Electric control steering method and steering system for vehicle

Abstract

The invention relates to an electronic control steering method and system for a vehicle. The vehicle comprises an electric control steering system, the electric control steering system comprises a hydraulic control system, steering knuckle arms arranged at all steering wheels and hydraulic wheel cylinders connected with all the steering knuckle arms through piston rods, and the method comprises the steps that steering parameters are received, the steering parameters comprise a steering input torque, a steering input angle, a vehicle speed, a transverse acceleration of the vehicle and actual piston positions of pistons of all hydraulic wheel cylinders; based on the steering parameters, determining a target steering radius of the vehicle and a target piston position of a piston of each hydraulic wheel cylinder; and based on the determined target piston position, the hydraulic control system is controlled to change the hydraulic pressure in each hydraulic wheel cylinder so as to change the position of the piston, so that the steering knuckle arms connected with the piston rods are driven by the piston rods to enable the corresponding steering wheels to deflect for steering.

Description

Technical Field

[0001] The present disclosure relates to an electronically controlled steering method and a steering system for a vehicle. Background Art

[0002] The steering system is an important part of the vehicle. Its function is to control the direction of the vehicle according to the driver's wishes by operating the steering wheel through the transmission mechanism to make the steering wheel deflect on the road surface, ensuring the normal and stable driving of the vehicle. Throughout the development of the steering system, it has evolved from pure mechanical human control relying on the driver's manual force to turn the steering wheel to power steering.

[0003] In recent years, with the continuous development of autonomous driving technology, electronic steering, such as the Steering-by-Wire (SBW) system, has become more and more common in vehicles, and is also an emerging and popular development direction of steering technology. The electronic steering system can eliminate the conventional mechanical linkage that connects the vehicle's steering wheel to its steering wheels, and instead converts the mechanical steering wheel input into an electrical signal and transmits it to the steering gear of the vehicle chassis for steering control, thus getting rid of the various limitations of the traditional steering system.

[0004] However, as the demand for electronically controlled steering continues to increase, there is still a need for further improvement and optimization of electronically controlled steering methods for vehicles.

[0005] Public Content

[0006] On the one hand, the present disclosure provides an electronically controlled steering method for a vehicle, the vehicle comprising an electronically controlled steering system, the electronically controlled steering system comprising a hydraulic control system, a steering knuckle arm arranged at each steering wheel, and a hydraulic wheel cylinder connected to each steering knuckle arm through a piston rod, the method comprising: receiving steering parameters, the steering parameters comprising a steering input torque, a steering input angle, a vehicle speed, a lateral acceleration of the vehicle and an actual piston position of a piston of each hydraulic wheel cylinder; determining a target steering radius of the vehicle and a target piston position of a piston of each hydraulic wheel cylinder based on the steering parameters; and controlling the hydraulic control system to change the hydraulic pressure in each hydraulic wheel cylinder to change the position of its piston based on the determined target piston position, so as to drive the steering knuckle arm connected thereto through the piston rod to deflect the corresponding steering wheel for steering.

[0007] On the other hand, the present disclosure also provides a steering system for a vehicle, comprising: an electronically controlled steering system, the electronically controlled steering system including a hydraulic control system, a steering knuckle arm arranged at each steering wheel, and a hydraulic wheel cylinder connected to each steering knuckle arm through a piston rod; and a first control circuit, the first control circuit being configured to execute an electronically controlled steering method according to an embodiment of the present disclosure.

[0008] In yet another aspect, the present disclosure further provides a vehicle, which includes a steering system for the vehicle according to an embodiment of the present disclosure.

[0009] The present disclosure provides an electric control steering method applicable to a hydraulic steering system, a steering system of a vehicle and a vehicle including the steering system. The electric control steering method according to an embodiment of the present disclosure can support a variety of steering postures of the vehicle, and contribute to the smooth and rapid steering of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments are briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present disclosure, and are not intended to limit the present disclosure.

[0011] Figure 1 A schematic diagram of a steering device suitable for an electric steering method according to at least one embodiment of the present disclosure is shown.

[0012] Figure 2 An example electric steering method according to at least one embodiment of the present disclosure is shown.

[0013] Figure 3 It further shows Figure 2 Flowchart of an example method for determining a target steering radius and a target piston position of a vehicle based on steering parameters at step S220 in FIG.

