A self-correcting steer-by-wire road feel simulator power-off anti-turn control method and system

Abstract

The application discloses a self-correcting steer-by-wire road feel simulator power-off anti-rotation control method and system, which comprises the following steps: obtaining the length adjustment range L of the mechanical limiting position of the steer-by-wire road feel simulator by adjusting the motor locked-rotor position; setting the soft stop point 1 and the soft stop point 2 within the length adjustment range L of the mechanical limiting position of the steer-by-wire road feel simulator, and determining the anti-rotation automatic locking area range of the steer-by-wire road feel simulator; setting the soft stop point 3 between the soft stop point 1 and the soft stop point 2, and ensuring that the relative position between the soft stop point 2 and the soft stop point 3 is unchanged; determining the range between the soft stop point 1 and the soft stop point 3 as the manual adjustment range L1 of the steer-by-wire road feel simulator; correcting the position offset of the soft stop point 3 through position self-learning; and entering the corresponding anti-rotation control mode under the vehicle power-on or power-off state, and performing the power-off anti-rotation control of the steer-by-wire road feel simulator.

Description

Technical Field

[0001] This invention relates to the field of vehicle steering control technology, and in particular to a method and system for preventing steering wheel spin under power-off conditions using a self-correcting steer-by-wire road feel simulator. Background Technology

[0002] When getting in and out of a car, users habitually use their hands to grip the steering wheel for leverage. In traditional steering systems, there's a mechanical connection between the steering wheel and the tires. Because of the friction between the tires and the ground, the steering wheel doesn't easily turn when the user is getting in or out, thus preventing leverage. However, steer-by-wire systems eliminate the mechanical connection between the steering wheel simulator and the steering gear, creating a central steering shaft. This allows the steering wheel to turn easily when the user is getting in or out. Furthermore, this free rotation causes a difference in steering wheel angle compared to the wheel angle. Since the vehicle needs to be electrically aligned before driving (synchronizing the two angles), a large angle difference can lead to excessively long synchronization times, causing user complaints.

[0003] In existing technologies, major OEMs install electronic locks on steer-by-wire road feel simulators to ensure that the steering wheel does not turn after the vehicle is powered off. Some automakers directly use a solution with an independent road feel simulator electronic lock controller and an independent motor to prevent the steering wheel from turning. However, adding an electronic lock to the steer-by-wire road feel simulator increases the size of the simulator, which is not conducive to space layout and increases costs and layout space.

[0004] The Hall position sensor used in the electric adjustment function of the road feel simulator is low in cost but low in accuracy. There is a risk that the accumulated error caused by the low accuracy of the Hall position sensor may cause the anti-rotation function to activate during driving even before the power is off, making it impossible to turn the steering wheel. Summary of the Invention

[0005] To address the problems of existing steer-by-wire systems where the steering wheel rotates freely after power-off, the inconvenience of independent road feel simulator electronic lock controllers in terms of space layout, and the low accuracy of Hall position sensors leading to steering wheel lock-up due to accumulated errors during driving, thus preventing the user from steering and causing danger, this invention provides a self-correcting steer-by-wire road feel simulator power-off anti-rotation control method and system. It shares the road feel simulator length adjustment motor and its controller with the steer-by-wire system, and through new control logic, it relearns the anti-rotation position in advance when the anti-rotation function is activated before the accumulated error reaches the point of driving.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] As a first aspect of the present invention, a method for preventing steering wheel spin under power-off conditions using a self-correcting steer-by-wire road feel simulator is provided, comprising the following steps:

[0008] S1. The length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator is obtained by adjusting the stall position of the motor;

[0009] S2. Set soft stop point 1 and soft stop point 2 within the length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator to determine the anti-rotation automatic locking area of ​​the steer-by-wire road feel simulator;

[0010] S3. Set soft stop point 3 between soft stop point 1 and soft stop point 2, and ensure that the relative position between soft stop point 2 and soft stop point 3 remains unchanged; the range between soft stop point 1 and soft stop point 3 is the manual adjustment range L1 of the steer-by-wire road feel simulator;

[0011] S4. Correct the position offset of soft stop point 3 through position self-learning;

[0012] S5. Enter the corresponding anti-rotation control mode when the vehicle is powered on or off, and perform anti-rotation control when the steer-by-wire road feel simulator is powered off.

