Estimation method and device for rack position of steer-by-wire system, vehicle and medium

Abstract

The invention relates to the technical field of vehicle steer-by-wire systems, in particular to a method and device for estimating the position of a rack of a steer-by-wire system, a vehicle and a medium, and the method comprises the steps that when the steer-by-wire system of the vehicle is powered on, an initialized neutral position calibration value of the rack of the steer-by-wire system is obtained; determining a target position variable quantity of the rack based on the initialized median calibration value and the physical rotation angle variable quantity of the motor, and obtaining a new median calibration value, meeting a preset calibration condition, of the rack; and determining a current value of the rack based on the target position variable quantity of the rack and the new median calibration value, so as to estimate the current position of the rack according to the current value. Therefore, the problems that the control diversity and safety of the steer-by-wire system are reduced due to the fact that no mechanical connecting mechanism exists between the hand feeling simulation mechanism and the steering actuator, the hardware cost of the steer-by-wire system is increased due to the fact that the steering actuator is additionally provided with a steering angle sensor, and the requirement for rack position estimation cannot be met in the related technology are solved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle steer-by-wire systems, and in particular to a method, device, vehicle and medium for estimating the rack position of a steer-by-wire system. Background Art

[0002] In the related art, in the steer-by-wire system, the driver transmits the steering intention to the RWA (Road Wheel Actuator) through the steering wheel of the hand-feel simulation mechanism to push the wheels to achieve the lateral movement of the vehicle. There is no mechanical connection mechanism between the hand-feel simulation mechanism and the steering actuator. The driver's steering intention is converted into an electrical signal of the steering wheel angle by the hand-feel simulation mechanism and transmitted to the steering actuator through wires. The steering actuator consists of a gear rack and an actuator motor. In order to measure the rack position of the steering actuator, a rack position sensor is required. The output torque of the actuator motor is calculated through the measurement signal of the rack position sensor. When there is no rack position sensor, an angle sensor is required. The output torque of the actuator motor is calculated through the angle signal measured by the angle sensor. Finally, the rack is pushed to move laterally to the target value through a reduction mechanism (ball screw or worm gear, etc.).

[0003] However, since there is no mechanical connection between the feel simulation mechanism and the steering actuator, the safety requirements of the wire-controlled steering system are very high. All vehicles need to implement redundant design. The cost of hardware is an industry problem. Adding a rack position sensor or a steering angle sensor will increase the hardware cost. Since the rack length of the wire-controlled steering system for front-wheel steering is relatively long, generally reaching 60 to 80 mm, there is currently no suitable rack position sensor on the market.

[0004] Therefore, in the related technology, since there is no mechanical connection mechanism between the hand feel simulation mechanism and the steering actuator, the control diversity and safety of the wire-controlled steering system are reduced, and the addition of an angle sensor to the steering actuator increases the hardware cost of the wire-controlled steering system, which cannot meet the requirements of rack position estimation and reduces the accuracy and reliability of rack position estimation, which needs to be urgently resolved. Summary of the invention

[0005] The present application provides a method, device, vehicle and medium for estimating the rack position of a wire-controlled steering system, so as to solve the problems in the related art that the control diversity and safety of the wire-controlled steering system are reduced due to the lack of a mechanical connection mechanism between the hand-feel simulation mechanism and the steering actuator, and the addition of a steering angle sensor to the steering actuator increases the hardware cost of the wire-controlled steering system and cannot meet the demand for rack position estimation.

[0006] A first aspect of the present application provides a method for estimating the rack position of a wire-controlled steering system, comprising the following steps: when the vehicle's wire-controlled steering system is powered on, obtaining an initialization median calibration value of the rack of the wire-controlled steering system; determining a target position change of the rack based on the initialization median calibration value and a change in the physical angle of the motor, and obtaining a new median calibration value of the rack that meets preset calibration conditions; determining a current value of the rack based on the target position change of the rack and the new median calibration value, so as to estimate the current position of the rack based on the current value.