[0014] Figure 4 Steering postures supported by the electric steering method according to at least one embodiment of the present disclosure are shown.

[0015] Figure 5 A graph showing the movement of a piston of a hydraulic wheel cylinder of a steering wheel following a target piston position under an electric steering method according to at least one embodiment of the present disclosure.

[0016] Figure 6 An example scenario is shown in which a steering wheel of a vehicle fails.

[0017] Figure 7 An example architecture of a control circuit for controlling a hydraulic steering system according to at least one embodiment of the present disclosure is shown.

[0018] Figure 8 An example steering system for a vehicle is shown in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the technical solution of the present disclosure clearer, the technical solution of the embodiment of the present disclosure will be clearly and completely described in combination with the drawings of the specific embodiments of the present disclosure. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0020] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present disclosure belongs. The words "first", "second" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not necessarily indicate a quantity restriction. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] Figure 1 1 is a schematic diagram of a steering device 100 applicable to an electric steering method according to at least one embodiment of the present disclosure. Figure 1As shown, taking the right front wheel as a steering wheel as an example, the steering device 100 may include a hydraulic wheel cylinder (which includes a cylinder body 101, a piston 102 and a piston rod 103), a steering tie rod 104, a steering knuckle arm 105 and a steering wheel 106. The steering knuckle arm 105 is arranged at each steering wheel (for example, the steering wheel 106) of the vehicle to drive the steering wheel 106 to deflect. Exemplarily, each hydraulic wheel cylinder includes a cylinder body 101 fixedly mounted on the vehicle frame and a piston rod 103 and a piston 102 that are telescopic in the cylinder body 101. A rod chamber 101-a and a rodless chamber 101-b are formed in the cylinder body 101, and the piston rod 103 is connected to the steering knuckle arm 105. A control circuit (e.g., an electronic control unit (ECU)) controls the hydraulic control system to change the hydraulic pressure of the hydraulic wheel cylinder (i.e., the hydraulic pressure between the rod chamber 101-a and the rodless chamber 101-b) so that the piston rod 103 extends and retracts in the cylinder body 101, thereby driving the steering knuckle arm 105 to move, and ultimately driving the steering wheel 106 to deflect at a specific angle corresponding to the steering control signal. In the present disclosure, a steering wheel is a wheel of a vehicle that can be deflected under the control of the vehicle's steering system. In one embodiment, the left front wheel and the right front wheel of the vehicle may be steering wheels. In another embodiment, all wheels of the vehicle may be steering wheels. For example, in an embodiment in which the vehicle has four wheels, the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel of the vehicle may all be steering wheels. In the case in which all wheels of the vehicle are steering wheels, more steering postures of the vehicle can be achieved (as described in reference hereinafter). Figure 4 ), which helps the vehicle to turn smoothly and quickly. In various embodiments, as Figure 1 As shown, a steering knuckle arm may be provided at each steered wheel, and each steering knuckle arm is connected to a hydraulic wheel cylinder via a piston rod.

[0022] In the present disclosure, the hydraulic control system and the control circuit may be a hydraulic control system and a control circuit known in the art. For example, the hydraulic control system may include a pressure oil circuit, a return oil circuit, and at least one hydraulic element corresponding to at least one hydraulic wheel cylinder. Each hydraulic element controls the connection state between the rod chamber and the rodless chamber of the corresponding hydraulic wheel cylinder and the pressure oil circuit and the return oil circuit. The control circuit may be implemented by a processor or a field programmable gate array (FPGA), etc.

[0023] Understandable, although Figure 1The piston rod 103 is shown to be connected to the knuckle arm 105 through the steering tie rod 104, but the piston rod 103 can also be connected to the knuckle arm 105 in various ways, such as welding, threaded connection, etc., so that the knuckle arm 105 is driven by the expansion and contraction of the piston rod 103 to deflect the steering wheel 106. The present disclosure does not impose any limitation on the above specific connection method.

[0024] Figure 2 According to at least one embodiment of the present disclosure, a Figure 1 The exemplary electric steering method 200 of the steering device 100 is shown. Figure 2 As shown, an example electric steering method 200 according to an embodiment of the present disclosure may start from S210. At S210, the control circuit of the steering system of the vehicle may receive steering parameters. The steering parameters may include, for example, steering input torque, steering input angle, vehicle speed, lateral acceleration of the vehicle, and actual piston positions of pistons of each hydraulic wheel cylinder corresponding to each steering wheel, etc. It should be understood that the steering input torque, steering input angle, vehicle speed, lateral acceleration of the vehicle, and actual piston positions of pistons of each hydraulic wheel cylinder are merely examples of steering parameters and are not limiting, and the steering parameters may include more or fewer parameters. For example, the steering parameters may also include longitudinal acceleration, etc.

