Redundant electromechanical brake actuator and control method thereof
By adopting redundant electronic control units and six-phase motor technology in the electronic mechanical brake actuator, the problems of high cost, heavy mass and difficult layout of the brake system are solved, and efficient, safe and economical braking effects are achieved.
Patent Information
- Application Number
- CN202510175924.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-18
- Publication Date
- 2025-03-28
AI Technical Summary
The existing electronic mechanical brake actuators have problems such as high cost, heavy unsprung mass, and difficult to arrange, especially when space is limited.
Redundant electronic mechanical brake actuators are adopted, including the main electronic control unit, the secondary electronic control unit, a six-phase motor and a force sensor. Through independent power supply and six-phase motor technology, redundant and efficient control of the brake system can be achieved.
While meeting vehicle safety needs, the cost and unsprung quality of the brake system are reduced, the system structure is simplified, and the clamping function can still be achieved in the case of single point failure of electronic and electrical appliances.
Smart Images
Figure CN119705393A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of vehicle structure and relates to a vehicle service brake system. Background Art
[0002] In modern vehicles, each individual wheel is assigned a brake unit with an electromechanical brake. Such a braking system is known as a "brake-by-wire" system.
[0003] In such a system, the brake pedal is used only to query the vehicle driver's braking demand. Based on this braking demand, the individual brake units are then activated with the aid of one or more electronic control units. There is no mechanical connection between the brake pedal and the brake units.
[0004] Since the brake system is a safety-related device of the vehicle, at least some components or functions are usually implemented redundantly in the brake system so that the brake system can operate reliably even in the event of a malfunction or defect. In other words, redundancy is provided in the brake system to achieve high operational reliability. In previous "brake-by-wire" systems, the electromechanical brake actuator was usually implemented with two completely independent drive units. The backup of the drive unit brings new problems. In part, the problem is the increase in cost. More importantly, the increase in unsprung mass brought by the two drive units is very obvious. At the same time, it is difficult to arrange two complete drive units when the installation space is limited. Summary of the invention
[0005] In view of the technical problems existing in the background technology, the present invention aims to provide a redundant electronic mechanical brake actuator and a control method thereof, which can solve the problems of high cost, heavy unsprung mass and difficult layout of the electronic mechanical brake actuator proposed in the above background technology while meeting the basic safety requirements of the vehicle.
[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: the redundant electronic mechanical brake actuator comprises a main structure, which comprises a main electronic control unit, a sub-electronic control unit, a controller, a redundant motor angle sensor, a six-phase motor and a force sensor. The main electronic control unit is electrically connected to a main power supply, the sub-electronic control unit is electrically connected to a sub-power supply, the controller interacts with the main electronic control unit and the sub-electronic control unit respectively, the redundant motor angle sensor is signal-connected to the main electronic control unit and the sub-electronic control unit respectively, the six-phase motor is three-phase controlledly connected to the main electronic control unit and the sub-electronic control unit respectively, the six-phase motor is connected to a caliper through a mechanical structure transmission, the force sensor is used to measure the clamping force of the caliper, and the force sensor is signal-connected to the main electronic control unit and the sub-electronic control unit respectively.
[0007] In this solution, the main electronic control unit and the sub-electronic control unit are equipped with independent power supplies and are independent of each other. When the main electronic control unit fails, the sub-electronic control unit can participate in the braking response. This is achieved through six-phase motor technology, which reduces costs while ensuring that the vehicle's safety requirements are met. At the same time, it simplifies the system structure and effectively reduces the unsprung mass.
[0008] Preferably, the controller comprises a main CAN module and a secondary CAN module, the main CAN module interacts with the main electronic control unit and the secondary electronic control unit respectively, and the secondary CAN module interacts with the main electronic control unit and the secondary electronic control unit respectively.
[0009] In this solution, in the event of any single-point failure of the electronic and electrical components of the electromechanical brake actuator, the clamping function can be achieved to meet the safety requirements of the vehicle.
