in combination with its dynamic characteristics to improve the following accuracy of the brake command signal.

[0052] Specifically, the present application provides a composite system optimization and coordinated control method, such as Figure 1 As shown, including:

[0053] (1) obtaining a brake pedal signal, and obtaining an amplitude and a rate of change of a brake command based on the brake pedal signal;

[0054] Similar to the prior art, the brake pedal signal is a brake pedal angle, and the brake pedal angle and the brake command are in a mapping relationship. The specific mapping function is obtained by tuning and matching by the car manufacturer, which is not involved in this application and will not be elaborated therein.

[0055] The timing signal of the brake pedal may show changes. For example, a larger angle means that the driver requires a larger braking torque, and a smaller angle means that the driver wants to reduce the braking torque. There may also be some disturbances. For example, the driver's foot may not step on the brake pedal smoothly. But in any case, the timing signal of the brake pedal can obtain a unique timing signal of the braking command, and then the change rate can be obtained based on the timing signal of the braking command.

[0056] In this embodiment, in order to avoid the problem of large error caused by the presence of noise when directly deriving the braking command signal, a tracking differentiator is used to obtain the rate of change of the braking command signal. The tracking differentiator can well solve the noise problem caused by the differential operation. The braking command signal can simultaneously output the amplitude and rate of change of the braking command signal through the tracking differentiator.

[0057] (ii) obtaining the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque;

[0058] The motor regenerative braking torque can generally be directly obtained by relevant sensors, so the actual value of the motor regenerative braking torque is used. However, the hydraulic braking torque is difficult to measure directly. Therefore, in this application, the output torque of the hydraulic braking system is regarded as an interference term of the motor regenerative braking system and an extended state observer is designed. The observed value of the hydraulic braking torque is obtained based on the extended state observer, and the extended state observer is obtained based on the wheel speed and the first sub-braking instruction.

[0059] The process of obtaining the observed value of the hydraulic braking torque includes:

[0060] Get the braking mode of the previous braking state;

[0061] Obtaining a first sub-braking instruction based on a braking mode of a previous braking state;

[0062] Based on the extended state observer, an observed value of the hydraulic braking torque is obtained according to the wheel speed and the first sub-braking command.

[0063] The amplitude saturation control of the motor regenerative braking system, the estimation of the attraction domain of the motor regenerative braking system and the extended state observer are designed together. In the compound braking system, the output braking torque of the motor regenerative braking system can be obtained more conveniently, while the output braking torque of the hydraulic braking system is more difficult to obtain. For this reason, similar to the prior art, the output torque of the hydraulic braking system is regarded as the interference term of the motor regenerative braking system and estimated by designing an extended state observer to realize the estimation of the output braking torque of the hydraulic braking system. First, a self-anti-disturbance control integrating anti-windup (anti-saturation) is designed for the motor regenerative braking system as an amplitude saturation controller. On this basis, an anti-windup compensator based on the difference between the signals before and after the amplitude saturation module is designed, and it is introduced into the extended state observer, and an extended state observer based on saturation control is designed. Finally, the gain of the anti-windup is calculated by the optimization algorithm, and the attraction domain of the closed-loop system with maximized gain is obtained, so as to realize the estimation of the attraction domain of the motor regenerative braking system. Since the observation value of the hydraulic braking torque obtained by using the extended state observer has been adopted in some prior arts, this application will not be repeated.

[0064] In addition, specifically, in this embodiment, the first sub-braking instruction is:

[0065] When the braking mode of the previous braking state is the first braking mode, the first sub-braking command T m,com The value is the reference value of the motor recovery brake system command signal T m,ref ;

[0066] When the braking mode of the previous braking state is the second braking mode, the first sub-braking command T m,com The values ​​are:

[0067] T m,com = T m,ref + T f,ref - T f *

[0068] in: T f,ref is the reference value of the hydraulic brake system command signal, T f * Compensation signal of hydraulic brake system.

[0069] (iii) based on the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque, respectively obtaining the change rates of the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque;

[0070] In this embodiment, similarly, in order to avoid the problem of large errors in direct derivation, a tracking differentiator may be used to obtain the rate of change.

