Electromechanical braking clamping force compensation system and control method

Abstract

The invention provides an electronic mechanical brake clamping force compensation system and a control method.The electronic mechanical brake clamping force compensation system comprises a brake pedal, a brake controller and electronic mechanical calipers arranged at the wheel ends of four wheels, each electronic mechanical caliper comprises a caliper body, a caliper motor, a transmission mechanism and a caliper controller, a brake force requirement calculation module is arranged in the brake controller, and a brake force requirement calculation module is arranged in the brake controller. A target clamping force correction module, a wheel edge braking force control module, a brake disc temperature calculation module, a caliper abrasion calculation module and a wheel speed estimation module are arranged in the caliper controller. According to the method, the target clamping force and the clamping force estimated value of the electronic mechanical calipers are compensated and corrected by adopting the working parameters of the actuator in the electronic mechanical braking system and other system parameters which are easily obtained on the whole vehicle, so that the control precision under various complex working conditions is improved, the braking smoothness is favorably improved, and the user experience is improved.

Description

Technical Field

[0001] This invention relates to the field of braking equipment technology, and in particular to an electromechanical braking clamping force compensation system and control method. Background Technology

[0002] Under frequent or high-intensity braking conditions, a large amount of heat is stored in the braking components within a short period of time, causing the temperature of braking components such as the brake discs to rise rapidly. The operating environment of the automotive braking system is complex and variable; overheating and wear can all affect braking performance, placing higher demands on the control precision of the electronic braking control system.

[0003] Electromechanical braking systems are a new type of braking system, and their adaptability to braking temperature and wear differs from that of traditional electrohydraulic braking systems. To maintain control accuracy in complex and variable braking conditions, it is necessary to develop a clamping force compensation control method for electromechanical braking systems. Summary of the Invention

[0004] The purpose of this invention is to provide an electromechanical braking clamping force compensation system and control method, which is beneficial to improving braking smoothness and enhancing user experience.

[0005] According to one objective of the present invention, an electromechanical braking clamping force compensation system is provided, comprising a brake pedal, a brake controller, and electromechanical calipers arranged at the ends of four wheels. The electromechanical calipers include a caliper body, a caliper motor, a transmission mechanism, and a caliper controller. The brake controller includes a braking force demand calculation module, and the caliper controller includes a target clamping force correction module, a wheel-side braking force control module, a brake disc temperature calculation module, a caliper wear calculation module, and a wheel speed estimation module.

[0006] According to another objective of the present invention, the present invention provides a control method for the above-mentioned electromechanical braking clamping force compensation system, comprising the following steps:

[0007] S1, the brake controller calculates the four-wheel braking force demand based on the input of the brake pedal and sends the target braking force to the four-wheel electromechanical calipers;

[0008] S2, after receiving the target clamping force, the electromechanical caliper compensates for the target clamping force to obtain a corrected target clamping force;

[0009] S3, the electromechanical caliper calculates the target clamping force based on the wheel-side braking force control module and sends a control command to the caliper motor, thereby causing the electromechanical caliper to actuate;

[0010] S4. Based on the operating parameters of the electromechanical caliper, the clamping force of the caliper is estimated. The estimation is based on the brake disc temperature and the wear of the friction pads. The estimated clamping force is compensated based on the brake disc temperature and the wear of the friction pads to obtain the corrected estimated clamping force.

[0011] S5, the wheel speed estimation module processes the wheel speed signal and the actual wheel angular acceleration based on the wheel speed sensor signal input; at the same time, it obtains the wheel angular acceleration prediction value based on the corrected clamping force; by comparing the actual wheel angular acceleration value and the wheel angular acceleration prediction value, it calculates the wheel angular acceleration compensation coefficient; the wheel angular acceleration compensation coefficient is input into the target clamping force correction module to compensate for the target clamping force.

[0012] Furthermore, in S5, the brake disc temperature calculated in S4 is input into the target clamping force correction module, and the target clamping force is comprehensively compensated at the same time.

[0013] Furthermore, in S1, the braking force demand calculation module in the brake controller calculates the four-wheel braking force demand based on the input of the brake pedal and sends the target clamping force to the four-wheel electromechanical calipers.

