Dual-redundancy steer-by-wire redundancy fault-tolerant control system

Abstract

The invention discloses a dual-redundancy steer-by-wire redundancy fault-tolerant control system, which comprises a dual-redundancy steering controller, a state monitoring controller, a dual-redundancy road sensing motor, a dual-redundancy steering motor, a control circuit and a dual-redundancy control network, the dual-redundancy steering controller and the state monitoring controller jointly form a controller group of the dual-redundancy steer-by-wire control system, receive a target rotation angle from a steering gear dual-redundancy road sensing motor through a redundancy control network, and feed back a road sensing control current at the same time; the dual-redundancy steering controller sends a current control signal to the steering motor according to a steering angle signal of the road sensing motor, and the steering motor feedback current is used for a torque signal of the road sensing motor; the state monitoring controller is responsible for monitoring the working state of the dual-redundancy steering controller and serves as a bridge for connecting the steering controller and the road feeling motor to guarantee system redundancy fault tolerance, and the working safety of the steer-by-wire system can be effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of automobiles, and belongs to automobile active safety and control. Background Art

[0002] With the development of in-vehicle intelligent systems, steer-by-wire (SBW) technology has received more and more attention. Steer-by-wire has gotten rid of the dependence on complex mechanical structures and shifted the technical focus to the design of active steering control strategies. The steering system is driven by a motor to control the steering movement of the car. At the same time, the steering wheel resistance torque during steering is also simulated by the motor, getting rid of the limitations of the mechanical connection of the traditional steering system and realizing the function of variable steering transmission ratio. The steering column is eliminated in the structure to avoid damage to the driver by the steering column in the event of a collision accident.

[0003] For example, a public document with publication number CN110325429A, publication date October 11, 2019, and patent name "Operation method for steer-by-wire steering system, control unit for steer-by-wire steering system, steer-by-wire steering system and vehicle" discloses an operation method for a steer-by-wire steering system, wherein the steer-by-wire steering system is constructed with a steering transmission mechanism module, a steering wheel module and a bus connecting the steering transmission mechanism module and the steering wheel module. In the operation method, the actual position in the steering transmission mechanism module is detected, and the theoretical position in the steering wheel module is regulated relative to the actual position in the steering transmission mechanism module by using association rules.

[0004] However, similar wire control systems all have certain safety risks. When the steering system fails, the connection column between the steering wheel and the steering mechanism is removed, which does not meet the "fail safety" state defined in the ISO26262 functional safety standard. In addition, the ISO21448 safety standard proposes a "fail operability" feature for steering systems in high-level assistance and autonomous driving scenarios. Summary of the invention

[0005] The technical problem to be solved by the present invention is to realize a dual-redundancy steer-by-wire redundant fault-tolerant control system that improves the working safety of the steer-by-wire system.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a redundant fault-tolerant control system with dual-redundant wire-controlled steering, a road sensing motor is installed at the end of the steering wheel, the road sensing motor outputs a sensing signal to the steering controller, the steering controller outputs a steering signal to the steering motor to perform a steering action, the road sensing motor is a dual-redundant road sensing motor, the dual-redundant road sensing motor has two sets of independent windings for sensing the steering angle of the steering wheel, and both sets of the windings output sensing signals to the steering controller.

[0007] The two sets of windings both output sensing signals to the state controller, and the state controller is used to determine whether the two sensing signals are normal. The state controller outputs dual redundant road sensing motor operating condition signals to the steering controller.

[0008] The dual redundant road sensor motor has one main and one auxiliary output signal, and the main and auxiliary signals are compared with each other as fault reference signals. When one set of windings fails, an alarm is triggered, and the other set of windings signal is used as the input signal of the steering controller, and an alarm is triggered in the vehicle at the same time.

[0009] The steering controller is a dual-redundant steering controller having two sets of independent control circuits and chips. The two sets of control circuits and chips complement each other and independently receive and process input signals from one set of windings of the dual-redundant road sensing motor.

[0010] The dual redundant steering controller is connected to and outputs a driving signal to the steering motor. The dual redundant steering controller is used to control the torque, speed and position of the steering motor. The steering motor is used to feedback current and act on the road sense motor to form steering wheel road sense feedback.