[0025] In the present disclosure, the steering input torque is a torque related to steering input to the steering system of the vehicle. The steering input angle is an angle related to steering input to the steering system of the vehicle. In one embodiment, the steering input torque and the steering input angle can be manually input. For example, in an embodiment where steering is performed by turning the steering wheel, the driver of the vehicle can input the steering input torque and the steering input angle by turning the steering wheel. In this case, the steering input torque and the steering input angle can be steering wheel torque and steering wheel angle. In other embodiments, such as in an embodiment where steering is controlled by a key, the steering input torque and the steering input angle can be input by a key. In another embodiment, the steering input torque and the steering input angle can be determined based on a steering request from an automatic driving system or a driving assistance system of the vehicle. In this case, the automatic driving system or the driving assistance system can automatically achieve steering without the need for driver operation.

[0026] At S220, the control circuit of the steering system of the vehicle may determine the target steering radius of the vehicle and the target piston position of the piston of each hydraulic wheel cylinder based on the steering parameter received at S210. In one embodiment, the target steering radius and the target piston position may be determined based on the steering parameter by the following steps: determining the actual steering radius of the vehicle based on the vehicle speed and the lateral acceleration of the vehicle; and determining the target steering radius and the target piston position of the piston of each hydraulic wheel cylinder based on the actual steering radius, the steering input torque, the steering input angle, the vehicle speed, and the actual piston position of the piston of each hydraulic wheel cylinder. In other embodiments, the target steering radius and the target piston position of the piston of each hydraulic wheel cylinder may be determined based on the steering parameter without determining the actual steering radius. Compared with the method of determining the target steering radius and the target piston position directly based on the steering parameter (e.g., by looking up a table) without determining the actual steering radius, the total computational complexity of determining the target steering radius and the target piston position may be reduced by determining the actual steering radius and determining the target steering radius and the target piston position based on the determined actual steering radius and other steering parameters.

[0027] In the present disclosure, in one embodiment, the lateral acceleration of the vehicle may be the lateral acceleration of one steering wheel of the vehicle. For example, in an embodiment where the steering wheels of the vehicle include a left front wheel and a right front wheel, the lateral acceleration of the vehicle may be the lateral acceleration of the right front wheel of the vehicle. In this case, the actual turning radius may be the actual turning radius of the right front wheel of the vehicle, and the target turning radius may be the target turning radius of the right front wheel of the vehicle. In another embodiment, the lateral acceleration of the vehicle may be the lateral acceleration of each steering wheel of the vehicle. Accordingly, the actual turning radius may be the actual turning radius of each steering wheel of the vehicle, and the target turning radius may be the target turning radius of each steering wheel of the vehicle. In this case, since the target turning radius of each steering wheel and the target piston position of each hydraulic wheel cylinder are determined based on the lateral acceleration of each steering wheel of the vehicle, the determined target turning radius and target piston position may be made more accurate. In yet another embodiment, the lateral acceleration of the vehicle may be the lateral acceleration at the equivalent center of mass of the vehicle, which may be determined based on the lateral acceleration of each steering wheel of the vehicle. Exemplarily, the lateral acceleration at the equivalent center of mass of the vehicle may be the weighted sum of the lateral accelerations of each steering wheel of the vehicle. In this case, the actual turning radius may be the actual turning radius at the equivalent center of mass of the vehicle, and the target turning radius may be the target turning radius at the equivalent center of mass of the vehicle. In this way, a good compromise between the accuracy and computational complexity of determining the target turning radius and the target piston position may be achieved.

[0028] In a further embodiment, the target turning radius and the target piston position can be used as feedback to determine the target turning radius and the target piston position at the next moment through closed-loop control. In this way, the target turning radius and the target piston position determined based on the received steering parameters can be adjusted based on the feedback of both the target turning radius and the target piston position, so that the determined target turning radius and the target piston position are more accurate.

