Electromechanical brake system and control method thereof

Abstract

The present invention proposes an electronic mechanical brake system and discloses a control method for the electronic mechanical brake system. The method installs a force sensor on at least one wheel of a vehicle, sets a wheel with a force sensor, obtains clamping force information through the force sensor, performs contact identification in combination with the motor current, updates the contact point stroke of the piston, and calculates the piston position according to the motor angle information. For wheels without force sensors, contact calculation is performed by obtaining vehicle parameters and motor current to obtain piston position information. The clamping force information of the wheel with a force sensor and the motor parameters of the wheel with a forceless sensor are used to perform stiffness fitting to determine the estimated clamping force of other wheels. Finally, a clamping or releasing operation is performed based on the obtained information. The present invention realizes precise control of the clamping force and effective monitoring of the wear of the friction lining, thereby improving the performance and reliability of the electronic brake system.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle electronic control, and in particular to an electronic mechanical braking system, and also to a control method of the electronic mechanical braking system. Background Art

[0002] With the development of automobile electronics and intelligence, the electronic braking system (Electronic Mechanical Brake) has gradually become an indispensable part of advanced driver assistance systems (ADAS) and autonomous driving technologies.

[0003] The Electronic Mechanical Brake (EMB) is an important technology in modern automobile braking systems. It uses an electric motor as the driving source of the braking force, and converts the power of the motor into braking force through a mechanical transmission mechanism to clamp the vehicle's brake disc or brake drum, thereby achieving the purpose of braking.

[0004] The clamping force control of the electronic brake system (EMB) is an important prerequisite for realizing the basic functions of the system, active braking, drive anti-skid and anti-lock braking. Accurate identification of the clamping force is the key to clamping force control. However, the clamping force sensors in the existing EMB system are expensive, and there are cost issues for car companies to widely use them in mass-produced models.

[0005] In addition, the layout of the clamping force sensor also faces many challenges. For example, if it is close to the friction lining, the service life will be shortened due to the high operating temperature. If it is placed deep in the EMB, it will cause hysteresis problems and affect the measurement accuracy. If the clamping force sensor is completely eliminated, it will increase the difficulty of accurately identifying the clamping force and make it difficult to judge the wear of the friction lining, thus affecting the control effect of the clamping force.

[0006] Based on the above problems existing in the prior art, how to accurately identify and control the clamping force in the EMB system becomes a problem to be solved by the present invention. Summary of the invention

[0007] One of the purposes of the present invention is to provide an electronic mechanical braking system to solve the accuracy and reliability problems of traditional mechanical braking systems. The system achieves high accuracy, fast response and redundant braking capabilities of braking operations through modular design.

[0008] In order to solve the above technical problems, the present invention provides an electronic mechanical braking system, comprising:

[0009] A control module, used for sending operation instructions;

[0010] The execution module includes a main execution module and a secondary execution module, wherein the main execution module is provided with a force sensor and obtains the clamping force through contact recognition, and the secondary execution module obtains the estimated clamping force through contact calculation.

[0011] In some embodiments, the main execution module includes:

[0012] The motor and the speed reducing and torque increasing mechanism are used to provide the necessary clamping or releasing power;

[0013] The motion conversion mechanism is connected to the motor and the deceleration and torque increasing mechanism, and converts the rotational motion of the motor into linear motion, wherein the force sensor is integrated in the motion conversion mechanism to measure the clamping force;

[0014] Motor position sensor, integrated into the motor or motor controller, used to sense the motor's rotation angle in real time;

[0015] The current sensor is integrated into the motor or motor controller and is used to sense the motor current in real time.

[0016] In some embodiments, the electronic mechanical braking system also includes a controller connected to the motor position sensor, the current sensor and the force sensor, for receiving instructions from the control module and controlling the rotation of the motor to perform clamping or releasing operations based on real-time information from the motor position sensor, the current sensor and the force sensor.

[0017] In some embodiments, the secondary execution module includes a calculation unit for calculating and estimating the clamping force through a preset algorithm according to the clamping force data and / or other relevant parameters of the primary execution module to provide redundant or auxiliary braking.

[0018] Another object of the present invention is to provide an electronic mechanical brake system control method, which achieves accurate control of the clamping force and effective monitoring of the wear of the friction lining by optimizing the sensor arrangement and the clamping force identification method.

