Vehicle steering system and method for controlling steering of a vehicle

Abstract

The invention relates to the field of vehicles, in particular to a vehicle steering system (1), comprising: a first control unit (11) configured for performing a steering function of a vehicle; a state detection unit (12) configured to detect an operating state of the first control unit (11); and at least one second control unit (13) configured to participate in the control of the steering function of the vehicle when an abnormal operating state of the first control unit (11) is detected. The invention also relates to a method for controlling steering of a vehicle and a computer program product. According to the invention, the redundancy of the steering system can be provided for a high-level automatic driving system and / or an auxiliary driving system, especially the redundancy design of the steer-by-wire system is realized, the driving safety of the vehicle is ensured, and the steering stability and comfort of the vehicle can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicles, and in particular to a vehicle steering system, a method for controlling vehicle steering, and a computer program product for at least assisting in implementing the steps of the method according to the present invention. Background Art

[0002] In a conventional vehicle steering system, such as a hydraulic steering system or an electric power steering system EPS (Electronic Power Steering), the steering wheel is always mechanically connected to the front wheels of the vehicle, so that the driver can still control the steering of the vehicle even when the hydraulic power steering or the electric power steering fails.

[0003] With the development of vehicle technology, the steering system of the vehicle has gradually developed into a steer-by-wire system. In the steer-by-wire system, since the transmission part of the steering column is omitted, the input control signal of the steering wheel is completely decoupled from the actuator of the front wheel. The input control signal of the steering wheel needs to be transmitted to the actuator of the front wheel through the steer-by-wire signal transmission unit. However, even if the steer-by-wire system itself is set to be redundant, some electronic components of the steer-by-wire system may still fail. During the driving process of the vehicle, steering control failure may occur due to the failure of these electronic components, which in turn affects the driving safety of the vehicle.

[0004] Therefore, how to set up a reliable vehicle steering system has become a technical problem that needs to be solved at present. Summary of the invention

[0005] The object of the present invention is to provide a vehicle steering system, a method for controlling vehicle steering, and a computer program product to solve the problems in the prior art.

[0006] According to a first aspect of the present invention, there is provided a vehicle steering system, the vehicle steering system comprising:

[0007] - a first control unit configured to perform a steering function of the vehicle;

[0008] - a state detection unit, the state detection unit being configured to detect an operating state of the first control unit; and

[0009] - at least one second control unit configured to participate in the control of the steering function of the vehicle if an abnormal operating state of the first control unit is detected.

[0010] The core concept of the present invention is that when the main steering system of the vehicle is in an abnormal operating state, the backup control unit with steering control function such as the electronic stability program system, the rear wheel steering system and / or the torque vector control system can be enabled to participate in the control of the vehicle's steering function. According to the embodiments of the present invention, not only can the redundancy of the steering system be provided for a high-level automatic driving system and / or an auxiliary driving system, especially the redundant design of the wire control steering system can be realized to ensure the driving safety of the vehicle, but also the stability and comfort of the vehicle steering can be effectively improved.

[0011] According to an optional embodiment of the present invention, the first control unit may include an electric power steering system or a wire-controlled steering system, etc. Optionally, the at least one second control unit may include one or more of the following components: an Electronic Stability Program system, a rear wheel steering system, and a torque vectoring system.

[0012] According to another optional embodiment of the present invention, the electronic stability program system can be used to control the braking torque of each wheel on the same side of the vehicle so that the vehicle turns in the desired steering direction, wherein the braking force is applied to each wheel on the same side or one of the wheels on the same side by means of a hydraulic brake mechanism and / or an electronic mechanical brake mechanism (Electronic Mechanical Brake) based on friction. Optionally, when understeering of the vehicle is detected, the electronic stability program system can be used to apply a braking force to one or more wheels on the side of the desired steering direction of the vehicle to apply a lateral torque to the vehicle body in the desired steering direction. Optionally, when oversteering of the vehicle is detected, the electronic stability program system can be used to apply a braking force to one or more wheels on the side of the vehicle in the direction opposite to the desired steering direction to apply a lateral torque to the vehicle body in the direction opposite to the desired steering direction.

