A method for determining the end position of a steering wheel rack and related devices

Abstract

This application provides a method and related apparatus for determining the end position of a steering wheel rack. The method includes: obtaining a first angle of the steering wheel corresponding to a first position of the rack and a second angle of the steering wheel corresponding to a second position; determining a first target position and a second target position based on the actual steering wheel angle, the first angle corresponding to the first position, and the second angle corresponding to the second position. The first and second positions are determined based on a pre-set end position of the rack, and the first and second target positions are the actual end positions of the rack, respectively. By comparing the actual steering wheel angle with the pre-set rack end position, the actual end position of the rack is determined. Then, the end of the rack is protected based on the actual end position, improving the stability and safety of the electric power steering system.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method and related apparatus for determining the position of the end of a steering wheel rack. Background Technology

[0002] When a vehicle steers by turning the steering wheel, the rotation of the wheels is typically achieved by the left-right movement of the rack. The rack is housed within the housing of a rack-and-pinion steering system, with both ends passing through the housing and connected to internal ball joints. When the steering wheel is turned to its left or right limits, the ends of the rack may impact the housing. This collision increases steering wheel resistance, affecting the driver's handling. Furthermore, frequent impacts can shorten the lifespan of components like the rack, compromising driving safety.

[0003] To prevent the rack from colliding with the housing, the rack's end position is usually pre-defined in the vehicle. Therefore, during rack movement, the position of the rack's end can be used to determine whether it is about to approach the housing. When it is close to the housing, the power steering system's output torque to the rack can be reduced, thus preventing a collision. Because the rack deviates laterally during movement, its end position changes. Determining the actual position of the rack's end is a crucial problem that needs to be solved. Summary of the Invention

[0004] This application provides a method and related apparatus for determining the end position of a steering wheel rack. The actual end position of the rack is determined based on the actual steering wheel angle, and then the assist torque of the electric power steering system is controlled based on the actual end position of the rack, thereby improving the safety and stability of the electric power steering system.

[0005] In a first aspect, embodiments of this application provide a method for determining the position of the end of a steering wheel rack, the method comprising:

[0006] Obtain the first angle of the steering wheel corresponding to the first position of the rack and the second angle of the steering wheel corresponding to the second position of the rack, wherein the distance between the first position and the first end position of the rack is less than or equal to a first preset distance, the distance between the second position and the second end position of the rack is less than or equal to a second preset distance, and the first end position and the second end position are preset end positions corresponding to the rack respectively;

[0007] Obtain the actual steering wheel angle;

[0008] The first target position and the second target position are determined based on the actual turning angle of the steering wheel, the first angle, and the second angle, wherein the actual turning angle of the steering wheel is used to drive the rack to move, and the first target position and the second target position are the actual end positions of the rack respectively.

[0009] In the above method, the first and second end positions are pre-set end positions of the rack, and the actual steering wheel angle is the angle generated when the vehicle actually rotates the steering wheel. Since the rotation of the steering wheel can drive the rack to move, the angle when the steering wheel is rotated to its limit can be used to characterize the travel distance of the rack to its end, thereby determining the position of the rack end based on the travel distance of the rack to its end. That is, the actual steering wheel angle can be used to determine the actual end position of the rack. Furthermore, by using the actual steering wheel angle and the pre-set first and second angles, the accuracy of the obtained rack end position can be improved.

[0010] In an optional embodiment of the first aspect, after determining the first target position and the second target position based on the actual steering wheel angle, the first angle, and the second angle, the method further includes:

[0011] The power steering torque of the electric power steering system is controlled based on the first target position and the second target position.

[0012] In the above method, controlling the electric power steering system based on the first and second target positions is equivalent to protecting the rack end based on its actual position. Compared to prior art, which protects the rack end at a fixed position, this application considers the possibility of rack end displacement. End protection based on determining the actual position of the rack end better reflects the actual condition of the vehicle. This application is easy to implement and has low cost. Furthermore, it improves the safety, stability, adaptability, and versatility of the electric power steering system.

[0013] In one optional embodiment of the first aspect, the actual steering wheel angle includes a first angle and a second angle, and determining the first target position and the second target position based on the actual steering wheel angle, the first angle, and the second angle includes:

[0014] The direction corresponding to the first turning angle is the same as the direction corresponding to the first angle, and the direction corresponding to the second turning angle is the same as the direction corresponding to the second angle;

[0015] When the first turning angle is greater than the first angle, the first target position is determined based on the first turning angle;

[0016] If the second turning angle is greater than the second angle, the second target position is determined based on the second turning angle.

[0017] In the above method, the actual steering wheel angle is determined based on the first angle and the second angle to determine whether it meets the requirements of the rack end position. Specifically, when the first steering wheel angle is greater than the first angle, the collected first angle meets the requirements, and the first target position can be determined based on the first angle. When the second steering wheel angle is greater than the second angle, the collected second angle meets the requirements, and the second target position can be determined based on the second angle.

[0018] In one alternative embodiment of the first aspect, determining the first target position based on the first turning angle includes:

[0019] The first deviation and the first total travel are determined based on the first turning angle and the second angle, wherein the first deviation is used to represent the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position, and the first total travel is used to represent the total travel of the steering wheel;

[0020] If the first deviation is less than the first threshold and the first total stroke is less than the total stroke threshold, the rack position corresponding to the first rotation angle is taken as the first target position.

[0021] In the above method, the judgment is based on the first steering wheel angle and the second angle. This is equivalent to checking whether the offset of the rack center and the total travel of the steering wheel meet the requirements, assuming the first angle is replaced by the first steering wheel angle. Only when both the first deviation and the first total travel are less than the corresponding thresholds can the first steering wheel angle replace the first angle. This ensures the accuracy and reliability of the collected steering wheel angle and reduces the error in determining the first target position.

[0022] In one alternative embodiment of the first aspect, determining the first target position based on the first turning angle includes:

[0023] The first torque and the first rotational speed of the steering wheel are obtained, wherein the first torque and the first rotational speed of the steering wheel correspond to the first turning angle of the steering wheel;

[0024] When the first torque is greater than the torque threshold and the first rotation speed is less than the rotation speed threshold, the first target position is determined based on the first rotation angle.

[0025] In the above method, the steering wheel angle is further determined based on the steering wheel torque and rotation speed to ensure it meets the requirements for the rack end position. If the steering wheel torque is too low, the steering wheel angle may not reach its limit, so the steering wheel torque needs to be greater than a torque threshold. Simultaneously, if the steering wheel rotation speed is too high, it may affect the acquisition of the first steering angle, so the steering wheel rotation speed needs to be less than a rotation speed threshold. This ensures the stability and accuracy of the sampling process and improves the efficiency of determining the rack end position.

[0026] In one alternative embodiment of the first aspect, determining the second target position based on the second turning angle includes:

[0027] The second deviation and the second total travel are determined based on the second turning angle and the first angle, wherein the second deviation is used to represent the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero point position, and the second total travel is used to represent the total travel of the steering wheel;

[0028] If the second deviation is less than the second threshold and the second total stroke is less than the total stroke threshold, the rack position corresponding to the second rotation angle is taken as the second target position.

[0029] In the above method, the judgment is made based on the second steering wheel angle and the first angle. This is equivalent to checking whether the offset of the rack center and the total travel of the steering wheel meet the requirements, assuming the second angle is replaced by the second steering wheel angle. Only when both the second deviation and the second total travel are less than the corresponding thresholds can the second steering wheel angle replace the second angle. This ensures the accuracy and reliability of the steering wheel angle acquisition and reduces the error in determining the second target position.

[0030] In one alternative embodiment of the first aspect, determining the second target position based on the second turning angle includes:

[0031] The second torque and the second rotational speed of the steering wheel are obtained, wherein the second torque and the second rotational speed of the steering wheel correspond to the second turning angle of the steering wheel;

[0032] When the second torque is greater than the torque threshold and the second rotation speed is less than the rotation speed threshold, the second target position is determined based on the second rotation angle.

[0033] In the above method, the steering wheel angle is further determined based on the steering wheel torque and rotation speed to ensure it meets the requirements for the rack end position. If the steering wheel torque is too low, the steering wheel angle may not reach its limit, so the steering wheel torque needs to be greater than a torque threshold. Simultaneously, if the steering wheel rotation speed is too high, it may affect the acquisition of the second steering angle, so the steering wheel rotation speed needs to be less than a rotation speed threshold. This ensures the stability and accuracy of the sampling process and improves the efficiency of determining the rack end position.