[0071] (iv) obtaining the state coordinates based on the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque and its rate of change, combined with the amplitude and rate of change of the braking command;

[0072] Specifically, this step needs to obtain the relevant state coordinates in the coordinate system of the attraction domain. Generally, a two-dimensional coordinate system is used. For this, first, the following error of the command signal can be used as the horizontal coordinate, and the vertical coordinate is obtained by the following errors of two change rates. Generally, the square root of the sum of the squares of the actual value change rate of the motor regenerative braking torque and the change rate of the observed value of the hydraulic braking torque can be used as the vertical coordinate. In this way, the state coordinates can be obtained.

[0073] The following error of the command signal is specifically T f + T m - T ref .

[0074] (V) Calculate the distance between the state coordinates and the boundary of the attraction domain of the motor regenerative braking system as the first distance μ 1 , and the distance between the state coordinates and the boundary of the attraction domain of the hydraulic brake system as the second distance μ 2 ;

[0075] μ =( μ 1 , μ 2}, μ ≤ d 1 , indicating that at least one of the first distance and the second distance is less than the first threshold distance d 1 , μ ≥ d 2 , indicating that both the first distance and the second distance are greater than the second threshold distance d 2 In addition, this application does not restrict other situations and can be determined based on actual conditions.

[0076] If at least one of the first distance and the second distance is less than the first threshold distance d 1 , then the first braking mode is executed, wherein the first braking mode is a correction mode of the dual closed-loop hydraulic braking system;

[0077] like Figure 3 As shown, the control process of the first braking mode includes:

[0078] The motor braking system compensation signal is obtained according to the reference value of the motor recovery braking system command signal T m *;

[0079] Subtract the motor brake system compensation signal from the sum of the reference value of the motor recovery brake system command signal and the reference value of the hydraulic brake system command signal T m *Get the second sub-brake command;

[0080] The second sub-braking instruction is respectively subtracted from the observed value of the pressing torque and the actual value of the motor regenerative braking torque to obtain a control signal acting on the hydraulic brake system.

[0081] In the first braking mode, the hydraulic brake system directly tracks the total braking torque demand, i.e. the brake command signal, and recovers the reference value of the brake system command signal from the motor. T m,ref The following prediction error (i.e. T m,ref - T m *) to compensate, that is, the second sub-brake command corresponding to the hydraulic brake system T f,com for T f,com = T f,ref + T m,ref - T m *), by compensating the following error of the motor brake system to its command signal through the dynamic coordination compensation module, the tracking effect of the large closed-loop system composed of the hydraulic brake system on the total braking torque demand can be accelerated. The motor regenerative braking system only performs closed-loop following control on its braking command signal, that is, T m,com = T m,ref The main purpose of the first braking mode is to enhance braking energy recovery and make the motor regenerative braking system work in the high-efficiency area of ​​braking energy recovery. The insufficient braking torque is supplemented by the hydraulic braking system, and the hydraulic braking system is responsible for the closed-loop following of the total braking torque demand.

[0082] If both the first distance and the second distance are greater than the second threshold distance d 2 , then the second braking mode is executed, wherein the second braking mode is a correction mode of the dual closed-loop motor regenerative braking system.

[0083] like Figure 4 As shown, the control process of the second braking mode includes:

[0084] The hydraulic brake system compensation signal is obtained according to the reference value of the hydraulic brake system command signal T f *;

[0085] Subtract the hydraulic brake system compensation signal from the sum of the reference value of the motor recovery brake system command signal and the reference value of the hydraulic brake system command signal T f *Get the first sub-brake command;

[0086] A control signal acting on the motor recovery braking system is generated based on the first sub-brake command and the actual value of the motor regenerative braking torque.