[0007] Optionally, in one embodiment of the present application, obtaining the initialization median calibration value of the rack of the wire-controlled steering system includes: determining a first target number of rotations of the motor based on a target direction based on a first counter of the physical number of rotations of the motor; obtaining a target difference between a target motor rotation design value total number of rotations and the first target number of rotations, and detecting whether the target difference is less than a preset threshold; when it is detected that the target difference is less than the preset threshold, determining the initialization median calibration value of the rack according to the first target number of rotations.

[0008] Optionally, in one embodiment of the present application, determining the target position change of the rack based on the initialized median calibration value and the physical rotation angle change of the motor includes: determining a second target number of rotations of the motor based on the target direction based on a second counter of the physical number of rotations of the motor; determining the actual rack position of the rack using the second target number of rotations and the total number of rotations of the motor design value; determining the median signed difference of the rack according to the actual rack position and the initialized median calibration value, so as to determine the target position change of the rack according to the signed difference.

[0009] Optionally, in one embodiment of the present application, after estimating the current position of the rack according to the current value, it also includes: determining a target adjustment value of the rack corresponding to the steering wheel angle of the vehicle; determining an actual output torque value of the motor using the target adjustment value and the current value of the rack; and based on the actual output torque value, driving the rack to move to the target position to complete steering.

[0010] Optionally, in one embodiment of the present application, after driving the rack to move to the target position based on the actual output torque value and completing the steering, it also includes: when the vehicle's steer-by-wire system is powered off and the user starts the action of restoring the steering wheel and rack to the center position, recording the rack position at power-off, and driving the steering wheel and the rack to return to the position corresponding to the new center calibration value.

[0011] A second aspect of the present application provides a method for estimating the rack position of a wire-controlled steering system, comprising: an acquisition module, used to acquire an initialization median calibration value of the rack of the wire-controlled steering system when the wire-controlled steering system of the vehicle is powered on; a determination module, used to determine a target position change of the rack based on the initialization median calibration value and a change in the physical angle of the motor, and to acquire a new median calibration value of the rack that meets preset calibration conditions; and an estimation module, used to determine a current value of the rack based on the target position change of the rack and the new median calibration value, so as to estimate the current position of the rack based on the current value.

[0012] Optionally, in one embodiment of the present application, the acquisition module includes: a first determination unit, used to determine a first target number of rotations of the motor based on a target direction based on a first counter of the physical number of rotations of the motor; an acquisition unit, used to obtain a target difference between the total number of rotations of the target motor design value and the first target number of rotations, and detect whether the target difference is less than a preset threshold; a second determination unit, used to determine the initialization median calibration value of the rack according to the first target number of rotations when it is detected that the target difference is less than the preset threshold.

[0013] Optionally, in one embodiment of the present application, the determination module includes: a third determination unit, used to determine a second target number of rotations of the motor based on the target direction based on a second counter of the physical number of rotations of the motor; a fourth determination unit, used to determine the actual rack position of the rack using the second target number of rotations and the total number of rotations of the motor design value; and a fifth determination unit, used to determine the signed difference of the median of the rack based on the actual rack position and the initialized median calibration value, so as to determine the target position change of the rack based on the signed difference.

[0014] Optionally, in one embodiment of the present application, the device of the embodiment of the present application also includes: an acquisition module, which is used to determine the target adjustment value of the rack corresponding to the steering wheel angle of the vehicle after estimating the current position of the rack according to the current value; a determination module, which is used to determine the actual output torque value of the motor using the target adjustment value and the current value of the rack after estimating the current position of the rack according to the current value; and a driving module, which is used to drive the rack to the target position based on the actual output torque value to complete the steering after estimating the current position of the rack according to the current value.

[0015] Optionally, in one embodiment of the present application, the device of the embodiment of the present application also includes: a control module, for driving the rack to move to the target position based on the actual output torque value, after completing the steering, when the vehicle's wire-controlled steering system is powered off and the user starts the steering wheel and rack to return to the center position, recording the rack position at power-off, and driving the steering wheel and the rack to return to the position corresponding to the new center calibration value.

