Braking torque estimation method, device, equipment, storage medium and program product

Abstract

The invention relates to the technical field of EMB systems, in particular to a braking torque estimation method, device and equipment, a storage medium and a program product.The method comprises the steps that the current disc temperature of a brake disc is obtained, and a current reference friction coefficient temperature vector is obtained according to the current disc temperature; a wheel end reference friction coefficient disturbance vector generated during last braking is obtained, and a friction plate estimated friction coefficient is obtained according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during last braking; and estimating the braking torque according to the estimated friction coefficient of the friction plate. Therefore, the friction coefficient is estimated by dynamically correcting the friction coefficient disturbance vector through the preset model and the filtering threshold value, the problems of inaccurate braking torque estimation, reference load data interference in the braking process, feedback control delay and the like are solved, the braking performance of an EMB system is remarkably improved, and the stability of a vehicle in the running process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of EMB systems, and in particular to a braking torque estimation method, device, equipment, storage medium and program product. Background Art

[0002] like Figure 1 As shown, Figure 1 The schematic diagram of the structure of the EMB system is shown in Figure 2. The EMB (Electro-mechanical Brake System) electronic mechanical brake system usually includes a brake pedal, a pedal force simulator, an EMB main controller, an EMB slave controller, a wheel-end EMB controller, an EMB caliper, a brake disc, etc. Among them, the EMB controller is the upper controller of the four wheel-end EMB controllers, and is connected to the wheel-end EMB controllers through the vehicle network. When the driver steps on the brake pedal, the EMB controller analyzes the pedal travel information, sends a clamping force request to the wheel-end EMB controller, and each wheel-end controller controls the EMB caliper to perform braking.

[0003] In the related art, most of the braking force estimation methods rely on feedback signals such as motor rotation angle to estimate the caliper clamping force.

[0004] However, the methods in the related art cannot accurately identify the mismatch between clamping force and torque caused by overheating of the braking system, which may cause problems such as control delays, affecting the vehicle's braking performance and passenger comfort, and needs to be solved urgently. Summary of the invention

[0005] The present application provides a braking torque estimation method, device, equipment, storage medium and program product to solve the problems of inaccurate braking torque estimation, reference load data interference during braking, feedback control delay, etc., significantly improving the braking performance of the EMB system and improving the stability of the vehicle during driving.

[0006] The first aspect of the present application provides a braking torque estimation method, comprising the following steps:

[0007] Acquire the current disc temperature of the brake disc, and obtain the current reference friction coefficient temperature vector according to the current disc temperature;

[0008] Obtaining a wheel end reference friction coefficient disturbance vector generated during the last braking, and obtaining an estimated friction coefficient of the friction plate according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking;

[0009] The braking torque is estimated based on the estimated friction coefficient of the friction plate.

[0010] Optionally, the acquiring the current disc temperature of the brake disc and obtaining the current reference friction coefficient temperature vector according to the current disc temperature includes:

[0011] Acquire a plurality of disc temperature estimation parameters of the brake disc and a disc temperature and friction coefficient relationship table;

[0012] Inputting the plurality of disc temperature estimation parameters into a preset brake disc temperature model to obtain the current disc temperature;

[0013] Based on the disk temperature and friction coefficient relationship table, the current reference friction coefficient temperature vector is obtained according to the current disk temperature.

[0014] Optionally, after estimating the braking torque according to the estimated friction coefficient of the friction plate, the method further includes:

[0015] Obtain the reference vehicle load, as well as the vehicle's X-direction deceleration, Y-direction acceleration, active direction angle, and passive direction angle during braking;

[0016] Based on the X-direction deceleration, the Y-direction acceleration, the active direction angle and the passive direction angle, and in combination with the reference vehicle load, a preset vehicle dynamics model is used to calculate a reference friction coefficient of each wheel end;

[0017] Calculating a reference friction coefficient disturbance vector of each wheel end according to the reference friction coefficient of each wheel end, and calculating a credible whole vehicle friction coefficient disturbance vector according to the reference friction coefficient disturbance vector of each wheel end;

[0018] If the absolute value of the credible vehicle friction coefficient disturbance vector is greater than the first filtering threshold, the current disk temperature is corrected based on the revised calibration value corresponding to the credible vehicle friction coefficient disturbance vector, and the credible vehicle friction coefficient disturbance vector is updated until the updated credible vehicle friction coefficient disturbance vector is less than the first filtering threshold.