[0010] This method for controlling a redundant electronic mechanical brake actuator, the vehicle includes the redundant electronic mechanical brake actuator described in claim 1, when the main structure does not fail, the main electronic control unit receives the clamping request sent by the controller and controls the operation of the six-phase motor, and the controller sends a motor shutdown control request to the sub-electronic control unit, and the sub-electronic control unit shuts down the three-phase control of the six-phase motor.
[0011] In this solution, when the main structure does not fail, the main electronic control unit controls the operation of the six-phase motor, and the auxiliary electronic control unit shuts down the three-phase control of the six-phase motor to avoid interference.
[0012] Preferably, the main electronic control unit controls the rotation of the six-phase motor based on the motor angle obtained by the redundant motor angle sensor, the controller sends a target clamping force request to the main electronic control unit, the force sensor feeds back the clamping force of the caliper to the main electronic control unit, the main electronic control unit compares the fed-back clamping force with the target clamping force and adjusts the rotation of the six-phase motor based on the comparison result.
[0013] In this solution, the main electronic control unit obtains the motor angle through redundant motor angle sensors, uses the FOC control algorithm to control the three phases of the six-phase motor to achieve motor rotation control, and accurately controls the size and direction of the magnetic field, so that the motor's movement torque is smooth, the noise is low, the efficiency is high, and it has a high-speed dynamic response.
[0014] Preferably, when the main electronic control unit fails, the secondary electronic control unit receives the controller request to control the operation of the six-phase motor. The main electronic control unit failure includes single-point failure of the main power supply, single-point failure of the main electronic control unit, single-point failure of the three-phase control connection between the main electronic control unit and the six-phase motor, and single-point failure of the signal connection between the redundant motor angle sensor and the main electronic control unit.
[0015] In this solution, when the main electronic control unit fails, the auxiliary electronic control unit receives the controller's request to control the six-phase motor to achieve the clamping function and meet the safety requirements of the vehicle.
[0016] Preferably, the sub-electronic control unit controls the rotation of the six-phase motor based on the motor angle obtained by the redundant motor angle sensor, the controller sends a target clamping force request to the sub-electronic control unit, the force sensor feeds back the clamping force of the caliper to the sub-electronic control unit, and the sub-electronic control unit compares the feedback clamping force with the target clamping force and adjusts the rotation of the six-phase motor based on the comparison result.
[0017] In this solution, the sub-electronic control unit obtains the motor angle through redundant motor angle sensors, uses the FOC control algorithm to control the three phases of the six-phase motor to achieve motor rotation control, and accurately controls the size and direction of the magnetic field, so that the motor's movement torque is smooth, the noise is low, the efficiency is high, and it has a high-speed dynamic response.
[0018] Preferably, the main electronic control unit sends relevant failure information to the controller and shuts down the three-phase control of the six-phase motor.
[0019] In this solution, the three-phase control of the six-phase motor by the main electronic control unit is turned off to avoid interference.
[0020] Preferably, the redundant electronic mechanical brake actuator also includes a force estimation model, which includes a brake disc temperature model, a friction pad temperature model, a brake disc thermal expansion estimation model, a friction pad thermal expansion estimation model, a friction pad wear estimation model, a current position and force learning curve estimation module, a motor cumulative angle calculation module, a mechanical position calculation module and a clamping force estimation module, and the main electronic control unit includes storage. When the force sensor fails, the controller sends the whole vehicle environmental parameters to the brake disc temperature model, the friction pad temperature model and the friction pad wear estimation model, the brake disc temperature model sends the brake disc estimated temperature to the brake disc thermal expansion estimation model based on the whole vehicle environmental parameters, the friction pad temperature model sends the friction pad estimated temperature to the friction pad thermal expansion estimation model and the friction pad wear estimation model based on the whole vehicle environmental parameters, the brake disc thermal expansion estimation model sends the brake disc thermal expansion amount to the current position and force learning curve estimation based on the brake disc estimated temperature, and the friction pad thermal expansion estimation model The thermal expansion of the friction plate is sent to the current position and force learning curve estimation based on the estimated temperature of the friction plate. The friction plate wear estimation model sends the friction plate wear to the current position and force learning curve estimation module based on the vehicle environmental parameters and the estimated temperature of the friction plate. The current position and force learning curve estimation module obtains the historical position and force learning curve from the storage, and sends the current position and force estimation curve to the clamping force estimation module based on the historical position, force learning curve, thermal expansion of the friction plate, thermal expansion of the brake disc and friction plate wear. The motor cumulative angle calculation module sends the motor cumulative angle to the mechanical position calculation module based on the motor angle of the motor angle sensor. The mechanical position calculation module sends the mechanical position to the clamping force estimation module based on the motor cumulative angle. The clamping force estimation module sends the estimated clamping force to the main electronic control unit based on the current position, the force estimation curve and the mechanical position. The main electronic control unit compares the estimated clamping force with the target clamping force and adjusts the rotation of the six-phase motor based on the comparison result.