[0019] The present invention provides an electronic mechanical brake system control method, wherein a force sensor is installed on the wheel of a vehicle; the control method comprises the following steps:

[0020] Obtain vehicle parameters and send the vehicle parameters to the contact calculation module; perform contact calculation based on the vehicle parameters and motor current;

[0021] If the vehicle parameters do not need to be obtained, the contact calculation is performed based on the motor current;

[0022] Based on the above contact calculation, the piston position calculation is performed according to the motor angle information of the powerless sensor wheel to obtain the piston position information of the powerless sensor wheel;

[0023] According to the clamping force information of the wheel with a force sensor, the motor current and the motor angle of the wheel with no force sensor, stiffness fitting is performed to determine the estimated clamping force of other wheels;

[0024] Based on the information obtained in the above steps, perform clamping or releasing.

[0025] In some embodiments, after the stiffness fitting is performed to obtain the estimated clamping force, before the clamping operation is performed, a friction identification step is also included, in which the friction torque required for friction compensation control is identified through the motor current, motor speed and estimated clamping force.

[0026] In some embodiments, the stiffness fitting method includes receiving the clamping force and piston position information of the wheel with a force sensor, performing data fitting to obtain a functional relationship between the clamping force and the piston position, and then calculating an estimated clamping force through the functional relationship based on the piston position information of the wheel without a force sensor.

[0027] In some embodiments, the method includes a force-free sensor wheel control method based on a vehicle wheel provided with a single force sensor and a force-free sensor wheel control method based on a vehicle wheel provided with two force sensors.

[0028] In some embodiments, the force-free sensor wheel control method based on setting a single force sensor on a vehicle wheel is as follows:

[0029] When a force sensor is provided on one of the wheels of the vehicle and no force sensor is provided on the other wheels, determining whether a condition for triggering contact calculation is satisfied;

[0030] If the conditions are met, perform the following steps:

[0031] Acquire vehicle parameter information; perform contact calculation based on the acquired vehicle parameter information and motor current;

[0032] First, the piston position is calculated according to the motor angle; then the clamping force of the force sensor wheel, the piston position information, and the piston position information of the current corresponding force sensor wheel are fitted with stiffness to obtain the estimated clamping force;

[0033] Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force;

[0034] Finally, the clamping / releasing instructions are judged and executed;

[0035] If the conditions are not met, perform the following steps:

[0036] First, calculate the piston position based on the motor angle;

[0037] Then, stiffness fitting is performed based on the clamping force and piston position information of the force sensor wheel and the piston position information of the current wheel to obtain the estimated clamping force.

[0038] Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force;

[0039] Finally, the clamping / releasing instructions are judged and executed.

[0040] The force sensor-free wheel control method based on setting two force sensors on the vehicle wheel is as follows:

[0041] Force sensors are arranged on two of the wheels of the vehicle, and no force sensors are arranged on the other wheels;

[0042] First, determine whether the conditions for triggering contact calculation are met:

[0043] If the conditions are met, perform the following steps:

[0044] First, the contact calculation is performed based on the motor current; then the piston position is calculated based on the motor angle;

[0045] Then, stiffness fitting is performed based on the clamping force information and piston position information of the wheel with a force sensor and the piston position information of the wheel with no force sensor to obtain an estimated clamping force;

[0046] Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force;

[0047] Finally, the clamping / releasing instructions are judged and executed;

[0048] If the condition is not met, perform the following steps:

[0049] First, the piston position is calculated according to the motor angle; then, the stiffness is fitted through the clamping force and piston position information of the force sensor wheel and the piston position information of the forceless sensor wheel to obtain the estimated clamping force;

[0050] Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force;

[0051] Finally, the clamping / releasing instructions are judged and executed.

[0052] Beneficial effects of the present invention:

[0053] 1. The present invention realizes accurate measurement and estimation of clamping force through the dual design of main execution module and secondary execution module, and improves the accuracy and reliability of the braking system. The redundant or auxiliary braking function of the secondary execution module enhances the safety of the system, and can ensure the normal operation of the braking system even if the main execution module fails. The controller controls the rotation of the motor according to the real-time information of multiple sensors, realizes accurate control of the braking operation, and improves the braking performance and response speed.

[0054] 2. The brake control of the vehicle wheel of the present invention adopts a brake control method that combines a force sensor wheel and a forceless sensor wheel. Force sensors are installed only on one or two wheels of the vehicle. For the force sensor wheel, the clamping force information of the wheel is directly obtained through the force sensor. For the forceless sensor wheel, stiffness fitting is performed based on the force sensor clamping force information and the piston position information to obtain an estimated clamping force. At the same time, contact point recognition and contact calculation are used respectively to update the piston contact point stroke information of the force sensor wheel and the forceless sensor wheel in real time, and the corresponding wheel piston position information is obtained through piston position calculation. The upper control system performs clamping or releasing operations through the clamping force or estimated clamping force combined with the wheel piston position information, thereby achieving precise control of the clamping force and improving the response speed of the braking system.