[0019] Optionally, after calculating the credible vehicle friction coefficient disturbance vector according to the reference friction coefficient disturbance vector of each wheel end, the method further includes:

[0020] Calculating the difference between the reference friction coefficient of each wheel end and the estimated friction coefficient to obtain the estimated error of each wheel end;

[0021] Based on the wheel end estimation errors, the wheel end reference friction coefficient disturbance vector of the target wheel end whose wheel end estimation error is greater than the second filtering threshold is corrected.

[0022] Optionally, obtaining a reference vehicle load includes:

[0023] Get the current wheel speed, current motor acceleration, current motor speed and current motor torque;

[0024] Calculating the vehicle acceleration according to the current wheel speed, the current motor acceleration and the current motor speed;

[0025] The whole vehicle acceleration and the current motor torque are input into a preset vehicle load estimation model to obtain the reference vehicle load.

[0026] A second aspect of the present application provides a braking torque estimation device, comprising:

[0027] A first acquisition module, used for acquiring a current disc temperature of the brake disc, and obtaining a current reference friction coefficient temperature vector according to the current disc temperature;

[0028] a second acquisition module, configured to acquire a wheel end reference friction coefficient disturbance vector generated during the last braking, and obtain an estimated friction coefficient of the friction plate according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking;

[0029] A calculation module is used to estimate the braking torque according to the estimated friction coefficient of the friction plate.

[0030] Optionally, the first acquisition module is specifically configured to:

[0031] Acquire a plurality of disc temperature estimation parameters of the brake disc and a disc temperature and friction coefficient relationship table;

[0032] Inputting the plurality of disc temperature estimation parameters into a preset brake disc temperature model to obtain the current disc temperature;

[0033] Based on the disk temperature and friction coefficient relationship table, the current reference friction coefficient temperature vector is obtained according to the current disk temperature.

[0034] Optionally, the computing module is further used for:

[0035] Obtain the reference vehicle load, as well as the vehicle's X-direction deceleration, Y-direction acceleration, active direction angle, and passive direction angle during braking;

[0036] Based on the X-direction deceleration, the Y-direction acceleration, the active direction angle and the passive direction angle, and in combination with the reference vehicle load, a preset vehicle dynamics model is used to calculate a reference friction coefficient of each wheel end;

[0037] Calculating a reference friction coefficient disturbance vector of each wheel end according to the reference friction coefficient of each wheel end, and calculating a credible whole vehicle friction coefficient disturbance vector according to the reference friction coefficient disturbance vector of each wheel end;

[0038] If the absolute value of the credible vehicle friction coefficient disturbance vector is greater than the first filtering threshold, the current disk temperature is corrected based on the revised calibration value corresponding to the credible vehicle friction coefficient disturbance vector, and the credible vehicle friction coefficient disturbance vector is updated until the updated credible vehicle friction coefficient disturbance vector is less than the first filtering threshold.

[0039] Optionally, the second acquisition module is further used to:

[0040] Calculating the difference between the reference friction coefficient of each wheel end and the estimated friction coefficient to obtain the estimated error of each wheel end;

[0041] Based on the wheel end estimation errors, the wheel end reference friction coefficient disturbance vector of the target wheel end whose wheel end estimation error is greater than the second filtering threshold is corrected.

[0042] Optionally, obtaining a reference vehicle load includes:

[0043] Get the current wheel speed, current motor acceleration, current motor speed and current motor torque;

[0044] Calculating the vehicle acceleration according to the current wheel speed, the current motor acceleration and the current motor speed;

[0045] The whole vehicle acceleration and the current motor torque are input into a preset vehicle load estimation model to obtain the reference vehicle load.