[0021] In this solution, the force estimation model in the event of force sensor failure is used to ensure that the safety requirements of the vehicle are met, while the cost is reduced due to the invalid redundant force sensors.
[0022] The beneficial effects of the present invention are that, in the case of any electronic and electrical single-point failure of the electronic mechanical brake actuator, the clamping function can be realized to meet the safety requirements of the vehicle; it is realized by the six-phase motor technology, which ensures that the safety requirements of the vehicle are met, and the cost is reduced, while simplifying the system structure and effectively reducing the unsprung mass; through the force estimation model in the case of force sensor failure, the cost is reduced because of the invalid redundant force sensor while ensuring that the safety requirements of the vehicle are met. Therefore, compared with the prior art, the present invention has substantial characteristics and progress. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The following describes the relevant details and working principles of the implementation mode and embodiments of the present invention in conjunction with the accompanying drawings.
[0024] Figure 1 It is a schematic diagram of the system structure of the present invention.
[0025] Figure 2 It is a functional interaction schematic diagram of the present invention.
[0026] Figure 3 It is a schematic diagram of functional interaction in the event of a related failure of the main electronic control unit of the present invention.
[0027] Figure 4 It is a schematic diagram of functional interaction when the main CAN module of the present invention fails.
[0028] Figure 5 It is a schematic diagram of functional interaction when the force sensor of the present invention fails.
[0029] Figure 6 It is a schematic diagram of the force estimation model of the present invention. DETAILED DESCRIPTION
[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the implementation mode of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.
[0031] In the description of the present application, it should be understood that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0032] In the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.
[0033] In the drawings, the main electronic control unit is the main ECU-A, the sub-electronic control unit is the sub-ECU-B, the main CAN module is CAN1, and the sub-CAN module is CAN2.
[0034] See attached Figure 1-5In an embodiment of the present embodiment, a redundant electronic mechanical brake actuator comprises a main structure, wherein the main structure comprises a main electronic control unit, a sub-electronic control unit, a controller, a redundant motor angle sensor, a six-phase motor and a force sensor, wherein the main electronic control unit is electrically connected to a main power supply, wherein the sub-electronic control unit is electrically connected to a sub-power supply, wherein the controller interacts with the main electronic control unit and the sub-electronic control unit respectively, wherein the controller comprises a main CAN module and a sub-CAN module, wherein the main CAN module interacts with the main electronic control unit and the sub-electronic control unit respectively, wherein the sub-CAN module interacts with the main electronic control unit and the sub-electronic control unit respectively, wherein the redundant motor angle sensor is signal-connected with the main electronic control unit and the sub-electronic control unit respectively, wherein the six-phase motor is three-phase-controlledly connected with the main electronic control unit and the sub-electronic control unit respectively, wherein the six-phase motor is transmission-connected with a caliper through a mechanical structure, wherein the force sensor is used to measure the clamping force of the caliper, wherein the force sensor is signal-connected with the main electronic control unit and the sub-electronic control unit respectively.