[0087] In the second braking mode, the motor regenerative braking system directly tracks the total braking torque demand and the reference value of the hydraulic braking system command signal T f,ref The following prediction error (i.e. T f,ref - T f *) to compensate, that is, the first sub-braking instruction corresponding to the motor regenerative braking system T m,com for T m,com = T m,ref + T f,ref - T f *), by compensating the following error of the hydraulic brake system to its command signal through the dynamic coordination compensation module, it can speed up the tracking effect of the large closed-loop system composed of the motor regenerative braking system on the total braking torque demand. The hydraulic brake system mainly realizes the closed-loop following control of its brake command signal, that is, T f,com = T f,ref The main purpose of the second braking mode is to ensure the braking stability of the braking system. When the composite braking system is on the verge of instability, the motor regenerative braking system with a faster response speed is responsible for tracking the total braking torque demand. In addition, the tracking differentiator used in the method for obtaining the dynamic characteristics of the total output torque of the composite braking system is the same as the aforementioned tracking differentiator, which will not be repeated here. The rules responsible for switching are described in the braking torque optimization allocation section of this application.

[0088] In addition, the hydraulic brake system in the compound brake system is mainly manifested as the problem of rate saturation, and its rate saturation value can be obtained by sweeping frequency testing the hydraulic brake system, and this application assumes that it is known. Relative to the total braking torque size requirement, the hydraulic brake system can meet the braking torque size requirement under any braking condition, that is, there is no problem of actuator amplitude constraint. When there is no amplitude constraint, relevant studies have shown that the control system design with actuator rate saturation can be converted into a control system design with amplitude saturation. The control design of the hydraulic brake system with rate saturation is converted into a control system design with amplitude saturation, and then the saturation controller is designed using the Lyapunov method with parameters and the LMI tool is used to solve the optimization problem of the system attraction domain estimation to obtain the maximum attraction domain under the corresponding rate saturation control.

[0089] In addition, in this embodiment, the reference value of the motor recovery braking system command signal and the reference value of the hydraulic braking system command signal are obtained by a first model, wherein the first model is based on the input of the amplitude of the braking command and the output is the reference value of the motor recovery braking system command signal and the reference value of the hydraulic braking system command signal.

[0090] The first model is a hybrid model, and the objective function of the first model is:

[0091] ,

[0092] Where: J is the objective function, N p For the prediction time domain, T ref ( k + i │ k ) is the braking command k Always k + i Predictions of the moment, T ( k + i │ k ) is the total braking torque k Always k + prediction at time i, Q T is the first weight, Δ T ( k + i │ k ) is the total braking torque change value in k Always k + i Prediction of the moment, Q ΔT is the second weight, N C To control the time domain, T f,ref ( k +i │ k ) is the reference value of the hydraulic brake system command signal k Always k + i Prediction of the moment, Q Tf is the third weight, ||·|| 2 is the Euclidean distance.

[0093] The constraints corresponding to the objective function of the first model include the dynamic response equation of the hydraulic braking system, the dynamic response equation of the motor regenerative braking system, and the quarter vehicle dynamics equation. The first-order delayed inertia of the dynamic response equation can be approximated by the first-order inertia link. In addition, the remaining inequality constraints include:

[0094] ,

[0095] Where: Δ T f,ref ( k ) is the reference value of the change rate of the hydraulic brake system command signal, Δ T max,f ( k ) is the rate saturation value of the hydraulic brake system, T m,ref ( k ) is the reference value of the motor recovery brake system command signal, T max,m ( k ) is the amplitude saturation value of the motor regenerative braking system.

[0096] The above expression represents that the planning value must be within the capabilities of each sub-braking system. The cost function predicted by the first model takes into account braking stability, braking impact and braking energy recovery at the same time, which can achieve the goal of improving braking impact and improving braking energy recovery under the premise of ensuring braking stability in any braking mode of the composite braking system.

[0097] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

Claims

1. A composite system optimization and coordinated control method, applied to braking force distribution, characterized in that: include: Acquire a brake pedal signal, and obtain an amplitude and a change rate of a brake command based on the brake pedal signal; Obtaining the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque; Based on the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque, respectively obtaining the change rates of the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque; Based on the actual value of the motor regenerative braking torque and the observed value of the hydraulic braking torque and its change rate, combined with the amplitude and change rate of the braking command, the state coordinates are obtained; Calculate the distance between the state coordinates and the boundary of the attraction domain of the motor regenerative braking system as the first distance μ 1, and the distance between the state coordinates and the boundary of the attraction domain of the hydraulic brake system as the second distance μ 2; If at least one of the first distance and the second distance is less than the first threshold distance d 1, then execute the first braking mode, wherein the first braking mode is a double closed-loop hydraulic brake system correction mode; If both the first distance and the second distance are greater than the second threshold distance d 2, then execute the second braking mode, wherein the second braking mode is a dual closed-loop motor regenerative braking system correction mode.