[0046] The third aspect of the present application provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are configured to execute the braking torque estimation method as described in the above embodiment.

[0047] The fourth aspect of the present application provides a computer-readable storage medium on which a computer program is stored. The program is executed by a processor to implement the braking torque estimation method as described in the above embodiment.

[0048] A fifth aspect of the present application provides a computer program product, which stores a computer program that, when executed by a processor, implements the braking torque estimation method as described in the above embodiment.

[0049] Therefore, after obtaining the current disc temperature of the brake disc and obtaining the current reference friction coefficient temperature vector according to the current disc temperature, the wheel end reference friction coefficient disturbance vector generated during the last braking is obtained, and the friction plate estimated friction coefficient is obtained according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking, and then the braking torque is estimated according to the friction plate estimated friction coefficient. Therefore, the friction coefficient disturbance vector is dynamically corrected by the preset model and the filtering threshold to estimate the friction coefficient, which solves the problems of inaccurate braking torque estimation, reference load data interference during braking, feedback control delay, etc., significantly improves the braking performance of the EMB system, and improves the stability of the vehicle during driving.

[0050] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0052] Figure 1 It is the structural diagram of EMB system;

[0053] Figure 2 A flowchart of a braking torque estimation method provided according to an embodiment of the present application;

[0054] Figure 3 A schematic diagram of determining a reference load in a braking torque estimation method provided according to an embodiment of the present application;

[0055] Figure 4 A flowchart of determining a reference load in a braking torque estimation method provided according to an embodiment of the present application;

[0056] Figure 5 A schematic diagram of a braking torque estimation system of a braking torque estimation method provided according to an embodiment of the present application;

[0057] Figure 6 A flowchart of a braking torque estimation system of a braking torque estimation method provided according to an embodiment of the present application;

[0058] Figure 7 A schematic diagram of a braking torque estimation device provided according to an embodiment of the present application;

[0059] Figure 8 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0060] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0061] Before introducing the braking torque estimation method of the embodiment of the present application, the braking torque estimation method in the related art is briefly introduced.

[0062] Specifically, a braking force estimation method, device, storage medium and vehicle are disclosed in the related art. The braking force estimation method includes: obtaining parameter information of the brake motor of the vehicle; obtaining the current feedback force of the brake pad according to the parameter information and the preset feedback force estimation model of the brake pad of the vehicle; and obtaining the current braking force of the vehicle according to the current feedback force. The technical solution disclosed in the present invention is low-cost compared with the prior art, and will not be affected by the working environment of the electronic brake system. The current braking force of the vehicle can be accurately estimated, so that the vehicle can be accurately braked and controlled.

[0063] However, this technology estimates the current caliper clamping force through feedback signals such as the EMB motor angle, rather than calculating the braking torque, and cannot identify the phenomenon of mismatch between clamping force and torque caused by factors such as overheating of the brake system. Therefore, when clamping for the first time, this type of control algorithm cannot adjust the clamping force in advance based on the actual vehicle state, but relies on feedback control to adjust the vehicle body state. This will inevitably lead to control delays, reduced passenger comfort and safety hazards.

[0064] Based on the above problems, this application proposes a braking torque estimation method, in which the current disc temperature of the brake disc is obtained, and the current reference friction coefficient temperature vector is obtained according to the current disc temperature; the wheel end reference friction coefficient disturbance vector generated during the last braking is obtained, and the friction plate estimated friction coefficient is obtained according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking; the braking torque is estimated according to the friction plate estimated friction coefficient. Therefore, the friction coefficient disturbance vector is dynamically corrected by a preset model and a filtering threshold to estimate the friction coefficient, which solves the problems of inaccurate braking torque estimation, reference load data interference during braking, feedback control delay, etc., significantly improves the braking performance of the EMB system, and improves the stability of the vehicle during driving.

[0065] Specifically, Figure 2 A schematic flow chart of a braking torque estimation method provided in an embodiment of the present application.