[0034] In one alternative of the first aspect, the difference between the angle corresponding to the first target position and the angle corresponding to the second target position is less than or equal to a third threshold, wherein the third threshold is used to represent the maximum offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position.

[0035] In the above method, the deviation between the rack centers corresponding to the first and second target positions must be less than the maximum offset. Since the first and second target positions are determined independently, although they each satisfy their respective conditions, the rack determined based on these positions may contain errors and not meet the overall conditions. Therefore, considering whether the first and second target positions meet the requirements simultaneously further ensures their accuracy.

[0036] In one alternative embodiment of the first aspect, the first position is determined based on the difference between the distance corresponding to the first end position and the first preset distance;

[0037] The second position is determined based on the difference between the distance corresponding to the second end position and the second preset distance.

[0038] In the above method, taking the second turning angle as an example, if the second turning angle is less than the angle corresponding to the second end position, there are two possible situations. The first is that the second turning angle is less than the angle at which the steering wheel is turned to the right from the zero point, meaning the user has not turned the steering wheel to the right limit. The second is that the rack has shifted to the left. Therefore, in this case, the vehicle cannot determine which of the above situations caused the second turning angle to be less than the second angle, and thus cannot determine the second target position. Therefore, to avoid the above problems, this application introduces a first position and a second position, and the second position is used as an example for explanation. When the second turning angle is less than the angle corresponding to the second position, the vehicle determines that the second turning angle is less than the angle at which the steering wheel is turned to the right from the zero point, meaning the vehicle determines that the user has not turned the steering wheel to the right limit, and the collected second turning angle is invalid. When the second turning angle is greater than the angle corresponding to the second position but less than the angle corresponding to the second end position, the vehicle determines that the rack has shifted to the left, and the vehicle can determine the second target position based on the second turning angle in this situation.

[0039] Secondly, embodiments of this application provide a device for determining the position of the end of a steering wheel rack. The device includes a processor and a memory. The processor is coupled to the memory, which stores a computer program. The processor is used to call and run the computer program, causing the vehicle to perform the method described in any of the preceding first aspects.

[0040] Thirdly, embodiments of this application provide a vehicle that includes a steering system and a device for determining the position of the end of a steering wheel rack as described in the second aspect.

[0041] Fourthly, embodiments of this application provide a computing device including a processor and a memory; the processor is coupled to the memory, the memory is used to store a computer program, and the processor is used to invoke and run the computer program so that the computing device performs the method as described in any of the preceding first aspects.

[0042] Optionally, the computing device further includes a communication interface for receiving and / or sending data, and / or for providing input and / or output to the processor.

[0043] It should be noted that the above embodiments are illustrated using a processor (or general-purpose processor) that executes the method by invoking a computer-specified instruction. In practice, the processor can also be a dedicated processor, in which case the computer instructions have been pre-loaded into the processor. Optionally, the processor can include both dedicated and general-purpose processors.

[0044] Optionally, the processor and memory may be integrated into a single device, meaning they can be combined.

[0045] Fifthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when run on a computer or processor, implements the method described in any of the first aspects above.

[0046] The beneficial effects of the technical solutions provided in the second to fifth aspects of this application can be referred to the beneficial effects of the first aspect, and will not be repeated here. Attached Figure Description

[0047] The accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0048] Figure 1 This is a schematic diagram of the architecture of a vehicle provided in an embodiment of this application;

[0049] Figure 2 This is a flowchart illustrating a method for determining the end position of a steering wheel rack according to an embodiment of this application;

[0050] Figure 3 This is a schematic diagram illustrating how to determine whether the position of the rack end can be determined, provided in an embodiment of this application.

[0051] Figure 4 This is a schematic diagram of an end position provided in an embodiment of this application;

[0052] Figure 5 This is a schematic diagram illustrating the determination of a first target location provided in an embodiment of this application;

[0053] Figure 6 This is a schematic diagram illustrating the determination of a second target location provided in an embodiment of this application;

[0054] Figure 7 This is a schematic diagram of the end of a self-learning rack provided in an embodiment of this application;

[0055] Figure 8 This is a functional unit block diagram of a device for determining the end position of a steering wheel rack provided in an embodiment of this application;

[0056] Figure 9 This is a schematic diagram of the structure of a computing device provided in an embodiment of this application. Detailed Implementation

[0057] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0058] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0059] To facilitate understanding of the embodiments of this application, the specific technical problems to be solved by this application will be analyzed and proposed below.

[0060] As vehicles become increasingly electrified and intelligent, the requirements for the safety and reliability of electric power steering (EPS) systems are also rising. For example, advanced driver assistance systems (ADAS) and autonomous driving functions demand higher steering wheel speeds, and greater emphasis is placed on the driving safety associated with high steering wheel rotation speeds. The electric power steering system applies a torque to the rack based on parameters such as the steering wheel angle and rotation speed, causing the rack to move left or right. This movement of the rack, in turn, drives the wheels.

[0061] In a rack-and-pinion steering system, the rack is housed within the housing, with both ends passing through the housing and connected to inner ball joints. When the steering wheel is turned to its left or right limits, the rack end may impact the housing. To prevent this collision, the rack end position is typically pre-configured in the vehicle. Therefore, during rack movement, the position of the rack end can be used to determine when it is about to approach the housing. This allows for a reduction in the electric power steering torque applied to the rack as it approaches the housing, preventing a collision. However, because the rack may shift left or right during movement, changing its end position, the timing of reducing the electric power steering torque based on the pre-configured end position may still result in a rack end collision, impacting the user experience.

[0062] For example, in situations including but not limited to: rack fatigue, rack wear, vehicle maintenance, and wheel alignment adjustments, the position of the rack's ends may change, causing the rack's ends to become asymmetrical with the steering wheel's center. Generally, a protective zone is installed at the rack's end to prevent impacts. However, when the rack's end position changes, a fixed protective zone cannot completely prevent mechanical impacts to the rack's end, thus affecting the vehicle's steering.

[0063] In one implementation, the vehicle selects a corresponding power assist current limiting curve based on the steering wheel speed. According to this curve, the power assist current of the EPS (Electric Power Steering) is limited in the rack end protection area, thereby reducing the power assist current used by the motor for steering and preventing collision at the rack end. However, since the location of the protection area is fixed, collision at the rack end cannot be completely avoided if the rack end position changes. Furthermore, the power assist current limiting curve needs to be calibrated according to different steering wheel speeds, which is labor-intensive and difficult to implement. Therefore, the specific location of the rack end needs to be determined before protecting the EPS rack end.

[0064] In summary, this application provides a method for determining the end position of a steering wheel rack. The vehicle determines a first position based on a pre-configured first end position and a second position based on a pre-configured second end position. The first and second end positions are pre-set end positions corresponding to the rack, respectively. Then, the vehicle determines the actual end position of the rack based on the actual steering wheel angle, a first angle corresponding to the first position, and a second angle corresponding to the second position.

[0065] The system architecture used in the embodiments of this application is described below. It should be noted that the system architecture and business scenarios described in this application are for the purpose of more clearly illustrating the technical solutions of this application, and do not constitute a limitation on the technical solutions provided in this application. As those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0066] Please see Figure 1 , Figure 1 This is a schematic diagram of the architecture of a vehicle provided in an embodiment of this application. Figure 1 As shown, vehicle 10 includes an electric power steering (EPS) system 101 and a torque angle sensor (TAS) 102.

[0067] Vehicle 10 can be a vehicle powered by electricity, a vehicle powered by gasoline, or a vehicle powered by a new energy hybrid powertrain. For example, when vehicle 10 is powered by electricity, it can be a new energy vehicle, such as a pure electric vehicle, a range-extended electric vehicle, a hybrid electric vehicle, or a fuel cell electric vehicle. When vehicle 10 is powered by gasoline, it can be a car, an agricultural transport vehicle, a tractor, or a trailer. When vehicle 10 is a car, it can be a sedan, an SUV, a truck, a bus, or a van.