[0016] A third aspect of the present application provides a vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for estimating the rack position of a wire-controlled steering system as described in the above embodiment.

[0017] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for estimating the rack position of a wire-controlled steering system.

[0018] A fifth aspect of the present application provides a computer program product, including a computer program, which, when executed, is used to implement the above-mentioned method for estimating the rack position of a wire-controlled steering system.

[0019] The embodiment of the present application can determine the target position change of the rack through the initialization mid-position calibration value of the rack of the steering-by-wire system and the change in the physical rotation angle of the motor when the steering-by-wire system of the vehicle is powered on, thereby obtaining a new mid-position calibration value of the rack, and determining the current value of the rack based on the target position change of the rack and the new mid-position calibration value, so as to estimate the current position of the rack according to the current value, thereby effectively improving the accuracy and reliability of the rack position estimation. Thus, the problem in the related art that there is no mechanical connection mechanism between the hand-feel simulation mechanism and the steering actuator, which reduces the control diversity and safety of the steering-by-wire system, and the steering actuator adds an angle sensor, which increases the hardware cost of the steering-by-wire system and cannot meet the requirements of rack position estimation is solved.

[0020] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0022] Figure 1 A flowchart of a method for estimating the rack position of a wire-controlled steering system provided according to an embodiment of the present application;

[0023] Figure 2 This is a diagram of the SBW (Steering By Wire) system architecture of a specific embodiment of the present application;

[0024] Figure 3 A schematic diagram of the relationship between the physical rotation angle direction of the motor and the position of the rack according to a specific embodiment of the present application;

[0025] Figure 4 This is a diagram of the electrical architecture of the SBW system of a specific embodiment of the present application;

[0026] Figure 5 It is a structural schematic diagram of a device for estimating the rack position of a wire-controlled steering system provided according to an embodiment of the present application;

[0027] Figure 6 It is a schematic diagram of the structure of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0029] The following describes the method, device, vehicle and medium for estimating the rack position of the wire steering system of the embodiment of the present application with reference to the accompanying drawings. In view of the problem that in the related technology mentioned in the background technology center, there is no mechanical connection mechanism between the hand feeling simulation mechanism and the steering actuator, which reduces the control diversity and safety of the wire steering system, and the steering actuator adds an angle sensor, which increases the hardware cost of the wire steering system and cannot meet the demand for rack position estimation, the present application provides a method for estimating the rack position of the wire steering system, in which when the wire steering system of the vehicle is powered on, the target position change of the rack can be determined by the initialization median calibration value of the rack of the wire steering system and the physical angle change of the motor, so as to obtain the new median calibration value of the rack, and the current value of the rack is determined based on the target position change of the rack and the new median calibration value, so as to estimate the current position of the rack according to the current value, thereby effectively improving the accuracy and reliability of the rack position estimation. Thereby, the problems in the related art that there is no mechanical connection mechanism between the hand feel simulation mechanism and the steering actuator, which reduces the control diversity and safety of the wire-controlled steering system, and the addition of an angle sensor to the steering actuator increases the hardware cost of the wire-controlled steering system and cannot meet the requirements of rack position estimation are solved.

[0030] Specifically, Figure 1A schematic flow chart of a method for estimating the rack position of a wire-controlled steering system provided in an embodiment of the present application.

[0031] like Figure 1 As shown, the method for estimating the rack position of the wire control steering system includes the following steps:

[0032] In step S101 , when the steer-by-wire system of the vehicle is powered on, an initialization mid-position calibration value of the rack of the steer-by-wire system is obtained.

[0033] It can be understood that the embodiment of the present application can obtain the initialization median calibration value of the rack of the steering-by-wire system in the following steps when the steering-by-wire system of the vehicle is powered on, that is, the median calibration value of the rack position obtained by adaptive learning when the vehicle is offline, and can also obtain the median calibration value of the steering wheel angle, thereby effectively improving the feasibility of the rack position estimation of the steering-by-wire system.

