A dual-redundant steer-by-wire system based on six-phase motors

Abstract

A dual-redundant wire-controlled steering system based on a six-phase motor relates to the technical field of wire-controlled systems, and includes a controller and a six-phase motor, wherein the controller includes a main control chip, an auxiliary control chip, a first power module, and a second power module; the main control chip is connected to the six-phase motor through the first power module to form a main control loop; the auxiliary control chip is connected to the six-phase motor through the second power module to form an auxiliary control loop; the main control chip and the auxiliary control chip are connected to each other in communication. The auxiliary control chip in the present invention not only has an ignition signal detection function, but also has a fault detection function and a control loop switching control function, which can effectively avoid the phenomenon that the control loop cannot be switched due to a main control loop failure, ensure that the controller does not lose the steering control function, effectively improve the controller's response speed to fault information, and realize safe redundant control.

Description

Technical Field

[0001] The present invention relates to the technical field of wire control systems, and in particular to a dual-redundant wire control steering system based on a six-phase motor. Background Art

[0002] The automobile steering system is a key assembly that determines the active safety of the automobile. The traditional automobile steering system is a mechanical system. The steering movement of the automobile is achieved by the driver operating the steering wheel, which is transmitted to the steering wheel through the steering gear and a series of rods. The wire control steering system eliminates the mechanical connection between the steering wheel and the steering wheel, and completely achieves steering by electric energy, getting rid of the various limitations of the traditional steering system. Not only can the force transmission characteristics of the automobile steering be freely designed, but also the angle transmission characteristics of the automobile steering can be designed, which brings unlimited space for the design of the automobile steering characteristics. It is a major innovation in the automobile steering system.

[0003] The steer-by-wire system usually consists of three parts: the steering wheel assembly, the steering execution assembly and the main controller. The main controller is used to analyze and process the collected signals, determine the movement state of the car, and send instructions to the steering wheel return force motor and the steering motor to control the operation of the two motors to ensure ideal vehicle response under various working conditions, so as to reduce the driver's compensation task for the changes in the steering characteristics of the car with the speed of the car and reduce the driver's burden. The main controller of the traditional steer-by-wire system usually has only one control chip and usually only one three-phase motor as the steering motor. When the control chip or the three-phase motor fails, the steering performance of the vehicle will be affected, so there is a serious safety hazard.

[0004] In order to solve this problem, the Chinese patent with announcement number CN214420544U discloses a wire-controlled EPS controller with dual-motor safety redundant control, which adopts the method of hybrid control of the main motor and the auxiliary motor by the main CPU and the auxiliary CPU to realize the safety redundant control of the wire-controlled steering system. However, in practical applications, the cross-hybrid control of the two steering motors by two CPUs not only has the problems of high control difficulty and complex algorithm programs, but also in the process of control switching, due to the coordinated switching of the two motor systems, there will be a delayed response, which will still affect the steering safety and stability of the vehicle. In addition, the arrangement of two three-phase motors will not only increase the design cost, but also take up extra space. Summary of the invention

[0005] The present invention provides a dual-redundant wire-controlled steering system based on a six-phase motor, the main purpose of which is to solve the problems existing in the prior art.

[0006] The present invention adopts the following technical solution:

[0007] A dual-redundant wire-controlled steering system based on a six-phase motor comprises a controller and a six-phase motor, wherein the controller comprises a main control chip, an auxiliary control chip, a first power module and a second power module; the main control chip is connected to the six-phase motor through the first power module to form a main control loop; the auxiliary control chip is connected to the six-phase motor through the second power module to form an auxiliary control loop; the main control chip and the auxiliary control chip are connected to each other in communication;

[0008] The control method of the dual redundant wire-controlled steering system comprises the following steps:

[0009] Step 1: The auxiliary control chip detects the vehicle's ignition signal in real time;

[0010] Step 2: When the ignition signal is collected, the auxiliary control chip first performs a fault detection on the auxiliary control circuit. If there is no fault in the auxiliary control circuit, step 3 is executed; if there is a fault in the auxiliary control circuit, step 4 is executed;

[0011] Step 3, the auxiliary control chip wakes up the main control chip and detects whether there is a fault in the main control circuit. If there is no fault in the main control circuit, execute step 5; if there is a fault in the main control circuit, determine whether the fault type of the main control circuit is a shutdown fault. If it is a shutdown fault, control the main control circuit to shut down and execute step 4. If it is not a shutdown fault, execute step 5;

[0012] Step 4: Determine whether the auxiliary control circuit has a shutdown fault. If there is no shutdown fault, execute step 6. If there is a shutdown fault, control the auxiliary control circuit to shut down and execute step 7.