[0014] Furthermore, in S2, the basis for compensating the target clamping force includes the brake disc temperature value calculated by the brake disc temperature calculation module in the caliper controller and the wheel angular acceleration compensation coefficient obtained by the wheel speed estimation module in the caliper controller.

[0015] Furthermore, in S3, during the operation of the caliper motor, the motor current and motor rotation angle signals are collected, and then the clamping force of the caliper is estimated based on the measured motor current and motor rotation angle operation parameters.

[0016] Furthermore, in S4, the brake disc temperature is calculated by the brake disc temperature calculation module based on the wheel speed signal, the corrected estimated clamping force, the ambient temperature, the sleep time, and the vehicle's operating parameters.

[0017] Furthermore, in S4, the predicted clamping force is corrected and combined with the wheel speed sensor information, and then input into the wheel speed estimation module to obtain the wheel angular acceleration correction coefficient.

[0018] Furthermore, in S4, the friction pad wear value is obtained by reading the stored value stored in the brake controller from the caliper wear calculation module. The friction pad wear value is detected and stored in the memory of the brake controller when the external conditions trigger the friction pad wear detection function.

[0019] Furthermore, in S2, when compensating for the target clamping force, the target clamping force is compensated for by wheel angular acceleration and brake disc temperature to obtain a corrected target clamping force; the wheel angular acceleration compensation method is the target clamping force multiplied by the wheel angular acceleration compensation coefficient, and the brake disc temperature compensation method is the target clamping force after wheel angular acceleration compensation multiplied by the brake disc temperature correction coefficient.

[0020] The technical solution of this invention uses the actuator working parameters inside the electromechanical braking system, as well as other system parameters that are easily obtained from the vehicle, to compensate and correct the target clamping force and clamping force estimate of the electromechanical caliper, thereby improving the control accuracy under various complex working conditions, which is beneficial to improving braking smoothness and enhancing user experience. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating the process of an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of an embodiment of the present invention;

[0024] Figure 3 This is a flowchart illustrating the clamping force compensation control method according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the wheel end target clamping force compensation method according to an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram illustrating the method for obtaining the brake disc temperature correction coefficient according to an embodiment of the present invention;

[0027] In the picture: 1. Brake pedal; 2. Brake controller; 3. Front left electromechanical caliper; 4. Front right electromechanical caliper; 5. Rear left electromechanical caliper; 6. Rear right electromechanical caliper. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] Example 1

[0032] like Figure 2 As shown, an electromechanical braking clamping force compensation system includes a brake pedal 1, a brake controller 2, and electromechanical calipers arranged at the ends of four wheels. The electromechanical calipers include a caliper body, a caliper motor, a transmission mechanism, and a caliper controller.

[0033] The brake controller 2 is equipped with a braking force demand calculation module, and the caliper controller is equipped with a target clamping force correction module, a wheel-side braking force control module, a brake disc temperature calculation module, a caliper wear calculation module, and a wheel speed estimation module.

[0034] The electromechanical calipers include a left front electromechanical caliper 3, a right front electromechanical caliper 4, a left rear electromechanical caliper 5, and a right rear electromechanical caliper 6, all located at the ends of the four wheels. The brake pedal 1, the brake controller 2, and the electromechanical calipers are connected via a wiring harness.

[0035] like Figure 1 and Figure 3 As shown, the control method of the above-mentioned electromechanical braking clamping force compensation system includes the following steps:

[0036] The braking force demand calculation module in brake controller 2 calculates the four-wheel braking force demand based on the input of the brake pedal and sends the target clamping force to the four-wheel electromechanical calipers;

[0037] Taking the left front wheel as an example, after the left front electromechanical caliper receives the target clamping force, it compensates for the target clamping force to obtain the corrected target clamping force. The main basis for the compensation is: 1. The brake disc temperature value calculated by the brake disc temperature calculation module in the caliper controller of the left front electromechanical caliper; 2. The wheel angular acceleration compensation coefficient obtained by the wheel speed estimation module in the caliper controller of the left front electromechanical caliper.