[0034] Among them, in one embodiment of the present application, the initialization median calibration value of the rack of the wire-controlled steering system is obtained, including: determining a first target number of rotations of the motor based on a target direction based on a first counter of the number of physical rotations of the motor; obtaining a target difference between the total number of rotations of the target motor design value and the first target number of rotations, and detecting whether the target difference is less than a preset threshold; when it is detected that the target difference is less than the preset threshold, determining the initialization median calibration value of the rack according to the first target number of rotations.

[0035] In the embodiment of the present application, the first target number of rotations based on the target direction is the physical number of rotations of the motor in the counterclockwise direction acquired by the first counter.

[0036] In the actual implementation process, Figure 2 As shown in the figure, it is the SBW system architecture diagram. After the vehicle is offline and the four-wheel alignment is completed, the SBW system is powered on and initialized. When the steering wheel, the steering actuator RWA rack position, and the HWA (Hand Wheel Actuator, hand-feel simulation mechanism) steering wheel are all in the physical middle position, the steering actuator RWA controller reads the total rack length design value d of the SBW system, where the total rack length can be pre-set according to the mechanical system design and is not specifically limited here.

[0037] Next, combine Figure 3 and Figure 4As shown, the RWA executes the motor controller, and after power-on, it starts the motor physical rotation counter 1 and starts counting the physical rotation a1 of the CW (Clockwise) rotation of the motor and the physical rotation b1 of the CCW (Counter-clockwise) rotation of the motor. The physical rotation calculation method is: execute the motor electrical angle / 180*the number of motor pole pairs (Formula 1), and the counter is +1 when the rotation is a full circle of 360 degrees, and the calculation result of Formula 1 is used when it is less than a circle. Assuming that the number of motor pole pairs is 4, the motor physical rotation angle rotates 2 circles and exceeds 270 degrees, then a1=2+270 / 180*4=2.375 circles, and the calculation method of the CCW physical rotation b1 is the same as that of the clockwise a1.

[0038] That is, in the embodiment of the present application, after the motor controller drives the motor to rotate clockwise until the physical end position of the rack, it continues to drive the motor to rotate counterclockwise until the end on the other side of the physical position of the rack. Record the physical number of CW rotations a1 and the physical number of CW rotations b1, and determine the total number of motor rotation design values ​​c according to the reduction ratio R of the RWA reduction mechanism (ball screw or worm gear), the stroke ratio S, and the total rack length design value d of the wire-controlled steering SBW system: the total number of motor rotation design values ​​c = d / (S / R). Then, the CCW physical number of rotations b1 and the total number of motor rotation design values ​​c can be compared. If the difference is less than a threshold (where the threshold can be calibrated by a technician), record the physical number of rotations b1 / 2 as the SBW rack center position, thereby determining the initialization center calibration value of the rack. At the same time, record the HWA steering wheel angle, write it into the NVM (Non-Volatile Memory) of the RWA controller, and record the rack position center calibration flag as ON.

[0039] In step S102, based on the initialized median calibration value and the change in the physical rotation angle of the motor, the target position change of the rack is determined, and a new median calibration value of the rack that meets a preset calibration condition is obtained.

[0040] In the embodiment of the present application, the preset calibration condition is the rack position neutral self-learning condition when the vehicle is in normal use.

[0041] It can be understood that the embodiments of the present application can be based on the initialized median calibration value and the change in the physical rotation angle of the motor, such as determining the number of counterclockwise and clockwise rotations of the motor according to the second counter of the number of physical rotations of the motor in the following steps, thereby determining the change in the position of the rack and obtaining a new median calibration value of the rack that meets certain calibration conditions. For example, after the SBW system is powered on and initialized during normal use of the vehicle, the embodiments of the present application can start the median self-learning function of the rack position in the application cycle scheduling to obtain a new median calibration value, thereby effectively improving the accuracy of the rack position estimation of the wire-controlled steering system.