[0013] Step 5, the main control circuit controls the six-phase motor to work; the six-phase motor includes a first winding and a second winding. In this step, firstly, it is detected whether the first winding and the second winding are faulty. If the first winding is not faulty, the main control circuit controls the six-phase motor to work through the first winding; if the first winding is faulty and the second winding is not faulty, the main control circuit controls the six-phase motor to work through the second winding; if both the first winding and the second winding are faulty, the controller shuts down and reports the winding fault information;

[0014] Step 6: The auxiliary control circuit controls the six-phase motor to work;

[0015] Step 7: The controller shuts down due to failure.

[0016] Furthermore, the controller also includes a second storage module connected to the auxiliary control chip; in step 2, if there is a fault in the auxiliary control circuit, the fault information of the auxiliary control circuit is written into the second storage module.

[0017] Furthermore, the controller also includes a first storage module connected to the main control chip; in step 3, if there is a fault in the main control circuit, the fault information of the main control circuit is written into the first storage module.

[0018] Furthermore, in step 3, if the main control chip cannot be awakened by the auxiliary control chip, the fault is recorded in the first storage module and step 4 is executed.

[0019] Further, in step 6, first detect whether the first winding and the second winding are faulty. If the second winding is not faulty, the auxiliary control circuit controls the six-phase motor to work through the second winding; if the second winding is faulty and the first winding is not faulty, the auxiliary control circuit controls the six-phase motor to work through the first winding; if both the first winding and the second winding are faulty, the controller shuts down and reports the winding fault information.

[0020] Furthermore, the main control chip and the auxiliary control chip achieve inter-chip communication via Ethernet.

[0021] Furthermore, the controller is also provided with a communication module and a signal switching chip, and the communication module is connected to the main control chip or the auxiliary control chip through the signal switching chip.

[0022] Furthermore, the controller also includes a first sampling module connected to the main control chip and a second sampling module connected to the auxiliary control chip.

[0023] Furthermore, the controller also includes a first fuse and a second fuse; in step 3, the auxiliary control chip cuts off the main control circuit through the first fuse, thereby quickly controlling the main control circuit to shut down; in step 4, the auxiliary control chip cuts off the auxiliary control circuit through the second fuse, thereby quickly controlling the auxiliary control circuit to shut down.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The auxiliary control chip in the present invention not only has the ignition signal detection function, but also has the fault detection function and the control circuit switching control function. When a fault is detected in the main control circuit, the main control circuit can be cut off in time, and the six-phase motor can be driven by the auxiliary control circuit, thereby ensuring that the controller will not lose the steering control function, and can effectively avoid the phenomenon that the control circuit cannot be switched due to the main control circuit failure, effectively improve the response speed of the controller to fault information, and realize safe redundant control.

[0026] 2. The present invention adopts a six-phase motor with dual windings and a single control strategy of a single control loop corresponding to a single winding, which not only realizes dual redundant control of the controller and improves the reliability of the system, but also greatly reduces the control difficulty, simplifies the control process, and can effectively ensure the steering safety and stability of the vehicle. In addition, compared with the use of two independent steering motors, the use of a six-phase motor has a lower design cost, does not take up extra space, and is more flexible in layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the dual redundant wire-controlled steering system in the present invention.

[0028] Figure 2 This is a control flow chart of the dual redundant steer-by-wire system of the present invention. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is described below with reference to the accompanying drawings. In order to fully understand the present invention, many details are described below, but for those skilled in the art, the present invention can be implemented without these details.

[0030] like Figure 1 As shown, a dual redundant wire-controlled steering system based on a six-phase motor includes a controller and a six-phase motor, wherein the controller includes a main control chip, an auxiliary control chip, a first power module, and a second power module; the main control chip is connected to the six-phase motor through the first power module to form a main control loop; the auxiliary control chip is connected to the six-phase motor through the second power module to form an auxiliary control loop; the main control chip and the auxiliary control chip are connected to each other in communication. The auxiliary control chip in the present invention is a spare chip, and the auxiliary control chip is used to control the six-phase motor only when there is a fault in the main control loop, thereby ensuring that the controller does not lose the steering control function.

