Method, device, electronic device and storage medium for protecting a terminal

Abstract

The application relates to a method and device for protecting a steering end. The method comprises the following steps: determining a soft stop point and a hard stop point of a steering wheel of a target vehicle in a target steering process; the hard stop point is an angle of the steering wheel when a steering mechanism reaches a limit position working condition in the target steering; the soft stop point is an angle of the steering wheel when an opening condition of an end protection mode is met; obtaining an angle of the steering wheel in the steering process; if the angle of the steering wheel is greater than an angle indicated by the soft stop point and smaller than an angle indicated by the hard stop point, a steering assistance motor is controlled to adopt a reduced assistance mode; if the angle of the steering wheel reaches the angle indicated by the hard stop point, the steering assistance motor is controlled to stop assisting, and a target counterforce opposite to steering of the steering wheel is provided to offset a torque applied to the steering wheel. The method can improve control stability of the steering assistance motor in the limit position working condition.

Description

Technical Field

[0001] This application relates to the field of automotive steering protection technology, and in particular to a method, device, electronic device, storage medium, and computer program product for protecting the steering end. Background Technology

[0002] Currently, commercial vehicles generally have hydraulic power steering mechanisms. When the vehicle is in extreme steering conditions, the driver manipulates the steering wheel to bring the steering mechanism to its extreme position. Ideally, when a collision is imminent, the unloading valve of the hydraulic power steering system will release the hydraulic power, making the steering wheel rotation heavy and preventing a collision between the mechanical structures.

[0003] However, in related technologies, the unloading valve of the hydraulic power steering system in commercial vehicles is extremely prone to damage. Damage to the unloading valve renders the hydraulic power steering system ineffective in protecting the mechanical structure under extreme position conditions, leading to collisions between mechanical components. This significantly increases the risk of damage to the steering mechanism, degrades the control stability of the power steering motor, and makes the vehicle's driving state highly unstable. Therefore, the stability of the power steering motor control under extreme position conditions is crucial to preventing collisions in the steering mechanism under these conditions and is also key to the overall stability of the power steering motor control. Summary of the Invention

[0004] Therefore, it is necessary to provide a method, device, electronic device, computer-readable storage medium, and computer program product for protecting the steering end of a power steering motor under extreme position conditions, which can improve the stability of power steering motor control under extreme position conditions.

[0005] On the one hand, this application provides a method for protecting the steering end, including:

[0006] Determine the soft and hard stops of the steering wheel of the target vehicle during the steering process;

[0007] Wherein, the hard stop is the angle of the steering wheel when the steering mechanism reaches its limit position in the target steering direction; the soft stop is the angle of the steering wheel when the activation conditions of the end protection mode are met; the angle indicated by the soft stop in the same steering direction is smaller than the angle indicated by the hard stop; the target steering direction includes turning left and turning right;

[0008] The steering wheel angle during the steering process is obtained. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode.

[0009] If the steering wheel angle reaches the angle indicated by the hard stop, the power steering motor is controlled to stop providing power and a target reaction force opposite to the steering wheel direction is provided to counteract the torque applied to the steering wheel.

[0010] In one embodiment, the power steering motor is controlled to provide reduced power assistance, including:

[0011] Obtain the angle difference between the steering wheel angle and the angle indicated by the soft stop, and determine the power assist reduction coefficient based on the angle difference;

[0012] The specified assistance provided by the power steering motor is determined by the reduction coefficient and the actual assistance provided by the power steering motor.

[0013] Obtain the torque gradient value and determine the torque difference between the actual assistance and the specified assistance;

[0014] Based on the torque difference and the torque gradient, the target assist of the power steering motor is determined;

[0015] The power steering motor is controlled to provide assistance with the target assistance, which is less than the actual assistance.

[0016] In one embodiment, determining the target assist of the power steering motor based on the torque difference and the torque gradient value includes:

[0017] If the torque difference is greater than the torque gradient value, then the difference between the actual assist and the torque gradient value is taken as the target assist of the power steering motor.

[0018] If the torque difference is less than or equal to the torque gradient value, then the specified assist is used as the target assist for the power steering motor.

[0019] In one embodiment, determining the soft stop and hard stop of the steering wheel of the target vehicle during the steering process includes:

[0020] Obtain a preset number of historical limit steering angles on the target steering direction, and use the average of the preset number of historical limit steering angles as the average steering angle on the target steering direction. The average steering angle includes the average steering angle to the left and the average steering angle to the right.

[0021] Based on the average left-hand steering angle and the average right-hand steering angle, the steering wheel's half-stroke and center offset are determined respectively.

[0022] During the steering process, the oversteer amount is obtained by consulting the calibration data table based on the vehicle speed of the target vehicle and the motor speed of the power steering motor.

[0023] Based on the steering half-stroke, the center offset, and the steering overshoot, the soft stop and hard stop on the target steering are determined respectively. The soft stop includes a left soft stop and a right soft stop, and the hard stop includes a left hard stop and a right hard stop.

[0024] In one embodiment, obtaining a preset number of historical limit steering angles on the target steering includes: periodically counting the limit steering angles of the steering mechanism under the limit position conditions on the target steering; and the number of times the steering mechanism is continuously in the limit position condition within each statistical period reaches a preset number.