[0013] According to another optional embodiment of the present invention, the rear wheel steering angle of the vehicle may be controlled by a rear wheel steering system so that the vehicle turns in a desired steering direction, wherein the direction of the rear wheel steering angle is opposite to the desired steering direction.

[0014] According to another optional embodiment of the present invention, the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be controlled by a torque vector control system. For example, braking force is applied to each wheel on one side of the vehicle by the torque vector control system or the braking system, and driving force is applied to each wheel on the other side of the vehicle by the torque vector control system, so that the vehicle turns in the desired steering direction.

[0015] According to another optional embodiment of the present invention, the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be cooperatively controlled by the torque vectoring control system and the electronic stability program system, so that the vehicle turns in the desired steering direction, wherein the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be controlled by the torque vectoring control system, and the electronic stability program system can participate in the control of the braking operation of each wheel on at least one side of the vehicle.

[0016] According to another optional embodiment of the present invention, the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be cooperatively controlled by the electronic stability program system and the rear-wheel steering system, so that the vehicle turns in the desired steering direction, wherein the braking torque of each wheel on the same side of the vehicle can be controlled by the electronic stability program system, and the rear wheel steering angle of the vehicle can be controlled by the rear-wheel steering system.

[0017] According to another optional embodiment of the present invention, the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be cooperatively controlled by a torque vectoring control system and a rear-wheel steering system, so that the vehicle turns in a desired steering direction, wherein the driving parameters and / or braking parameters of each wheel on each side of the vehicle are controlled by the torque vectoring control system, and the rear wheel steering angle of the vehicle is controlled by the rear-wheel steering system.

[0018] According to another optional embodiment of the present invention, the desired steering direction can be determined according to the driver's operating instructions and / or determined according to the automatic driving system and / or the auxiliary driving system based on the current driving scenario.

[0019] According to a second aspect of the present invention, a method for controlling vehicle steering is provided, wherein the method is performed by means of a vehicle steering system according to the present invention, the method comprising the following steps:

[0020] - detecting an operating state of a first control unit for performing a steering function of the vehicle;

[0021] - determining whether an abnormal operating state of the first control unit occurs; and

[0022] If an abnormal operating state of the first control unit occurs, at least one second control unit is enabled to participate in the control of the steering function of the vehicle.

[0023] According to a third aspect of the present invention, a computer program product, such as a computer-readable program carrier, is provided, comprising computer program instructions, which, when executed by a processor, at least assist in implementing the steps of the method according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present invention can be better understood. The accompanying drawings include:

[0025] Figure 1 A structural block diagram of a vehicle steering system according to an exemplary embodiment of the present invention is shown;

[0026] Figure 2 A flow chart showing a method for controlling the steering of a vehicle according to an exemplary embodiment of the present invention;

[0027] Figure 3 A schematic diagram showing a principle of controlling a steering function of a vehicle in which an electronic stability program system participates according to another exemplary embodiment of the present invention;

[0028] Figure 4 A schematic diagram showing a principle of controlling a steering function of a vehicle in which an electronic stability program system participates according to another exemplary embodiment of the present invention;

[0029] Figure 5 A schematic diagram showing a principle of controlling a steering function of a vehicle in which a rear-wheel steering system participates according to another exemplary embodiment of the present invention;

[0030] Figure 6 A schematic diagram showing a principle of controlling a steering function of a vehicle in which a rear-wheel steering system and an electronic stability program system participate according to another exemplary embodiment of the present invention;

[0031] Figure 7 A schematic diagram showing a principle of controlling a steering function of a vehicle in which a rear-wheel steering system participates according to another exemplary embodiment of the present invention;

[0032] Figure 8 A schematic diagram showing a principle of a torque vector control system participating in the control of a steering function of a vehicle according to another exemplary embodiment of the present invention; and

[0033] Fig. 9 A schematic diagram showing the principle of a torque vector control system and a rear-wheel steering system participating in the control of a steering function of a vehicle according to another exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the scope of protection of the present invention.

[0035] It should be noted that, in this article, the expressions "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance, nor should they be understood as implicitly indicating the number of the indicated technical features.

[0036] Figure 1 A structural block diagram of a vehicle steering system according to an exemplary embodiment of the present invention is shown.