[0013] Further, step S1 includes:

[0014] S11. Initialize the position of the steer-by-wire road feel simulator controller;

[0015] S12. Obtain the stall point 1 and stall point 2 of the regulating motor;

[0016] S13. The distance between stall point 1 and stall point 2 is the length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator.

[0017] Further, step S12 includes: adjusting the road feel simulator from the middle position to the shortest position in the length direction using the adjustment button of the steer-by-wire road feel simulator, at which point the adjustment motor stalls, and recording stall point 2; adjusting the road feel simulator to the longest position in the length direction using the adjustment button, at which point the adjustment motor stalls, and recording stall point 1.

[0018] Further, step S2 includes:

[0019] S21. The distance Δx between the soft stop point and the stall point is converted into Hall number using the spacing calculation formula: Hall number = Δx / thread lift of the transmission pair;

[0020] S22. Set the positions of soft stop point 1 and soft stop point 2, wherein the distance between soft stop point 1 and stall point 1 is equal to the distance between soft stop point 2 and stall point 2;

[0021] S23. The range between soft stop point 2 and stall point 2 is the locking area of ​​the steer-by-wire road feel simulator; the range between stall point 1 and soft stop point 2 is the automatic retraction range of the steer-by-wire road feel simulator.

[0022] Further, step S3 includes:

[0023] S31. The distance △Y between soft stop point 3 and soft stop point 2 is converted into Hall number using the distance calculation formula: Hall number = △Y / thread lift of transmission pair, and △y > △x;

[0024] S32. Set the position of soft stop point 3 by the spacing Hall number, so that soft stop point 2 and soft stop point 3 are offset synchronously and the relative position between the two points remains unchanged;

[0025] S33. The range between soft stop point 1 and soft stop point 3 is the manual adjustment range L1 of the steer-by-wire road feel simulator.

[0026] Furthermore, step S4 includes: during user operation, the road sensor simulator continuously monitors the current of the road sensor motor, and when the current reaches the stall current, the position self-learning function is activated, and steps S1 to S4 are repeated.

[0027] Further, step S5 includes:

[0028] S51. When the vehicle is in the power-on state, the anti-rotation function is turned off, the steer-by-wire road feel simulator enters the manual adjustment mode, and the length adjustment range of the steer-by-wire road feel simulator in the manual adjustment mode is the manual adjustment range L1 of the steer-by-wire road feel simulator.

[0029] S52. When the vehicle is powered off, the anti-rotation function is activated and the steer-by-wire road feel simulator enters the anti-rotation control mode: When the driver turns off the engine and powers off, the steer-by-wire road feel simulator drives the steering wheel to retract to the manual adjustment range L1, and then the steer-by-wire road feel simulator controller adjusts to continue retracting the △Y distance. At this time, the mechanical locking structure of the road feel simulator enters the anti-rotation automatic locking area to achieve power-off anti-rotation.

[0030] S53. When the vehicle goes from the power-off state to the power-on state, the steer-by-wire road feel simulator enters the automatic return mode: the driver presses IG ON, the steer-by-wire road feel simulator controller adjusts the steer-by-wire road feel simulator to the length before the last power-off. At this time, the road feel simulator is adjusted to the manual adjustment range L1, the mechanical locking mechanism is not in the locking area, and the driver can use the steering function normally.

[0031] As another aspect of the present invention, a self-correcting steer-by-wire road feel simulator power-off anti-rotation control system is provided, which is used to implement the self-correcting steer-by-wire road feel simulator power-off anti-rotation control method described in the present invention. The control system is characterized in that the steer-by-wire road feel simulator and the road feel simulator controller are provided, and the steer-by-wire road feel simulator is provided with a locking structure, an adjustment motor and an adjustment button.

[0032] The present invention has the following beneficial effects:

[0033] This invention provides a self-correcting anti-rotation control method and system for a steer-by-wire road feel simulator. It shares the road feel simulator length adjustment motor and its controller with the steer-by-wire system. Through new control logic, it preemptively relearns the anti-rotation position before the anti-rotation function is activated during driving, even before the accumulated error reaches the required level. This invention, while ensuring the user's normal adjustment range L1, adds ΔY for steering wheel anti-rotation. To address the position offset problem, a strategy of simultaneous offsetting of two soft stop points is implemented: soft stop point 2 and soft stop point 3 offset synchronously while maintaining their relative positions and the distance between them can be converted into an integer Hall effect signal. Simultaneously, Δy > Δx is set, so even if soft stop point 2 and soft stop point 3 simultaneously offset to their extreme positions, soft stop point 3 will not offset into the locking area. This ensures that the anti-rotation mechanism of the road feel simulator remains within the manual adjustment range during driving, preventing the anti-rotation mechanism from offsetting into the locking range due to accumulated errors and thus preventing the steering wheel from becoming unmanageable. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0035] Figure 1 This is a flowchart of a self-correcting steer-by-wire road feel simulator power-off anti-steering control method according to an embodiment of the present invention;