[0025] The preset number of extreme steering angles within the most recent statistical period are determined as historical extreme steering angles.

[0026] In one embodiment, determining the steering wheel's half-stroke and center offset based on the left-hand average steering angle and the right-hand average steering angle, respectively, includes:

[0027] Determine the difference between the average left-hand steering angle and the average right-hand steering angle, and determine the steering half-stroke based on the difference;

[0028] The left-hand average steering angle and the right-hand average steering angle are summed, and the center offset is determined based on the summation result.

[0029] In one embodiment, determining the soft stop and hard stop on the target steering based on the steering half-stroke, the center offset, and the steering overshoot includes:

[0030] The left soft stop is obtained by weighted summation of the steering half-stroke and the center offset.

[0031] The right soft stop is obtained by weighted subtraction of the steering half-stroke and the center offset.

[0032] The left soft stop and the steering overshoot are weighted and summed to obtain the left hard stop;

[0033] The rightward soft stop and the steering overshoot are weighted and subtracted to obtain the rightward hard stop.

[0034] On the other hand, this application also provides a protective device for the steering end, comprising:

[0035] The determination module is used to determine the soft stop and hard stop of the steering wheel of the target vehicle in the target steering direction during the steering process; wherein, the hard stop is the angle of the steering wheel when the steering mechanism reaches the limit position in the target steering direction; the soft stop is the angle of the steering wheel when the activation conditions of the end protection mode are met; the angle indicated by the soft stop in the same steering direction is smaller than the angle indicated by the hard stop; the target steering includes left steering and right steering;

[0036] The first control module is used to obtain the steering wheel angle during the steering process. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode.

[0037] The second control module is used to control the power steering motor to stop providing power steering assistance if the steering wheel angle reaches the angle indicated by the hard stop, and to provide a target reaction force opposite to the steering wheel direction to counteract the torque applied to the steering wheel.

[0038] On the other hand, this application also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0039] Determine the soft and hard stops of the steering wheel of the target vehicle during the steering process;

[0040] Wherein, the hard stop is the angle of the steering wheel when the steering mechanism reaches its limit position in the target steering direction; the soft stop is the angle of the steering wheel when the activation conditions of the end protection mode are met; the angle indicated by the soft stop in the same steering direction is smaller than the angle indicated by the hard stop; the target steering direction includes turning left and turning right;

[0041] The steering wheel angle during the steering process is obtained. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode.

[0042] If the steering wheel angle reaches the angle indicated by the hard stop, the power steering motor is controlled to stop providing power and a target reaction force opposite to the steering wheel direction is provided to counteract the torque applied to the steering wheel.

[0043] On the other hand, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0044] Determine the soft and hard stops of the steering wheel of the target vehicle during the steering process;

[0045] Wherein, the hard stop is the angle of the steering wheel when the steering mechanism reaches its limit position in the target steering direction; the soft stop is the angle of the steering wheel when the activation conditions of the end protection mode are met; the angle indicated by the soft stop in the same steering direction is smaller than the angle indicated by the hard stop; the target steering direction includes turning left and turning right;

[0046] The steering wheel angle during the steering process is obtained. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode.

[0047] If the steering wheel angle reaches the angle indicated by the hard stop, the power steering motor is controlled to stop providing power and a target reaction force opposite to the steering wheel direction is provided to counteract the torque applied to the steering wheel.

[0048] On the other hand, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0049] Determine the soft and hard stops of the steering wheel of the target vehicle during the steering process;

[0050] Wherein, the hard stop is the angle of the steering wheel when the steering mechanism reaches its limit position in the target steering direction; the soft stop is the angle of the steering wheel when the activation conditions of the end protection mode are met; the angle indicated by the soft stop in the same steering direction is smaller than the angle indicated by the hard stop; the target steering direction includes turning left and turning right;

[0051] The steering wheel angle during the steering process is obtained. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode.

[0052] If the steering wheel angle reaches the angle indicated by the hard stop, the power steering motor is controlled to stop providing power and a target reaction force opposite to the steering wheel direction is provided to counteract the torque applied to the steering wheel.

[0053] The aforementioned methods, devices, electronic equipment, storage media, and computer programs for protecting the steering end of a vehicle first determine the soft and hard stops of the target vehicle during steering for each ignition cycle. This allows for adaptation to changes in vehicle structure and ensures the accuracy of soft and hard stop calculations within each ignition cycle. Then, based on the soft and hard stops adapted to the vehicle structure, when the steering wheel angle is greater than the angle indicated by the soft stop but less than the angle indicated by the hard stop, the power steering motor is controlled to provide reduced power assistance. When the steering wheel angle is greater than the angle indicated by the hard stop, the power steering motor is controlled to provide a counterforce to counteract the torque applied by the driver to the steering wheel, preventing oversteering. Thus, without increasing the steering mechanical structure, the collision risk at the steering end under extreme position conditions can be improved, the control stability of the power steering motor under extreme position conditions can be enhanced, and the steering end protection function can be achieved throughout the entire vehicle lifecycle. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating a protection method for the steering end in one embodiment;

[0056] Figure 2 This is a schematic diagram of a process using a de-assisted method in one embodiment;

[0057] Figure 3 This is a flowchart illustrating a method for determining soft and hard stops in one embodiment;

[0058] Figure 4 This is a flowchart illustrating a protection method for the steering end in another embodiment;

[0059] Figure 5 This is a schematic diagram of vehicle signal validity detection in one embodiment;

[0060] Figure 6 This is a flowchart illustrating a method for determining the target assistance of a power steering motor in one embodiment.