[0068] EPS101 is a power steering system that relies on an assist motor to provide assist torque. The assist torque generated by the motor assists the vehicle 10 in power steering, thereby reducing the driver's workload and improving driving comfort and safety. This application utilizes EPS101 to provide end-effector protection based on the positions of the rack's ends. For example, during vehicle steering via left and right rack movement, when the rack approaches its end position, the assist torque of EPS101 is reduced to prevent collision noise or damage to mechanical components during impacts. Furthermore, it also prevents damage to EPS101 due to overheating.

[0069] The TAS102 is used to collect data such as steering wheel angle, steering wheel speed, and steering wheel torque. Furthermore, the steering wheel angle signal can also be collected using an angle sensor, and the steering wheel speed signal can be collected using an angular velocity sensor; this is not a limitation.

[0070] TAS102 is also used to send the collected steering wheel angle, steering wheel speed and steering wheel torque to vehicle 10 and / or EPS101.

[0071] In one implementation, vehicle 10 receives a first steering angle and a second steering angle from TAS 102. When the first steering angle is greater than a first angle, a first target position is determined based on the first steering angle. When the second steering angle is greater than a second angle, a second target position is determined based on the second steering angle. Then, vehicle 10 sends the first target position and the second target position to EPS 101, which performs end protection on the rack based on the first target position and the second target position.

[0072] In one implementation, EPS101 receives a first steering wheel angle and a second steering wheel angle from TAS102. When the first steering wheel angle is greater than a first angle, a first target position is determined based on the first steering wheel angle. When the second steering wheel angle is less than a second angle, a second target position is determined based on the second steering wheel angle. Then, EPS101 uses the first and second target positions as the end positions of the rack, respectively. As the rack approaches the end positions, the assist torque is reduced to avoid collision noise or damage to mechanical components during collisions.

[0073] Please see Figure 2 , Figure 2 This is a flowchart illustrating a method for determining the end position of a steering wheel rack according to an embodiment of this application. The method is applied to, for example... Figure 1 The vehicle shown. (As shown) Figure 2 As shown, the method includes, but is not limited to, the following steps:

[0074] Step S201: Obtain the first angle of the steering wheel corresponding to the first position of the rack and the second angle of the steering wheel corresponding to the second position of the rack.

[0075] The first end position is a pre-set end position at one end of the rack, and the second end position is a pre-set end position at the other end of the rack. The distance between the first position and the first end position is less than or equal to a first preset distance, and the distance between the second position and the second end position is less than or equal to a second preset distance. The first position corresponds to a first angle, and the second position corresponds to a second angle.

[0076] In one implementation, the positions of the two ends of the rack relative to the vehicle when the steering wheel is at the zero position can be used as the first and second end positions, respectively. Since turning the steering wheel moves the rack, the angle of the steering wheel can be used to characterize the position of any point on the rack. For example, when the steering wheel is turned to the left from the zero position to its extreme position, the travel distance of the steering wheel moving the rack corresponds to the distance from the center of the rack to the left end position. Since the distance from the center of the rack to the left end position can be used to determine the left end position of the rack, the steering wheel angle corresponding to the leftward rotation from the zero position to the extreme position can be used to characterize the left end position of the rack. For example, if the steering wheel angle from the zero position to the leftward extreme position is 480°, then the angle corresponding to the left end position of the rack is 480°. Therefore, the vehicle can use the theoretical left and right extreme values ​​of the steering wheel angle at the factory as the angles corresponding to the first and second end positions of the rack, respectively.

[0077] In one possible implementation, with the steering wheel angle zero point calibrated, the vehicle can determine the first end position and the second end position of the rack based on the total travel of the steering wheel.

[0078] Specifically, the total travel of the steering wheel is the sum of the maximum angles the steering wheel can turn left or right during a turn. With the steering wheel's zero-angle calibrated, the left and right limits of the steering wheel's angle are symmetrical about the center of the steering wheel; that is, the maximum leftward rotation angle is equal to the maximum rightward rotation angle, and the sum of these two maximum leftward and rightward rotation angles is the total travel of the steering wheel. For example, the maximum leftward and rightward rotation angles of a steering wheel are typically 480°. Therefore, the total travel of the steering wheel can be 960°. Furthermore, since the rack's travel corresponds to the steering wheel's angle, the rack's travel can be represented by the steering wheel's angle. For example, when the steering wheel is rotated from the zero position to the left limit position, the rack also moves to the left end of the rack through the gear. At this time, the rack travel corresponds to the maximum leftward rotation angle of the rack. When the steering wheel is rotated from the zero position to the right limit position, the rack also moves to the right end of the rack through the gear. At this time, the rack travel corresponds to the maximum rightward rotation angle of the rack.

[0079] Furthermore, when the maximum leftward rotation angle of the steering wheel is equal to the maximum rightward rotation angle, the rack's travel distance to the left and right via the gears is also equal, and the sum of these two travel distances is the rack's total travel distance. At this point, the rack center corresponding to the steering wheel's zero-point position coincides with the rack's midpoint, and the first and second end positions of the rack are symmetrical to the aforementioned rack centers. For example, if the total steering wheel travel distance is 960°, then the angle corresponding to the rack's total travel distance is also 960°. Since the maximum leftward rotation angle of the steering wheel is equal to the maximum rightward rotation angle, both the maximum leftward and rightward rotation angles are 480°. Because the rack's travel distance corresponds to the steering wheel's rotation angle, the angles corresponding to the first and second end positions of the rack are both 480°.

[0080] In one possible implementation, the vehicle determines a first position based on the difference between the distance corresponding to the first end position and a first preset distance, and determines a second position based on the difference between the distance corresponding to the second end position and a second preset distance.

[0081] Specifically, the distance corresponding to the first end position can be understood as the distance between the center of the rack when the steering wheel is at the zero position and the first end position. The distance corresponding to the second end position can be understood as the distance between the center of the rack when the steering wheel is at the zero position and the second end position. The distance between the first position and the center of the rack when the steering wheel is at the zero position is less than the distance corresponding to the first end position, so the first position can be determined based on the difference between the distance corresponding to the first end position and the first preset distance. The distance between the second position and the center of the rack when the steering wheel is at the zero position is less than the distance corresponding to the second end position, so the second position can be determined based on the difference between the distance corresponding to the second end position and the second preset distance. The reason for setting the first and second positions in this embodiment will be explained in step S202. Figure 4 Let me introduce it.

[0082] The following section will explain how to determine whether the position of the rack end can be determined for a vehicle.

[0083] Please see Figure 3 , Figure 3 This is a schematic diagram illustrating how to determine whether the position of the rack end can be determined, as provided in an embodiment of this application. Figure 3 As shown, the vehicle first determines whether the steering wheel's zero-angle point has been calibrated. For example, the vehicle can obtain the zero-angle calibration status bit from the TAS and determine whether the steering wheel's zero-angle point has been calibrated based on the zero-angle calibration status bit.

[0084] from Figure 3 It can be seen that without a calibrated zero point for the steering wheel's angle, the vehicle is not suitable for determining the rack end position according to the embodiments of this application. This is because calibrating the zero point for the steering wheel's angle is to ensure that the left and right end positions of the rack are symmetrical about the rack center when the steering wheel is at the zero point. If the zero point for the steering wheel's angle is not calibrated, the left and right end positions of the rack may not be symmetrical about the rack center. Since the first end position and the second end position are symmetrical about the rack center, without a calibrated zero point for the steering wheel's angle, the vehicle cannot determine the actual end position of the rack based on the first end position and the second end position.

[0085] from Figure 3 It can also be seen that, given the zero point of the steering wheel's turning angle has been determined, the following situations exist:

[0086] Scenario 1: Determine if the steering wheel angle is effective and if the EPS system is functioning correctly.

[0087] For example, the vehicle acquires steering angle signals and fault signals. The steering angle signal determines whether the steering wheel angle is valid, and the fault signal determines whether there is a fault in the EPS system.

[0088] Scenario 2: The vehicle determines whether it has not performed self-learning on the position of the left end of the rack.

[0089] For example, it can be determined whether the left end position of the rack has not been self-learned. If the vehicle has not self-learned the left end position of the rack, the vehicle can use the first end position as the preset left end position of the rack.

[0090] Scenario 3: The vehicle determines whether it has not performed self-learning on the position of the right end of the rack.