[0055] 3. After the stiffness fitting is used to obtain the estimated clamping force and before the clamping operation is performed, the present invention introduces a friction identification step. By identifying and compensating for the friction effect in real time, the deviation between the estimated clamping force and the actual clamping force can be reduced, thereby improving the accuracy of braking. At the same time, friction compensation helps to eliminate the braking fluctuations and jitters caused by friction uncertainty, and improves the smoothness and stability of braking. In addition, precise friction control and compensation can reduce the risk of wear and damage to braking components, thereby extending the service life of the entire braking system. In summary, by introducing the friction identification step and combining it with real-time monitoring and identification and compensation mechanisms, the braking performance and reliability of the electronic mechanical braking system are significantly improved.

[0056] 4. In the wheel with force sensor, the present invention realizes adaptive compensation of friction lining through contact identification and updating of piston contact point stroke, thereby improving the adaptability of the braking system. In the wheel without force sensor, the clamping force is estimated through stiffness fitting, and contact calculation is performed in combination with motor current and contact point stroke of the wheel with force sensor, and the contact point stroke of the piston of the wheel with no force sensor is updated, thereby realizing adaptive compensation of friction lining of no force sensor and ensuring the stability of the braking system.

[0057] 5. The present invention sets force sensors on some wheels, while the other wheels estimate the clamping force by stiffness fitting, which reduces the complexity of the system. Compared with the solution of installing force sensors on each wheel, the present invention has lower cost and is more economical.

[0058] 6. The present invention achieves a reasonable distribution of the vehicle's braking force by precisely controlling the clamping force of each wheel, thereby improving the vehicle's overall braking performance, improving the response speed and accuracy of the braking system, helping to shorten the braking distance, and reducing unstable factors during braking, thereby improving the safety of the vehicle.

[0059] In summary, the electronic mechanical braking system and control method thereof proposed in the present invention improve braking accuracy and response speed, enhance the adaptability and stability of the braking system, reduce system complexity and cost, and improve the overall braking performance and safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0061] Figure 1 This is a control principle diagram of the electronic mechanical brake system in the present invention;

[0062] Figure 2 This is a flow chart of the overall clamping force control of four wheels based on a single force sensor of the present invention;

[0063] Figure 3 This is a flow chart of the overall clamping force control of four wheels based on two force sensors of the present invention;

[0064] Figure 4 The present invention is a flow chart of wheel clamping force control based on a single or two force sensors;

[0065] Figure 5 A flow chart of the wheel clamping force control without force sensor based on a single force sensor according to the present invention;

[0066] Figure 6 The present invention is a flow chart of the wheel clamping force control without force sensor based on two force sensors; DETAILED DESCRIPTION

[0067] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is not intended to be any limitation on the present invention and its application or use. The present invention can be implemented in other different forms and is not limited to the embodiments described herein.

[0068] The clamping force sensor currently used in the EMB system is expensive, so it is difficult for car companies to widely use it in mass-produced models. At the same time, if the clamping force sensor is arranged close to the friction lining, the service life will be shortened due to excessively high operating temperature. However, if it is arranged deep in the EMB, it will cause hysteresis problems that affect the measurement accuracy. If the clamping force sensor is completely eliminated, the clamping force cannot be accurately identified, and the wear of the friction lining cannot be determined. The present invention specifically provides a technical solution to the above problems. The technical solution, working principle and technical effect of the present invention are described in detail below in conjunction with specific embodiments.

[0069] The present invention realizes the identification and control of clamping force based on an electric brake system. The electric brake system includes a main controller, an electromechanical brake system and a brake disc. The main controller and the electromechanical brake system realize the clamping control of the brake disc, generate the required clamping force or estimate the clamping force signal, and transmit the required clamping force signal to each wheel via IVN (in-vehicle network).

[0070] Reference Figure 1 ,The electronic mechanical braking system includes a control module and an execution module.

[0071] The control module is used to send operation instructions, while the execution module is responsible for performing clamping or releasing operations according to the instructions. The execution module is further subdivided into the main execution module and the secondary execution module to improve the reliability and redundancy of the system.

[0072] The main execution module is the core part of the braking system. It includes the motor and the deceleration and torque increase mechanism, the motion conversion mechanism, the motor position sensor and the current sensor, which are integrated inside the motor or the motor controller. The motor position sensor and the current sensor provide real-time feedback, enabling the controller to accurately control the rotation angle and current of the motor.