[0061] Figure 7 This is a structural block diagram of a protection device at the steering end in one embodiment;

[0062] Figure 8This is a diagram of the internal structure of an electronic device in one embodiment. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0064] In one exemplary embodiment, such as Figure 1 As shown, a protection method for the steering end is provided. This method is applied to an electric power steering system, which uses the power generated by the power steering motor to assist the driver in steering operations. The electric power steering system mainly consists of three parts: a signal sensing unit, a steering assist mechanism (including a power assist motor, clutch, and reduction gear mechanism), and an electronic control unit (controller). This method is executed by the electronic control unit (controller) and includes steps 102 to 106. Wherein:

[0065] Step 102: Determine the soft stop and hard stop of the steering wheel of the target vehicle during the steering process.

[0066] Here, the hard stop is the steering wheel angle when the steering mechanism reaches its limit position in the target steering direction; the soft stop is the steering wheel angle when the activation conditions of the end-of-life protection mode are met; the angle indicated by the soft stop in the same steering direction is smaller than the angle indicated by the hard stop; the target steering direction includes left turn and right turn. The limit position condition is the extreme position that the steering wheel of the target vehicle can reach when turning left or right, at which point the steering mechanism is about to collide.

[0067] Within any ignition cycle of the target vehicle, there are multiple steering operations. During each steering operation, when the target vehicle is at its limit position, the driver manipulates the steering wheel to place the steering mechanism at its limit position. To minimize the risk of collision with the steering mechanism, the steering wheel is connected to the steering mechanism, and the controller determines the soft and hard stops of the steering wheel in the target steering direction. Soft stops include the left soft stop for left turns and the right soft stop for right turns, while hard stops include the left hard stop for left turns and the right hard stop for right turns. The end-of-strike protection mode refers to a mode in which, in electronically assisted steering scenarios, the power steering motor begins to reduce assistance, increasing the heaviness of the steering wheel during steering to warn the driver that the steering mechanism is approaching its limit position. If the driver continues to steering, the power steering motor will stop assisting and provide a counterforce to counteract the torque applied to the steering wheel by the driver, preventing oversteering.

[0068] In actual implementation, the controller can determine whether the end protection mode can be started normally by receiving vehicle signals. The vehicle signals include vehicle speed, steering wheel speed, steering wheel angle, steering torque, etc. The end protection mode needs to work within a certain vehicle speed range. When the vehicle speed is too high, the probability of the steering wheel being in the extreme position is low. The steering wheel speed signal and steering angle signal are used to determine the position of the steering wheel. Based on the judgment logic of the vehicle signals, if it is determined that the end protection mode can be started normally, the steering end protection method of this embodiment is executed.

[0069] Step 104: Obtain the steering wheel angle during the steering process. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, control the power steering motor to use the reduced power steering mode.

[0070] In practice, after determining the soft stop and hard stop of the target direction within this ignition cycle, the controller acquires the steering wheel angle in real time during the steering process. If the steering wheel angle does not reach the angle indicated by the soft stop on the target direction, the power steering motor provides normal assistance. If the steering wheel angle is greater than or equal to the angle indicated by the soft stop but less than or equal to the angle indicated by the hard stop, the power steering motor uses a reduced assistance mode. The reduced assistance mode refers to decreasing the assistance provided by the power steering motor during the steering process starting from the soft stop.

[0071] Step 106: If the steering wheel angle reaches the angle indicated by the hard stop, control the power steering motor to stop assisting and provide a target reaction force opposite to the steering wheel to counteract the torque applied to the steering wheel.

[0072] In actual implementation, after the steering wheel angle reaches the angle indicated by the hard stop, the steering mechanism is about to collide. The power steering motor is controlled to provide a counterforce opposite to the target steering to counteract the torque applied by the driver to the steering wheel, thereby preventing the driver from rotating the steering wheel to the extreme working position and avoiding a collision of the mechanical structure of the steering mechanism.

[0073] In the aforementioned end-of-steering protection method, for each ignition cycle, the soft stop and hard stop points of the target vehicle during steering are first determined. This adapts to changes in vehicle structure and ensures the accuracy of soft and hard stop point calculations within each ignition cycle. Then, based on the soft and hard stop points adapted to the target vehicle's structure, when the steering wheel angle is greater than the angle indicated by the soft stop point but less than the angle indicated by the hard stop point, the power steering motor is controlled to provide reduced power assistance. When the steering wheel angle is greater than the angle indicated by the hard stop point, the power steering motor is controlled to provide a counterforce to counteract the torque applied by the driver to the steering wheel, preventing oversteering. Thus, without increasing the steering mechanical structure, the collision risk at the end of the steering process under extreme conditions can be effectively improved, and the control stability of the power steering motor under extreme position conditions can be enhanced. Consequently, end-of-steering protection can play a good role throughout the entire vehicle lifecycle.