[0029] When determining the target steering radius and the target piston position based on the steering parameters, in one embodiment, the target steering radius and the target piston position can be determined based on the received steering parameters by using a lookup table. The lookup table can be predetermined based on testing. In one embodiment, the lookup table can be predetermined based on the steering parameters. Figure 3 The flowchart shown is used to determine the target steering radius and target piston position of the vehicle based on the steering parameters by looking up the table. It should be understood that in addition to the lookup table, the target piston position of each piston can also be determined based on the steering parameters by other methods (e.g., neural network, etc.).

[0030] like Figure 3 As shown, the actual steering radius 306 can be determined based on the received vehicle lateral acceleration 301 and vehicle speed 302; the steering radius difference 307 between the actual steering radius 306 and the target steering radius 309 at the previous moment is determined; the piston position difference 308 between the actual piston position 305 and the target piston position 310 at the previous moment is determined; and then the vehicle speed 302, steering input torque 303, steering input angle 304, determined steering radius difference 307 and piston position difference 308 in the received steering parameters are used as inputs to a lookup table 311 for determining the target steering radius and the target piston position to determine the target steering radius and the target piston position.

[0031] return Figure 2 At S230, the control circuit of the steering system of the vehicle controls the hydraulic control system of the steering system of the vehicle to change the hydraulic pressure in each hydraulic wheel cylinder to change the position of its piston based on the target piston position of the piston of each hydraulic wheel cylinder determined at S220, so as to drive the steering knuckle arm connected thereto through the piston rod to deflect the corresponding steering wheel for steering. Exemplarily, the control circuit can control each hydraulic element of the hydraulic control system based on the determined target piston position of each hydraulic wheel cylinder, thereby controlling the flow direction, flow rate, speed and other parameters of the hydraulic oil in each hydraulic wheel cylinder, thereby causing the piston in the corresponding hydraulic wheel cylinder to move toward the target piston position, and then drive the steering knuckle arm connected thereto through the piston rod to deflect the corresponding steering wheel in the desired direction, thereby achieving the desired steering.

[0032] In the above, the present disclosure combines Figures 1 to 3The electronically controlled steering method for a vehicle according to an embodiment of the present disclosure is described. The electronically controlled steering method of the present disclosure can support a variety of steering postures of the vehicle (e.g., Figure 4 Steering posture shown in Figure 1) helps the vehicle to turn smoothly and quickly. Figure 3 The target steering radius and target piston position determined based on the received steering parameters are adjusted based on the feedback of both the target steering radius and the target piston position, so that the determined target steering radius and target piston position can be more accurate.

[0033] Figure 4 Steering postures supported by the electric steering method according to at least one embodiment of the present disclosure are shown. Figure 4 The figure shows the steering postures that can be supported by the electronically controlled steering method according to the embodiment of the present disclosure when all four wheels of a four-wheel vehicle are steering wheels. For example, the electronically controlled steering method of the present disclosure can support Figure 4 In Figure 4 B and 4C show all-wheel steering, where Figure 4 B can be all-wheel steering at low speeds, and Figure 4 In Figure 4 Compared with the conventional front-wheel steering shown in A, it can reduce the turning radius, thereby increasing the maneuverability of the vehicle. Figure 4 In Figure 4 C can be all-wheel steering at high speeds, and Figure 4 In Figure 4 Compared with the conventional front-wheel steering shown in A, it can increase the turning radius, thereby increasing the steering stability of the vehicle. Figure 4 In Figure 4 D shows all-wheel steering for pivot steering operation. Figure 4 In Figure 4 E shows the vehicle's direction-invariant all-wheel steering, which can keep the vehicle's direction unchanged during the steering process. Figure 4 In Figure 4 F shows dynamic toe-in / out all-wheel steering, which can increase the stability of vehicle steering. It should be understood that Figure 4 The vehicle steering posture described is merely an example of the steering posture that can be supported by the electronically controlled steering method according to the embodiment of the present disclosure, and is not limiting.