[0031] like Figure 1 The six-phase motor is provided with a first winding and a second winding. Specifically, the six-phase motor is a dual-winding motor, that is, each three phases constitute a winding. More specifically, the six phases of the six-phase motor are named A phase, B phase, C phase, D phase, E phase and F phase. The first winding defined in the present invention is composed of A phase, B phase and C phase, and the second winding is composed of D phase, E phase and F phase. The first winding and the second winding are connected with neutral point isolation, which can facilitate the independent control of each three phases and simplify the control difficulty. At the same time, the two isolated windings can not interfere with each other. Even if one of the windings burns out, it will not cause the other winding to burn out. The two windings also form a dual redundant structure, further improving redundancy.

[0032] like Figure 1As shown, the controller also includes a first storage module connected to the main control chip and a second storage module connected to the auxiliary control chip. As a preferred solution: the first storage module and the second storage module are preferably EEPROM modules, which have erase and read functions, and can be used to monitor and record the health status of the chip at all times, and store relevant data for technicians to read information, thereby quickly troubleshooting.

[0033] like Figure 1 As shown, the auxiliary control chip is provided with an ignition signal detection port for detecting the ignition signal of the vehicle in real time, thereby starting the controller.

[0034] like Figure 1 As shown, the controller also includes a first sampling module and a second sampling module, the first sampling module is arranged between the first power module and the main control chip, and the second sampling module is arranged between the second power module and the auxiliary control chip. The first sampling module and the second sampling module are both used to collect relevant control parameters during the operation of the six-phase motor, such as bus voltage, six-phase current, power device temperature, etc.

[0035] like Figure 1 As shown, the controller also includes a signal switching chip and a communication module, and the communication module is provided with a CAN communication module and an SPI communication module. The communication mode between the main control chip and the auxiliary control chip and the vehicle controller is CAN communication, and the access ID is consistent, so that the corresponding operation can be performed when the same request instruction is received. The SPI communication module specifically refers to installing a magnetic encoder on the hardware PCB board and installing an induction magnet on the motor shaft. When the motor shaft rotates, the magnetic encoder can read the motor rotor position information based on the electromagnetic induction principle using SPI communication. Specifically, when the six-phase motor is controlled to work through the main control loop, the signal switching chip cuts off the connection between the auxiliary control chip and the communication module, so that the main control chip communicates with the vehicle controller through the CAN communication module, thereby obtaining vehicle data, and obtaining electronic rotor position information through the SPI communication module; when the six-phase motor is controlled to work through the auxiliary control loop, the signal switching module cuts off the connection between the main control chip and the communication module, so that the auxiliary control chip communicates with the vehicle controller through the CAN communication module, thereby obtaining vehicle data, and obtaining electronic rotor position information through the SPI communication module. In addition, the main control chip and the auxiliary control chip can also obtain relevant parameters such as temperature sampling signals and torque sensor output signals through the communication module.

[0036] like Figure 1 As shown, the controller also includes a first overcurrent protection module and a second overcurrent protection module. The first overcurrent protection module is arranged between the first power module and the main control chip, and the second overcurrent protection module is arranged between the second power module and the auxiliary control chip. It can prevent the chip from burning out due to overcurrent and effectively improve the safety performance of the controller.

[0037] like Figure 1 As shown, the controller also includes a first power module and a second power module. The first power module is arranged between the vehicle-mounted battery and the first power module, and is used to power the main control circuit; the second power module is arranged between the vehicle-mounted battery and the second power module, and is used to power the auxiliary control circuit.

[0038] like Figure 1 As shown, the controller is also provided with a first bus relay and a first fuse connected to the vehicle battery for the main control circuit, and a second bus relay and a second fuse connected to the vehicle battery for the auxiliary control circuit. When the main control circuit fails, the first fuse can be used to cut off the main control circuit, thereby quickly controlling the main control circuit to shut down; when the auxiliary control circuit fails, the second fuse can be used to cut off the auxiliary control circuit, thereby quickly controlling the auxiliary control circuit to shut down.

[0039] like Figure 1 As shown, as a preferred solution: the main control chip and the auxiliary control chip realize inter-chip communication through Ethernet, thereby improving the real-time performance of information interaction.

[0040] like Figure 2 As shown, in order to more clearly explain the working principle of the dual redundant wire-controlled steering system, the control method thereof is described in detail below. The control method thereof includes the following steps:

[0041] Step 1: The auxiliary control chip detects the vehicle's ignition signal in real time through the ignition signal detection port.