[0074] In one exemplary embodiment, such as Figure 2 As shown, the power steering motor is controlled to use a reduced power steering assist method, including steps 202 to 210. Wherein:

[0075] Step 202: Obtain the angle difference between the steering wheel angle and the angle indicated by the soft stop, and determine the power assist reduction coefficient based on the angle difference.

[0076] In actual implementation, after the steering wheel angle reaches the angle indicated by the soft stop, the controller obtains the power steering reduction coefficient by reading a table. The table records the power steering reduction coefficient corresponding to the angle difference between the steering wheel angle and the angle indicated by the soft stop. That is, the controller can determine the power steering reduction coefficient corresponding to the angle difference by determining the angle difference between the steering wheel angle and the angle indicated by the soft stop. The power steering reduction coefficient is set by calibration based on multiple tests.

[0077] Step 204: Determine the specified assistance provided by the power steering motor by reducing the assistance coefficient and the actual assistance provided by the power steering motor.

[0078] In actual implementation, the controller determines the actual assistance when the power steering motor starts to reduce assistance, determines the product of the reduction coefficient and the actual assistance, and uses the sum of the product and the preset offset (which can be zero) as the specified assistance provided by the power steering motor.

[0079] Step 206: Obtain the torque gradient value and determine the torque difference between the actual assist and the specified assist.

[0080] In practice, if the rate of change (reduction) of the power steering assist provided by the power steering motor is too rapid during the power steering assist reduction process, it usually causes steering instability and a steering kicking phenomenon. Therefore, a trapezoidal incremental method is usually used to change the power steering assist, setting a torque gradient value (also known as a torque change gradient value) between adjacent sampling periods. The torque difference between the actual assist and the specified assist is determined, and the torque difference is compared with the torque gradient value.

[0081] Step 208: Determine the target assist of the power steering motor based on the torque difference and torque gradient value.

[0082] In practice, if the difference in torque represented by the comparison result is greater than the torque gradient value, it indicates that the power assist is reduced too quickly, potentially causing steering instability. In this case, the specified power assist cannot be used directly; instead, the difference between the actual power assist and the torque gradient value is determined as the target power assist corresponding to the power assist reduction method.

[0083] Step 210: Control the power steering motor to provide power assistance at the target level, where the target power assistance is less than the actual power assistance.

[0084] In actual implementation, the controller controls the power steering motor to provide assistance with the target assistance, that is, the assistance provided by the power steering motor is the target assistance, where the magnitude of the target assistance is less than the actual assistance.

[0085] In this embodiment, the torque gradient value is used to adjust the specified assist determined based on the assist reduction coefficient, so as to determine the target assist mode of the power steering motor. This can provide stable assist changes, maintain the steering stability of the target vehicle, avoid steering kick-out, and improve the human-machine interaction experience.

[0086] In an exemplary embodiment, determining the target assist of the power steering motor based on the torque difference and the torque gradient value includes: if the torque difference is greater than the torque gradient value, then the difference between the actual assist and the torque gradient value is taken as the target assist of the power steering motor; if the torque difference is less than or equal to the torque gradient value, then the specified assist is taken as the target assist of the power steering motor.

[0087] In practice, if the torque difference is greater than the torque gradient value, it indicates that the power assist is reduced too quickly, resulting in unstable steering and a poor driver experience. In this case, the specified power assist cannot be used directly; instead, the difference between the actual power assist and the torque gradient value is used as the target power assist for the power assist reduction method. If the torque difference is less than or equal to the torque gradient value, it means that using the specified power assist during the power assist reduction process can maintain stability. Therefore, the specified power assist is used as the target power assist for the power steering motor.

[0088] In the above embodiments, determining the target assist mode of the power steering motor by the torque gradient value can ensure the accuracy of the target assist provided by the power steering motor during the assist reduction process, thereby ensuring the stability of the vehicle during the steering process.

[0089] In one exemplary embodiment, such as Figure 3 As shown, determining the soft and hard stops of the steering wheel of the target vehicle during the steering process includes steps 302 to 308. Wherein:

[0090] Step 302: Obtain a preset number of historical limit steering angles on the target steering direction, and use the average of the preset number of historical limit steering angles as the average steering angle on the target steering direction. The average steering angle includes the average steering angle to the left and the average steering angle to the right.

[0091] In actual implementation, the controller determines the historical limit steering angles under extreme steering wheel positions at the target direction, and uses the average of the most recent preset number of historical limit steering angles as the average steering angle at the target direction. The average steering angle for left turns is the left-hand average steering angle, and the average steering angle for right turns is the right-hand average steering angle.

[0092] Step 304: Based on the average left-hand steering angle and the average right-hand steering angle, determine the steering wheel's half-stroke and center offset, respectively.

[0093] In practice, the controller can determine the steering wheel's half-stroke and center offset using the average left-hand and right-hand steering angles corresponding to the current ignition cycle. Simultaneously, with left turn as the positive direction, the difference between the average left-hand and right-hand steering angles, and the sum of these two angles, are calculated. The difference is used as the steering half-stroke, and the sum is used as the center offset.

[0094] Step 306: During the steering process, based on the target vehicle speed and the steering assist motor speed, query the calibration data table to obtain the steering overshoot.

[0095] In practice, steering overshoot refers to the angle difference between the angle indicated by the hard stop and the angle indicated by the soft stop on the target steering path. Steering overshoot has a significant impact on steering feel and can be calibrated using a factor-based approach. During steering, by reading values ​​such as vehicle speed and motor speed, a suitable steering overshoot calibration value is selected from the calibration data table.