[0037] like Figure 1 As shown, the vehicle steering system 1 may include a first control unit 11, which is configured to perform the steering function of the vehicle. In the current embodiment of the present invention, the first control unit 11 can be understood as the main steering system of the vehicle, which takes over the control of the steering function of the vehicle during normal operation of the vehicle.

[0038] The first control unit 11 may include, for example, an electric power steering system, and its components include, for example, a mechanical steering mechanism, a torque sensor, a vehicle speed sensor, an electronic control unit, and a motor. The operating principle of the electric power steering system is described as follows: the steering wheel is connected to the front wheels through a mechanical steering mechanism. When the driver manipulates the steering wheel to steer, the torque sensor can detect the steering direction of the steering wheel and the magnitude of the torque and convert them into electrical signals and transmit them to the electronic control unit. The electronic control unit sends a control signal to the motor according to these electrical signals and the vehicle speed signal detected by the vehicle speed sensor, so that the motor outputs a steering assist torque of corresponding magnitude and direction, so as to provide the mechanical steering mechanism with a steering assist adapted to the current vehicle speed.

[0039] The first control unit 11 may also include a wire-controlled steering system, which is different from the traditional vehicle steering system. The wire-controlled steering system cancels the mechanical connection mechanism between the steering wheel and the actuator, and the steering function of the vehicle is completely realized by the electronic control system. The components of the wire-controlled steering system include, for example, a steering wheel module, a steering actuator, and an electronic control unit, and its operating principle is described as follows: the steering intention of the driver is obtained by measuring the steering wheel angle through the steering wheel module, and it is converted into a digital signal and transmitted to the electronic control unit. At the same time, the electronic control unit sends a corresponding torque control signal and generates a positioning torque of the steering wheel through the steering wheel positioning torque motor to provide the driver with corresponding road feeling information; the electronic control unit also outputs a control signal to the steering actuator according to the collected signal, thereby controlling the steering motor to output the torque required for steering and realizing the driver's steering intention.

[0040] It is understandable that the steering wheel and the actuator are decoupled in the steer-by-wire system. Once the electronic components in the steer-by-wire system that are not redundantly configured fail, the steering operation cannot be performed. Therefore, a redundant design of the steer-by-wire system is required.

[0041] The vehicle steering system 1 may further include a state detection unit 12 and at least one second control unit 13, wherein the state detection unit 12 is configured to detect the operating state of the first control unit 11, and the second control unit 13 is configured to participate in the control of the vehicle's steering function when an abnormal operating state of the first control unit 11 is detected.

[0042] The following combination Figure 2 The flowchart of the method for controlling the steering of a vehicle according to an exemplary embodiment of the present invention illustrates the operating principle of the vehicle steering system 1 in detail.

[0043] The method may include steps S1 to S3. In step S1, the operating state of the first control unit 11 for executing the steering function of the vehicle may be detected, in particular, by the state detection unit 12. In the sense of the present invention, the operating state of the first control unit 11 may be divided into a normal operating state and an abnormal operating state, wherein, in the normal operating state of the first control unit 11, the first control unit 11 can control the vehicle to steer in a desired steering direction based on the driver's steering intention, wherein the desired steering direction may be determined according to the driver's operating instructions, or may be determined according to the automatic driving system and / or the auxiliary driving system based on the current driving scene; in the abnormal operating state of the first control unit 11, the first control unit 11 is no longer able to control the vehicle to steer in the desired steering direction based on the driver's steering intention, that is, it can only partially participate in the steering control of the vehicle (for example, the output torque of the main steering system is less than the torque determined based on the driver's operating instructions), or even completely unable to participate in the steering control of the vehicle, especially when the first control unit 11 fails (for example, sensor failure, electronic control unit failure, steering motor failure, power failure of the power supply unit, etc.), the steering function of the vehicle can no longer be performed by the first control unit 11.

[0044] In step S2, it is determined whether an abnormal operating state of the first control unit 11 occurs. If an abnormal operating state of the first control unit 11 occurs, at least one second control unit 13 is enabled in step S3 to participate in the control of the steering function of the vehicle. In particular, for high-level (e.g., level SAE L2 and above) autonomous driving systems and / or assisted driving systems, the redundancy of the vehicle's steering system is required to cover the backup time required for the vehicle to regain a safe state in the event that the steering system itself loses control. If the output parameters of the vehicle's main steering system cannot meet the requirements of relevant laws / regulations on the redundancy of the steering system, or the output parameters of the vehicle's main steering system cannot meet the requirements for driving comfort, at least one second control unit 13 can be enabled to participate in the control of the vehicle's steering function.