[0066] like Figure 2 As shown, the braking torque estimation method includes the following steps:

[0067] In step S201, the current disc temperature of the brake disc is acquired, and the current reference friction coefficient temperature vector is obtained according to the current disc temperature.

[0068] Optionally, in some embodiments, the current disc temperature of the brake disc is obtained, and a current reference friction coefficient temperature vector is obtained based on the current disc temperature, including: obtaining multiple disc temperature estimation parameters of the brake disc and a disc temperature and friction coefficient relationship table; inputting the multiple disc temperature estimation parameters into a preset brake disc temperature model to obtain the current disc temperature; and obtaining the current reference friction coefficient temperature vector based on the current disc temperature based on the disc temperature and friction coefficient relationship table.

[0069] Among them, the current disc temperature of the brake disc refers to the actual temperature of the brake disc; the current reference friction coefficient temperature vector (μtmp) refers to the friction coefficient temperature vector found from the preset brake disc temperature model and friction coefficient relationship table based on the current disc temperature of the brake disc.

[0070] It can be understood that the embodiments of the present application can optimize the control strategy of the braking system by acquiring the brake disc temperature and friction coefficient in real time, thereby improving the braking performance and safety; for example, overheating of the brake disc may cause the brake pad to stop working due to brake attenuation, or even cause brake failure, which requires timely adjustment; by monitoring the brake disc temperature and friction coefficient, potential brake failure risks can be discovered in time and corresponding preventive measures can be taken; reasonable braking control strategies can reduce the wear and heat accumulation of the brake disc, thereby extending its service life; by real-time monitoring and adjustment of braking parameters, it can ensure that the brake disc operates in the best working state, reducing unnecessary wear and damage.

[0071] In step S202, the wheel end reference friction coefficient disturbance vector generated during the last braking is obtained, and the friction plate estimated friction coefficient is obtained according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking.

[0072] Among them, the wheel-end reference friction coefficient disturbance vector (μk(t-1x)) is used to dynamically correct and optimize the estimation of the braking torque, reflecting the difference between the current estimated friction coefficient and the actual friction coefficient, helping to adjust the braking torque more accurately.

[0073] Specifically, by obtaining the estimated friction coefficient (μt) through vector addition, the vehicle control system can more accurately judge key parameters such as braking distance, braking time and braking force, which helps the vehicle to achieve more stable and faster braking in a short time and improve braking performance; the accurate estimated friction coefficient helps the vehicle avoid dangerous situations such as skidding and loss of control during emergency braking; by analyzing the difference between the estimated friction coefficient and the actual friction coefficient, the braking system can be further optimized and improved to reduce the failure rate.

[0074] In step S203 , the braking torque is estimated according to the estimated friction coefficient of the friction plate.

[0075] Among them, braking torque refers to the torque applied to the wheels by the braking system during braking, which determines the deceleration effect of the vehicle. The size of the braking torque directly affects the braking distance and stability of the vehicle.

[0076] Specifically, according to the current disc temperature of the brake disc, the current reference friction coefficient temperature vector is obtained by looking up the table, the wheel end reference friction coefficient disturbance vector generated during the last braking is read from the non-volatile memory, the estimated friction coefficient of the friction plate is calculated, the clamping force is obtained through sensor measurement or model estimation, and after the friction force is calculated, the braking torque is calculated. By estimating the friction coefficient and estimating the braking torque, the performance of the braking system can be more accurately understood, and the appropriate braking material can be selected to achieve the best braking effect. In practical applications, the accuracy of the estimated friction coefficient and the estimated braking torque also needs to be verified through experiments; if there are differences, adjustments can be made based on the experimental results to optimize the performance of the braking system.

[0077] Therefore, by modeling the key parameters that affect the friction coefficient of the wheel-end disc and adopting the machine learning method, the EMB controller can dynamically grasp the friction coefficient state of the friction plate at each wheel end, realize the dynamic calibration of the EMB friction coefficient, and estimate the friction coefficient before braking; estimate the correspondence between the clamping force of the EMB and the wheel-end braking torque before braking, improve the accuracy of the EMB wheel-end braking torque, and reduce the frequency of clamping force feedback adjustment; collect key vehicle motion parameters for the intelligent chassis domain control, and provide input for other chassis domain control precision algorithms.