[0096] Step 308: Based on the steering half-stroke, center offset, and steering overshoot, determine the soft stop and hard stop on the target steering direction, respectively. The soft stop includes the left soft stop and the right soft stop, and the hard stop includes the left hard stop and the right hard stop.

[0097] In practice, the controller determines the soft stop on the target steering position by mapping the steering halfway point to the center offset. It then determines the hard stop on the target steering position by mapping the soft stop to the steering transition amount.

[0098] In the above implementation, based on the driving conditions and the structural characteristics of the vehicle itself, steering half-stroke, center offset, and steering transition are set. The positions of the soft stop and hard stop are obtained through mathematical calculations of these three physical quantities. This is to adapt to changes in the vehicle structure, ensuring that the end-of-life protection plays a good role throughout the entire vehicle lifecycle.

[0099] In an exemplary embodiment, obtaining a preset number of historical limit steering angles on the target steering direction includes: periodically counting the limit steering angles of the steering mechanism in the limit position conditions on the target steering direction; the number of times the steering mechanism is continuously in the limit position condition within each statistical period reaches a preset number; and determining the preset number of limit steering angles in the most recent statistical period as historical limit steering angles.

[0100] In practice, the controller determines the soft stop and hard stop based on the historical limit steering angles of the steering wheel during each of the target vehicle's historical ignition cycles when it reaches its limit position. These historical limit steering angles include the historical limit steering angles for left turns and right turns. Within each statistical cycle, the controller counts the number of times the steering mechanism is continuously in its limit position for the target steering direction. If this number reaches a preset threshold, the preset number of limit steering angles from the most recent statistical cycle is determined as the historical limit steering angles. If the target steering direction is left turn, the historical limit steering angle is the left-hand historical limit steering angle; if the target steering direction is right turn, the historical limit steering angle is the right-hand historical limit steering angle.

[0101] The above-mentioned method for determining the historical limit steering angle takes into account both the driving conditions and the structural characteristics of the vehicle itself, ensuring the accuracy of the soft stop and hard stop determined in each ignition cycle.

[0102] In an exemplary embodiment, the steering wheel's half-stroke and center offset are determined based on the left-hand average steering angle and the right-hand average steering angle, respectively, including: determining the difference between the left-hand average steering angle and the right-hand average steering angle; determining the steering half-stroke based on the difference; summing the left-hand average steering angle and the right-hand average steering angle; and determining the center offset based on the summation result.

[0103] In actual implementation, the controller determines the corresponding left-hand average steering angle SAB_Left and right-hand average steering angle SAB_Right within the current ignition cycle. Simultaneously, it sets left turn as the positive direction and determines the difference between the left-hand and right-hand average steering angles (SAB_Left - SAB_Right), as well as the sum of the left-hand and right-hand average steering angles (SAB_Left + SAB_Right). It determines the proportionality coefficient α of the steering half-stroke relative to the difference and the proportionality coefficient β of the center offset relative to the sum. Steering half-stroke = α × (SAB_Left - SAB_Right), Center offset = β × (SAB_Left + SAB_Right). If α = 1 / 2, then steering half-stroke = (SAB_Left - SAB_Right) / 2; if β = 1 / 2, then center offset = (SAB_Left + SAB_Right) / 2.

[0104] In the above embodiments, the steering half-stroke is directly determined based on the difference between the average left-hand steering angle and the average right-hand steering angle. Simultaneously, the center offset is directly determined based on the sum of the average left-hand steering angle and the average right-hand steering angle. This not only ensures the accuracy of the steering half-stroke and center offset calculations but also reduces the calculation process and improves efficiency.

[0105] In an exemplary embodiment, the soft stop and hard stop on the target steering are determined based on the steering half-stroke, center offset, and steering overshoot, respectively, including: weighted summation of the steering half-stroke and center offset to obtain the left soft stop; weighted difference of the steering half-stroke and center offset to obtain the right soft stop; weighted summation of the left soft stop and steering overshoot to obtain the left hard stop; and weighted difference of the right soft stop and steering overshoot to obtain the right hard stop.

[0106] In practical implementation, the setting of soft and hard stops in the end-of-line protection function can be combined with the driving conditions and the structural characteristics of the vehicle itself. Steering half-stroke, center offset, and steering transition can be set, and the positions of the soft and hard stops can be obtained through mathematical calculations of these three physical quantities. Specifically, after the controller determines the steering half-stroke and center offset, it calculates the soft stop, still taking leftward turn as the positive direction. The steering half-stroke and center offset are weighted and summed, where the weight of the steering half-stroke is α1, and the weight of the center offset is β1. Left soft stop = α1 × steering half-stroke + β1 × center offset. If α... 1＝ If β1 = 1, then the left soft stop = half-stroke + center offset; the weighted difference between the half-stroke and center offset is calculated, with the weight of the half-stroke as α2 and the weight of the center offset as β2, where the right soft stop = α2 × half-stroke + β2 × center offset. If α2＝ If β2 = 1, then the right soft stop = halfway steering stroke + center offset.