[0011] The steering motor is a dual-redundant steering motor having two independent motors outputting driving force to the steering actuator of the vehicle. The two outputs of the dual-redundant steering controller are respectively connected to the two independent motors of the dual-redundant steering motor.

[0012] The dual redundant steering controller is provided with two independent CPUs, each of which is equipped with an independent driver, both of which are connected to and output drive signals to two independent motors of the dual redundant steering motor, the two CPUs communicate with each other, and both of which communicate with the status monitor.

[0013] When the status monitor works normally, it processes the data collected from the redundant network, monitors and coordinates the operation of multiple CPUs, and then controls the operation of the drive to generate a sine wave to control the rotation of the dual redundant motors; when the status monitor works abnormally, the two CPUs communicate to complete mutual monitoring, and the CPU is used to monitor the working status of the connected drive.

[0014] The CPU and the state monitor jointly send and receive heartbeat messages to the redundancy network, and determine whether the target device is working properly through the heartbeat message. When one of the CPUs is not working properly, the heartbeat message is stopped. The state monitor determines the working state of the CPU according to whether the heartbeat message is received. The state monitor also sends a heartbeat message to the CPU while receiving the heartbeat message of the CPU. The CPU determines the working state of the state monitor according to whether the heartbeat message is received;

[0015] The system is provided with two sets of independent control networks, and the two sets of windings communicate with the steering controller and the state controller respectively through the independent control networks.

[0016] The motor of the system is composed of multiple windings with non-isolated neutral points. If one of the windings fails during operation, the model of the motor after the failure is reconstructed from a six-phase motor model to a five-phase motor model.

[0017] The dual redundant steering controller and the state monitoring controller of the present invention together constitute a controller group of a dual redundant wire-controlled steering gear control system, which receives the target angle from the dual redundant road sensing motors of the steering gear through a redundant control network and feeds back the road sensing control current; the dual redundant steering controller sends a current control signal to the steering motor according to the angle signal of the road sensing motor, and the steering motor feedback current is used for the road sensing motor torque signal; the state monitoring controller is responsible for monitoring the working status of the dual redundant steering controller and serves as a bridge connecting the steering controller and the road sensing motor to ensure system redundancy and fault tolerance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following is a brief description of the contents expressed in each figure in the specification of the present invention:

[0019] Figure 1 This is the principle block diagram of the dual-redundant steer-by-wire redundant fault-tolerant control system;

[0020] Figure 2 This is a redundant fault-tolerant principle block diagram of the controller of a dual-redundant steer-by-wire redundant fault-tolerant control system;

[0021] Figure 3 This is the block diagram of the motor redundant fault-tolerant principle of the dual-redundant wire-controlled steer-by-wire redundant fault-tolerant control system. DETAILED DESCRIPTION

[0022] The following is a further detailed description of the specific implementation methods of the present invention, such as the shape, structure, relative position and connection relationship between the various components involved, the function and working principle of each part, the manufacturing process and operation method, etc., through the description of the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0023] The system includes a dual-redundant steering controller, a state controller, a dual-redundant road-sensing motor, a dual-redundant steering motor, a control circuit and a dual-redundant control network. The dual-redundant steering controller and the state controller together form a controller group of a dual-redundant wire-controlled steering control system. The dual-redundant road-sensing motor and the dual-redundant steering motor also have redundant fault-tolerant functions. When a set of windings fails, the motor can still continue to complete the corresponding work instructions. The system cancels the connecting rod structure of the traditional steering steering wheel and the chassis steering actuator, and controls the vehicle steering by installing a dual-redundant road-sensing motor at the end of the steering wheel and installing a dual-redundant steering motor on the chassis steering actuator instead of the steering column mechanism.

[0024] The dual-redundancy control network is used to connect the redundant steering controller and the state controller for mutual communication, and at the same time send torque signals to the dual-redundant road sensing motors and receive steering angle signals.

[0025] The dual redundant steering controller consists of multiple sets of independent control circuits and chips. The control circuits complement each other and are controlled by their own chips. When problems occur in some of the circuits or chips, the other circuits and chips can still ensure the normal operation of the dual redundant wire-controlled steering redundant fault-tolerant control system.