[0078] Optionally, in some embodiments, after estimating the braking torque based on the estimated friction coefficient of the friction plate, it also includes: obtaining a reference vehicle load, and the vehicle's X-direction deceleration, Y-direction acceleration, active direction angle and passive direction angle during the braking process; based on the X-direction deceleration, Y-direction acceleration, active direction angle and passive direction angle, in combination with the reference vehicle load, using a preset vehicle dynamics model to calculate the reference friction coefficient of each wheel end; calculating the reference friction coefficient disturbance vector of each wheel end based on the reference friction coefficient of each wheel end, and calculating a credible whole vehicle friction coefficient disturbance vector based on the reference friction coefficient disturbance vector of each wheel end; if the absolute value of the credible whole vehicle friction coefficient disturbance vector is greater than the first filtering threshold, correcting the current disk temperature based on the revised calibration value corresponding to the credible whole vehicle friction coefficient disturbance vector, and updating the credible whole vehicle friction coefficient disturbance vector until the updated credible whole vehicle friction coefficient disturbance vector is less than the first filtering threshold.

[0079] Among them, in some embodiments, obtaining a reference vehicle load includes: obtaining the current wheel speed, the current motor acceleration, the current motor speed and the current motor torque; calculating the whole vehicle acceleration according to the current wheel speed, the current motor acceleration and the current motor speed; inputting the whole vehicle acceleration and the current motor torque into a preset vehicle load estimation model to obtain a reference vehicle load.

[0080] Among them, the first filtering threshold is used to determine whether the credible vehicle friction coefficient disturbance vector μk(t) exceeds the normal range. When the absolute value of the credible vehicle friction coefficient disturbance vector μk(t) is greater than the first filtering threshold, the embodiment of the present application considers that the current friction coefficient disturbance is too large and needs to be corrected to avoid misjudgment due to noise or abnormal data; the first filtering threshold can be a threshold pre-set by the user, a threshold obtained through a limited number of experiments, or a threshold obtained through a limited number of computer simulations, which is not specifically limited here. Vehicle load refers to the total weight borne by the vehicle during driving, including the weight of the vehicle itself, the weight of passengers, the weight of cargo, etc.

[0081] It is understandable that if Figure 3 and Figure 4 As shown, Figure 3 This is a schematic diagram of a structure for determining a reference load according to an embodiment of the present application. Figure 4 The flowchart of determining the reference load of the embodiment of the present application; the embodiment of the present application introduces the vehicle dynamic parameters and the reference vehicle load to calculate the reference friction coefficient disturbance vector μk(tx) of each wheel end, which more comprehensively reflects the actual state of the vehicle during braking and improves the accuracy of friction coefficient estimation; the dynamic parameters of the vehicle will change during braking. By monitoring these parameters in real time and adjusting the estimation of the friction coefficient accordingly, the braking system can better adapt to the dynamic changes of the vehicle; by continuously correcting and updating the credible vehicle friction coefficient disturbance vector μk(t), it is ensured that the braking system can provide stable braking performance under various working conditions and improve the stability and reliability of the braking system; by calculating the acceleration of the whole vehicle and combining it with the motor torque, a more accurate load estimation can be performed. The embodiment of the present application monitors the load changes of the vehicle in real time, promptly discovers and handles overload or underload problems, optimizes the transportation efficiency and safety of the vehicle, and provides strong support for vehicle scheduling and maintenance. For example, in terms of vehicle scheduling, transportation tasks can be reasonably arranged according to real-time load information to avoid empty or overloaded vehicles.