[0091] For example, it can be determined whether the right end position of the rack has not been self-learned. If the vehicle has not self-learned the right end position of the rack, the vehicle can use the second end position as the preset right end position of the rack.

[0092] like Figure 3 As shown, when conditions 1, 2 and 3 are all satisfied, the vehicle can determine the position of the rack end, the self-learning enable at the left end position of the rack is triggered, and the self-learning enable at the right end position of the rack is triggered.

[0093] Step S202: Obtain the actual steering wheel angle.

[0094] In one possible implementation, the vehicle uses a TAS (Traction Sensor) to collect data such as steering wheel angle, steering wheel speed, and steering wheel torque. Furthermore, the steering wheel angle signal can also be collected using an angle sensor, and the steering wheel speed signal can be collected using an angular velocity sensor; this is not a limitation here.

[0095] Step S203: Determine the first target position and the second target position based on the actual steering wheel angle, the first angle, and the second angle.

[0096] The steering wheel angle is used to drive the rack movement. The first target position is the actual end position of one end of the rack, and the second target position is the actual end position of the other end of the rack.

[0097] The following will combine Figure 4 The first end position, the second end position, the first position, the second position, the first target position, and the second target position are described in detail.

[0098] Please see Figure 4 , Figure 4 This is a schematic diagram illustrating an end position provided in an embodiment of this application. For example... Figure 4As shown, the left and right end positions of the rack that has not shifted are symmetrical about the center of the first rack, and the center of the first rack coincides with the midpoint of the rack that has not shifted. The center of the first rack is the rack center corresponding to the position of the steering wheel at zero.

[0099] The first and second end positions can respectively correspond to Figure 4 The two ends of the rack that have not shifted are described below. For example, let's take the first end position as the left end position of the rack that has not shifted. Then the second end position is the right end position of the rack that has not shifted. The first position and the second position are as follows: Figure 4 As shown, the distance between the first position and the first end position is less than or equal to a first preset distance, and the distance between the second position and the second end position is less than or equal to a second preset distance. For example, if the total travel of the steering wheel is 960°, then the single-sided travel of the steering wheel is 480°. In the rack without offset, the angle corresponding to the left end position, i.e., the first end position, is equal to the single-sided travel of the steering wheel. Similarly, the angle corresponding to the right end position, i.e., the second end position, is also equal to the single-sided travel of the steering wheel. Assuming the angle corresponding to the first preset distance is 10°, that is, the steering wheel needs to rotate 10° to move the rack from the first position to the first end position. Then the first angle corresponding to the first position is 470°. Assuming the angle corresponding to the second preset distance is 10°, that is, the steering wheel needs to rotate 10° to move the rack from the second position to the second end position. Then the second angle corresponding to the second position is 470°.

[0100] The first and second target positions correspond to the actual end positions of the rack, taking a leftward shift of the rack as an example. Figure 4 In this embodiment, the rack that did not deviate and the rack that deviated are the same rack, but the rack that deviated was offset to the left compared to the rack that did not deviate, so the position of the rack end relative to the vehicle also changed. For example, the actual left end of the rack that deviated actually corresponds to the first target position, and the actual right end corresponds to the second target position. The purpose of this application embodiment is to determine the actual end position (e.g., the first target position and the second target position) based on the preset end position (e.g., the first end position and the second end position).

[0101] In one possible implementation, the actual steering wheel angle includes a first angle and a second angle. The direction corresponding to the first angle is the same as the direction corresponding to the first angle, and the direction corresponding to the second angle is the same as the direction corresponding to the second angle. When the first angle is greater than the first angle, a first target position is determined based on the first angle. When the second angle is greater than the second angle, a second target position is determined based on the second angle.

[0102] Specifically, the actual steering wheel angle can be the angle produced when the user turns the steering wheel left or right. For example, when the user turns the steering wheel to the left, the vehicle determines the angle of rotation as the first angle. When the user turns the steering wheel to the right, the vehicle determines the angle of rotation as the second angle. Because the vehicle needs to determine the actual end position of the rack, the steering wheel needs to be rotated from the zero point to its limit position. For example, when the steering wheel is rotated from the zero point to the left limit, the stroke that can drive the rack to move is the center of the rack (e.g., ...). Figure 4 The distance from the center of the first rack in the steering wheel to the first target position. Therefore, the first target position can be determined based on the angle at which the steering wheel is turned to the left from the zero point to the left limit. The distance from the center of the rack to the right from the zero point to the right limit is the stroke of the rack center (e.g., the distance from the center of the first rack in the steering wheel to the left limit). Figure 4 The second target position is determined by the angle from the center of the first rack in the steering wheel to the right limit, from the zero position to the right limit.

[0103] Since the first and second turning angles are the angles created by the user turning the steering wheel, the user may not turn the steering wheel to its maximum position due to operational errors. For example, if the user turns the steering wheel to the right, the second turning angle is not the angle from the zero point to the right limit. In this case, the second turning angle will be smaller than the angle from the zero point to the right limit. If this second turning angle is considered the angle from the zero point to the right limit to determine the second target position, the determined second target position will be inaccurate. Therefore, the vehicle needs to first determine whether the second turning angle corresponds to the angle from the zero point to the right limit. Once the angle corresponding to the second turning angle is determined, the vehicle can determine the second target position based on the second turning angle.

[0104] For example, with Figure 4 Taking an example, if the second turning angle is less than the angle corresponding to the second end position, there are two possibilities. First, the second turning angle is less than the angle at which the steering wheel is turned to the right from the zero point, meaning the user has not turned the steering wheel to the right limit. Second, the rack has shifted to the left, for example... Figure 4The travel distance corresponding to the second target position is less than that of the second end position. Therefore, in this situation, the vehicle cannot determine which of the above-mentioned reasons causes the second angle to be less than the angle corresponding to the second end position, and thus the vehicle cannot determine the second target position. Therefore, to avoid the above problem, this application introduces a first position and a second position, and the second position is used as an example for explanation. When the second angle is less than the angle corresponding to the second position, the vehicle determines that the second angle is less than the angle at which the steering wheel is turned to the right from the zero position to the right limit; that is, the vehicle determines that the user has not turned the steering wheel to the right limit, and the collected second angle is invalid. When the second angle is greater than the angle corresponding to the second position but less than the angle corresponding to the second end position, the vehicle determines that the rack has shifted to the left, and the vehicle can determine the second target position based on the second angle in this situation.

[0105] In one possible implementation, the vehicle determines a first deviation and a first total travel based on a first steering angle and a second angle. If the first deviation is less than a first threshold and the first total travel is less than a total travel threshold, the rack position corresponding to the first steering angle is taken as the first target position.

[0106] The first deviation is used to represent the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position, and the first total travel is used to represent the total travel of the steering wheel.

[0107] In one possible implementation, the relative position of the center of the first rack and the midpoint of the rack can be used to determine whether the rack has shifted. This is because a shifted rack will have its midpoint not coinciding with the center of the first rack. For example, Figure 4 In the diagram, the rack that has not shifted has a midpoint that coincides with the center of the first rack. Therefore, the relative position of the center of the first rack and the midpoint of the rack can be used to determine whether the rack has shifted.

[0108] For example, such as Figure 4 As shown, the midpoint of the offset rack is also offset to the left relative to the center of the first rack, and the amount of offset can be measured by the following expression (1):

[0109] Offset of rack center = (AO - BO) / 2 (1)

[0110] Wherein, point A represents the left end position of the rack that has deviated (i.e., the first target position to be determined), and point B represents the right end position of the rack that has deviated (i.e., the second target position to be determined). AO represents the value corresponding to the limit angle of rotation of the steering wheel from the zero position to the left end position of the rack that has deviated, i.e., the first angle, and BO represents the value corresponding to the limit angle of rotation of the steering wheel from the zero position to the right end position of the rack that has deviated, i.e., the second angle. The offset of the rack center can be the rack travel between the rack midpoint and the first rack center. The first rack center is related to the zero position of the steering wheel, so the first rack center of the rack that has not deviated and the rack that has deviated are the same.