[0026] The state controller, as the core of the dual-redundant wire-controlled redundant fault-tolerant control system, is used to process information from the dual-redundant steering controllers, determine whether the controllers are working normally, and perform fault-tolerant processing when some circuits fail to ensure the normal operation of the steering system. The redundant control adjusts the coordinated work between multiple circuits and chips of the dual-redundant steering controllers to prevent interference and control the coordinated operation of the steering system. It receives information from the redundant network for processing, calculates the target torque of the road sense motor through the current feedback from the steering motor, and calculates the target position, target current and target speed of the steering motor through the target angle speed feedback from the road sense motor.

[0027] The redundancy network is responsible for the mutual communication between the functional components of the wire-controlled steering. Through the redundancy network, each component receives the control information it needs to perform the next step of control, and at the same time sends the feedback information it needs to the redundancy network. The control circuit connects the redundant steering controller, the dual redundant road sensing motor of the steering machine, and the power supply circuit of the dual redundant steering motor. The dual redundant steering controller has circuit redundancy and chip redundancy. The controller has multiple sets of control circuits, main control chips, and drive circuits. The circuits and chips work redundantly. When a circuit or chip fails, the set of circuits stops working and other circuits complete the work. Each control chip sends a heartbeat message through redundancy to inform other control chips of its working status. When a control chip fails or the circuit it is in fails, an error status is sent to inform other control chips that the control chip and the circuit it is in cannot work normally.

[0028] The state controller monitors the normal operation of each function, receives the heartbeat message of each functional device through the redundant network to determine whether each functional device is operating normally, and sends the heartbeat message of the state controller to allow each functional device to determine whether the state controller is operating normally. When the state controller is working normally, the work of each functional device is scheduled by the state controller, and each function works redundantly. When the function cannot work, it sends an error state, the state controller obtains the error state, and schedules the work to other circuits for fault tolerance. When the state controller stops working, it sends an error state, the controller receives the error state, stops the state controller from scheduling functions, and the controller runs in priority order. High-priority devices work, and low-priority devices are in sleep state. When a high-priority device sends a fault, it sends an error state to stop working, and the second-highest priority device works.

[0029] like Figure 1 As shown, the dual-redundant wire-controlled steer-to-wire redundant fault-tolerant control system includes dual-redundant road-sensing motors, dual-redundant steering controllers, state controllers, and dual-redundant steering motors. The dual-redundant road-sensing motors are connected to the steering wheel and receive torque signals through the redundancy network to feedback the road-sensing torque to the driver. The angle value of the road-sensing motor is sent to the redundancy network. The state controller receives the position signal of the road-sensing motor, calculates the feedback value of the angle sensor to obtain the road-sensing motor current, and sends it to the dual-redundant controller, thereby controlling the motor to work to the target position.

[0030] like Figure 2 As shown in the figure, the redundant fault-tolerant scheme of the dual-redundant wire-controlled steering redundant fault-tolerant control system is to design multiple sets of circuits with the same functions in the dual-redundant steering controller. When some circuits in all drivers fail, other circuits can be used to ensure the normal operation of the dual-redundant wire-controlled steering redundant fault-tolerant control system. Multiple CPUs and state monitors communicate with each other to ensure the normal operation of the functions. The CPU and the state controller can communicate separately or through the redundant network. When the state monitor works normally, the data collected from the redundant network is processed, the operation of multiple CPUs is monitored and coordinated, and then the operation of the driver is controlled to generate a sine wave to control the rotation of the dual redundant motor. When the state monitor works abnormally, the CPU communicates with another CPU. At this time, there will be a CPU working priority. When the high-priority CPU works normally, the high-priority CPU is used. When the high-priority CPU is abnormal, the second-highest priority CPU is used, and so on. The fault diagnosis of the driver circuit is diagnosed by the CPU, and the driver circuit also has a priority selection order when the state monitor fails.