[0082] Optionally, in some embodiments, after calculating a credible vehicle friction coefficient disturbance vector based on the reference friction coefficient disturbance vector of each wheel end, it also includes: calculating the difference between the reference friction coefficient of each wheel end and the estimated friction coefficient to obtain the estimation error of each wheel end; based on the estimation error of each wheel end, correcting the wheel end reference friction coefficient disturbance vector of the target wheel end whose wheel end estimation error is greater than the second filtering threshold.

[0083] Among them, the second filtering threshold is used to determine whether the estimated error U(tk) of each wheel end exceeds the normal range. When it is greater than the second filtering threshold, the embodiment of the present application believes that there is a large error in the friction coefficient estimation of the wheel end, and the wheel end reference friction coefficient disturbance vector needs to be corrected; the second filtering threshold can be a threshold set in advance by the user, it can be a threshold obtained through a finite number of experiments, or it can be a threshold obtained through a finite number of computer simulations, and no specific limitation is made here.

[0084] It is understandable that if Figure 5 and Figure 6 As shown, Figure 5 is a schematic diagram of a braking torque estimation system according to an embodiment of the present application, Figure 6 This is a flow chart of the braking torque estimation system of an embodiment of the present application; the embodiment of the present application obtains the estimated error of each wheel end by calculating the difference between the reference friction coefficient of each wheel end and the estimated friction coefficient, and based on the calculated estimated error, identifies which wheel ends have larger estimated errors, that is, target wheel ends whose wheel end estimated errors are larger than the second filtering threshold. These wheel ends may be affected by factors such as noise, abnormal data or inaccurate model; for the wheel ends with larger errors identified, the disturbance vector of the reference friction coefficient of the wheel end is corrected to optimize the braking performance, handling performance, etc. of the vehicle.

[0085] Therefore, the embodiment of the present application separates the driving process from the braking process, calculates the vehicle load during the driving process, and latches the data for calculating the actual wheel-end braking torque during the braking process; the key point is not the load estimation algorithm itself, but the storage of the load calculated during the vehicle driving process and its application in the vehicle braking process control algorithm, while preventing the acceleration generated during the braking process from interfering with the reference load data; then, the embodiment of the present application models the key parameters that affect the friction coefficient of the wheel-end disc, and adopts a machine learning method, so that the EMB controller can dynamically grasp the friction coefficient state of the friction plate of each wheel end, and combined with the clamping force model, it can accurately control the braking torque of each wheel end, thereby improving the stability of the vehicle during driving.

[0086] According to the embodiment of the present application, a braking torque estimation method is proposed. After obtaining the current disc temperature of the brake disc and obtaining the current reference friction coefficient temperature vector according to the current disc temperature, the wheel end reference friction coefficient disturbance vector generated during the last braking is obtained, and the friction plate estimated friction coefficient is obtained according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking, and then the braking torque is estimated according to the friction plate estimated friction coefficient. Thus, the friction coefficient disturbance vector is dynamically corrected by a preset model and a filtering threshold to estimate the friction coefficient, which solves the problems of inaccurate braking torque estimation, reference load data interference during braking, feedback control delay, etc., significantly improves the braking performance of the EMB system, and improves the stability of the vehicle during driving.

[0087] Next, the braking torque estimation device proposed in accordance with the embodiment of the present application is described with reference to the accompanying drawings.

[0088] Figure 7 It is a block diagram of a braking torque estimation device according to an embodiment of the present application.

[0089] like Figure 7 As shown, the braking torque estimation device 10 includes: a first acquisition module 100 , a second acquisition module 200 and a calculation module 300 .

[0090] The first acquisition module 100 is used to acquire the current disc temperature of the brake disc and obtain the current reference friction coefficient temperature vector according to the current disc temperature;

[0091] The second acquisition module 200 is used to acquire the wheel end reference friction coefficient disturbance vector generated during the last braking, and obtain the friction plate estimated friction coefficient according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking;

[0092] The calculation module 300 is used to estimate the braking torque according to the estimated friction coefficient of the friction plate.