[0073] The motor and the torque reduction and torque increase mechanism provide the necessary clamping or releasing power, while the motion conversion mechanism converts the motor's rotational motion into linear motion to achieve braking operation.

[0074] The force sensor is integrated into the motion conversion mechanism to measure the clamping force in real time to ensure the accuracy and stability of the braking effect.

[0075] The secondary execution module, as a redundant or auxiliary part of the main execution module, includes a calculation unit. The calculation unit calculates and estimates the clamping force through a preset algorithm based on the clamping force data and / or other relevant parameters of the main execution module. In this way, when the main execution module fails, the secondary execution module can take over the braking task, provide redundant braking capabilities, and enhance the reliability and safety of the system.

[0076] The controller is the "brain" of the brake system. It is connected to the motor position sensor, current sensor and force sensor, receives instructions from the control module, and controls the rotation of the motor according to the real-time information of these sensors. By accurately controlling the rotation angle and current of the motor, the controller can perform precise clamping or releasing operations.

[0077] When working, the control module sends operation instructions to the controller, and the controller controls the rotation of the motor according to the instructions and the real-time information of the sensor. The main execution module provides power through the motor and the deceleration and torque increase mechanism, and the motion conversion mechanism converts the rotational motion into linear motion to realize the braking operation.

[0078] Specifically, when the control module sends a braking command, the controller receives the command and accurately controls the rotation of the motor based on the real-time information of the motor position sensor, current sensor and force sensor. The motor provides the necessary power through the deceleration and torque increase mechanism, and drives the motion conversion mechanism to convert the rotational motion into linear motion, thereby achieving clamping or releasing operations. The force sensor measures the clamping force in real time to ensure the accuracy and stability of the braking effect. At the same time, the secondary execution module calculates and estimates the clamping force based on the clamping force data and / or other relevant parameters of the main execution module to provide redundant or auxiliary braking and enhance the reliability and safety of the system.

[0079] like Figure 2 , Figure 3 As shown, according to the above-mentioned electronic mechanical brake system, the present invention records a control method of the electronic mechanical brake system. Based on this method, each functional module is first described:

[0080] Upper control system: used to issue instructions to control the clamping / release of the actuator.

[0081] Vehicle parameters: Vehicle parameters that affect the wear difference of friction linings, such as the distribution ratio before and after the braking force is sent to the contact calculation module in each wheel without force sensor for a single force sensor solution.

[0082] Contact point identification: It is used to update the contact point stroke of the piston in the force sensor wheel according to the change of the clamping force obtained by the force sensor and the change of the motor current of the wheel actuator, so as to judge the wear of the friction lining and realize adaptive compensation of the friction lining.

[0083] Contact calculation: It is used to update the contact point stroke of the piston in the wheel without force sensor according to the contact point identification module in the wheel with force sensor, combined with the change of the motor current of the wheel actuator, so as to judge the wear condition of the friction lining and realize adaptive compensation of the friction lining.

[0084] Piston position calculation: The motor angle is sensed in real time by the motor position sensor, and then integrated according to the actuator parameters to obtain the piston position.

[0085] Force sensor: senses the clamping force and transmits the clamping force in the force sensor wheel to the force sensor wheels.

[0086] Stiffness fitting: It is used to receive the clamping force and piston position information of the force sensor wheel in the force-free sensor wheel to perform stiffness fitting, and then obtain the estimated clamping force according to the piston position of the wheel.

[0087] Friction identification: The friction torque required for friction compensation control is identified in the force sensor wheel based on the motor current, motor speed and clamping force; the friction torque required for friction compensation control is identified in the force sensor wheel based on the motor current, motor speed and estimated clamping force.

[0088] Execution layer clamping / release control: When the upper control system issues a clamping / release command, the wheel with force sensor executes the motor drive according to the piston position, contact point stroke and clamping force, and completes the clamping or releasing of the actuator and the clamping / release command of the friction lining replacement control. The wheel without force sensor executes the motor drive according to the piston position, contact point stroke and the estimated clamping force obtained by the stiffness fitting module, and completes the clamping or releasing command of the actuator.

[0089] Actuator: responds to motor torque and completes braking needs by converting motor torque into clamping force acting on the brake disc.