[0035] In this embodiment, the controller sends a clamping request to the electronic control unit, and the electronic control unit controls the six-phase motor to drive the caliper to clamp through the mechanical structure according to the motor angle. The electronic control unit compares the clamping force fed back by the force sensor with the target clamping force, and adjusts the rotation of the six-phase motor. When the main CAN module fails, the main electronic control unit receives the controller request, controls the six-phase motor to move, and realizes the clamping force output of the caliper. The auxiliary electronic control unit receives the motor control shutdown request sent by the controller through the auxiliary CAN module, and shuts down the three-phase control of PMSM-B. The main electronic control unit receives the target clamping force request sent by the controller through the auxiliary CAN module. The other control processes are consistent with the main structure not failing. Among them, the auxiliary electronic control unit can participate in the response when the main electronic control unit fails. The main and auxiliary electronic control units are each configured with a power supply, so that the failure of a single power supply will not affect another electronic control unit; the auxiliary CAN module can participate in the response when the main CAN module fails; the redundant motor angle sensor sends the angle signal of the six-phase motor to the main electronic control unit through the sensor channel A, and the redundant motor angle sensor sends the angle signal of the six-phase motor to the auxiliary electronic control unit through the sensor channel B; the main electronic control unit controls PMSM-A The three phases control the rotation and output torque of the six-phase motor, and the sub-electronic control unit controls the rotation and output torque of the six-phase motor by controlling the three phases of the PMSM-B.
[0036] See attached Figure 2In an embodiment of the present embodiment, a control method for a redundant electronic mechanical brake actuator is provided. The vehicle includes the redundant electronic mechanical brake actuator described in claim 1. When the main structure does not fail, the main electronic control unit receives the clamping request sent by the controller and controls the operation of the six-phase motor, and the controller sends a motor shutdown request to the auxiliary electronic control unit. The auxiliary electronic control unit shuts down the three-phase control of the six-phase motor. The main electronic control unit controls the rotation of the six-phase motor according to the motor angle obtained by the redundant motor angle sensor. The controller sends a target clamping force request to the main electronic control unit. The force sensor feeds back the clamping force of the caliper to the main electronic control unit. The main electronic control unit compares the feedback clamping force with the target clamping force and adjusts the rotation of the six-phase motor according to the comparison result.
[0037] In this embodiment, the main electronic control unit receives the target clamping force request sent by the controller through the main CAN module. The main electronic control unit obtains the motor angle feedback through the redundant motor angle sensor A channel, and uses the FOC control (Field-Oriented Control) algorithm to control the PMSM-A three-phase of the six-phase motor to achieve motor rotation control. The rotation of the six-phase motor is transmitted to the caliper by the mechanical structure to achieve clamping. The clamping of the caliper generates clamping force. The force sensor detects the clamping force and feeds it back to the main ECU-A (electronic control unit). The main ECU-A (electronic control unit) corrects the motor rotation control of the six-phase motor according to the feedback clamping force and the target clamping force request, and finally achieves consistency between the feedback clamping force and the target clamping force request.
[0038] See attached Figure 3 When the main electronic control unit fails, the sub-electronic control unit receives the controller's request to control the six-phase motor. The main electronic control unit failure includes a single-point failure of the main power supply, a single-point failure of the main electronic control unit, a single-point failure of the three-phase control connection between the main electronic control unit and the six-phase motor, and a single-point failure of the signal connection between the redundant motor angle sensor and the main electronic control unit. The sub-electronic control unit controls the rotation of the six-phase motor according to the motor angle obtained by the redundant motor angle sensor. The controller sends a target clamping force request to the sub-electronic control unit, and the force sensor feeds back the clamping force of the caliper to the sub-electronic control unit. The sub-electronic control unit compares the feedback clamping force with the target clamping force and adjusts the rotation of the six-phase motor according to the comparison result. The main electronic control unit sends relevant failure information to the controller and turns off the three-phase control of the six-phase motor.