[0093] Optionally, the first acquisition module 100 is specifically used to: obtain multiple disc temperature estimation parameters of the brake disc and a disc temperature and friction coefficient relationship table; input the multiple disc temperature estimation parameters into a preset brake disc temperature model to obtain the current disc temperature; based on the disc temperature and friction coefficient relationship table, obtain the current reference friction coefficient temperature vector according to the current disc temperature.

[0094] Optionally, the calculation module 300 is also used to: obtain a reference vehicle load, and the X-direction deceleration, Y-direction acceleration, active direction angle and passive direction angle of the vehicle during braking; based on the X-direction deceleration, Y-direction acceleration, active direction angle and passive direction angle, in combination with the reference vehicle load, calculate the reference friction coefficient of each wheel end using a preset vehicle dynamics model; calculate the reference friction coefficient disturbance vector of each wheel end according to the reference friction coefficient of each wheel end, and calculate the credible whole vehicle friction coefficient disturbance vector according to the reference friction coefficient disturbance vector of each wheel end; if the absolute value of the credible whole vehicle friction coefficient disturbance vector is greater than the first filtering threshold, correct the current disk temperature based on the revised calibration value corresponding to the credible whole vehicle friction coefficient disturbance vector, and update the credible whole vehicle friction coefficient disturbance vector until the updated credible whole vehicle friction coefficient disturbance vector is less than the first filtering threshold.

[0095] Optionally, the second acquisition module 200 is further used to: calculate the difference between the reference friction coefficient of each wheel end and the estimated friction coefficient to obtain the estimation error of each wheel end; based on the estimation error of each wheel end, correct the wheel end reference friction coefficient disturbance vector of the target wheel end whose wheel end estimation error is greater than the second filtering threshold.

[0096] Optionally, obtaining a reference vehicle load includes: obtaining a current wheel speed, a current motor acceleration, a current motor speed, and a current motor torque; calculating a whole vehicle acceleration based on the current wheel speed, the current motor acceleration, and the current motor speed; and inputting the whole vehicle acceleration and the current motor torque into a preset vehicle load estimation model to obtain a reference vehicle load.

[0097] It should be noted that the above explanation of the braking torque estimation method embodiment is also applicable to the braking torque estimation device of this embodiment, and will not be repeated here.

[0098] According to the braking torque estimation device proposed in the embodiment of the present application, after obtaining the current disc temperature of the brake disc and obtaining the current reference friction coefficient temperature vector according to the current disc temperature, the wheel end reference friction coefficient disturbance vector generated during the last braking is obtained, and the friction plate estimated friction coefficient is obtained according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking, and then the braking torque is estimated according to the friction plate estimated friction coefficient. Therefore, the friction coefficient disturbance vector is dynamically corrected by a preset model and a filtering threshold to estimate the friction coefficient, which solves the problems of inaccurate braking torque estimation, reference load data interference during braking, feedback control delay, etc., significantly improves the braking performance of the EMB system, and improves the stability of the vehicle during driving.

[0099] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0100] A memory 801 , a processor 802 , and a computer program stored in the memory 801 and executable on the processor 802 .

[0101] When the processor 802 executes the program, the braking torque estimation method provided in the above embodiment is implemented.

[0102] Furthermore, the electronic device further comprises:

[0103] The communication interface 803 is used for communication between the memory 801 and the processor 802 .

[0104] The memory 801 is used to store computer programs that can be executed on the processor 802 .

[0105] The memory 801 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0106] If the memory 801, the processor 802 and the communication interface 803 are implemented independently, the communication interface 803, the memory 801 and the processor 802 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 8 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0107] Optionally, in a specific implementation, if the memory 801, the processor 802 and the communication interface 803 are integrated on a chip, the memory 801, the processor 802 and the communication interface 803 can communicate with each other through an internal interface.

[0108] The processor 802 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0109] An embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the above braking torque estimation method is implemented.

[0110] An embodiment of the present application also provides a computer program product, which stores a computer program, and when the program is executed by a processor, the above braking torque estimation method is implemented.