[0045] Here, when the first control unit 11 is completely unable to participate in the steering control of the vehicle, the at least one second control unit 13 can completely take over the steering control of the vehicle; when the first control unit 11 can only partially participate in the steering control of the vehicle, the second control unit 13 and the first control unit 11 can collaboratively control the steering function of the vehicle.

[0046] In addition, it should be noted that the step numbers described herein do not necessarily represent a chronological order, but are merely a reference numeral. The order may be changed according to specific circumstances as long as the technical purpose of the present invention can be achieved.

[0047] Optionally, the second control unit 13 may include one or more of the following components: an electronic stability program system 131, a rear wheel steering system 132 and a torque vector control system 133. According to different second control units equipped in the vehicle, the control process of the vehicle steering system 1 is specifically described below in combination with different embodiments.

[0048] In an optional embodiment of the present invention, the second control unit 13 may include an electronic stability program system 131. It is understandable that most vehicles are currently equipped with an electronic stability program system, and the actuator of the electronic stability program system is a braking mechanism that can brake each wheel individually, and the braking mechanism can apply corresponding braking force to each wheel according to actual needs when the driver does not perform a braking operation. The braking mechanism can be either a traditional hydraulic braking mechanism or an electronic mechanical braking mechanism based on friction, which does not require hydraulic pipelines, but can provide clamping force through motors arranged on the brake calipers on the sides of the four wheels.

[0049] Under certain road conditions and vehicle load conditions, the maximum adhesion that a wheel can provide is a fixed value, that is, under extreme conditions, the longitudinal force (along the rolling direction of the wheel) and the lateral force (perpendicular to the rolling direction of the wheel) on the wheel are in a trade-off relationship. For example, when the longitudinal force on the wheel reaches an extreme value (such as tire locking), the lateral force is 0, and the lateral movement of the vehicle will be uncontrolled at this time, so it is impossible to turn according to the driver's operating intention. The electronic stability program system can apply longitudinal braking force to each wheel separately, thereby affecting the lateral force on the wheel, that is, generating corresponding lateral torque on the vehicle body to assist the vehicle in driving in the direction desired by the driver.

[0050] Here, the braking torque of each wheel on the same side of the vehicle can be controlled by the electronic stability program system 131, so that the vehicle is steered in the desired steering direction, wherein the braking force is applied to each wheel on the same side or one of the wheels on the same side by means of a hydraulic brake mechanism and / or an electronic mechanical brake mechanism based on friction. Figure 32 shows a schematic diagram of the principle of the electronic stability program system participating in the control of the steering function of the vehicle according to another exemplary embodiment of the present invention. When the driver operates the vehicle to steer to the left, when it is detected that the vehicle has understeering under the control of the first control unit 11, that is, the actual steering angle of the vehicle in the curve is smaller than the expected steering angle determined based on the driver's operation instruction, the electronic stability program system 131 can apply longitudinal braking forces F to the two left wheels FL and RL respectively. BF 、F BR , especially applying longitudinal braking force F to the left rear wheel RL BR As the longitudinal force on the left wheel increases, the lateral force it can provide decreases accordingly, thus generating a lateral torque T on the vehicle body in the desired steering direction (here, the left side). L , to assist the vehicle to travel in the desired turning direction. It should be noted that "side" refers to the side of the vehicle body along the driving direction, which includes the left and right sides of the vehicle body along the driving direction.

[0051] exist Figure 4 1 is a schematic diagram showing the principle of the electronic stability program system participating in the control of the steering function of the vehicle according to another exemplary embodiment of the present invention. When it is detected that the vehicle is oversteering under the control of the first control unit 11, that is, the actual steering angle of the vehicle in the curve is greater than the expected steering angle determined based on the driver's operation instruction, the electronic stability program system 131 can apply longitudinal braking forces F to the two right wheels FR and RR respectively. BF 、F BR , especially applying a longitudinal braking force F to the right front wheel FR BF As the longitudinal force on the right wheel increases, the lateral force it can provide decreases accordingly, thus generating a lateral torque T in the opposite direction to the desired steering direction (here, on the right side) on the vehicle body. R , used to resist oversteering of the vehicle.