[0034] Figure 5 A graph showing the movement of the piston of the hydraulic wheel cylinder of the steering wheel following the target piston position under the electronically controlled steering method according to at least one embodiment of the present disclosure. Figure 5 As shown, the control circuit of the steering system of the vehicle can control the hydraulic control system according to the electric steering method of the embodiment of the present disclosure so that the piston of the hydraulic wheel cylinder moves in a step time (for example, Figure 5The piston moves to the target piston position within the step times Δt1 and Δt2 shown in the figure, thereby achieving the desired steering of the vehicle. Figure 5 In the example, the current actual piston position (e.g. Figure 5 The actual piston position B) is the piston position of the hydraulic wheel cylinder at the beginning of the step time (e.g., Δt2) (e.g., t i+1 The actual piston position (for example, Figure 5 The actual piston position B in the target piston position (for example, Figure 5 The target piston position A in the figure is the target piston position determined by the electric steering method according to the embodiment of the present disclosure within the previous step time (e.g., Δt1), that is, the target piston position at the end of the previous step time (e.g., t i The target piston position (i.e., Figure 5 Target piston position A'). Figure 5 The graph shown is a graph of the piston of a hydraulic wheel cylinder corresponding to a steering wheel following the target piston position under the electronic steering method according to an embodiment of the present disclosure. The graphs showing the change in the position of the piston of the hydraulic wheel cylinder corresponding to other steering wheels and Figure 5 In practice, the actual piston position may be overdamped or overshoot to ensure control stability and response time.

[0035] In addition, from Figure 5 It can be seen that the actual piston position (e.g. Figure 5 The actual piston position B) in the equation does not correspond to the target piston position (e.g. Figure 5 Therefore, in some embodiments, the determined target piston position can be further adjusted based on the difference between the target piston position and the actual piston position. Figure 2 The target piston position (e.g., target piston position A') determined at S220 shown in the figure is added to the difference between the target piston position at the previous moment and the actual piston position (e.g., the difference between the target piston position C and the actual piston position D) to further adjust the determined target piston position (e.g., target piston position A'). Different from the above method of using the target piston position as feedback to determine the target piston position at the next moment through, for example, a predetermined lookup table, this method can adjust the target piston position based on the actual working condition of the vehicle's steering system, thereby achieving the desired target steering more accurately.

[0036] In practice, there may be a steering failure of the steering wheel, for example, leakage of the hydraulic wheel cylinder, failure of a component corresponding to a steering wheel in the hydraulic control system, and so on. Figure 6 The left front steering wheel of the vehicle is shown ( Figure 6In this case, another target piston position of the piston of each hydraulic wheel cylinder corresponding to the steering wheel without steering failure among the steering wheels can be determined based on the steering parameters described above. Then, based on the determined other target piston position, the hydraulic control system is controlled to change the hydraulic pressure of each hydraulic wheel cylinder corresponding to the steering wheel without steering failure to change the position of its piston, thereby achieving steering. In this way, the desired steering can be achieved even when one or more steering wheels among the steering wheels have steering failure. In one embodiment, the above can be combined with the above. Figure 2-3 A method is described to determine another target piston position based on the steering parameters. For example, the target piston position can be determined based on the actual steering radius, the steering input torque, the steering input angle, the vehicle speed, and the actual piston positions of the pistons of the respective hydraulic wheel cylinders corresponding to the steering wheels without steering failures, by using a lookup table corresponding to the steering wheels without steering failures (e.g., in Figure 6 In the case of Figure 6 Another target piston position is determined by using a lookup table corresponding to the steering wheels RR, FL and FR) in the figure.

[0037] In addition, the inventors of the present disclosure have observed that in order to achieve the desired steering, whether or not there is a steering wheel with a steering failure among the steering wheels, based on the steering parameters (for example, by combining the above Figure 2-3 The target turning radius determined by the method is the same. Figure 6 In the example of FIG. 1 , the target turning radius OB, OC and OD determined when the steering wheel has no steering failure are respectively equal to the left front steering wheel among the steering wheels (ie, Figure 6 Based on this observation, the present disclosure proposes another method for determining another target piston position of the piston of each hydraulic wheel cylinder corresponding to the steering wheel without steering failure among the steering wheels based on the steering parameters when a steering wheel fails. The method comprises: determining an indication of the steering direction based on the steering input angle in the steering parameters; and determining another target piston position based on the determined indication of the steering direction and the target steering radius determined when it is assumed that there is no steering failure. Exemplarily, in one embodiment, the indication of the steering direction and the target steering radius may be used as inputs to a lookup table for determining the target piston position corresponding to the steering wheel without steering failure to determine another target piston position. For example, in Figure 6In the example of FIG. 1 , an indication of the steering direction, i.e., an indication of a left turn, can be determined based on the steering input angle. Then, another target piston position is determined based on the indication of a left turn and the target steering radii OB, OC, and OD as inputs to a lookup table corresponding to the steering wheels RR, FL, and FR without a steering fault, so as to achieve the desired steering position based on the determined another target piston position. Figure 6 In Figure 6 The steering posture shown in B is used to achieve the desired steering.