[0038] The left front electromechanical caliper calculates the target clamping force through the wheel-side braking force control module and sends control commands to the caliper motor, thereby actuating the electromechanical caliper. During the caliper motor's actuation, motor current and motor rotation angle signals are collected.

[0039] The clamping force of the electromechanical caliper is estimated based on its motor current and rotation angle. The estimated clamping force is then compensated for by the brake disc temperature and friction pad wear, resulting in a corrected estimated clamping force. The estimation is based on: 1. Brake disc temperature, calculated by the brake disc temperature calculation module based on wheel speed signals, corrected estimated clamping force, ambient temperature, sleep time, and other vehicle operating parameters. 2. Friction pad wear value, obtained by the caliper wear calculation module by reading stored values ​​in the brake controller. This value is detected and stored in the brake controller's memory when external conditions trigger the friction pad wear detection function.

[0040] The wheel speed estimation module processes the left front wheel speed signal and the actual wheel angular acceleration based on the input signal from the left front wheel speed sensor. Simultaneously, it obtains the predicted wheel angular acceleration value based on the corrected clamping force. By comparing the actual wheel angular acceleration value with the predicted wheel angular acceleration value, it calculates the wheel angular acceleration compensation coefficient. This coefficient is input into the target clamping force correction module to compensate for the target clamping force.

[0041] like Figure 4 The figure shows a method for compensating for the clamping force on the wheel end target.

[0042] Taking the left front brake caliper as an example, the target clamping force F _ fl needs to undergo wheel angular acceleration compensation and brake disc temperature compensation to obtain the corrected target clamping force A. _ w*A _ T*F _ fl;

[0043] Among them, the wheel angular acceleration compensation method is the target clamping force F _ fl multiplied by the wheel angular acceleration compensation coefficient A _w, the brake disc temperature compensation method is the target clamping force A after wheel angular acceleration compensation. _ w*F _ fl multiplied by brake disc temperature correction factor A _ T;

[0044] like Figure 5 The diagram shows the method for obtaining the brake disc temperature correction coefficient, specifically represented by the brake disc temperature correction coefficient A. _ The functional relationship between temperature T and brake disc temperature T is stored in the caliper controller in caliper controller in caliper controller form.

[0045] The working principle of this invention is as follows:

[0046] The braking force demand calculation module in the brake controller calculates the braking force demand of the four wheels based on the input of the brake pedal and sends the target braking force to the four-wheel electromechanical calipers.

[0047] Taking the left front wheel as an example, after the left front electromechanical caliper receives the target clamping force, it compensates for the target clamping force to obtain the corrected target clamping force;

[0048] The main basis for compensation is: 1. The brake disc temperature value A calculated by the brake disc temperature calculation module in the left front wheel electromechanical caliper controller; 2. The wheel angular acceleration compensation coefficient obtained by the wheel speed estimation module in the left front wheel electromechanical caliper controller;

[0049] The left front electromechanical caliper calculates the target clamping force through the wheel-side braking force control module and sends control commands to the caliper motor, thereby actuating the electromechanical caliper. Based on the electromechanical caliper actuation parameters (current, motor rotation angle, etc.), the caliper clamping force is estimated, and the estimated clamping force is compensated for based on the brake disc temperature and friction pad wear to obtain a corrected estimated clamping force.

[0050] By combining the estimated clamping force with vehicle operating parameters such as ambient temperature and sleep time, and inputting this information into the brake disc temperature calculation module, the brake disc temperature can be calculated. Similarly, by combining the estimated clamping force with wheel speed sensor information and inputting this information into the wheel speed estimation module, the wheel angular acceleration correction coefficient can be obtained.

[0051] This invention uses the actuator operating parameters inside the electromechanical braking system, as well as other system parameters that are easily obtained from the vehicle, to compensate and correct the target clamping force and clamping force estimate of the electromechanical caliper, thereby improving the control accuracy under various complex working conditions, which is beneficial to improving braking smoothness and enhancing the user experience.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electromechanical braking clamping force compensation system, characterized in that, It includes a brake pedal, a brake controller, and electromechanical calipers arranged at the ends of the four wheels. The electromechanical calipers include a caliper body, a caliper motor, a transmission mechanism, and a caliper controller. The brake controller is equipped with a braking force demand calculation module, and the caliper controller is equipped with a target clamping force correction module, a wheel-side braking force control module, a brake disc temperature calculation module, a caliper wear calculation module, and a wheel speed estimation module.