[0042] Among them, in the application cycle scheduling, the embodiment of the present application needs to meet the following conditions before the rack position median self-learning function can be started. The conditions are as follows: the rack position median calibration flag is ON, the rack position median self-learning flag is OFF, the HWA steering wheel angle sensor is normal, the RWA execution motor position sensor is normal, and the HWA steering wheel angle median value and the rack position median value exceed the threshold (the threshold can be calibrated by a technician).

[0043] Next, combine Figure 3 and Figure 4 As shown, the RWA executes the motor controller, starts the motor physical rotation number counter 1 after power-on, executes the motor controller to drive the motor to rotate clockwise until the physical end position of the rack, and then drives the motor to rotate counterclockwise until the end of the other side of the physical position of the rack. The motor physical rotation number counter 1 re-records the new physical rotation number a1 of CW rotation and the new physical rotation number b1 of CCW physical rotation, and calculates the total number of motor rotation design value c=d / (S / R) according to the reduction ratio R of the RWA reduction mechanism (ball screw or worm gear), the stroke ratio S, and the total rack length design value d of the SBW system, and compares the new CCW physical rotation number b1 with the b1 value saved in the NVM, such as the initialization median calibration value saved above. If the difference is less than the threshold value (wherein the threshold value can be calibrated), the new physical rotation number b1 / 2 is recorded as the new SBW rack position median value and written into the NVM for storage and use, and the rack position median self-learning flag is set to ON.

[0044] Optionally, in one embodiment of the present application, the target position change of the rack is determined based on the initialized median calibration value and the physical rotation angle change of the motor, including: determining a second target number of rotations of the motor based on the target direction based on a second counter based on the physical number of rotations of the motor; determining the actual rack position of the rack using the second target number of rotations and the total number of rotations of the motor design value; determining the median signed difference of the rack according to the actual rack position and the initialized median calibration value, so as to determine the target position change of the rack based on the signed difference.

[0045] In the embodiment of the present application, the second target number of rotations based on the target direction is the physical number of rotations of the motor in the counterclockwise direction acquired by the second counter.

[0046] As a possible way to achieve this, combining Figure 3 and Figure 4 As shown, the embodiment of the present application can be used when the vehicle is in normal use and the steer-by-wire SBW system is powered on and initialized, and the physical rotation number b1 / 2 of the motor is executed by the steering actuator RWA, that is, the initialized median calibration value is used as the median position of the SBW rack position; then, the steering actuator RWA executes the motor controller to start the motor physical rotation number counter 2 after power-on, records the physical rotation number a2 of the CW rotation and the physical rotation number b2 of the CCW rotation, and calculates the total number of motor rotation design value c=d / (S / R) according to the reduction ratio R of the RWA reduction mechanism (ball screw or worm gear), the stroke ratio S, and the total rack length design value d of the SBW system, so as to determine the actual rack position, so as to determine the median signed difference of the SBW rack position according to the actual rack position and the initialized median calibration value, so as to determine the position change of the rack according to the signed difference, thereby effectively improving the robustness of the rack position prediction of the steer-by-wire system.

[0047] In step S103, the current value of the rack is determined based on the target position change of the rack and the new median calibration value, so as to estimate the current position of the rack according to the current value.

[0048] It can be understood that the embodiment of the present application can calculate the current value of the rack based on the position change of the rack and the new median calibration value when the SBW rack position median calibration flag is ON, so as to estimate the current position of the rack according to the current value, and mark the SBW rack position current value as available, thereby effectively improving the accuracy and reliability of the rack position estimation.

[0049] Optionally, in one embodiment of the present application, after estimating the current position of the rack based on the current value, it also includes: determining a target adjustment value of the rack corresponding to the steering wheel angle of the vehicle; determining an actual output torque value of the motor using the target adjustment value and the current value of the rack; and based on the actual output torque value, driving the rack to move to the target position to complete the steering.