[0090] like Figure 2 , Figure 4 As shown, based on the above description, the following is a method for controlling the wheel clamping force of a force sensor based on a single force sensor, in which one of the four wheels of the vehicle is equipped with a force sensor, and the other three wheels are not equipped with force sensors:

[0091] S101: directly obtaining a clamping force value of the wheel through a clamping force sensor;

[0092] S102: Determine whether the conditions for triggering contact recognition are met:

[0093] If it is satisfied, contact identification is performed based on the motor current and clamping force, and then the piston position is calculated based on the motor rotation angle;

[0094] Then, the friction torque required for friction compensation control is identified according to the motor current, motor speed and clamping force;

[0095] If it is not satisfied, the piston position is directly calculated according to the motor rotation angle; then the friction torque required for friction compensation control is identified according to the motor current, motor speed and clamping force;

[0096] S103: Determine whether a clamping / releasing instruction is received from the upper control system:

[0097] If received, the corresponding instruction is executed according to the clamping force and piston position;

[0098] If not received, no clamping / releasing action is performed.

[0099] Combining the above steps, the specific implementation process is as follows:

[0100] Get the real-time clamping force value directly through the clamping force sensor installed on the wheel or brake system.

[0101] After obtaining the clamping force value, a judgment is made as to whether the conditions for triggering contact recognition are met.

[0102] a: If the conditions for triggering contact recognition are met:

[0103] Contact recognition is performed based on the changes in motor current and clamping force. This step is usually used to determine whether the wheel and brake disc are in close contact to ensure that subsequent control actions can be accurately executed.

[0104] Next, the position of the piston is calculated based on the change in the motor angle. The functional relationship between the motor angle and the piston position is:

[0105]

[0106] s is the piston position, θ is the mechanical angle of the motor rotation, k is the transmission ratio of the deceleration and torque increase mechanism, p is the thread pitch, r is the pitch circle radius,

[0107] The current position of the piston can be indirectly known by measuring the motor angle.

[0108] If a clamping / releasing command is received from the upper control system at this time, the corresponding command is executed according to the current clamping force and piston position.

[0109] For example, if the instruction is clamping and the current clamping force does not reach the set value, the motor current is increased to increase the clamping force; if the instruction is releasing, the motor current is reduced to reduce the clamping force.

[0110] If no clamping / releasing command is received, no clamping or releasing action is performed and the current state is maintained.

[0111] b: If the conditions for triggering contact recognition are not met:

[0112] The piston position is calculated directly based on the change in the motor angle, skipping the contact identification step.

[0113] The subsequent steps are the same as when the conditions are met, that is, the corresponding clamping / releasing actions are performed or the current state is maintained according to the instructions and the current state.

[0114] In some implementations, such as Figure 3 , Figure 4 As shown, based on the installation of force sensors in two of the four wheels of the vehicle and the absence of force sensors in the other wheels, the wheel clamping force control method based on two force sensors is the same as the wheel clamping force control method based on a single force sensor, which will not be elaborated here.

[0115] like Figure 2 , Figure 5 As shown, in some embodiments, a force sensor is installed on only one wheel (e.g., the left front wheel) of the vehicle, while no force sensor is installed on the other wheels. The purpose of this embodiment is to achieve effective control and monitoring of the wheel without a force sensor (hereinafter referred to as a "wheel without force sensor") through the data of a single force sensor.

[0116] A force sensor is set on one of the four wheels, and no force sensor is set on the other three wheels, that is, a force sensor-free wheel control method based on a single force sensor is as follows:

[0117] S1: Determine whether the conditions for triggering contact calculation are met;

[0118] S2: If the conditions are met, perform the following steps:

[0119] S201: Acquiring vehicle parameter information, including front and rear force distribution ratio, etc., which affects the wear difference of front and rear brake linings;

[0120] S202: performing contact calculation according to the acquired vehicle parameter information and motor current;

[0121] S203: Calculate the piston position according to the motor angle;

[0122] S204: performing stiffness fitting based on the clamping force and piston position information of the force sensor wheel and the piston position information of the current wheel to obtain an estimated clamping force;

[0123] S205: identifying the friction torque required for friction compensation control according to the motor current, the motor speed and the estimated clamping force;

[0124] S206: Determine whether a clamping / releasing instruction is received from the upper control system. If received, execute the corresponding instruction according to the estimated clamping force and piston position; if not received, do not perform the clamping / releasing action.

[0125] S3: If the conditions are not met, perform the following steps:

[0126] Step 301: Calculate the piston position according to the motor angle;

[0127] Step 302: performing stiffness fitting based on the clamping force and piston position information of the force sensor wheel and the piston position information of the current wheel to obtain an estimated clamping force;

[0128] Step 303: Identify the friction torque required for friction compensation control according to the motor current, the motor speed and the estimated clamping force;

[0129] Step 304: Determine whether a clamping / releasing instruction is received from an upper control system;

[0130] If received, the corresponding command is executed according to the estimated clamping force and piston position;

[0131] If not received, no clamping / releasing action will be performed.