[0042] Step 2: When the ignition signal is collected, the auxiliary control chip first performs a fault detection on the auxiliary control circuit. If there is no fault in the auxiliary control circuit, step 3 is executed. If there is a fault in the auxiliary control circuit, the fault information is recorded and written into the second storage module, and step 4 is executed.

[0043] Step 3: The auxiliary control chip wakes up the main control chip and detects whether there is a fault in the main control circuit. If there is no fault in the main control circuit, step 5 is executed; if there is a fault in the main control circuit, the fault is recorded and written into the first storage module, and it is further determined whether the fault type of the main control circuit is a shutdown fault. If it is a shutdown fault, the main control circuit is cut off by the first fuse, so as to control the main control circuit to shut down, and step 4 is executed. If it is not a shutdown fault, step 5 is executed. In this step, if the main control chip cannot be awakened by the auxiliary control chip, the fault is recorded in the first storage module, and step 4 is executed.

[0044] Step 4: Determine whether the auxiliary control circuit has a shutdown fault. If not, execute step 6. If there is a shutdown fault, control the auxiliary control circuit to shut down and execute step 7.

[0045] Step 5, the main control circuit controls the six-phase motor to work. In this step, first detect whether the first winding and the second winding are faulty. If the first winding is not faulty, the main control circuit controls the six-phase motor to work through the first winding; if the first winding is faulty and the second winding is not faulty, the main control circuit controls the six-phase motor to work through the second winding; if both the first winding and the second winding are faulty, the controller shuts down and reports the winding fault information.

[0046] Step 6: The auxiliary control circuit controls the six-phase motor. In this step, firstly, whether the first winding and the second winding are faulty is detected. If the second winding is not faulty, the auxiliary control circuit controls the six-phase motor to work through the second winding; if the second winding is faulty and the first winding is not faulty, the auxiliary control circuit controls the six-phase motor to work through the first winding; if both the first winding and the second winding are faulty, the controller shuts down and reports the winding fault information.

[0047] Step 7: The controller shuts down due to failure.

[0048] The present invention specifically subdivides the fault types of the main control circuit and the auxiliary control circuit into shutdown faults and common faults. Specifically, shutdown faults refer to serious faults that affect the control circuit and require shutdown processing, such as steering motor overtemperature faults, steering motor controller overtemperature faults, stall faults, phase failure faults, current detection faults, torque angle sensor faults, and CAN communication faults, etc.; common faults refer to general faults that do not affect the control circuit and do not require shutdown processing, such as bus undervoltage faults and current limiting faults, etc. The level distinction of fault types is conducive to clarifying the control strategy and improving the response efficiency, and various fault types are recorded in the first storage module and the second storage module, so that it is convenient for technicians to read information and quickly troubleshoot faults.

[0049] The auxiliary control chip in the present invention not only has the function of ignition signal detection, but also has the function of fault detection and switching control of the main control circuit. When the vehicle ignition switch is turned on, the auxiliary control chip will perform fault detection on the main control circuit. When the main control circuit has a shutdown fault, the main control circuit is directly cut off through the first fuse, and the PWM signal output by the main control circuit is not allowed to drive the six-phase motor. Instead, the control circuit is switched to the auxiliary control circuit, and the six-phase motor is driven by the PWM signal output by the auxiliary control circuit. Such a design can avoid the phenomenon that the control circuit cannot be switched due to a main control circuit failure, so that the controller can quickly respond to the fault information of the main control circuit, and thereby realize safe redundant control.

[0050] In addition to the ignition signal detection function, fault detection function and control circuit switching function, the auxiliary control chip is usually used as a backup chip, that is, the control function of the auxiliary control circuit will only be enabled when the main control circuit has a shutdown fault. Therefore, in step 2, if the auxiliary control chip detects that the auxiliary control circuit has a fault, it means that the main control circuit must have a serious shutdown fault. At this time, the main control circuit can be directly cut off, and the six-phase motor can be controlled through the auxiliary control circuit, which can effectively simplify the control process and improve the control efficiency. If even the auxiliary control circuit has a shutdown fault, the controller needs to be powered off and maintenance and repairs must be carried out in time.