[0052] In another optional embodiment of the present invention, the second control unit 13 may further include a rear-wheel steering system 132. At present, more and more vehicles are also equipped with rear-wheel steering systems. Considering that vehicles usually oversteer when driving at high speeds, that is, the actual steering angle of the vehicle in a curve is larger than the steering angle of the front wheels, the rear-wheel steering system 132 can be used to control the rear wheels to steer in the same direction as the front wheels, thereby compensating for the oversteering tendency of the vehicle and improving the driving stability and driving comfort of the vehicle.

[0053] Figure 5FIG. 2 is a schematic diagram showing the principle of a rear-wheel steering system participating in the control of a vehicle's steering function according to another exemplary embodiment of the present invention. For example, the driver operates the vehicle to steer to the left, and when it is detected that the first control unit 11 cannot control the vehicle's steering function (for example, the electric power steering system or the wire control steering system fails), as shown in FIG. Figure 5 As shown in FIG. 1 , the front wheels FL and FR cannot be steered to the left by the actuator, but the rear wheels RL and RR of the vehicle can be controlled to deflect to the right by the rear wheel steering system 132, that is, the direction of the rear wheel steering angle is opposite to the desired steering direction, thereby generating a lateral torque T on the vehicle body in the desired steering direction (here, the left side). L , enabling the vehicle to steer to the left, thereby effectively preventing steering loss caused by a failed front wheel actuator and ensuring the redundancy of the steering system.

[0054] exist Figure 6 In another embodiment shown, the driving parameters and / or braking parameters of each wheel on each side of the vehicle can also be controlled cooperatively by the electronic stability program system 131 and the rear wheel steering system 132, so that the vehicle turns in the desired steering direction, wherein the braking force F can be applied to the left front wheel FL of the vehicle by the electronic stability program system 131. BF , and the rear wheels RL and RR of the vehicle are controlled to deflect to the right side through the rear wheel steering system 132, that is, the direction of the rear wheel steering angle is opposite to the desired steering direction (here, the left side), thereby generating a lateral torque T on the vehicle body in the desired steering direction. L , realizing the steering operation of the vehicle to the left. Through the coordinated control of the electronic stability program system 131 and the rear wheel steering system 132, not only can the steering loss caused by the failure of the front wheel actuator be effectively prevented, the redundancy of the steering system is ensured, but also the driving stability and comfort of the vehicle can be improved.

[0055] Figure 7 A schematic diagram of the principle of the rear-wheel steering system participating in the control of the steering function of the vehicle according to another exemplary embodiment of the present invention is shown. For example, the driver operates the vehicle to steer to the left, and when it is detected that the steering angle of the front wheels FL, FR is less than the desired steering angle determined based on the driver's operating instruction and the steering angle of the front wheels FL, FR cannot be further increased through the control of the first control unit 11, for example, the vehicle deviates from the desired steering direction due to a large lateral wind force on the vehicle body, the rear wheels RL, RR of the vehicle can also be controlled by the rear-wheel steering system 132 to deflect to the right, that is, the direction of the rear wheel steering angle is opposite to the desired steering direction, thereby generating a lateral torque T on the vehicle body in the desired steering direction (here, the left side) L , which is used to offset the influence of lateral wind force on the vehicle's turning direction, so that the vehicle can turn in the desired turning direction.

[0056] In another optional embodiment of the present invention, the second control unit 13 may further include a torque vector control system 133. With the development of vehicle electrification, more and more electric vehicles are equipped with torque vector control systems, which can, for example, independently control the driving parameters and / or braking parameters of each wheel, including torque, rotation speed and / or rotation direction, etc., by means of four electric motors arranged on the four wheel sides, thereby improving the vehicle's handling performance, especially the steering performance.