[0132] Among the four wheels of the vehicle, this embodiment specifically selects one wheel (for example, the left front wheel) as the installation location of the force sensor, while the other three wheels are not equipped with force sensors. The core goal of this solution is to achieve effective control and precise monitoring of all wheels (especially those "force sensor-free wheels" without sensors installed) through the data of this single force sensor. The detailed implementation process is as follows:

[0133] Trigger condition evaluation:

[0134] First, the system needs to determine whether the current state meets the conditions for triggering contact calculation. These conditions may involve changes in vehicle speed, brake system status, or motor current.

[0135] If the conditions meet the triggering conditions, the system will execute the following steps:

[0136] Vehicle parameter acquisition: Collect key vehicle parameters, such as the front and rear force distribution ratio, which are crucial to understanding the wear difference of the front and rear brake linings during braking.

[0137] Contact calculation: Combines acquired vehicle parameters with real-time motor current data to perform contact calculations to preliminarily estimate the contact state of the brake pad and the possible clamping force range.

[0138] Piston position calculation: Based on the motor angle information, the piston positions of all current wheels (including wheels with force sensors and wheels with no force sensors) are accurately calculated.

[0139] Stiffness fitting and estimated clamping force: The actual clamping force and piston position information of the wheel with a strong sensor are used together with the piston position information of the current wheel with no force sensor, and are input into the preset stiffness fitting model to perform stiffness fitting calculations to estimate the clamping force of the wheel with no force sensor.

[0140] Friction identification: Identifies the friction torque required for friction compensation control based on motor current, motor speed and estimated clamping force.

[0141] Command response: Determine whether the clamping / releasing command is received from the upper control system. If received, the corresponding clamping or releasing action is accurately performed according to the estimated clamping force and piston position information; if no command is received, the current state is maintained unchanged.

[0142] Execution flow when the trigger condition is not met:

[0143] If the current state does not meet the conditions for triggering contact calculation, the system will simplify the process and directly execute the following steps:

[0144] Piston position calculation: Also based on the motor angle information, the piston positions of all wheels are calculated.

[0145] Stiffness fitting and estimated clamping force: Similar to the method of satisfying the trigger condition, but this time there is no need to perform additional contact calculations. The existing data can be directly used for stiffness fitting to estimate the clamping force of the wheel without force sensor.

[0146] Friction identification: Identifies the friction torque required for friction compensation control based on motor current, motor speed and estimated clamping force.

[0147] Command response: Also check and respond to the commands of the upper control system, perform corresponding clamping / releasing actions or maintain the status quo.

[0148] This embodiment significantly reduces hardware costs by installing a force sensor on only one wheel, while achieving enhanced system adaptability for the entire vehicle. This method can adapt to different vehicle parameters and driving conditions, and improves the adaptability and flexibility of the system by obtaining vehicle parameter information (such as the front and rear force distribution ratio) and performing corresponding calculations and adjustments.

[0149] In addition, the data of the wheel with force sensor is combined with the information of motor current, piston position, etc. to perform stiffness fitting, estimate the clamping force of the wheel without force sensor, and identify the friction torque required for friction compensation control based on the motor current, motor speed and estimated clamping force. This achieves precise control of the wheel without force sensor and improves the overall performance and safety of the braking system.

[0150] This method can determine in real time whether the clamping / releasing command from the upper control system has been received, and quickly execute the corresponding command based on the estimated clamping force and piston position, ensuring the rapid response and reliability of the braking system. And through real-time monitoring and estimation of wheel clamping force, potential problems of the braking system, such as wear of the brake lining, can be discovered in time, which helps to optimize maintenance plans and extend the service life of the braking system.

[0151] This embodiment uses a single force sensor to effectively control and monitor the wheel without force sensor, reduces costs, and improves the reliability and safety of the braking system. At the same time, the method combines vehicle parameters and motor status information to improve the accuracy of estimated clamping force, providing strong support for the intelligent control of vehicle braking systems.