[0039] See attached Figure 5-6The redundant electronic mechanical brake actuator also includes a force estimation model, which includes a brake disc temperature model, a friction pad temperature model, a brake disc thermal expansion estimation model, a friction pad thermal expansion estimation model, a friction pad wear estimation model, a current position and force learning curve estimation module, a motor cumulative angle calculation module, a mechanical position calculation module and a clamping force estimation module. The main electronic control unit includes a storage. When the force sensor fails, the controller sends the whole vehicle environmental parameters to the brake disc temperature model, the friction pad temperature model and the friction pad wear estimation model. The brake disc temperature model sends the brake disc estimated temperature to the brake disc thermal expansion estimation model based on the whole vehicle environmental parameters. The friction pad temperature model sends the friction pad estimated temperature to the friction pad thermal expansion estimation model and the friction pad wear estimation model based on the whole vehicle environmental parameters. The brake disc thermal expansion estimation model sends the brake disc thermal expansion amount to the current position and force learning curve estimation based on the brake disc estimated temperature. The friction pad thermal expansion estimation model sends the brake disc thermal expansion amount to the current position and force learning curve estimation based on the brake disc estimated temperature. According to the estimated temperature of the friction plate, the thermal expansion of the friction plate is sent to the current position and force learning curve estimation. The friction plate wear estimation model sends the friction plate wear to the current position and force learning curve estimation module based on the vehicle environmental parameters and the estimated temperature of the friction plate. The current position and force learning curve estimation module obtains the historical position and force learning curve from the storage, and sends the current position and force estimation curve to the clamping force estimation module based on the historical position, force learning curve, thermal expansion of the friction plate, thermal expansion of the brake disc and friction plate wear. The motor cumulative angle calculation module sends the motor cumulative angle to the mechanical position calculation module based on the motor angle of the motor angle sensor. The mechanical position calculation module sends the mechanical position to the clamping force estimation module based on the motor cumulative angle. The clamping force estimation module sends the estimated clamping force to the main electronic control unit based on the current position, force estimation curve and mechanical position. The main electronic control unit compares the estimated clamping force with the target clamping force and adjusts the rotation of the six-phase motor based on the comparison result.
[0040] In this embodiment, when the force sensor fails, the main electronic control unit receives the controller request and estimates the clamping force through the force estimation model, controls the action of the six-phase motor, and realizes the clamping force output of the caliper, wherein the auxiliary electronic control unit receives the motor control shutdown request sent by the controller through the main CAN module, shuts down the control of the PMSM-B three-phase, the main electronic control unit receives the target clamping force request sent by the controller through the main CAN module, the main electronic control unit obtains the motor angle feedback through the redundant motor angle sensor A channel, uses the FOC control (Field-Oriented Control) algorithm to control the PMSM-A three-phase of the six-phase motor to realize motor rotation control, the rotation of the six-phase motor is transmitted to the caliper by the mechanical structure to realize clamping, the caliper clamping generates clamping force, the main electronic control unit calculates the estimated clamping force through the force estimation model, and the main electronic control unit corrects the motor rotation control of the six-phase motor according to the comparison between the estimated clamping force and the target clamping force request, and finally realizes the consistency between the estimated clamping force and the target clamping force request.
[0041] The above is a preferred embodiment of the present invention, and it should be noted that the protection scope of the present invention is not limited thereto. For those skilled in the art, multiple improvements and modifications or equivalent substitutions can be made without departing from the equivalent inventive concept of the technical scope disclosed by the present invention, which are also regarded as the protection scope of the present invention.
Claims
1. A redundant electromechanical brake actuator, characterized in that: The main structure includes a main electronic control unit electrically connected to a main power supply; a secondary electronic control unit electrically connected to a secondary power supply; a controller, which interacts with the main electronic control unit and the sub-electronic control unit respectively; A redundant motor angle sensor, which is signal-connected to the main electronic control unit and the auxiliary electronic control unit respectively; A six-phase motor, which is respectively connected to the main electronic control unit and the auxiliary electronic control unit in three-phase control, and the six-phase motor is connected to a caliper through a mechanical structure transmission; A force sensor is used to measure the clamping force of the caliper, and the force sensor is respectively connected to the main electronic control unit and the auxiliary electronic control unit by signal.
2. A redundant electromechanical brake actuator as claimed in claim 1, characterized in that: The controller includes a main CAN module, which interacts with the main electronic control unit and the secondary electronic control unit respectively; The slave CAN module interacts with the main electronic control unit and the slave electronic control unit respectively.