[0057] Figure 8 A schematic diagram of the principle of a torque vector control system participating in the control of a steering function of a vehicle according to another exemplary embodiment of the present invention is shown. For example, when the driver operates the vehicle to steer to the left, when a fault (such as a sensor fault, an electronic control unit fault, a steering motor fault, and / or a power failure of the power supply unit) is detected in the first control unit 11, the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be controlled by the torque vector control system 133, for example, the braking force F is applied to the two wheels FL and RL on the left side of the vehicle respectively through the torque vector control system 133 or the braking system. BF 、F BR , and a driving force F is applied to the two wheels FR and RR on the right side of the vehicle through the torque vector control system 133. AF 、F AR , thus generating a lateral torque T on the vehicle body in the desired steering direction (here, the left side) L , so that the vehicle turns in the desired turning direction.

[0058] For example, an electric vehicle may be equipped with only three electric motors, wherein one electric motor is arranged on the front axle for simultaneously controlling the two front wheels FL, FR, and two electric motors are arranged on the rear axle for respectively controlling the two rear wheels RL, RR. Figure 7 In the illustrated embodiment, when it is detected that the steering angle of the front wheels FL, FR is less than the desired steering angle determined based on the driver's operating instructions, this may be caused, for example, by insufficient power supply of the electric motor on the front axle or a limited driving force of the electric motor on the front axle, or may be caused by a large lateral wind force on the vehicle body. The driving parameters and / or braking parameters of each wheel on each side of the vehicle can be controlled collaboratively by the torque vectoring control system 133 and the electronic stability program system 131, wherein the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be controlled by the torque vectoring control system 133, and the electronic stability program system 131 participates in the control of the braking operation of each wheel on at least one side of the vehicle. Figure 8 In the embodiment shown, the torque vector control system 133 and the electronic stability program system 131 can be used to apply braking force F to the left wheels FL and RL respectively through the coordinated control.BF 、F BR The torque vector control system 133 applies driving force F to the right wheels FR and RR respectively. AF 、F AR , thus generating a lateral torque T on the vehicle body in the desired steering direction (here, the left side) L , so that the vehicle turns in the desired turning direction, thereby effectively improving the driving stability and safety of the vehicle.

[0059] In addition, Fig. 9 In another embodiment shown, the driver operates the vehicle to steer to the left. When it is detected that the first control unit 11 cannot control the vehicle steering function (for example, the electric power steering system or the wire control steering system fails), that is, the front wheels FL and FR cannot be steered to the left by the actuator, the driving parameters and / or braking parameters of each wheel on each side of the vehicle can be controlled in coordination with the torque vector control system 133 and the rear wheel steering system 132, so that the vehicle steers in the desired steering direction, wherein the driving parameters and / or braking parameters of each wheel on each side of the vehicle are controlled by the torque vector control system 133 (here, the braking force F is applied to the left wheels FL and FR). BF 、F BR , applying driving force F to the right wheels FR and RR AF 、F AR ), and the rear wheel steering angle of the rear wheels RL and RR of the vehicle is controlled by the rear wheel steering system 132 (here, rightward deflection), thereby generating a lateral torque T on the vehicle body in the desired steering direction (here, left side) L , realizing the steering operation of the vehicle to the left, thereby more effectively preventing the steering loss caused by the failure of the front wheel actuator, and realizing the redundancy of the steering system.

[0060] It should be noted that, in the above-mentioned embodiments, the electronic stability program system 131, the rear-wheel steering system 132 and the torque vector control system 133 can all participate in the control in a coordinated manner, thereby achieving a better control effect of the vehicle steering function.

[0061] In addition, the second control unit 13 is any vehicle-mounted component that can participate in controlling the vehicle steering function, and is not limited to the listed electronic stability program system 131 , rear wheel steering system 132 and torque vector control system 133 .

[0062] According to an embodiment of the present invention, when an abnormal operating state occurs in the main steering system of a vehicle, a backup control unit with a steering control function, such as an electronic stability program system, a rear-wheel steering system and / or a torque vector control system, can be enabled to participate in the control of the steering function of the vehicle. This can not only provide redundancy of the steering system for a high-level autonomous driving system and / or an assisted driving system, especially realize a redundant design of the wire-controlled steering system to ensure the driving safety of the vehicle, but also effectively improve the steering stability and comfort of the vehicle.

[0063] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even when only a single embodiment is described with respect to specific features. The feature examples provided in the present disclosure are intended to be illustrative, not limiting, unless otherwise stated. In specific implementations, multiple features may be combined with each other as required and as technically feasible. Various substitutions, changes, and modifications may also be conceived without departing from the spirit and scope of the present invention.