[0038] Combined with the above example Figure 3 Compared with the method described in the present invention to determine another target piston position when a steering wheel fails, the method of determining another target piston position based on the indication of the steering direction and the target steering radius can reduce storage space and increase calculation speed. For example, in the example of using a lookup table, combined with Figure 3 The described method requires a lookup table with five inputs (i.e., a five-dimensional lookup table), while the method based on the indication of the turning direction and the target turning radius only requires two lookup tables with one input (i.e., two one-dimensional lookup tables, corresponding to the indication of turning left and the indication of turning right, respectively), which can significantly reduce the storage space and improve the lookup speed.

[0039] Figure 7 FIG. 7 shows an example architecture 700 of a control circuit for controlling a hydraulic steering system according to at least one embodiment of the present disclosure. Figure 7 As described above, the electric steering system according to the embodiment of the present disclosure may include: Figure 7 The first control circuit 701 and the second control circuit 702 are shown. The control circuit 701 may include a microprocessor 701-a, a bridge driver 701-b, a bridge 701-c, a valve driver 701-d and a data bus 701-e. The control circuit 702 may include a microprocessor 702-a, a bridge driver 702-b, a bridge 702-c, a valve driver 702-d and a data bus 702-e. The control circuit 701 may be connected to the power supply of the vehicle via a vehicle power connector 705-a, and connected to the vehicle communication connector 706-b of the vehicle via a data bus 701-e. Similarly, the control circuit 702 may be connected to the power supply of the vehicle via a vehicle power connector 705-a, and connected to the vehicle communication connector 706-b of the vehicle via a data bus 702-e. It should be understood that Figure 7 The example architecture of the control circuit shown is only an example and is not limiting. For example, the control circuit(s) included in the electric steering system according to an embodiment of the present disclosure may include: Figure 7 The control circuits 701 or 702 shown may be configured with more or fewer components. Figure 7 The control circuit shown is a different way to implement the control circuit for controlling the hydraulic steering system.

[0040] The control circuits 701 and 702 can independently execute the above combined Figure 1-Figure 6 The electronically controlled steering method described herein, i.e., the target piston position of the piston of each hydraulic wheel cylinder is determined based on the steering parameter 704, and the hydraulic control system of the steering system of the vehicle is controlled based on the determined target piston position. In one example, the control circuit 701 and the control circuit 702 can be respectively connected to 3 phases of the 6-phase motor stator in the hydraulic control system, so that any one of the control circuits can fully control the output of the motor of the hydraulic control system, thereby independently controlling the hydraulic control system. In addition, the control circuit 701 and the control circuit 702 can also control the hydraulic control system based on the state of the motor in the monitored hydraulic control system.

[0041] In one embodiment, the control circuit 701 can be used as a main control circuit to calculate the target piston position and control the hydraulic control system based on it, while the control circuit 702 can be in a standby state as a backup control circuit. When the control circuit 701 fails due to a fault, the second control circuit 702 can immediately take over the control. This can be achieved by, for example, the microprocessor 701-a and the microprocessor 702-a in the control circuit 701 and the control circuit 702 are a pair of mutually locked microprocessors. In this way, the redundancy requirements of the electronically controlled steering for control and execution can be met. In the present disclosure, the control circuit may fail due to the following reasons: power failure or cut-off from the vehicle power connector to the control circuit, communication failure from the vehicle communication connector to the control circuit through the data bus, loss of sensor signals of the control circuit, detection of internal component failure in the control circuit, detection of internal component failure in the bridge drive, detection of internal component failure in the valve driver, and the like.