[0111] Based on the above expression (1) for measuring rack offset, an expression for the first deviation can be obtained. For example, the first deviation can be the absolute value of the sum of the first steering angle and the second steering angle. The vehicle determines whether the first deviation is less than a first threshold according to the following expression:

[0112] First deviation = |First turning angle + Second angle| < First threshold

[0113] To distinguish whether the steering wheel is turned left or right, leftward rotation is set as positive and rightward rotation as negative. Therefore, the first angle to the left is positive, and the second angle to the right is negative. Since the vehicle can determine the offset of the rack center according to the above expression (1), that is, the offset of the rack center is determined by the difference between the limit travel of the steering wheel to the left and the limit travel of the steering wheel to the right. Since the limit travel of the steering wheel in the direction of the second target position is currently unknown, the second angle can be used to represent the limit travel of the steering wheel in the direction of the second target position. And since the first angle of the steering wheel is positive and the second angle is negative, the absolute value of the sum of the first angle and the second angle of the steering wheel can be used to represent the offset of the rack center. When the first deviation is less than the first threshold, the first angle of the steering wheel meets the requirement of rack center offset.

[0114] For example, the first total travel can be the sum of the absolute values ​​of a first steering wheel angle and a second steering wheel angle. For instance, the vehicle determines whether the first total travel is less than a total travel threshold based on the following expression:

[0115] First total travel = |First turning angle| + |Second angle| < Total travel threshold

[0116] Since the limit of the steering wheel's rotation in the direction of the second target position is currently unknown, it can be represented by a second angle. That is, the sum of the first and second angles of the steering wheel corresponds to the total steering wheel travel, which must be less than a total steering wheel travel threshold. For example, since the rack's travel corresponds to the steering wheel's angular travel, the total travel threshold can be the sum of the rack's theoretically designed total travel and a first threshold. The first threshold is used to determine the deviation range. For example, the rack's theoretically designed total travel is 960°, and the first threshold is 20°.

[0117] In one implementation, the first turning angle is satisfied if the first deviation is less than a first threshold and the first total stroke is less than the total stroke threshold.

[0118] In one implementation, the first turning angle collected does not meet the requirements if the first deviation is less than a first threshold and the first total travel is greater than or equal to the total travel threshold.

[0119] In one implementation, if the first deviation is greater than or equal to the first threshold and the first total travel is less than the total travel threshold, the collected first turning angle does not meet the requirements.

[0120] In one implementation, the first turning angle collected does not meet the requirements if the first deviation is greater than or equal to the first threshold and the first total travel is greater than or equal to the total travel threshold.

[0121] In one possible implementation, when the first steering wheel angle meets the above conditions, the steering wheel speed and steering wheel torque corresponding to the first steering wheel angle also need to meet certain requirements. The vehicle can acquire the first steering wheel torque and the first steering wheel speed. If the first steering wheel torque is greater than a torque threshold and the first steering wheel speed is less than a speed threshold, the first target position is determined based on the first steering wheel angle. Here, the first steering wheel torque is the torque corresponding to the first steering wheel angle, and the first steering wheel speed is the speed corresponding to the first steering wheel angle.

[0122] The vehicle can determine the first torque and the first rotational speed of the steering wheel based on the following expressions:

[0123] The first torque of the steering wheel is greater than the torque threshold and the first speed of the steering wheel is less than the speed threshold.

[0124] Specifically, if the torque required to turn the steering wheel is too small, it will be difficult to turn the steering wheel to its limit position. Therefore, in order for the first steering angle to be infinitely close to the limit position, the steering wheel needs to be turned with considerable force. That is, the first torque of the steering wheel needs to be greater than the torque threshold. The torque threshold can be 5 N·m. Similarly, to facilitate the vehicle's self-learning of the rack's end position, the steering wheel needs to be turned at a relatively low speed, while the duration of the forceful, slow steering wheel turn needs to be relatively long. For example, the speed threshold could be 15° / s, and the duration of the forceful, slow steering wheel turn could exceed 300 ms.

[0125] In one implementation, the first steering angle is valid when the first torque of the steering wheel is greater than the torque threshold and the first rotational speed of the steering wheel is less than the rotational speed threshold.

[0126] In one implementation, the first steering angle is invalid if the first torque of the steering wheel is less than or equal to a torque threshold and the first rotational speed of the steering wheel is less than a rotational speed threshold.

[0127] In one implementation, the first steering angle is invalid if the first torque of the steering wheel is greater than a torque threshold and the first rotational speed of the steering wheel is greater than or equal to a rotational speed threshold.

[0128] In one implementation, the first steering angle is invalid if the first torque of the steering wheel is less than or equal to a torque threshold and the first rotational speed of the steering wheel is greater than or equal to a rotational speed threshold.

[0129] For example, please refer to Figure 5 , Figure 5 This is a schematic diagram illustrating how to determine the location of a first target according to an embodiment of this application. Figure 5 As shown, the vehicle first determines its initial position, and then checks whether the first steering wheel angle meets the requirements. Specifically, the vehicle can determine whether the first steering angle meets the requirements based on the following conditions:

[0130] |First angle + second angle| < first threshold, and |first angle| + |second angle| < the theoretical design total stroke of the rack + first threshold.

[0131] like Figure 5 As shown, when the vehicle's first turning angle does not meet the above requirements, the vehicle's first end position remains unchanged. When the vehicle's first turning angle meets the above requirements, the vehicle then determines whether the first steering wheel torque and the first steering wheel speed meet the requirements according to the following expression:

[0132] The initial torque of the steering wheel is greater than the torque threshold, and the initial rotational speed of the steering wheel is less than the rotational speed threshold.

[0133] like Figure 5As shown, when the first torque and / or the first rotational speed of the steering wheel do not meet the above requirements, the first end position of the vehicle remains unchanged. When the first torque and the first rotational speed of the steering wheel meet the above requirements, the vehicle determines the first target position based on the first steering angle.

[0134] In one possible implementation, the vehicle determines a second deviation and a second total travel based on a second steering angle and a first angle. If the second deviation is less than a second threshold and the first total travel is less than a total travel threshold, the rack position corresponding to the second steering angle is taken as the second target position.

[0135] The second deviation represents the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position, and the second total travel represents the total travel of the steering wheel.

[0136] Specifically, let's take the example of the rack shifting to the left to illustrate this. Figure 4 It can be seen that, compared with the rack that has not deviated, the angle corresponding to the right end position (e.g., the second target position) of the rack that has deviated is greater than the second angle. The midpoint of the rack that has deviated is also shifted to the left relative to the center of the first rack. Therefore, based on the above expression (1) for measuring rack deviation, an expression for the second deviation can be obtained. For example, the second deviation can be the absolute value of the sum of the second steering angle and the first angle, and the vehicle determines whether the second deviation is less than the second threshold according to the following expression:

[0137] Second deviation = |Second turning angle + First angle| < Second threshold

[0138] To distinguish whether the steering wheel is turned left or right, leftward rotation is set as positive and rightward rotation as negative. Therefore, the second angle to the right is negative, and the first angle to the left is positive. Since the vehicle can determine the offset of the rack center according to the above expression (1), that is, the offset of the rack center is determined by the difference between the limit travel of the steering wheel to the left and the limit travel of the steering wheel to the right. Since the limit travel of the steering wheel in the direction of the first target position is currently unknown, the first angle can be used to represent the limit travel of the steering wheel in the direction of the first target position. And since the second angle of the steering wheel is negative and the first angle is positive, the absolute value of the sum of the second angle and the first angle of the steering wheel can be used to represent the offset of the rack center. When the second deviation is less than the second threshold, the second angle of the steering wheel meets the requirement of rack center offset. The second threshold and the first threshold can be the same or different, for example, the second threshold can be 20°.

[0139] For example, the second total travel can be the sum of the absolute value of the second steering wheel angle and the absolute value of the first angle. For instance, the vehicle determines whether the second total travel is less than a total travel threshold based on the following expression:

[0140] Second total travel = |Second turning angle| + |First angle| < Total travel threshold

[0141] Since the limit of the steering wheel's rotation in the direction of the first target position is currently unknown, it can be represented by a first angle. That is, the sum of the second steering angle and the first angle corresponds to the total steering wheel travel, which must be less than a total steering wheel travel threshold. For example, since the rack's travel corresponds to the steering wheel's angular travel, the total travel threshold can be the sum of the rack's theoretically designed total travel and a second threshold. The second threshold is used to determine the deviation range. For example, the rack's theoretically designed total travel is 960°, and the second threshold is 20°.