Claims

1. A vehicle steering system (1), the vehicle steering system (1) comprising: A first control unit (11), the first control unit (11) being configured to perform a steering function of the vehicle; A state detection unit (12), the state detection unit (12) being configured to detect an operating state of the first control unit (11); and At least one second control unit (13) is configured to participate in the control of the steering function of the vehicle when an abnormal operating state of the first control unit (11) is detected.

2. The vehicle steering system (1) according to claim 1, characterized in that: The at least one second control unit (13) includes one or more of the following components: an electronic stability program system (131), a rear wheel steering system (132) and a torque vector control system (133).

3. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The first control unit (11) comprises an electric power steering system or a steer-by-wire system.

4. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The electronic stability program system (131) controls the braking torque of each wheel on the same side of the vehicle so that the vehicle steers in a desired steering direction, wherein braking force is applied to each wheel on the same side or one of the wheels on the same side by means of a hydraulic brake mechanism and / or an electronic mechanical brake mechanism based on friction.

5. A vehicle steering system (1) according to any one of the preceding claims, characterised in that When understeering of the vehicle is detected, applying a braking force to one or more wheels on the side of the desired steering direction of the vehicle through the electronic stability program system (131) to apply a lateral torque to the vehicle body in the desired steering direction; and / or When oversteering of the vehicle is detected, the electronic stability program system (131) applies braking force to one or more wheels on the side of the vehicle opposite to the desired steering direction, so as to apply lateral torque to the vehicle body in the direction opposite to the desired steering direction.

6. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The rear wheel steering angle of the vehicle is controlled by a rear wheel steering system (132) so that the vehicle is turned in a desired turning direction, wherein the direction of the rear wheel steering angle is opposite to the desired turning direction.

7. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The driving parameters and / or braking parameters of each wheel on each side of the vehicle are controlled by the torque vector control system (133), for example, braking force is applied to each wheel on one side of the vehicle by the torque vector control system (133) or the braking system, and driving force is applied to each wheel on the other side of the vehicle by the torque vector control system (133), so that the vehicle turns in the desired turning direction.

8. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The driving parameters and / or braking parameters of each wheel on each side of the vehicle are cooperatively controlled by the torque vector control system (133) and the electronic stability program system (131), so that the vehicle turns in a desired steering direction, wherein the driving parameters and / or braking parameters of each wheel on each side of the vehicle are controlled by the torque vector control system (133), and the electronic stability program system (131) participates in the control of the braking operation of each wheel on at least one side of the vehicle.

9. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The driving parameters and / or braking parameters of each wheel on each side of the vehicle are cooperatively controlled by the electronic stability program system (131) and the rear-wheel steering system (132), so that the vehicle turns in a desired steering direction, wherein the braking torque of each wheel on the same side of the vehicle is controlled by the electronic stability program system (131), and the rear-wheel steering angle of the vehicle is controlled by the rear-wheel steering system (132).

10. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The driving parameters and / or braking parameters of each wheel on each side of the vehicle are cooperatively controlled by the torque vector control system (133) and the rear-wheel steering system (132), so that the vehicle turns in a desired steering direction, wherein the driving parameters and / or braking parameters of each wheel on each side of the vehicle are controlled by the torque vector control system (133), and the rear-wheel steering angle of the vehicle is controlled by the rear-wheel steering system (132).

11. A vehicle steering system (1) according to any one of the preceding claims, characterised in that The desired steering direction is determined according to an operating instruction of the driver and / or determined according to an automatic driving system and / or an auxiliary driving system based on a current driving scenario.

12. A method for controlling vehicle steering, wherein: The method is performed by means of a vehicle steering system (1) according to any one of claims 1 to 11, the method comprising the following steps: Detecting an operating state of a first control unit (11) for performing a steering function of a vehicle; determining whether an abnormal operating state of the first control unit (11) occurs; and If an abnormal operating state of the first control unit (11) occurs, at least one second control unit (13) is enabled to participate in the control of the steering function of the vehicle. 13 . A computer program product, such as a computer-readable program carrier, comprising computer program instructions which, when executed by a processor, at least assist in implementing the steps of the method according to claim 1 .

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