[0111] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0112] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0113] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0114] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0115] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

Claims

1. A braking torque estimation method, characterized in that: The following steps are involved: Acquire the current disc temperature of the brake disc, and obtain the current reference friction coefficient temperature vector according to the current disc temperature; Obtaining a wheel end reference friction coefficient disturbance vector generated during the last braking, and obtaining an estimated friction coefficient of the friction plate according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking; The braking torque is estimated based on the estimated friction coefficient of the friction plate.

2. The method according to claim 1, characterized in that The step of acquiring the current disc temperature of the brake disc and obtaining the current reference friction coefficient temperature vector according to the current disc temperature includes: Acquire a plurality of disc temperature estimation parameters of the brake disc and a disc temperature and friction coefficient relationship table; Inputting the plurality of disc temperature estimation parameters into a preset brake disc temperature model to obtain the current disc temperature; Based on the disk temperature and friction coefficient relationship table, the current reference friction coefficient temperature vector is obtained according to the current disk temperature.

3. The method according to claim 1, characterized in that After estimating the braking torque according to the estimated friction coefficient of the friction plate, the method further includes: Obtain the reference vehicle load, as well as the vehicle's X-direction deceleration, Y-direction acceleration, active direction angle, and passive direction angle during braking; Based on the X-direction deceleration, the Y-direction acceleration, the active direction angle and the passive direction angle, and in combination with the reference vehicle load, a preset vehicle dynamics model is used to calculate a reference friction coefficient of each wheel end; Calculating a reference friction coefficient disturbance vector of each wheel end according to the reference friction coefficient of each wheel end, and calculating a credible whole vehicle friction coefficient disturbance vector according to the reference friction coefficient disturbance vector of each wheel end; If the absolute value of the credible vehicle friction coefficient disturbance vector is greater than the first filtering threshold, the current disk temperature is corrected based on the revised calibration value corresponding to the credible vehicle friction coefficient disturbance vector, and the credible vehicle friction coefficient disturbance vector is updated until the updated credible vehicle friction coefficient disturbance vector is less than the first filtering threshold.

4. The method according to claim 3, characterized in that After calculating the credible vehicle friction coefficient disturbance vector according to the reference friction coefficient disturbance vector of each wheel end, the method further includes: Calculating the difference between the reference friction coefficient of each wheel end and the estimated friction coefficient to obtain the estimated error of each wheel end; Based on the wheel end estimation errors, the wheel end reference friction coefficient disturbance vector of the target wheel end whose wheel end estimation error is greater than the second filtering threshold is corrected.

5. The method according to claim 3, characterized in that: The obtaining of the reference vehicle load comprises: Get the current wheel speed, current motor acceleration, current motor speed and current motor torque; Calculating the vehicle acceleration according to the current wheel speed, the current motor acceleration and the current motor speed; The whole vehicle acceleration and the current motor torque are input into a preset vehicle load estimation model to obtain the reference vehicle load.

6. A braking torque estimation device, characterized in that: include: A first acquisition module, used for acquiring a current disc temperature of the brake disc, and obtaining a current reference friction coefficient temperature vector according to the current disc temperature; a second acquisition module, configured to acquire a wheel end reference friction coefficient disturbance vector generated during the last braking, and obtain an estimated friction coefficient of the friction plate according to the current reference friction coefficient temperature vector and the wheel end reference friction coefficient disturbance vector generated during the last braking; A calculation module is used to estimate the braking torque according to the estimated friction coefficient of the friction plate.

7. The device according to claim 6, characterized in that The first acquisition module is specifically used to: Acquire a plurality of disc temperature estimation parameters of the brake disc and a disc temperature and friction coefficient relationship table; Inputting the plurality of disc temperature estimation parameters into a preset brake disc temperature model to obtain the current disc temperature; Based on the disk temperature and friction coefficient relationship table, the current reference friction coefficient temperature vector is obtained according to the current disk temperature.

8. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the braking torque estimation method according to any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the braking torque estimation method as described in any one of claims 1 to 5.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the braking torque estimation method according to any one of claims 1 to 5 is implemented.

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