[0152] like Figure 3 , Figure 6 As shown, in some embodiments, force sensors are set on two of the four wheels, and the force sensor-free wheel control method based on setting a single force sensor on the vehicle wheel is as follows:

[0153] a) Determine whether the conditions for triggering contact calculation are met;

[0154] b) If the conditions for triggering contact calculation are met, the following steps are performed:

[0155] S401: performing contact calculation based on motor current;

[0156] S402: Calculate the piston position according to the motor angle;

[0157] S403: performing stiffness fitting based on the clamping force and piston position information of the wheel with a force sensor and the piston position information of the wheel with no force sensor to obtain an estimated clamping force;

[0158] S404: identifying the friction torque required for friction compensation control according to the motor current, the motor speed and the estimated clamping force;

[0159] S405: Determine whether a clamping / releasing instruction is received from an upper control system;

[0160] If yes, executing corresponding clamping / releasing commands according to the estimated clamping force and piston position;

[0161] If no, no clamping / releasing action is performed;

[0162] c) If the conditions for triggering contact calculation are not met, perform the following steps:

[0163] S501: Calculate the piston position directly based on the motor angle;

[0164] S502: similarly performing stiffness fitting based on the clamping force and piston position information of the force sensor wheel and the piston position information of the forceless sensor wheel to obtain an estimated clamping force;

[0165] S503: Identifying the friction torque required for friction compensation control according to the motor current, the motor speed and the estimated clamping force;

[0166] S504: Determine whether a clamping / releasing instruction is received from an upper control system;

[0167] If yes, executing corresponding clamping / releasing commands according to the estimated clamping force and piston position;

[0168] If no, no clamping / releasing action is performed.

[0169] This embodiment proposes a method for controlling a wheel without force sensors based on two force sensors installed on the vehicle wheels. The method aims to achieve effective control and monitoring of the wheel without force sensors by installing force sensors only on the two wheels of the vehicle. The specific implementation process is as follows:

[0170] Force sensor installation: Force sensors are installed on the left front wheel and right rear wheel of the vehicle, and no force sensors are installed on other wheels. These two force sensors will be used to measure the clamping force of the wheels and provide data support for subsequent contact calculation and stiffness fitting.

[0171] Trigger condition judgment: The system continuously monitors the vehicle status to determine whether the conditions for triggering contact calculation are met. These conditions may include whether the vehicle speed exceeds a certain threshold, whether the brake system is activated, whether the motor current changes, etc. If the conditions are met, proceed to the next step; if not, the piston position calculation is directly executed.

[0172] Contact calculation and piston position calculation: When the trigger condition is met, the system first performs contact calculation based on the motor current to estimate the contact state of the brake pad and the possible clamping force range. Then, the piston position of the force sensor wheel and the force sensor wheel is calculated based on the motor angle.

[0173] Stiffness fitting and estimated clamping force: The system uses the clamping force information and piston position information of the wheel with force sensor and the piston position information of the wheel with no force sensor to perform stiffness fitting. Through stiffness fitting calculation, the system obtains the estimated clamping force of the wheel with no force sensor. This estimated clamping force will be used for subsequent control and monitoring.

[0174] Friction identification: Identifies the friction torque required for friction compensation control based on motor current, motor speed and estimated clamping force.

[0175] Piston position calculation and stiffness fitting: If the trigger condition is not met, the system first calculates the piston position based on the motor angle. Then, stiffness fitting is performed based on the clamping force and piston position information of the wheel with force sensor and the piston position information of the wheel with no force sensor to obtain the estimated clamping force of the wheel with no force sensor. Then, the friction torque required for friction compensation control is identified based on the motor current, motor speed and estimated clamping force.

[0176] Execute clamping / releasing instructions: The system determines and executes the clamping / releasing instructions of the upper control system. Based on the estimated clamping force and piston position, the system controls the clamping or releasing action of the wheel to achieve actual control of the wheel clamping force.

[0177] In this method, the contact state of the brake pad and the possible clamping force range can be accurately estimated by performing contact calculations using the motor current and vehicle parameter information. This provides important data support for subsequent stiffness fitting. By using the clamping force information and piston position information of the force sensor wheel and the piston position information of the force sensor wheel for stiffness fitting, the estimated clamping force of the force sensor wheel can be obtained, and the friction torque required for friction compensation control can be identified based on the motor current, motor speed and estimated clamping force. This method effectively solves the problem that the clamping force of the force sensor wheel cannot be directly measured.

[0178] Since the present embodiment only installs force sensors on two wheels of the vehicle, the complexity and cost of the system can be significantly reduced. This makes the method more economical and feasible in practical applications. Through precise contact calculation and stiffness fitting, the method can achieve accurate estimation and control of the clamping force of the forceless sensor wheel. This ensures the stability and safety of the vehicle braking system.

[0179] In practical applications, this method can be adjusted and optimized according to the specific characteristics of the vehicle and the braking system to achieve the best control effect.