2. The control method of the electromechanical braking clamping force compensation system according to claim 1, characterized in that, Includes the following steps: S1, the brake controller calculates the four-wheel braking force demand based on the input of the brake pedal and sends the target braking force to the four-wheel electromechanical calipers; S2, after receiving the target clamping force, the electromechanical caliper compensates for the target clamping force to obtain a corrected target clamping force; S3, the electromechanical caliper calculates the target clamping force based on the wheel-side braking force control module and sends a control command to the caliper motor, thereby causing the electromechanical caliper to actuate; S4. Based on the operating parameters of the electromechanical caliper, the clamping force of the caliper is estimated. The estimation is based on the brake disc temperature and the wear of the friction pads. The estimated clamping force is compensated based on the brake disc temperature and the wear of the friction pads to obtain the corrected estimated clamping force. S5, the wheel speed estimation module processes the wheel speed signal and the actual wheel angular acceleration based on the wheel speed sensor signal input; at the same time, it obtains the wheel angular acceleration prediction value based on the corrected clamping force; by comparing the actual wheel angular acceleration value and the wheel angular acceleration prediction value, it calculates the wheel angular acceleration compensation coefficient; the wheel angular acceleration compensation coefficient is input into the target clamping force correction module to compensate for the target clamping force.

3. The control method of the electromechanical braking clamping force compensation system according to claim 2, characterized in that, In S5, the brake disc temperature calculated in S4 is input into the target clamping force correction module, and the target clamping force is comprehensively compensated at the same time.

4. The control method of the electromechanical braking clamping force compensation system according to claim 3, characterized in that, In S1, the braking force demand calculation module in the brake controller calculates the four-wheel braking force demand based on the input of the brake pedal and sends the target clamping force to the four-wheel electromechanical calipers.

5. The control method of the electromechanical braking clamping force compensation system according to claim 3, characterized in that, In S2, the basis for compensating the target clamping force includes the brake disc temperature value calculated by the brake disc temperature calculation module in the caliper controller and the wheel angular acceleration compensation coefficient obtained by the wheel speed estimation module in the caliper controller.

6. The control method of the electromechanical braking clamping force compensation system according to claim 3, characterized in that, In S3, during the operation of the caliper motor, the motor current and motor rotation angle signals are collected, and then the clamping force of the caliper is estimated based on the measured motor current and motor rotation angle operation parameters.

7. The control method of the electromechanical braking clamping force compensation system according to claim 3, characterized in that, In S4, the brake disc temperature is calculated by the brake disc temperature calculation module based on the wheel speed signal, the corrected estimated clamping force, the ambient temperature, the sleep time, and the vehicle's operating parameters.

8. The control method of the electromechanical braking clamping force compensation system according to claim 3, characterized in that, In S4, the predicted clamping force is corrected by combining the wheel speed sensor information and inputting it into the wheel speed estimation module to obtain the wheel angular acceleration correction coefficient.

9. The control method of the electromechanical braking clamping force compensation system according to claim 3, characterized in that, In S4, the friction pad wear value is obtained by reading the stored value stored in the brake controller from the caliper wear calculation module. The friction pad wear value is detected and stored in the memory of the brake controller when the friction pad wear detection function is triggered by external conditions.

10. The control method of the electromechanical braking clamping force compensation system according to claim 3, characterized in that, In S2, when compensating for the target clamping force, the target clamping force is compensated for by wheel angular acceleration and brake disc temperature to obtain the corrected target clamping force. The wheel angular acceleration compensation method is to multiply the target clamping force by the wheel angular acceleration compensation coefficient, and the brake disc temperature compensation method is to multiply the target clamping force after wheel angular acceleration compensation by the brake disc temperature correction coefficient.

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