[0107] The hard stop is related to the preset steering overshoot, which is the angular interval between the target soft stop and the hard stop. The steering overshoot has a significant impact on the driver's feel during steering operations and is calibrated using a factor correlation method. During steering, by reading the vehicle speed and motor speed, a suitable calibrated value for the steering overshoot is selected, and then the hard stop is calculated. Still taking left turn as the positive direction, the left hard stop = left soft stop + steering overshoot; the right hard stop = right soft stop - steering overshoot.

[0108] The above-mentioned method for determining the soft and hard stops of the target vehicle during steering can adapt to changes in vehicle structure, ensure the accuracy of soft and hard stop calculations in each ignition cycle, and thus ensure that end-of-life protection plays a good role in preventing collisions of the steering mechanism throughout the entire vehicle life cycle.

[0109] To illustrate the steering end protection method in this application in detail, an embodiment of steering end protection applicable to the steering system of a commercial vehicle in an electronically assisted steering scenario is described below. In this embodiment, see... Figure 4 , Figure 4 This embodiment illustrates the steering end protection method, the specific process of which is as follows: Step 1) Acquire vehicle signals such as vehicle speed, steering wheel angle, steering wheel speed, motor speed, and steering torque. Step 2) Verify the validity of the acquired vehicle signals and output a signal validity flag. Specifically, the vehicle signals undergo signal injection processing to obtain processed usable signals. When the validity flag is true, the vehicle signals are normal, and the steering end protection function operates normally; otherwise, for safe driving considerations, the steering end protection function will be terminated. Specifically... Figure 5 The system performs a signal validity check on the vehicle signal. Once the check passes, the steering end protection function operates normally. Step 3) assesses the self-learning condition and calculates the soft stop position at the end of the vehicle's steering. Step 4) acquires the steering transition amount and calculates the hard stop position at the end of the vehicle's steering. Step 5) checks if the steering wheel angle is less than or equal to the angle indicated by the soft stop. Step 6) If step 5) is true, the end protection function is inactive, and the power steering motor provides normal assistance. Step 7) If step 5) is false, it checks if the steering wheel angle is greater than the angle indicated by the soft stop but less than the angle indicated by the hard stop. Step 8) If step 7) is true, it reduces power steering assistance for end protection and sets a torque gradient value. Step 9) If step 7) is false, it provides a counterforce to counteract the torque applied to the steering wheel. The torque on the steering wheel is generally the driver's hand force.

[0110] In practical implementation, steering half-stroke, center offset, and steering transition can be set according to driving conditions and the vehicle's structural characteristics. Through mathematical calculations of these three physical quantities, the positions of the soft and hard stops used by the vehicle in the current ignition cycle are determined. To adapt to changes in vehicle structure and ensure effective end-of-life protection throughout the vehicle's lifespan, steering half-stroke and center offset can be collected via self-learning. Self-learning requires meeting set target conditions: 1) The absolute value of the steering wheel angle is greater than or equal to the target angle setting; 2) The steering wheel angle signal is valid; 3) The absolute value of the steering wheel speed is less than or equal to the target speed setting; 4) The absolute value of the steering wheel torque is greater than or equal to the target torque setting; 5) The steering wheel torque signal is valid. Self-learning cannot proceed if the vehicle's steering conditions do not meet these requirements. Reasonable calibration values ​​for steering half-stroke, center offset, and steering transition should be pre-set in the vehicle controller's storage area. When self-learning is performed normally, the steering half-stroke and center offset calculated by self-learning will overwrite the original corresponding calibration values ​​in the storage area.

[0111] During the self-learning process, the steering wheel angles collected under the above conditions are recorded as limit steering angles. Limit steering angles include left-hand limit steering angles and right-hand limit steering angles. The average value of the limit steering angles of the target quantity within the most recent statistical period is taken as the left-hand average steering angle SAB_Left and the right-hand average steering angle SAB_Right. With left-hand steering set as the positive direction, the following can be determined:

[0112] Half-stroke steering distance = (SAB_Left - SAB_Right) / 2;

[0113] Center offset = (SAB_Left + SAB_Right) / 2;

[0114] Accordingly, the soft stop is calculated as follows:

[0115] Left soft stop = steering halfway point + center offset;

[0116] Right soft stop = -(half travel of steering stroke - center offset);

[0117] Since steering overshoot significantly impacts steering feel, a factor-based calibration method is used to set the steering overshoot. During steering, by reading factors such as vehicle speed and motor speed, an appropriate steering overshoot calibration value is selected, and then the hard stop is calculated. The hard stop calculation method is as follows:

[0118] Left hard stop = Left soft stop + Oversteer;

[0119] Right hard stop = Right soft stop - Oversteer;

[0120] In practice, if the steering wheel angle is between the angles indicated by the soft stop and the hard stop, the power steering motor is controlled to reduce power assist. During the reduction process, the motor's assist cannot change significantly within a unit of time; otherwise, it will cause steering instability and lead to steering wheel kicking. Therefore, it is necessary to change the assist using a trapezoidal gradient method, setting the torque change gradient value between adjacent sampling periods. The target assist of the motor is determined as follows:

[0121] Among them, the method for determining the target assist of the power steering motor is as follows: Figure 6 As shown, when the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, proceed to step 1) determine the specified assist value of the current motor based on the angle difference between the steering wheel angle and the angle indicated by the soft stop; proceed to step 2) determine whether the current actual assist value - specified assist value > torque gradient value holds true; proceed to step 3) if step 2) holds true, determine the target assist value of the power steering motor = current actual assist value - torque gradient value; proceed to step 4) if step 2) does not hold true, determine the target assist value of the power steering motor = specified assist value of the motor.