[0180] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

[0181] In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it; when the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A control method for an electromechanical brake system, wherein a force sensor is installed on a wheel of a vehicle; characterized in that: The electronic mechanical brake system includes a control module for sending operation instructions to control the operation of the brake system; an execution module including a main execution module and a secondary execution module, wherein the main execution module is provided with a force sensor and obtains the clamping force through contact recognition, and the secondary execution module obtains the estimated clamping force through contact calculation; The control method comprises the following steps: Obtain vehicle parameters and send the vehicle parameters to the contact calculation module; perform contact calculation based on the vehicle parameters and motor current; if the vehicle parameters do not need to be obtained, perform contact calculation based on the motor current; Based on the above contact calculation, the piston position calculation is performed according to the motor angle information of the powerless sensor wheel to obtain the piston position information of the powerless sensor wheel; According to the clamping force information of the wheel with a strong sensor, the motor current and the motor angle of the wheel with no force sensor, stiffness fitting is performed to determine the estimated clamping force of other wheels; According to the information obtained in the above steps, clamping or releasing is performed; The above control method includes a force-free sensor wheel control method based on a single force sensor being set on a vehicle wheel, and the force-free sensor wheel control method based on a single force sensor being set on a vehicle wheel is as follows: When a force sensor is provided on one of the wheels of the vehicle and no force sensor is provided on the other wheels, determining whether a condition for triggering contact calculation is satisfied; If the conditions are met, perform the following steps: Acquire vehicle parameter information; perform contact calculation based on the acquired vehicle parameter information and motor current; First, the piston position is calculated according to the motor angle; then the clamping force of the force sensor wheel, the piston position information, and the piston position information of the current corresponding force sensor wheel are fitted with stiffness to obtain the estimated clamping force; Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force; Finally, the clamping / releasing instructions are judged and executed.

2. The method according to claim 1, characterized in that The main execution module includes a motor and a deceleration and torque-increasing mechanism, which are used to provide clamping or releasing power; a motion conversion mechanism, which is connected to the motor and the deceleration and torque-increasing mechanism and converts the rotational motion of the motor into linear motion, wherein a force sensor is integrated in the motion conversion mechanism and is used to measure the clamping force; a motor position sensor, which is integrated in the motor or the motor controller and is used to sense the rotation angle of the motor in real time; The current sensor is integrated into the motor or motor controller and is used to sense the motor current in real time.

3. The method according to claim 2, characterized in that It also includes a controller connected to the motor position sensor, current sensor and force sensor, which is used to receive instructions from the control module and control the rotation of the motor according to real-time information from the motor position sensor, current sensor and force sensor to perform clamping or releasing operations.

4. The method according to claim 1, characterized in that: The secondary execution module includes a calculation unit for calculating and estimating the clamping force through a preset algorithm according to the clamping force data and / or other relevant parameters of the primary execution module to provide redundant or auxiliary braking.

5. The method according to claim 1, characterized in that After the stiffness fitting is performed to obtain the estimated clamping force, before the clamping operation is performed, a friction identification step is also included. In the friction identification step, friction compensation is identified through motor current, motor speed and estimated clamping force to control the required friction torque.

6. The method according to claim 5, characterized in that The stiffness fitting method includes receiving the clamping force and piston position information of the wheel with a force sensor, performing data fitting to obtain a functional relationship between the clamping force and the piston position, and then calculating the estimated clamping force through the functional relationship based on the piston position information of the wheel without a force sensor.

7. The method according to claim 1, characterized in that If the conditions for triggering contact calculation are not met, perform the following steps: First, calculate the piston position based on the motor angle; Then, stiffness fitting is performed based on the clamping force and piston position information of the force sensor wheel and the piston position information of the current wheel to obtain the estimated clamping force. Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force; Finally, the clamping / releasing instructions are judged and executed.

8. The method according to claim 1, characterized in that The forceless sensor wheel control method based on setting two force sensors on the vehicle wheels is as follows: Force sensors are arranged on two of the wheels of the vehicle, and no force sensors are arranged on the other wheels; First, determine whether the conditions for triggering contact calculation are met. If the conditions are met, perform the following steps: First, the contact calculation is performed based on the motor current; then the piston position is calculated based on the motor angle; Then, stiffness fitting is performed based on the clamping force information and piston position information of the wheel with a force sensor and the piston position information of the wheel with no force sensor to obtain an estimated clamping force; Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force; Finally, the clamping / releasing instructions are judged and executed; If the condition is not met, perform the following steps: First, the piston position is calculated according to the motor angle; then, the stiffness is fitted through the clamping force and piston position information of the force sensor wheel and the piston position information of the forceless sensor wheel to obtain the estimated clamping force; Then, the friction torque required for friction compensation control is identified based on the motor current, the motor speed and the estimated clamping force; Finally, the clamping / releasing instructions are judged and executed.

Images