[0042] Furthermore, in some embodiments, Figure 7 The control circuit 701 and the control circuit 702 shown can be respectively combined according to the above Figure 1-Figure 6The electronically controlled steering method described herein determines the target steering radius and the target piston position, and cross-checks the determined target steering radius and the target piston position to further increase the robustness of the electronically controlled steering method disclosed herein. Exemplarily, the cross-check can be performed by the following method. When the target steering radius and the target piston position determined by the control circuit 701 and the control circuit 702 are inconsistent but close (for example, the difference is within the first predetermined range), as long as the control circuit 701 does not detect a fault, the control is performed using the calculation result of the control circuit 701 as the output. When the target steering radius and the target piston position determined by the control circuit 701 and the control circuit 702 are inconsistent and differ greatly (for example, the difference is outside the first predetermined range), regardless of whether a fault is detected, only the calculation result of the previous (not the current) calculation cycle (for example, 50ms ago) is used for control. When the results calculated by the control circuit 701 and the control circuit 702 are greatly different for multiple consecutive times (for example, within 10 calculation cycles), the system sends an alarm reminder.

[0043] In the above, the present disclosure combines Figures 1 to 7 The present invention describes an electric steering method for a vehicle according to an embodiment of the present invention. Figure 8 A steering system of a vehicle according to an embodiment of the present disclosure is described.

[0044] Figure 8 An example steering system 800 for a vehicle is shown in accordance with at least one embodiment of the present disclosure. Figure 8 As shown, the steering system 800 of a vehicle according to an embodiment of the present disclosure may include a first control circuit 810 and an electric steering system 820. The electric steering system 820 may include a hydraulic control system, a steering knuckle arm provided at each steering wheel, and a hydraulic wheel cylinder connected to each steering knuckle arm through a piston rod. The first control circuit 810 may be, for example, Figure 7 The first control circuit 810 may be configured to execute the electric control steering method according to an embodiment of the present disclosure. Additionally, the vehicle steering system 800 may further include a second control circuit (not shown) (e.g., Figure 7 In the control circuit 702 of the first control circuit 810). When the first control circuit 810 fails, the second control circuit can take over the control and execute the electric control steering method according to the embodiment of the present disclosure. In the case where the vehicle steering system 800 also includes a second control circuit, the first control circuit 801 and the second control circuit can both determine the target steering radius and the target piston position respectively, and cross-check the determined target steering radius and the target piston position.

[0045] In addition, the present disclosure also provides a vehicle, which includes a steering system of a vehicle according to an embodiment of the present disclosure (for example, Figure 8Steering system 800 of the vehicle shown).

[0046] So far, the present disclosure is combined with Figure 1-Figure 8 The electronically controlled steering method, the steering system of a vehicle and the vehicle including the same according to the embodiments of the present disclosure are described. The electronically controlled steering method according to the embodiments of the present disclosure can support various steering postures of the vehicle, which is helpful for the smooth and rapid steering of the vehicle. Figure 3 The target steering radius and the target piston position determined based on the received steering parameters are adjusted based on the feedback of both the target steering radius and the target piston position, so that the determined target steering radius and the target piston position are more accurate. In addition, the electronically controlled steering method according to the embodiment of the present disclosure can determine another piston position of the piston of the hydraulic wheel cylinder corresponding to the steering wheel without steering failure when one or more steering wheels among the steering wheels fail, thereby achieving the desired steering when the steering wheel fails.

[0047] It should be noted that the above description is only some embodiments of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) to form a technical solution.

[0048] In addition, although each operation is described in a specific order, this should not be understood as requiring these operations to be performed in the specific order shown or in a sequential order. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present disclosure. Some features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination mode.

[0049] Although the subject matter has been described in language specific to structural features and / or methodological logical actions, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. On the contrary, the specific features and actions described above are merely example forms of implementing the claims.

Claims

1. An electronically controlled steering method for a vehicle, the vehicle comprising an electronically controlled steering system, the electronically controlled steering system comprising a hydraulic control system, a steering knuckle arm disposed at each steering wheel, and a hydraulic wheel cylinder connected to each steering knuckle arm via a piston rod, the method comprising: receiving steering parameters, the steering parameters including steering input torque, steering input angle, vehicle speed, lateral acceleration of the vehicle, and actual piston positions of the pistons of the respective hydraulic wheel cylinders; determining a target steering radius of the vehicle and a target piston position of the piston of each hydraulic wheel cylinder based on the steering parameter; as well as Based on the determined target piston position, the hydraulic control system is controlled to change the hydraulic pressure in each hydraulic wheel cylinder to change the position of its piston, so as to drive the steering knuckle arm connected thereto through the piston rod to deflect the corresponding steering wheel for steering.