2. A composite system optimization and coordinated control method according to claim 1, characterized in that: The magnitude and change rate of the braking command are obtained based on a tracking differentiator.

3. A composite system optimization and coordinated control method according to claim 1, characterized in that: The observed value of the hydraulic braking torque is obtained based on an extended state observer, and the extended state observer is obtained based on a wheel speed and a first sub-braking command.

4. A composite system optimization and coordinated control method according to claim 3, characterized in that: The process of obtaining the observed value of the hydraulic braking torque includes: Get the braking mode of the previous braking state; Obtaining a first sub-braking instruction based on a braking mode of a previous braking state; Based on the extended state observer, an observed value of the hydraulic braking torque is obtained according to the wheel speed and the first sub-braking command.

5. A composite system optimization and coordinated control method according to claim 3, characterized in that: The first sub-brake instruction is: When the braking mode of the previous braking state is the first braking mode, the first sub-braking command T m,com The value is the reference value of the motor recovery brake system command signal T m,ref ; When the braking mode of the previous braking state is the second braking mode, the first sub-braking command T m,com The values ​​are: T m,com = T m,ref + T f,ref - T f * in: T f,ref is the reference value of the hydraulic brake system command signal, T f * Compensation signal of hydraulic brake system.

6. A composite system optimization and coordinated control method according to claim 5, characterized in that: The reference value of the motor recovery braking system command signal and the reference value of the hydraulic braking system command signal are obtained by a first model, wherein the first model is based on the input of the amplitude of the braking command and outputs the reference value of the motor recovery braking system command signal and the reference value of the hydraulic braking system command signal.

7. A composite system optimization and coordinated control method according to claim 6, characterized in that: The first model is a hybrid model, and the objective function of the first model is: , Where: J is the objective function, N p For the prediction time domain, T ref ( k + i │ k ) is the braking command k Always k + i Predictions of the moment, T ( k + i │ k ) is the total braking torque k Always k + prediction at time i, Q T is the first weight, Δ T ( k + i │ k ) is the total braking torque change value in k Always k + i Moment prediction, Q ΔT is the second weight, N C To control the time domain, T f,ref ( k + i │ k ) is the reference value of the hydraulic brake system command signal k Always k + i Moment prediction, Q Tf is the third weight, ||·|| 2 is the Euclidean distance.

8. A composite system optimization and coordinated control method according to claim 5, characterized in that: The control process of the first braking mode includes: The motor braking system compensation signal is obtained according to the reference value of the motor recovery braking system command signal T m *; Subtract the motor brake system compensation signal from the sum of the reference value of the motor recovery brake system command signal and the reference value of the hydraulic brake system command signal T m *Get the second sub-brake command; The second sub-braking instruction is respectively subtracted from the observed value of the pressing torque and the actual value of the motor regenerative braking torque to obtain a control signal acting on the hydraulic brake system.

9. A composite system optimization and coordinated control method according to claim 5, characterized in that: The control process of the second braking mode includes: The hydraulic brake system compensation signal is obtained according to the reference value of the hydraulic brake system command signal T f *; Subtract the hydraulic brake system compensation signal from the sum of the reference value of the motor recovery brake system command signal and the reference value of the hydraulic brake system command signal T f *Get the first sub-brake command; A control signal acting on the motor recovery braking system is generated based on the first sub-brake command and the actual value of the motor regenerative braking torque.

10. A composite system optimization and coordination control device, comprising a memory, a processor, and a program stored in the memory, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 9 is implemented.

11. A storage medium having a program stored thereon, characterized in that: When the program is executed, the method according to any one of claims 1 to 9 is implemented.

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