[0122] If the steering wheel continues to turn, and the steering wheel angle is greater than or equal to the angle indicated by the hard stop, the power steering motor is controlled to provide a counterforce to counteract the hand force. In order to prevent the steering wheel (or steering mechanism) from kicking back when returning to its original position, the counterforce provided by the power steering motor must be less than the power assist threshold.

[0123] In the above embodiments, the relationship between the steering wheel angle and the soft and hard stops is used to control the power steering motor to protect the steering end. Simultaneously, a torque gradient value is set to determine the target assist of the power steering motor during the reduction of assist. This effectively prevents oversteering caused by driver input while maintaining driving feel. By using a self-learning method to determine the soft and hard stops within the ignition cycle, it can effectively adapt to changes in the steering end caused by variations in the vehicle's structure, resulting in low cost and high robustness. Ultimately, without adding to the steering mechanism, it effectively improves the collision risk at the steering end under extreme position conditions, while preventing the risk of motor burnout due to excessive current caused by a collision, providing good protection during the final steering stage.

[0124] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0125] Based on the same inventive concept, this application also provides a steering end protection device for implementing the steering end protection method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations of one or more steering end protection device embodiments provided below can be found in the limitations of the steering end protection method described above, and will not be repeated here.

[0126] In one exemplary embodiment, such as Figure 7 As shown, a protection device for the steering end is provided, comprising: a determining module 710, a first control module 720, and a second control module 730, wherein:

[0127] The determination module is used to determine the soft stop and hard stop of the steering wheel of the target vehicle in the target steering direction during the steering process; wherein, the hard stop is the angle of the steering wheel when the steering mechanism reaches the limit position in the target steering direction; the soft stop is the angle of the steering wheel when the activation conditions of the end protection mode are met; the steering wheel angle indicated by the soft stop in the same steering direction is smaller than the steering wheel angle indicated by the hard stop; the target steering includes left turn and right turn.

[0128] The first control module is used to obtain the steering wheel angle during the steering process. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode.

[0129] The second control module is used to control the power steering motor to stop providing power steering assistance if the steering wheel angle reaches the angle indicated by the hard stop, and to provide a target reaction force opposite to the steering wheel direction to counteract the torque applied to the steering wheel.

[0130] In one embodiment, the first control module is further configured to acquire the angle difference between the steering wheel angle and the angle indicated by the soft stop, determine a power assist reduction coefficient based on the angle difference, determine a specified power assist provided by the power steering motor by using the power assist reduction coefficient and the actual power assist of the power steering motor, acquire a torque gradient value and determine the torque difference between the actual power assist and the specified power assist, determine a target power assist of the power steering motor based on the torque difference and the torque gradient value, and control the power steering motor to provide power assist with the target power assist, wherein the target power assist is less than the actual power assist.

[0131] In one embodiment, the first control module is further configured to, if the torque difference is greater than the torque gradient value, use the difference between the actual assist and the torque gradient value as the target assist of the power steering motor; and if the torque difference is less than or equal to the torque gradient value, use the specified assist as the target assist of the power steering motor.

[0132] In one embodiment, the determining module is further configured to obtain a preset number of historical limit steering angles on the target steering direction, and use the average of the preset number of historical limit steering angles as the average steering angle on the target steering direction, the average steering angle including the left-hand average steering angle and the right-hand average steering angle; based on the left-hand average steering angle and the right-hand average steering angle, determine the steering wheel's half-stroke and center offset respectively; during the steering process, according to the target vehicle's speed and the steering assist motor's motor speed, query the calibration data table to obtain the steering overshoot; based on the steering half-stroke, center offset, and steering overshoot, determine the soft stop and hard stop on the target steering direction respectively, the soft stop including the left-hand soft stop and the right-hand soft stop, and the hard stop including the left-hand hard stop and the right-hand hard stop.

[0133] In one embodiment, the determining module is further configured to periodically count the limit steering angles of the steering mechanism in the limit position condition of the target steering; the number of times the steering mechanism is continuously in the limit position condition within each statistical period reaches a preset number; and the preset number of limit steering angles in the most recent statistical period are determined as historical limit steering angles.

[0134] In one embodiment, the determining module is further configured to determine the difference between the left-hand average steering angle and the right-hand average steering angle, and based on the difference, determine the steering half-stroke; sum the left-hand average steering angle and the right-hand average steering angle, and based on the summation result, determine the center offset.

[0135] In one embodiment, the determining module is further configured to perform a weighted summation of the steering half-stroke and center offset to obtain a left soft stop; perform a weighted difference of the steering half-stroke and center offset to obtain a right soft stop; perform a weighted summation of the left soft stop and steering overshoot to obtain a left hard stop; and perform a weighted difference of the right soft stop and steering overshoot to obtain a right hard stop.

[0136] Each module in the aforementioned protection device at the steering end can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the operations corresponding to each module.