[0051] The six-phase motor of the present invention has a first winding and a second winding, and the first winding and the second winding are both connected to the main control circuit and the auxiliary control circuit. When one of the windings fails, the control circuit can drive the six-phase motor through the other winding. Therefore, the use of the six-phase motor can not only use smaller capacity devices to achieve a high-power drive environment, but also realize dual redundant control and improve the reliability of the system. However, no matter at any time, the controller only controls one of the windings through the PWM signal output by a single control circuit. Therefore, there is no cross-mixing control problem of two control circuits for two steering motors, which greatly reduces the control difficulty and simplifies the control process. In addition, the coordinated switching of the two motor systems is not involved in the switching process of the control circuit, so there will be no delayed response, which can effectively ensure the steering safety and stability of the vehicle. In addition, compared with the use of two independent steering motors, the use of the six-phase motor has a lower design cost, does not take up extra space, and is more flexible in layout.

[0052] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A dual redundant steer-by-wire system based on a six-phase motor, characterized in that: The invention comprises a controller and a six-phase motor, wherein the controller comprises a main control chip, an auxiliary control chip, a first power module and a second power module; the main control chip is connected to the six-phase motor through the first power module, thereby forming a main control loop; the auxiliary control chip is connected to the six-phase motor through the second power module, thereby forming an auxiliary control loop; the main control chip and the auxiliary control chip are connected to each other for communication; the controller is further provided with a communication module and a signal switching chip, wherein the communication module is connected to the main control chip or the auxiliary control chip through the signal switching chip; The control method of the dual redundant wire-controlled steering system comprises the following steps: Step 1: The auxiliary control chip detects the vehicle's ignition signal in real time; Step 2: When the ignition signal is collected, the auxiliary control chip first performs a fault detection on the auxiliary control circuit. If there is no fault in the auxiliary control circuit, step 3 is executed; if there is a fault in the auxiliary control circuit, step 4 is executed; the controller further includes a second storage module connected to the auxiliary control chip. If there is a fault in the auxiliary control circuit, the fault information of the auxiliary control circuit is written into the second storage module; Step 3, the auxiliary control chip wakes up the main control chip and detects whether there is a fault in the main control circuit. If there is no fault in the main control circuit, step 5 is executed; if there is a fault in the main control circuit, it is determined whether the fault type of the main control circuit is a shutdown fault. If it is a shutdown fault, the main control circuit is controlled to shut down and step 4 is executed. If it is not a shutdown fault, step 5 is executed; the controller also includes a first storage module connected to the main control chip. If there is a fault in the main control circuit, the fault information of the main control circuit is written into the first storage module; if the main control chip cannot be awakened by the auxiliary control chip, the fault is recorded in the first storage module and step 4 is executed; Step 4: Determine whether the auxiliary control circuit has a shutdown fault. If there is no shutdown fault, execute step 6. If there is a shutdown fault, control the auxiliary control circuit to shut down and execute step 7. Step 5, the main control circuit controls the six-phase motor to work; the six-phase motor includes a first winding and a second winding, the first winding and the second winding are connected with neutral point isolation, in this step, firstly detect whether the first winding and the second winding are faulty, if the first winding is not faulty, the main control circuit controls the six-phase motor to work through the first winding; If the first winding fails and the second winding is not faulty, the main control circuit controls the six-phase motor to work through the second winding; if both the first winding and the second winding fail, the controller shuts down and reports the winding fault information; Step 6: The auxiliary control circuit controls the six-phase motor to work; Step 7: The controller shuts down due to a fault.

2. A dual-redundant steer-by-wire system based on a six-phase motor as claimed in claim 1, characterized in that: In step 6, firstly, whether the first winding and the second winding are faulty is detected. If the second winding is not faulty, the auxiliary control circuit controls the six-phase motor to work through the second winding; If the second winding fails and the first winding is not faulty, the auxiliary control circuit controls the six-phase motor to operate through the first winding; if both the first winding and the second winding fail, the controller shuts down and reports the winding fault information.

3. A dual redundant steer-by-wire system based on a six-phase motor as claimed in claim 1, characterized in that: The main control chip and the auxiliary control chip realize inter-chip communication through Ethernet.

4. A dual-redundant steer-by-wire system based on a six-phase motor as claimed in claim 1, characterized in that: The controller further comprises a first sampling module connected to the main control chip and a second sampling module connected to the auxiliary control chip.

5. A dual-redundant steer-by-wire system based on a six-phase motor as claimed in claim 1, characterized in that: The controller also includes a first fuse and a second fuse; in step 3, the auxiliary control chip cuts off the main control circuit through the first fuse, thereby quickly controlling the main control circuit to shut down; in step 4, the auxiliary control chip cuts off the auxiliary control circuit through the second fuse, thereby quickly controlling the auxiliary control circuit to shut down.

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