[0036] Figure 2 This is a flowchart illustrating the anti-rotation adjustment process of a self-correcting steer-by-wire road feel simulator power-off anti-rotation control method as described in an embodiment of the present invention when the vehicle is in the starting state.

[0037] Figure 3 This is a flowchart illustrating the anti-rotation adjustment process of a self-correcting steer-by-wire road feel simulator power-off anti-rotation control method according to an embodiment of the present invention when the vehicle is off.

[0038] Figure 4 This is a schematic diagram of the anti-rotation adjustment range of a self-correcting steer-by-wire road feel simulator anti-rotation control method according to an embodiment of the present invention. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Example 1

[0040] like Figure 1 As shown, this embodiment is a power-off anti-steering control method for a self-correcting steer-by-wire road feel simulator, including the following steps:

[0041] S1. The length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator is obtained by adjusting the motor stall position:

[0042] S11. Initialize the position of the steer-by-wire road feel simulator controller;

[0043] S12. Obtain the stall point 1 and stall point 2 of the regulating motor: (e.g.) Figure 1 , Figure 4 As shown, by adjusting the road feel simulator using the adjustment buttons on the steer-by-wire simulator, the length direction (i.e., the longitudinal axis of the steering wheel) is adjusted from the middle position to the shortest. At this point, the adjustment motor stalls, and stall point 2 is recorded. Figure 1 ; Adjust the road feel simulator to its longest length using the adjustment button. At this point, the motor stalls. Record stall point 1.

[0044] S13. The distance between stall point 1 and stall point 2 is the length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator;

[0045] S2. Within the length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator, set soft stop point 1 and soft stop point 2 to determine the anti-rotation automatic locking area range of the steer-by-wire road feel simulator:

[0046] S21. The distance Δx between the soft stop point and the stall point is converted into Hall number using the spacing calculation formula: Hall number = Δx / thread lift of the transmission pair;

[0047] S22. Set the positions of soft stop point 1 and soft stop point 2, wherein the distance between soft stop point 1 and stall point 1 is equal to the distance between soft stop point 2 and stall point 2, that is, the Hall number between soft stop point 1 and stall point 1 is equal to the Hall number between soft stop point 2 and stall point 2, both of which are Δx / drive pair thread lift;

[0048] S23. The range between soft stop point 2 and stall point 2 is the locking area of ​​the steer-by-wire road feel simulator; the range between stall point 1 and soft stop point 2 is the automatic retraction range of the steer-by-wire road feel simulator.

[0049] S3. Set a soft stop point 3 between soft stop point 1 and soft stop point 2, and ensure that the relative positions between soft stop point 2 and soft stop point 3 remain unchanged. The range between soft stop point 1 and soft stop point 3 is the manual adjustment range L1 of the steer-by-wire road feel simulator.

[0050] S31. The distance △Y between soft stop point 3 and soft stop point 2 is converted into Hall number using the distance calculation formula: Hall number = △Y / thread lift of transmission pair, and △y > △x;

[0051] S32. Set the position of soft stop point 3 by the spacing Hall number, so that soft stop point 2 and soft stop point 3 are offset synchronously and the relative position between the two points remains unchanged;

[0052] S33. The range between soft stop point 1 and soft stop point 3 is the manual adjustment range L1 of the steer-by-wire road feel simulator;

[0053] The position of soft stop point 3 is set by adjusting the spacing Hall effect number, so that soft stop points 2 and 3 are synchronously offset while their relative positions remain unchanged. Since Δy > Δx is set, even if soft stop points 2 and 3 synchronously offset to their extreme positions, soft stop point 3 will not shift into the anti-steering automatic locking zone of the steer-by-wire road feel simulator. The position of soft stop point 3 is set according to soft stop point 2 each time IG ON and IG OFF are activated. Figure 3 , Figure 4 As shown;

[0054] S4. Correct the position offset of soft stop point 3 through position self-learning:

[0055] During user operation, the road sensor simulator constantly monitors the current of the road sensor motor. When the current reaches the stall current, the position self-learning function is activated, that is, steps S1 to S4 are repeated.