[0050] In some embodiments, Figure 4 As shown, in the embodiment of the present application, the driver can input the SBW rack target position to RWA through HWA to determine the adjustment value of the rack, and RWA determines the actual output torque value of the motor according to the current value and the adjustment value of the rack position, so as to control the deceleration mechanism to push the rack to the target position by outputting the appropriate torque value, complete the steering, and effectively improve the user's driving experience.

[0051] That is to say, the rack position value of the SBW system estimated by the embodiment of the present application has high accuracy and reliability, can be used for HWA or other vehicle systems to control the rack position of RWA, and can also be used to estimate the steering angle of the wheel, thereby reducing the hardware cost of the SBW system while increasing the control diversity and safety of the SBW system.

[0052] Optionally, in one embodiment of the present application, after driving the rack to move to the target position based on the actual output torque value and completing the steering, it also includes: when the vehicle's steer-by-wire system is powered off and the user starts the steering wheel and rack to return to the center position, the rack position at power-off is recorded, and the steering wheel and rack are driven to return to the position corresponding to the new center calibration value.

[0053] In some embodiments, the embodiments of the present application can implement the HWA steering wheel and rack position restoration action when the vehicle's SBW is powered off, and can also allow the user to choose not to restore the center position, but the rack position when the power is off must be recorded; when the SBW is powered on again, the embodiments of the present application can implement the HWA steering wheel and RWA rack position centering action based on the rack position recorded when the power was last off. If the HWA steering wheel angle median value and the rack position median value exceed the threshold, the rack position median can be self-learned in the above steps, effectively improving the vehicle automation level and enhancing the user's driving experience.

[0054] In addition, when the vehicle is being repaired or re-aligned for other reasons, the embodiment of the present application can recalibrate and adaptively learn the HWA steering wheel angle and the SBW rack position center, effectively improving the safety and reliability of the vehicle.

[0055] According to the method for estimating the rack position of a steer-by-wire system proposed in the embodiment of the present application, when the steer-by-wire system of the vehicle is powered on, the target position change of the rack can be determined by the initialization mid-position calibration value of the rack of the steer-by-wire system and the change in the physical rotation angle of the motor, thereby obtaining a new mid-position calibration value of the rack, and the current value of the rack can be determined based on the target position change of the rack and the new mid-position calibration value, so as to estimate the current position of the rack based on the current value, thereby effectively improving the accuracy and reliability of the rack position estimation. Thus, the problem in the related art that there is no mechanical connection mechanism between the hand-feel simulation mechanism and the steering actuator, which reduces the control diversity and safety of the steer-by-wire system, and the steering actuator adds an angle sensor, which increases the hardware cost of the steer-by-wire system and cannot meet the requirements of rack position estimation is solved.

[0056] Next, a device for estimating the rack position of a steer-by-wire system according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0057] Figure 5It is a block diagram of a device for estimating the rack position of a steer-by-wire system according to an embodiment of the present application.

[0058] like Figure 5 As shown, the device 10 for estimating the rack position of a steer-by-wire system includes: an acquisition module 100 , a determination module 200 and an estimation module 300 .

[0059] Specifically, the acquisition module 100 is used to acquire the initialization mid-position calibration value of the rack of the steer-by-wire system when the steer-by-wire system of the vehicle is powered on.

[0060] The determination module 200 is used to determine the target position change of the rack based on the initialization median calibration value and the motor physical angle change, and obtain a new median calibration value of the rack that meets the preset calibration conditions.

[0061] The estimation module 300 is used to determine the current value of the rack based on the target position change of the rack and the new median calibration value, so as to estimate the current position of the rack according to the current value.

[0062] Optionally, in one embodiment of the present application, the acquisition module 100 includes: a first determination unit, an acquisition unit and a second determination unit.

[0063] The first determination unit is used to determine a first target number of rotations of the motor based on a target direction based on a first counter of the number of physical rotations of the motor.