3. A control method for a redundant electromechanical brake actuator, characterized in that: The vehicle includes the redundant electronic mechanical brake actuator described in claim 1. When the main structure does not fail, the main electronic control unit receives the clamping request sent by the controller and controls the operation of the six-phase motor, and the controller sends a motor shutdown request to the secondary electronic control unit, and the secondary electronic control unit shuts down the three-phase control of the six-phase motor.
4. A control method for a redundant electromechanical brake actuator as claimed in claim 3, characterized in that: The main electronic control unit controls the rotation of the six-phase motor according to the motor angle obtained by the redundant motor angle sensor. The controller sends a target clamping force request to the main electronic control unit. The force sensor feeds back the clamping force of the caliper to the main electronic control unit. The main electronic control unit compares the fed-back clamping force with the target clamping force and adjusts the rotation of the six-phase motor according to the comparison result.
5. A control method for a redundant electromechanical brake actuator as claimed in claim 3, characterized in that: When the main electronic control unit fails, the slave electronic control unit receives the controller request to control the six-phase motor. The main electronic control unit failures include single point failure of the main power supply, single point failure of the main electronic control unit, single point failure of the three-phase control connection between the main electronic control unit and the six-phase motor, and single point failure of the signal connection between the redundant motor angle sensor and the main electronic control unit.
6. A control method for a redundant electromechanical brake actuator as claimed in claim 5, characterized in that: The sub-electronic control unit controls the rotation of the six-phase motor according to the motor angle obtained by the redundant motor angle sensor. The controller sends a target clamping force request to the sub-electronic control unit. The force sensor feeds back the clamping force of the caliper to the sub-electronic control unit. The sub-electronic control unit compares the fed-back clamping force with the target clamping force and adjusts the rotation of the six-phase motor according to the comparison result.
7. A control method for a redundant electromechanical brake actuator as claimed in claim 5, characterized in that: The main electronic control unit sends relevant failure information to the controller and shuts down the three-phase control of the six-phase motor.
8. A control method for a redundant electromechanical brake actuator as claimed in claim 4, characterized in that: The redundant electronic mechanical brake actuator also includes a force estimation model, which includes a brake disc temperature model, a friction plate temperature model, a brake disc thermal expansion estimation model, a friction plate thermal expansion estimation model, a friction plate wear estimation model, a current position and force learning curve estimation module, a motor cumulative angle calculation module, a mechanical position calculation module and a clamping force estimation module. The main electronic control unit includes a storage. When the force sensor fails The controller sends vehicle environmental parameters to the brake disc temperature model, the friction pad temperature model and the friction pad wear estimation model; The brake disc temperature model sends the brake disc estimated temperature to the brake disc thermal expansion estimation model according to the vehicle environmental parameters; The friction plate temperature model sends the friction plate estimated temperature to the friction plate thermal expansion estimation model and the friction plate wear estimation model according to the vehicle environmental parameters; The brake disc thermal expansion estimation model sends the brake disc thermal expansion amount to the current position and force learning curve estimation based on the brake disc estimated temperature; The friction plate thermal expansion estimation model sends the friction plate thermal expansion amount to the current position and force learning curve estimation based on the estimated temperature of the friction plate; The friction plate wear estimation model sends the friction plate wear amount to the current position and force learning curve estimation module based on the vehicle environmental parameters and the friction plate estimated temperature; The current position and force learning curve estimation module obtains the historical position and force learning curve from the storage, and sends the current position and force estimation curve to the clamping force estimation module according to the historical position, the force learning curve, the thermal expansion of the friction plate, the thermal expansion of the brake disc and the wear of the friction plate; The motor cumulative angle calculation module sends the motor cumulative angle to the mechanical position calculation module according to the motor angle of the motor angle sensor; The mechanical position calculation module sends the mechanical position to the clamping force estimation module based on the motor's accumulated angle; The clamping force estimation module sends an estimated clamping force to the main electronic control unit based on the current position, the force estimation curve and the mechanical position; The main electronic control unit compares the estimated clamping force with the target clamping force and adjusts the rotation of the six-phase motor according to the comparison result.