[0056] Since the relative positions of soft stop point 2 and soft stop point 3 remain unchanged and they shift together, when soft stop point 2 shifts to stall point 2, if the position of soft stop point 3 enters the locking area of ​​the steer-by-wire road feel simulator (i.e., the position of soft stop point 3 enters between soft stop point 2 and stall point 2), it will cause the steer-by-wire road feel simulator to automatically lock when the vehicle is powered on and started. Therefore, it is necessary to correct the position shift of soft stop point 3 through position self-learning, that is, repeat the above steps, to prevent the steer-by-wire road feel simulator from automatically locking when the vehicle is powered on.

[0057] S5. Enter the corresponding anti-rotation control mode when the vehicle is powered on or off:

[0058] S51. For example Figure 2 As shown, when the vehicle is powered on, the anti-rotation function is disabled, and the steer-by-wire road feel simulator enters manual adjustment mode:

[0059] The driver can adjust the length of the steer-by-wire road feel simulator using the adjustment button. In manual adjustment mode, the length adjustment range of the steer-by-wire road feel simulator is the manual adjustment range L1 of the steer-by-wire road feel simulator. The driver's adjustment of the position of the steer-by-wire road feel simulator using the button is only effective within this range.

[0060] S52. For example Figure 3 As shown, when the vehicle is powered off, the anti-rotation function is activated, and the steer-by-wire road feel simulator enters the anti-rotation control mode:

[0061] When the driver turns off the engine and disconnects the power, the steer-by-wire road feel simulator drives the steering wheel to retract to the manual adjustment range L1 and then continues to retract the △Y distance. This △Y distance cannot be manually adjusted by the driver through the adjustment button. It can only be adjusted by the steer-by-wire road feel simulator controller when IG OFF (vehicle power off). At this time, the mechanical locking structure of the road feel simulator also enters the locking area, realizing the anti-rotation function when power off.

[0062] S53. When the vehicle transitions from a power-off state to a power-on state, the steer-by-wire road feel simulator enters automatic return mode:

[0063] When the driver is ready to drive the vehicle, pressing IG ON will adjust the steer-by-wire road feel simulator controller to extend the steer-by-wire road feel simulator to the length before the last power-off. At this time, the road feel simulator is adjusted to the manual adjustment range L1 (the range between soft stop point 1 and soft stop point 3), and the mechanical locking mechanism is not in the locking area, so the driver can use the steering function normally.

[0064] This embodiment adds ΔY for steering wheel anti-rotation while ensuring the user's normal adjustment range L1. However, the road feel simulator uses a low-cost, low-precision, industry-standard Hall sensor to record the adjustment position. After a period of use, all soft stop points will shift. To solve this problem, this embodiment adopts a strategy of simultaneous shifting of two soft stop points: soft stop point 2 and soft stop point 3 shift synchronously while maintaining their relative positions and converting their distance into an integer Hall signal. Simultaneously, Δy is set to be greater than Δx. This ensures that even when soft stop point 2 and soft stop point 3 shift to their extreme positions, soft stop point 3 will not shift into the locking area. This guarantees that the anti-rotation mechanism of the road feel simulator remains within the manual adjustment range during driving, preventing error accumulation from causing the anti-rotation mechanism to shift into the locking range and thus preventing the steering wheel from turning. Example 2

[0065] A self-correcting steer-by-wire road feel simulator power-off anti-rotation control system is provided to implement the self-correcting steer-by-wire road feel simulator power-off anti-rotation control method described in Example 1. The control system includes a steer-by-wire road feel simulator and a road feel simulator controller. The steer-by-wire road feel simulator is equipped with a locking structure, an adjustment motor, and adjustment buttons.