2. The method according to claim 1, wherein determining the target turning radius and the target piston position of the piston of each hydraulic wheel cylinder comprises: determining an actual turning radius of the vehicle based on the vehicle speed and the lateral acceleration of the vehicle; as well as The target steering radius and the target piston position of the piston of each hydraulic wheel cylinder are determined based on the actual steering radius, the steering input torque, the steering input angle, the vehicle speed, and the actual piston position of the piston of each hydraulic wheel cylinder.

3. The method according to claim 2, wherein the target steering radius and the target piston position can be used as feedback to determine the target steering radius and the target piston position at the next moment through closed-loop control.

4. The method according to claim 3, wherein determining the target turning radius and target piston position at the next moment comprises: determining an actual turning radius at a next moment based on the received vehicle speed at a next moment and the lateral acceleration of the vehicle; Determining a turning radius difference between the target turning radius and the actual turning radius at the next moment; determining a piston position difference between the target piston position and an actual piston position received at a next instant; as well as The received steering input torque, steering input angle, vehicle speed, the steering radius difference and the piston position difference at the next moment are used as inputs of a lookup table for determining a target steering radius and a target piston position to determine a target steering radius and a target piston position at the next moment.

5. The method according to claim 2, wherein the lateral acceleration of the vehicle is the lateral acceleration of each steering wheel of the vehicle, the actual turning radius is the actual turning radius of each steering wheel of the vehicle, and the target turning radius is the target turning radius of each steering wheel of the vehicle. 6 . The method of claim 1 , wherein the steering input torque and the steering input angle are manually input or determined based on a steering request from an autonomous driving system or a driving assistance system of the vehicle.

7. The method according to claim 1, further comprising: When a steering failure occurs to one or more of the steering wheels, based on the steering parameter, another target piston position of the piston of each hydraulic wheel cylinder corresponding to the steering wheel without the steering failure among the steering wheels is determined; as well as Based on the determined another target piston position, the hydraulic control system is controlled to change the hydraulic pressure of each hydraulic wheel cylinder corresponding to the steering wheel without steering failure to change the position of its piston, so as to drive the steering knuckle arm connected thereto through the piston rod to deflect the corresponding steering wheel for steering.

8. The method of claim 7, wherein determining the other target piston position based on the steering parameter comprises: determining an actual turning radius of the vehicle based on the vehicle speed and the lateral acceleration of the vehicle; as well as The other target piston position is determined based on the actual steering radius, the steering input torque, the steering input angle, the vehicle speed, and actual piston positions of pistons of the respective hydraulic wheel cylinders corresponding to the steering wheels without steering failure.

9. The method of claim 7, wherein determining the another target piston position based on the steering parameter comprises: determining an indication of a steering direction based on the steering input angle; as well as The further target piston position is determined using the target steering radius and the indication of the steering direction as inputs to a lookup table for determining target piston positions corresponding to the steering wheels without steering failure.

10. The method according to claim 1, wherein: The electronically controlled steering system includes a first control circuit and a second control circuit, wherein the first control circuit and the second control circuit independently control the hydraulic control system, and the method further includes: the first control circuit controls the hydraulic control system based on the target piston positions of the pistons of the respective hydraulic wheel cylinders determined by the first control circuit; and When the first control circuit fails, the second control circuit controls the hydraulic control system based on the target piston positions of the pistons of the respective hydraulic wheel cylinders determined by the second control circuit.

11. The method according to claim 10, further comprising: The first control circuit and the second control circuit both determine the target turning radius and the target piston position, respectively; as well as The target steering radius and the target piston position determined by the first control circuit and the second control circuit are cross-checked.

12. The method of claim 1, wherein the steered wheels include a left front wheel and a right front wheel of the vehicle, or wherein the steered wheels include all wheels of the vehicle.

13. A steering system for a vehicle, comprising: An electronically controlled steering system, the electronically controlled steering system comprising a hydraulic control system, a steering knuckle arm disposed at each steering wheel, and a hydraulic wheel cylinder connected to each steering knuckle arm via a piston rod; and A first control circuit, the first control circuit being configured to perform the method according to any one of claims 1 to 9 and 12.

14. The steering system according to claim 13, further comprising a second control circuit, The second control circuit is configured to execute the method according to any one of claims 1 to 9 and 12 when the first control circuit fails.

15. The steering system of claim 14, wherein The first control circuit and the second control circuit both determine a target steering radius and a target piston position, respectively, and cross-check the determined target steering radius and target piston position.

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