[0137] In one exemplary embodiment, an electronic device is provided, which may be a control unit of a target vehicle, and its internal structure diagram may be as follows: Figure 8 As shown, this electronic device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs in the non-volatile storage media. The database stores driving data of the target vehicle, historical limit steering angles, etc. The I / O interfaces are used for information exchange between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a steering end protection method.

[0138] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0139] In one exemplary embodiment, an electronic device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0140] In one exemplary embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above-described method embodiments.

[0141] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0142] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0143] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0144] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0145] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A protection method for the steering end, characterized in that, The method includes: Determine the soft and hard stops of the steering wheel of the target vehicle during the steering process; The hard stop is the angle of the steering wheel when the steering mechanism reaches its limit position in the target steering direction. The soft stop is determined by calculating the mapping relationship between the steering half-stroke and the center offset based on multiple sets of limit steering angle data collected within a statistical period. The soft stop is the angle of the steering wheel when the activation conditions of the end protection mode are met. The angle indicated by the soft stop on the same steering direction is smaller than the angle indicated by the hard stop. The target steering direction includes left steering and right steering. The steering wheel angle during the steering process is obtained. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode. If the steering wheel angle reaches the angle indicated by the hard stop, the power steering motor is controlled to stop providing power and a target reaction force opposite to the steering wheel direction is provided to counteract the torque applied to the steering wheel.

2. The method according to claim 1, characterized in that, The power steering motor is controlled using a reduced power steering method, including: Obtain the angle difference between the steering wheel angle and the angle indicated by the soft stop, and determine the power assist reduction coefficient based on the angle difference; The specified assistance provided by the power steering motor is determined by the reduction coefficient and the actual assistance provided by the power steering motor. Obtain the torque gradient value and determine the torque difference between the actual assistance and the specified assistance; Based on the torque difference and the torque gradient, the target assist of the power steering motor is determined; The power steering motor is controlled to provide assistance with the target assistance, which is less than the actual assistance.

3. The method according to claim 2, characterized in that, Determining the target assist of the power steering motor based on the torque difference and the torque gradient value includes: If the torque difference is greater than the torque gradient value, then the difference between the actual assist and the torque gradient value is taken as the target assist of the power steering motor. If the torque difference is less than or equal to the torque gradient value, then the specified assist is used as the target assist for the power steering motor.

4. The method according to claim 1, characterized in that, Determine the soft and hard stops of the steering wheel of the target vehicle during the steering process, including: Obtain a preset number of historical limit steering angles on the target steering direction, and use the average of the preset number of historical limit steering angles as the average steering angle on the target steering direction. The average steering angle includes the average steering angle to the left and the average steering angle to the right. Based on the average left-hand steering angle and the average right-hand steering angle, the steering wheel's half-stroke and center offset are determined respectively. During the steering process, the oversteer amount is obtained by consulting the calibration data table based on the vehicle speed of the target vehicle and the motor speed of the power steering motor. Based on the steering half-stroke, the center offset, and the steering overshoot, the soft stop and hard stop on the target steering are determined respectively. The soft stop includes a left soft stop and a right soft stop, and the hard stop includes a left hard stop and a right hard stop.

5. The method according to claim 4, characterized in that, The acquisition of a preset number of historical limit steering angles on the target steering path includes: The limit steering angle of the steering mechanism under the extreme position condition of the target steering is periodically counted; the number of times the steering mechanism is continuously in the extreme position condition in each statistical period reaches a preset number; The preset number of extreme steering angles within the most recent statistical period are determined as historical extreme steering angles.

6. The method according to claim 4, characterized in that, The determination of the steering wheel's steering half-stroke and center offset based on the average left-hand steering angle and the average right-hand steering angle includes: Determine the difference between the average left-hand steering angle and the average right-hand steering angle, and determine the steering half-stroke based on the difference; The average left-hand steering angle and the average right-hand steering angle are summed, and the center offset is determined based on the summation result.

7. The method according to claim 4, characterized in that, The step of determining the soft stop and hard stop on the target steering based on the steering half-stroke, the center offset, and the steering overshoot includes: The left soft stop is obtained by weighted summation of the steering half-stroke and the center offset. The right soft stop is obtained by weighted subtraction of the steering half-stroke and the center offset. The left soft stop and the steering overshoot are weighted and summed to obtain the left hard stop; The rightward soft stop and the steering overshoot are weighted and subtracted to obtain the rightward hard stop.

8. A protective device for the steering end, characterized in that, The device includes: The determination module is used to determine the soft stop and hard stop of the steering wheel of the target vehicle in the target steering direction during the steering process; wherein, the hard stop is the angle of the steering wheel when the steering mechanism reaches the limit position in the target steering direction; the soft stop is the angle of the steering wheel when the activation condition of the end protection mode is met; the angle indicated by the soft stop in the same steering direction is smaller than the angle indicated by the hard stop; the target steering includes left steering and right steering; The first control module is used to obtain the steering wheel angle during the steering process. If the steering wheel angle is greater than the angle indicated by the soft stop and less than the angle indicated by the hard stop, the power steering motor is controlled to use a reduced power steering mode. The second control module is used to control the power steering motor to stop providing power steering assistance if the steering wheel angle reaches the angle indicated by the hard stop, and to provide a target reaction force opposite to the steering wheel direction to counteract the torque applied to the steering wheel.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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