[0064] The acquisition unit is used to acquire a target difference between a total number of rotations of the target motor design value and a first target number of rotations, and detect whether the target difference is less than a preset threshold.

[0065] The second determination unit is used to determine the initialization median calibration value of the rack according to the first target number of revolutions when it is detected that the target difference is less than a preset threshold.

[0066] Optionally, in one embodiment of the present application, the determination module 200 includes: a third determination unit, a fourth determination unit and a fifth determination unit.

[0067] The third determination unit is used to determine a second target number of rotations of the motor based on a target direction based on a second counter of the number of physical rotations of the motor.

[0068] The fourth determining unit is used to determine the actual rack position of the rack by using the second target number of revolutions and the total number of revolutions of the motor's design value.

[0069] The fifth determining unit is used to determine the median signed difference of the rack according to the actual rack position and the initialized median calibration value, so as to determine the target position change of the rack according to the signed difference.

[0070] Optionally, in one embodiment of the present application, the device 10 of the embodiment of the present application further includes: an acquisition module, a determination module and a driving module.

[0071] The acquisition module is used to determine the target adjustment value of the rack corresponding to the steering wheel angle of the vehicle after estimating the current position of the rack according to the current value.

[0072] The determination module is used to determine the actual output torque value of the motor using the target adjustment value and the current value of the rack after estimating the current position of the rack according to the current value.

[0073] The driving module is used to drive the rack to move to the target position based on the actual output torque value after estimating the current position of the rack according to the current value to complete the steering.

[0074] Optionally, in one embodiment of the present application, the device 10 of the embodiment of the present application further includes: a control module.

[0075] Among them, the control module is used to drive the rack to move to the target position based on the actual output torque value. After the steering is completed, when the vehicle's wire-controlled steering system is powered off and the user starts the steering wheel and rack to return to the center position, record the rack position when power is off, and drive the steering wheel and rack to return to the position corresponding to the new center calibration value.

[0076] It should be noted that the above explanation of the embodiment of the method for estimating the rack position of a steer-by-wire system is also applicable to the device for estimating the rack position of a steer-by-wire system of this embodiment, and will not be repeated here.

[0077] According to the device for estimating the rack position of a wire-controlled steering system proposed in the embodiment of the present application, when the vehicle's wire-controlled steering system is powered on, the target position change of the rack can be determined by the initialization mid-position calibration value of the rack of the wire-controlled steering system and the change in the physical angle of the motor, thereby obtaining a new mid-position calibration value of the rack, and the current value of the rack can be determined based on the target position change of the rack and the new mid-position calibration value, so as to estimate the current position of the rack based on the current value, thereby effectively improving the accuracy and reliability of the rack position estimation. Thus, the problem in the related art that there is no mechanical connection mechanism between the hand-feel simulation mechanism and the steering actuator, which reduces the control diversity and safety of the wire-controlled steering system, and the steering actuator adds an angle sensor, which increases the hardware cost of the wire-controlled steering system and cannot meet the needs of rack position estimation is solved.

[0078] Figure 6 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include:

[0079] A memory 601 , a processor 602 , and a computer program stored in the memory 601 and executable on the processor 602 .

[0080] When the processor 602 executes the program, the method for estimating the rack position of the steer-by-wire system provided in the above embodiment is implemented.

[0081] Furthermore, the vehicle also includes:

[0082] The communication interface 603 is used for communication between the memory 601 and the processor 602 .

[0083] The memory 601 is used to store computer programs that can be executed on the processor 602 .

[0084] The memory 601 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0085] If the memory 601, the processor 602 and the communication interface 603 are implemented independently, the communication interface 603, the memory 601 and the processor 602 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 6 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0086] Optionally, in a specific implementation, if the memory 601, the processor 602 and the communication interface 603 are integrated on a chip, the memory 601, the processor 602 and the communication interface 603 can communicate with each other through an internal interface.