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preventing steering wheel rotation under power-off conditions using a self-correcting steer-by-wire road feel simulator, characterized in that, Includes the following steps: S1. Obtain the length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator by adjusting the stall position of the motor; step S1 includes: S11. Initialize the position of the steer-by-wire road feel simulator controller; S12. Obtain the stall point 1 and stall point 2 of the regulating motor; S13. The distance between stall point 1 and stall point 2 is the length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator; S2. Within the length adjustment range L of the mechanical limit of the steer-by-wire road feel simulator, set soft stop point 1 and soft stop point 2 to determine the anti-rotation automatic locking area range of the steer-by-wire road feel simulator; step S2 includes: S21. The distance Δx between the soft stop point and the stall point is converted into Hall number using the spacing calculation formula: Hall number = Δx / thread lift of the transmission pair; S22. Set the positions of soft stop point 1 and soft stop point 2, wherein the distance between soft stop point 1 and stall point 1 is equal to the distance between soft stop point 2 and stall point 2; S23. The range between soft stop point 2 and stall point 2 is the locking area of ​​the steer-by-wire road feel simulator; the range between stall point 1 and soft stop point 2 is the automatic retraction range of the steer-by-wire road feel simulator. S3. Set soft stop point 3 between soft stop point 1 and soft stop point 2, and ensure that the relative position between soft stop point 2 and soft stop point 3 remains unchanged; the range between soft stop point 1 and soft stop point 3 is the manual adjustment range L1 of the steer-by-wire road feel simulator; S4. Correct the position offset of soft stop point 3 through position self-learning; S5. Enter the corresponding anti-rotation control mode when the vehicle is powered on or off, and perform anti-rotation control when the steer-by-wire road feel simulator is powered off.

2. The anti-steering control method for a self-correcting steer-by-wire road feel simulator as described in claim 1, characterized in that, Step S12 includes: adjusting the road feel simulator from the middle position to the shortest position in the length direction using the adjustment button of the steer-by-wire road feel simulator, at which point the adjustment motor stalls, and recording stall point 2; adjusting the road feel simulator to the longest position in the length direction using the adjustment button, at which point the adjustment motor stalls, and recording stall point 1.

3. The anti-steering control method for a self-correcting steer-by-wire road feel simulator as described in claim 1, characterized in that, Step S3 includes: S31. The distance △Y between soft stop point 3 and soft stop point 2 is converted into Hall number using the distance calculation formula: Hall number = △Y / thread lift of transmission pair, and △y > △x; S32. Set the position of soft stop point 3 by the spacing Hall number, so that soft stop point 2 and soft stop point 3 are offset synchronously and the relative position between the two points remains unchanged; S33. The range between soft stop point 1 and soft stop point 3 is the manual adjustment range L1 of the steer-by-wire road feel simulator.

4. The anti-steering control method for a self-correcting steer-by-wire road feel simulator as described in claim 1, characterized in that, Step S4 includes: during user operation, the road sensor simulator constantly monitors the current of the road sensor motor. When the current reaches the stall current, the position self-learning function is activated, and steps S1 to S4 are repeated.

5. The anti-steering control method for a self-correcting steer-by-wire road feel simulator as described in claim 1, characterized in that, Step S5 includes: S51. When the vehicle is in the power-on state, the anti-rotation function is turned off, the steer-by-wire road feel simulator enters the manual adjustment mode, and the length adjustment range of the steer-by-wire road feel simulator in the manual adjustment mode is the manual adjustment range L1 of the steer-by-wire road feel simulator. S52. When the vehicle is powered off, the anti-rotation function is activated and the steer-by-wire road feel simulator enters the anti-rotation control mode: When the driver turns off the engine and powers off, the steer-by-wire road feel simulator drives the steering wheel to retract to the manual adjustment range L1, and then the steer-by-wire road feel simulator controller adjusts to continue retracting the △Y distance. At this time, the mechanical locking structure of the road feel simulator enters the anti-rotation automatic locking area to achieve power-off anti-rotation. S53. When the vehicle goes from the power-off state to the power-on state, the steer-by-wire road feel simulator enters the automatic return mode: the driver presses IG ON, the steer-by-wire road feel simulator controller adjusts the steer-by-wire road feel simulator to the length before the last power-off. At this time, the road feel simulator is adjusted to the manual adjustment range L1, the mechanical locking mechanism is not in the locking area, and the driver can use the steering function normally.

6. A power-off anti-rotation control system for a self-correcting steer-by-wire road feel simulator, used to implement the power-off anti-rotation control method for a self-correcting steer-by-wire road feel simulator as described in claim 1, characterized in that, The control system includes a steer-by-wire road feel simulator and a road feel simulator controller. The steer-by-wire road feel simulator is equipped with a locking structure, an adjustment motor, and adjustment buttons.

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