[0142] In one implementation, the second turning angle is considered to meet the requirements when the second deviation is less than the second threshold and the second total stroke is less than the total stroke threshold.

[0143] In one implementation, the second turning angle collected does not meet the requirements if the second deviation is less than the second threshold and the second total travel is greater than or equal to the total travel threshold.

[0144] In one implementation, if the second deviation is greater than or equal to the second threshold and the second total travel is less than the total travel threshold, the collected second turning angle does not meet the requirements.

[0145] In one implementation, the second turning angle collected does not meet the requirements if the second deviation is greater than or equal to the second threshold and the second total travel is greater than or equal to the total travel threshold.

[0146] In one possible implementation, when the second steering wheel angle meets the above conditions, the steering wheel speed and steering wheel torque corresponding to the second steering wheel angle also need to meet certain requirements. The vehicle can acquire the second steering wheel torque and the second steering wheel speed. If the absolute value of the second steering wheel torque is greater than a torque threshold and the absolute value of the second steering wheel speed is less than a speed threshold, the second target position is determined based on the second steering wheel angle. Here, the second steering wheel torque is the torque corresponding to the second steering wheel angle, and the second steering wheel speed is the speed corresponding to the second steering wheel angle. Since the second steering wheel angle is the angle at which the steering wheel rotates towards the direction of the second target position, the second steering wheel angle is a negative value. Correspondingly, the second steering wheel torque and the second steering wheel speed are also negative values, so they need to be compared based on the absolute values ​​of the second steering wheel torque and the second steering wheel speed.

[0147] The vehicle can determine the second torque and second rotational speed of the steering wheel according to the following expressions:

[0148] The second torque of the steering wheel is greater than the torque threshold and the second speed of the steering wheel is less than the speed threshold.

[0149] Specifically, if the torque required to turn the steering wheel is too small, it will be difficult to turn the steering wheel to its limit position. Therefore, in order for the second steering angle to approach the limit position infinitely, the steering wheel needs to be turned with considerable force. That is, the absolute value of the second torque of the steering wheel needs to be greater than the torque threshold. The torque threshold can be 5 N·m. Similarly, to facilitate the vehicle's self-learning of the rack's end position, the steering wheel needs to be turned at a relatively low speed, while the duration of the forceful, slow steering wheel turn needs to be relatively long. For example, the speed threshold could be 15° / s, and the duration of the forceful, slow steering wheel turn could exceed 300 ms.

[0150] In one implementation, the second steering angle is valid when the second torque of the steering wheel is greater than the torque threshold and the second rotational speed of the steering wheel is less than the rotational speed threshold.

[0151] In one implementation, the second steering angle is invalid if the second torque of the steering wheel is less than or equal to the torque threshold and the second rotational speed of the steering wheel is less than the rotational speed threshold.

[0152] In one implementation, the second steering angle is invalid if the second torque of the steering wheel is greater than the torque threshold and the second rotation speed of the steering wheel is greater than or equal to the rotation speed threshold.

[0153] In one implementation, the second steering angle is invalid if the second torque of the steering wheel is less than or equal to the torque threshold and the second rotation speed of the steering wheel is greater than or equal to the rotation speed threshold.

[0154] For example, please refer to Figure 6 , Figure 6 This is a schematic diagram illustrating how to determine the location of a second target according to an embodiment of this application. Figure 6 As shown, the vehicle first determines the second position, and then judges whether the second steering wheel angle meets the requirements. Specifically, the vehicle can judge whether the second steering wheel angle meets the requirements based on the following conditions:

[0155] |Second turning angle + First angle| < Second threshold, and |Second turning angle| + |First angle| < Theoretical design total stroke of rack + Second threshold.

[0156] like Figure 6As shown, when the vehicle's second turning angle does not meet the above requirements, the vehicle's second end position remains unchanged. When the vehicle's second turning angle meets the above requirements, the vehicle then determines whether the second torque and second rotation speed of the steering wheel meet the following requirements:

[0157] The second torque of the steering wheel is greater than the torque threshold, and the second speed of the steering wheel is less than the speed threshold.

[0158] like Figure 6 As shown, when the second torque and / or the second rotational speed of the steering wheel do not meet the above requirements, the second end position of the vehicle does not change. When the second torque and the second rotational speed of the steering wheel meet the above requirements, the vehicle determines the second target position based on the second steering angle.

[0159] After the vehicle determines the first target position based on the first turning angle and the second target position based on the second turning angle, the vehicle can further determine whether the first and second target positions are accurate based on the determined first and second target positions.

[0160] In one possible implementation, the difference between the angle corresponding to the first target position and the angle corresponding to the second target position is less than or equal to a third threshold, wherein the third threshold is used to represent the maximum offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position.

[0161] The vehicle can determine the difference between the angle corresponding to the first target position and the angle corresponding to the second target position using the following expression:

[0162]

[0163] According to the above expression (1), the offset of the rack center can be determined by the travel distance from the rack center to the first target position when the steering wheel is at the zero position, and the travel distance from the rack center to the second target position when the steering wheel is at the zero position. To distinguish whether the steering wheel is turned left or right, left turn is set as positive and right turn as negative. Therefore, the angle corresponding to the first target position is positive to the left, and the angle corresponding to the second target position is negative to the right. Therefore, according to the above expression, the offset of the rack center can be determined by simultaneously considering the angles corresponding to the first and second target positions. When the angles corresponding to the first and second target positions simultaneously meet the above requirements, the accuracy of the first and second target positions determined by the vehicle is high, and the result of the vehicle's self-learning of the rack end position is successful.

[0164] In one possible implementation, the vehicle can store a first target position and a second target position of the rack, and then protect the end of the rack according to the stored first and second target positions.

[0165] For example, after the EPS (Electrically Powered Transmission System) is powered off, the vehicle can store the first and second target positions of the rack in an Electrically Erasable Programmable Read-Only Memory (EEPROM). EEPROM is a type of memory chip that retains data even after power loss; existing information can be erased and reprogrammed on a computer or dedicated equipment, offering high availability.

[0166] In one possible implementation, the vehicle controls the assist torque of the electric power steering system based on a first target position and a second target position.

[0167] Specifically, the vehicle determines the protective torque based on the first and second target positions learned through self-learning, thereby providing end-point protection for the steering system. For example, when the rack approaches the first or second target position, the vehicle can reduce the assist torque of the electric power steering system to avoid collision noise or damage to mechanical components during a collision. Furthermore, it can also prevent damage caused by overheating of the motor and controller.

[0168] For example, when the mechanical components of the rack experience fatigue or wear, causing a change in the end position, or when the vehicle is undergoing maintenance or wheel alignment adjustments, there may be a significant deviation in the protection range of the left and right ends of the rack. This can lead to inconsistent steering feel at the ends, and in severe cases, knocking noise at the limit positions. According to the embodiments of this application, the vehicle can learn the limit positions of both ends of the rack. Then, within a certain travel distance when the steering is close to the limit position, the motor assistance is reduced to slow down the impact speed of the steering rack on the ends. This can provide the user with better end damping feel, improve handling quality, and enhance noise, vibration, and harshness (NVH) performance.

[0169] For example, please refer to Figure 7 , Figure 7 This is a schematic diagram of the end of a self-learning rack provided in an embodiment of this application. Figure 7 As shown, the steps by which the vehicle determines the first target position and the second target position of the rack through self-learning include any of steps 1-7, as detailed below:

[0170] Step 1, Self-learning enable trigger. Based on the current state, if it is determined that it is appropriate to perform self-learning on the rack end position, the vehicle triggers the left end position learning enable and the right end position learning enable.

[0171] Step 2: Determine whether the first steering wheel angle meets the requirements, and then determine whether the second steering wheel angle meets the requirements. The vehicle determines whether the first steering wheel angle meets the requirements based on the first steering wheel angle, the first steering wheel torque, and the first steering wheel speed. The vehicle can also determine whether the second steering wheel angle meets the requirements based on the second steering wheel angle, the second steering wheel torque, and the second steering wheel speed. For specific determination conditions and processes, please refer to the above embodiment.

[0172] Step 3: If the first steering wheel angle meets the requirements, determine the first target position based on the first steering wheel angle, and use this first target position as the left end position of the rack. Furthermore, the left end position learning status bit of the rack is valid, marked as CCW_Valid = 1. If the first steering wheel angle does not meet the requirements, the left end position of the rack remains the first end position, and the left end position learning status bit of the rack is invalid, marked as CCW_Valid = 0.