[0087] The processor 602 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0088] This embodiment also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for estimating the rack position of a wire-controlled steering system as described above is implemented.

[0089] This embodiment also provides a computer program product, including a computer program, which, when executed, is used to implement the above method for estimating the rack position of a steer-by-wire system.

[0090] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0091] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0092] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0093] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0094] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0095] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0096] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0097] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for estimating the rack position of a wire steering system, characterized in that: The following steps are involved: When the vehicle's steer-by-wire system is powered on, obtaining an initialization mid-position calibration value of a rack of the steer-by-wire system; Based on the initialization median calibration value and the change in the physical rotation angle of the motor, determining the target position change of the rack, and obtaining a new median calibration value of the rack that meets a preset calibration condition; Based on the target position change of the rack and the new mid-position calibration value, a current value of the rack is determined to estimate the current position of the rack according to the current value.

2. The method according to claim 1, characterized in that The obtaining of the initialization mid-position calibration value of the rack of the steer-by-wire system comprises: Determine a first target number of revolutions of the motor based on a target direction based on a first counter of the number of physical revolutions of the motor; Obtaining a target difference between the target motor rotation design value total number of revolutions and the first target number of revolutions, and detecting whether the target difference is less than a preset threshold; When it is detected that the target difference is less than the preset threshold, the initialization median calibration value of the rack is determined according to the first target number of revolutions.

3. The method according to claim 2, characterized in that The step of determining the target position change of the rack based on the initialization mid-position calibration value and the physical rotation angle change of the motor includes: Determining a second target number of rotations of the motor based on the target direction based on a second counter of the number of physical rotations of the motor; Determine the actual rack position of the rack by using the second target number of revolutions and the total number of revolutions of the motor design value; A median signed difference of the rack is determined according to the actual rack position and the initialized median calibration value, so as to determine a target position change of the rack according to the signed difference.

4. The method according to claim 1, characterized in that: After estimating the current position of the rack according to the current value, the method further includes: Determining a target adjustment value of the rack corresponding to a steering wheel angle of the vehicle; Determining an actual output torque value of the motor using the target adjustment value and the current value of the rack; Based on the actual output torque value, the rack is driven to move to the target position to complete the steering.

5. The method according to claim 4, characterized in that After driving the rack to move to the target position based on the actual output torque value and completing the steering, the method further includes: When the vehicle's steer-by-wire system is powered off and the user starts the action of restoring the steering wheel and rack to the neutral position, the rack position at power-off is recorded, and the steering wheel and rack are driven to return to the position corresponding to the new neutral calibration value.

6. A device for estimating the rack position of a wire steering system, characterized in that: include: An acquisition module, used for acquiring an initialization mid-position calibration value of a rack of the vehicle's steer-by-wire system when the steer-by-wire system is powered on; A determination module, configured to determine a target position change of the rack based on the initialization median calibration value and a change in the motor physical rotation angle, and obtain a new median calibration value of the rack that meets a preset calibration condition; An estimation module is used to determine the current value of the rack based on the target position change of the rack and the new median calibration value, so as to estimate the current position of the rack according to the current value.

7. The device according to claim 6, characterized in that The acquisition module comprises: A first determining unit, configured to determine a first target number of rotations of the motor based on a target direction based on a first counter of the number of physical rotations of the motor; An acquisition unit, used for acquiring a target difference between a target motor rotation design value total number of revolutions and the first target number of revolutions, and detecting whether the target difference is less than a preset threshold; The second determination unit is used to determine the initialization median calibration value of the rack according to the first target number of revolutions when it is detected that the target difference is less than the preset threshold.

8. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for estimating the rack position of a wire-controlled steering system as described in any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the method for estimating the rack position of a steer-by-wire system as described in any one of claims 1 to 5.

10. A computer program product, comprising a computer program, characterized in that The computer program is executed by a processor to implement the method for estimating the rack position of a steer-by-wire system as claimed in any one of claims 1 to 5.

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