[0031] When the dual-redundant wire-controlled steering system is working, multiple CPUs and status monitors jointly send and receive heartbeat messages to the redundant network, and use the heartbeat messages to determine whether the target device is working properly. When CPU1 is not working properly, CPU1 stops sending heartbeat messages, and the status monitor cannot receive the heartbeat message from CPU1. It determines that CPU1 is working abnormally, stops CPU1's work, and other CPUs complete the work. While receiving the heartbeat message from the CPU, the status monitor also sends a heartbeat message to the CPU. The CPU receives the heartbeat message from the status monitor and determines that the status monitor is working normally, otherwise it determines the fault mode; when it is determined that the status monitor is working abnormally, the CPU receives heartbeat messages from other CPUs in the redundant network and works according to priority.

[0032] like Figure 3 As shown, the dual redundant motors of the dual-redundancy wire-controlled redundant fault-tolerant control system are composed of multiple windings with non-isolated neutral points. When one of the windings fails, the model of the motor after the failure is reconstructed from a normal six-phase motor model to a five-phase motor model.

[0033] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A redundant fault-tolerant control system of dual-redundant wire-controlled steering, wherein a road sensing motor is installed at the end of the steering wheel, the road sensing motor outputs a sensing signal to a steering controller, and the steering controller outputs a steering signal to a steering motor to perform a steering action, characterized in that: The road sensing motor is a dual-redundant road sensing motor, which has two sets of independent windings for sensing the steering angle of the steering wheel, and both sets of windings output sensing signals to the steering controller.

2. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 1, characterized in that: The two sets of windings both output sensing signals to the state controller, and the state controller is used to determine whether the two sensing signals are normal. The state controller outputs dual redundant road sensing motor operating condition signals to the steering controller.

3. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 2, characterized in that: The dual redundant road sensor motor has one main and one auxiliary output signal, and the main and auxiliary signals are compared with each other as fault reference signals. When one set of windings fails, an alarm is triggered, and the other set of windings signal is used as the input signal of the steering controller, and an alarm is triggered in the vehicle at the same time.

4. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 3, characterized in that: The steering controller is a dual-redundant steering controller having two sets of independent control circuits and chips. The two sets of control circuits and chips complement each other and independently receive and process input signals from one set of windings of the dual-redundant road sensing motor.

5. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 4, characterized in that: The dual redundant steering controller is connected to and outputs a driving signal to the steering motor. The dual redundant steering controller is used to control the torque, speed and position of the steering motor. The steering motor is used to feedback current and act on the road sense motor to form steering wheel road sense feedback.

6. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 5, characterized in that: The steering motor is a dual-redundant steering motor having two independent motors outputting driving force to the steering actuator of the vehicle. The two outputs of the dual-redundant steering controller are respectively connected to the two independent motors of the dual-redundant steering motor.

7. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 6, characterized in that: The dual redundant steering controller is provided with two independent CPUs, each of which is equipped with an independent driver, both of which are connected to and output drive signals to two independent motors of the dual redundant steering motor, the two CPUs communicate with each other, and both of which communicate with the status monitor.

8. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 7, characterized in that: When the status monitor works normally, it processes the data collected from the redundant network, monitors and coordinates the operation of multiple CPUs, and then controls the operation of the drive to generate a sine wave to control the rotation of the dual redundant motors; when the status monitor works abnormally, the two CPUs communicate to complete mutual monitoring, and the CPU is used to monitor the working status of the connected drive.

9. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to claim 8, characterized in that: The CPU and the state monitor jointly send and receive heartbeat messages to the redundancy network, and determine whether the target device is working properly through the heartbeat message. When one of the CPUs is not working properly, the heartbeat message is stopped. The state monitor determines the working state of the CPU according to whether the heartbeat message is received. The state monitor also sends a heartbeat message to the CPU while receiving the heartbeat message of the CPU. The CPU determines the working state of the state monitor according to whether the heartbeat message is received; The system is provided with two sets of independent control networks, and the two sets of windings communicate with the steering controller and the state controller respectively through the independent control networks.

10. The redundant fault-tolerant control system of dual-redundant steer-by-wire according to any one of claims 1 to 9, characterized in that: The motor of the system is composed of multiple windings with non-isolated neutral points. If one of the windings fails during operation, the model of the motor after the failure is reconstructed from a six-phase motor model to a five-phase motor model.

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