[0173] If the second steering wheel angle meets the requirements, the second target position is determined based on the second steering wheel angle and taken as the right end position of the rack. Furthermore, the right end position learning status bit of the rack is valid, marked as CW_Valid = 1. If the second steering wheel angle does not meet the requirements, the right end position of the rack remains the second end position, and the right end position learning status bit of the rack is invalid, marked as CW_Valid = 0.

[0174] Step 4: Output the left end position of the rack, the right end position of the rack, the left end position learning state, and the right end position learning state.

[0175] Step 5: Determine whether the positions of the left and right ends of the rack meet the requirements. The determination conditions 1, 2, and 3 are as follows:

[0176] Judgment condition 1: The angles corresponding to the left end position and the right end position of the rack both satisfy the following expression:

[0177] |(Lmax, Rmax)| < Total steering wheel travel / 2 + 10° & |Lmax + Rmax| / 2 < 30°

[0178] Where Lmax is the angle corresponding to the left end position of the rack, and Rmax is the angle corresponding to the right end position of the rack. Both Lmax and Rmax must be less than the total travel of the steering wheel / 2 + 10°.

[0179] Judgment condition 2: The angles corresponding to the left end position and the right end position of the rack both satisfy the following expression:

[0180] |(Lmax, Rmax)|> Total steering wheel travel / 2 + 10° and / or |Lmax + Rmax| / 2> 30°

[0181] Where Lmax is the angle corresponding to the left end position of the rack, and Rmax is the angle corresponding to the right end position of the rack. Both Lmax and Rmax must be greater than the total travel of the steering wheel / 2 + 10°.

[0182] Judgment condition 3: The learning states at the left and right ends satisfy the following expression:

[0183] CCW_Valid=1&CW_Valid=1

[0184] Where CCW_Valid = 1 indicates that the left end position learning state bit of the rack is valid, and CW_Valid = 1 indicates that the right end position learning state bit of the rack is valid. & indicates that both the left and right end position learning state bits of the rack are valid.

[0185] Step 6: When the left end position and the right end position of the rack satisfy judgment condition 1 and judgment condition 3, the vehicle's self-learning of the rack end position is successful, and the learning success flag is output as RackLearnSuccess=1.

[0186] When the left and right end positions of the rack meet conditions 2 and 3 respectively, the vehicle's self-learning of the rack end positions fails, and the learning failure flag is output as RackLearnFail=1.

[0187] Step 7: Determine if a reset is needed. The vehicle uses its status information to determine the current self-learning status and position of the rack end, and then determines whether a reset is required.

[0188] For example, the vehicle first acquires the status bits of relevant signals, and then determines whether self-learning has failed (status bit RackLearnFail = 1), corner zero-point calibration not completed (status bit corner zero-point calibration status = 0), corner zero-point routine completed (status bit corner zero-point routine completion flag = 1), or the reset button has been pressed (status bit reset button = 1). If any of the above flags appear, the status is marked as reset (status bit StatusReset = 1). If none of the above status bits appear, the status is marked as not reset (status bit StatusNotReset = 1).

[0189] Then, the vehicle determines whether the left-end position learning status is valid and the status is not reset (status bit CCW_Valid = 1 and StatusNotReset = 1). If it is true, the left-end position learning is valid (status bit CCW_Valid_write = 1). If it is not true, the left-end position learning is invalid (status bit CCW_Valid_write = 0).

[0190] The vehicle can also determine whether the right-end position learning status is valid and the status is not reset (status bit CW_Valid = 1 and StatusNotReset = 1). If it is true, the right-end position learning is valid (status bit CCW_Valid_write = 1). If it is false, the right-end position learning is invalid (status bit CCW_Valid_write = 0).

[0191] The vehicle can also determine whether the learning success flag and the status not being reset (status bits: RackLearnSuccess = 1 and StatusNotReset = 1) are true. If true, the learning from the end position of the rack is complete (status bits: Lmax_write = Lmax, Rmax_write = Rmax). If false, the learning from the end position of the rack is incomplete (status bits: Lmax_write = angle corresponding to the first end position, Rmax_write = angle corresponding to the second end position).

[0192] The methods of the embodiments of this application have been described in detail above. The apparatus of the embodiments of this application is provided below.

[0193] Please see Figure 8 , Figure 8 This is a functional unit block diagram of a steering rack end position determination device provided in an embodiment of this application. The steering rack end position determination device 80 may include a processing unit 801 and a communication unit 802. The steering rack end position determination device 80 is used to implement the aforementioned steering rack end position determination method, for example... Figure 2 The method for determining the position of the end of the steering wheel rack is shown.

[0194] It should be noted that the above division of multiple units is only a logical division based on function and does not constitute a limitation on the specific structure of the steering wheel rack end position determining device 80. In actual implementation, some functional modules may be subdivided into more smaller functional modules, and some functional modules may be combined into a single functional module.

[0195] In one possible implementation, the communication unit 802 is used to obtain the first angle of the steering wheel corresponding to the first position of the rack and the second angle of the steering wheel corresponding to the second position of the rack, wherein the distance between the first position and the first end position of the rack is less than or equal to a first preset distance, the distance between the second position and the second end position of the rack is less than or equal to a second preset distance, and the first end position and the second end position are preset end positions corresponding to the rack respectively.

[0196] The communication unit 802 is also used to obtain the actual steering wheel angle;

[0197] The processing unit 801 is used to determine the first target position and the second target position based on the actual steering angle of the steering wheel, the first angle and the second angle, wherein the actual steering angle of the steering wheel is used to drive the rack to move, and the first target position and the second target position are the actual end positions of the rack respectively.

[0198] In one possible implementation, after determining the first target position and the second target position based on the actual steering wheel angle, the first angle, and the second angle, the processing unit 801 further includes:

[0199] The power steering torque of the electric power steering system is controlled based on the first target position and the second target position.

[0200] In one possible implementation, the actual steering wheel angle includes a first angle and a second angle. The processing unit 801 is specifically configured to determine a first target position and a second target position based on the actual steering wheel angle, the first angle, and the second angle, including:

[0201] The direction corresponding to the first turning angle is the same as the direction corresponding to the first angle, and the direction corresponding to the second turning angle is the same as the direction corresponding to the second angle.

[0202] If the first turning angle is greater than the first angle, the position of the first target is determined based on the first turning angle;

[0203] If the second turning angle is greater than the second angle, the position of the second target is determined based on the second turning angle.

[0204] In one possible implementation, the processing unit 801 is specifically configured to determine the first target position based on the first turning angle, including:

[0205] The first deviation and the first total travel are determined based on the first turning angle and the second angle, wherein the first deviation is used to represent the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position, and the first total travel is used to represent the total travel of the steering wheel;

[0206] If the first deviation is less than the first threshold and the first total stroke is less than the total stroke threshold, the rack position corresponding to the first rotation angle is taken as the first target position.

[0207] In one possible implementation, the processing unit 801 is specifically configured to determine the first target position based on the first turning angle, including:

[0208] The first torque and the first rotation speed of the steering wheel are obtained through the communication unit 802, wherein the first torque and the first rotation speed of the steering wheel correspond to the first turning angle of the steering wheel;

[0209] When the first torque is greater than the torque threshold and the first rotation speed is less than the rotation speed threshold, the first target position is determined based on the first rotation angle.

[0210] In one possible implementation, the processing unit 801 is specifically configured to determine the second target position based on the second turning angle, including:

[0211] The second deviation and the second total travel are determined based on the second turning angle and the first angle, wherein the second deviation is used to represent the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position, and the second total travel is used to represent the total travel of the steering wheel;

[0212] If the second deviation is less than the second threshold and the second total stroke is less than the total stroke threshold, the rack position corresponding to the second rotation angle is taken as the second target position.

[0213] In one possible implementation, the processing unit 801 is specifically configured to determine the second target position based on the second turning angle, including:

[0214] The second torque and second rotation speed of the steering wheel are obtained through the communication unit 802, wherein the second torque and second rotation speed of the steering wheel correspond to the second steering angle of the steering wheel;

[0215] When the second torque is greater than the torque threshold and the second rotation speed is less than the rotation speed threshold, the second target position is determined based on the second rotation angle.

[0216] In one possible implementation, the difference between the angle corresponding to the first target position and the angle corresponding to the second target position is less than or equal to a third threshold, wherein the third threshold is used to represent the maximum offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position.

[0217] In one possible implementation, the first position is determined based on the difference between the distance corresponding to the first end position and a first preset distance;

[0218] The second position is determined based on the difference between the distance corresponding to the second end position and the second preset distance.

[0219] It should be noted that, in the embodiments of this application, the specific implementation and technical effects of each unit can also be referred to accordingly. Figure 2 The corresponding description of the method embodiments shown.

[0220] Please see Figure 9 , Figure 9 This is a schematic diagram of the structure of a computing device provided in an embodiment of this application. Figure 9 As shown, the computing device 90 may include one or more processors 901, one or more memories 902, and one or more communication interfaces 903. These components may be connected via a bus 904 or other means. Figure 9 Taking a connection via bus 904 as an example. Where:

[0221] The communication interface 903 can be used by the computing device 90 to communicate with other communication devices, such as other computing devices. Specifically, the communication interface 903 can be a wired interface.

[0222] The memory 902 can be coupled to the processor 901 via a bus 904 or an input / output port, or the memory 902 can be integrated with the processor 901. The memory 902 is used to store various software programs and / or multiple sets of instructions or data. Specifically, the memory 902 can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited thereto. Memory 902 may include high-speed random access memory and may also include non-volatile memory, such as one or more disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. Memory 902 may store an operating system (hereinafter referred to as the system), such as uCOS, VxWorks, RTLinux, or other embedded operating systems. Memory 902 may also store network communication programs that can be used to communicate with one or more additional devices, one or more user devices, or one or more terminals. Memory 902 may exist independently and be connected to processor 901 via bus 904. Memory 902 may also be integrated with processor 901.

[0223] The memory 902 stores the application code for executing the above scheme, and its execution is controlled by the processor 901. The processor 901 executes the application code stored in the memory 902.

[0224] Processor 901 may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in connection with this disclosure. Processor 901 may also be a combination that implements a specific function, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, etc.

[0225] It should be noted that, in the embodiments of this application, the specific implementation and technical effects of each unit can also be referred to accordingly. Figure 2 The corresponding description of the method embodiments shown.

[0226] This application also provides a device for determining the position of the end of a steering wheel rack. The device includes a processor and a memory, the processor being coupled to the memory. The memory stores a computer program, and the processor calls and runs the computer program, causing the vehicle to execute the aforementioned method for determining the position of the end of the steering wheel rack. Figure 2 The method.

[0227] This application also provides a vehicle, including a steering device and a device for determining the position of the end of a steering wheel rack.

[0228] This application also provides a computer-readable storage medium storing instructions that, when executed on at least one processor, implement the aforementioned method for determining the position of the end of a steering wheel rack, for example... Figure 2 The method.

[0229] This application also provides a computer program product comprising computer instructions that, when executed by a computing device, implement the aforementioned method for determining the position of the end of a steering wheel rack, for example... Figure 2 The method.

[0230] In this application, the terms "for example" or "for instance" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "for example" or "for instance" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Rather, the use of terms such as "for example" or "for instance" is intended to present the relevant concepts in a specific manner.

[0231] In this application, "at least one" in the embodiments refers to one or more items, and "more than one" refers to two or more items. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c, (a and b), (a and c), (b and c), or (a and b and c), where a, b, and c can be single or multiple. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0232] Furthermore, unless otherwise stated, the use of ordinal numbers such as "first" and "second" in the embodiments of this application is for distinguishing multiple objects and is not for limiting the order, sequence, priority, or importance of multiple objects. For example, "first device" and "second device" are only for ease of description and do not indicate that the first device and the second device are different in structure, importance, etc. In some embodiments, the first device and the second device may also be the same device.

[0233] In the above embodiments, the term "when..." can be interpreted, depending on the context, as meaning "if...", "after...", "in response to determining...", or "in response to detecting...". The above are merely optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of this application should be included within the protection scope of this application.

[0234] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0235] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for determining the position of the end of a steering wheel rack, characterized in that, The method includes: Obtain the first angle of the steering wheel corresponding to the first position of the rack and the second angle of the steering wheel corresponding to the second position of the rack, wherein the distance between the first position and the first end position of the rack is less than or equal to a first preset distance, the distance between the second position and the second end position of the rack is less than or equal to a second preset distance, and the first end position and the second end position are preset end positions corresponding to the rack respectively; Obtain the actual steering wheel angle; The first target position and the second target position are determined based on the actual turning angle of the steering wheel, the first angle, and the second angle, wherein the actual turning angle of the steering wheel is used to drive the rack to move, and the first target position and the second target position are the actual end positions of the rack respectively.

2. The method according to claim 1, characterized in that, After determining the first target position and the second target position based on the actual steering wheel angle, the first angle, and the second angle, the method further includes: The power steering torque of the electric power steering system is controlled based on the first target position and the second target position.

3. The method according to claim 1 or 2, characterized in that, The actual steering wheel angle includes a first angle and a second angle. Determining the first target position and the second target position based on the actual steering wheel angle, the first angle, and the second angle includes: The direction corresponding to the first turning angle is the same as the direction corresponding to the first angle, and the direction corresponding to the second turning angle is the same as the direction corresponding to the second angle; When the first turning angle is greater than the first angle, the first target position is determined based on the first turning angle; If the second turning angle is greater than the second angle, the second target position is determined based on the second turning angle.

4. The method according to claim 3, characterized in that, Determining the first target position based on the first turning angle includes: The first deviation and the first total travel are determined based on the first turning angle and the second angle, wherein the first deviation is used to represent the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position, and the first total travel is used to represent the total travel of the steering wheel; If the first deviation is less than the first threshold and the first total stroke is less than the total stroke threshold, the rack position corresponding to the first rotation angle is taken as the first target position.

5. The method according to claim 3 or 4, characterized in that, Determining the first target position based on the first turning angle includes: The first torque and the first rotational speed of the steering wheel are obtained, wherein the first torque and the first rotational speed of the steering wheel correspond to the first turning angle of the steering wheel; When the first torque is greater than the torque threshold and the first rotation speed is less than the rotation speed threshold, the first target position is determined based on the first rotation angle.

6. The method according to claim 4 or 5, characterized in that, Determining the second target position based on the second turning angle includes: The second deviation and the second total travel are determined based on the second turning angle and the first angle, wherein the second deviation is used to represent the offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position, and the second total travel is used to represent the total travel of the steering wheel; If the second deviation is less than the second threshold and the second total stroke is less than the total stroke threshold, the rack position corresponding to the second rotation angle is taken as the second target position.

7. The method according to claim 5 or 6, characterized in that, Determining the second target position based on the second turning angle includes: The second torque and the second rotational speed of the steering wheel are obtained, wherein the second torque and the second rotational speed of the steering wheel correspond to the second turning angle of the steering wheel; When the second torque is greater than the torque threshold and the second rotation speed is less than the rotation speed threshold, the second target position is determined based on the second rotation angle.

8. The method according to any one of claims 1-7, characterized in that, The difference between the angle corresponding to the first target position and the angle corresponding to the second target position is less than or equal to a third threshold, wherein the third threshold is used to represent the maximum offset of the rack center relative to the midpoint of the rack when the steering wheel is at the zero position.

9. The method according to any one of claims 1-8, characterized in that, The first position is determined based on the difference between the distance corresponding to the first end position and the first preset distance; The second position is determined based on the difference between the distance corresponding to the second end position and the second preset distance.

10. A device for determining the end position of a steering wheel rack, characterized in that, The device includes a processor and a memory, the processor being coupled to the memory for storing a computer program, and the processor for calling and running the computer program to cause the vehicle to perform the method as described in any one of claims 1-9.

11. A vehicle, characterized in that, It includes a steering system and a device for determining the position of the end of a steering wheel rack as described in claim 10.

12. A computing device, characterized in that, The device includes a processor coupled to a memory for storing a computer program, and the processor is configured to invoke and run the computer program, causing the computing device to perform the method as described in any one of claims 1-9.

13. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including instructions for performing the method as described in any one of claims 1-9.

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