Electric power assisted steering compensation method, controller, steering system, vehicle and medium

Abstract

The application discloses an electric power steering compensation method, a controller, a steering system, a vehicle and a medium. The method comprises the following steps: acquiring a basic friction compensation torque; determining an adaptive friction compensation torque according to a steering wheel torque signal and the basic friction compensation torque; and when the basic friction compensation torque and the adaptive friction compensation torque meet a preset condition, controlling the steering mechanism to work according to the adaptive friction compensation torque. The method can make the friction compensation torque of the steering mechanism related to the aging degree of the steering mechanism, and is helpful to guarantee the steering smoothness and comfort of the steering mechanism, and further guarantee the driving control stability and safety.

Description

Technical Field

[0001] This invention relates to the field of vehicle driving control technology, and in particular to an electric power steering compensation method, controller, steering system, vehicle, and medium. Background Technology

[0002] With the rapid development of automotive technology, people's demands for driving experience are also increasing. Vehicle ride comfort and handling stability, as characteristics affecting passenger sensory experience and personal safety, are receiving more and more attention. As a key component for driver control, the steering system's smoothness and comfort directly determine the overall vehicle safety and handling stability. Existing steering systems exhibit high friction torque at low speeds, resulting in steering sticking and poor feel during active steering. During active return-to-center, the return force is insufficient, hindering return to center, but it effectively suppresses vibrations and provides high handling stability. At high speeds, the rotational inertia is large, and the friction torque is small, making it prone to increased overshoot during return-to-center.

[0003] The friction in existing steering systems mainly originates from the friction between the rack and pinion, and the friction of the column bearings, manifesting as Coulomb friction. During vehicle steering control, a force in the same direction as the motor's motion is typically applied based on a table consulted to overcome this Coulomb friction. However, due to the aging process of mechanical components during vehicle use, the friction changes over time, significantly affecting the driver's feel and consequently impacting the smoothness and comfort of the steering system. Summary of the Invention

[0004] This invention provides an electric power steering compensation method, controller, steering system, vehicle, and medium to solve the problem that existing steering systems cannot guarantee smooth and comfortable steering.

[0005] An electric power steering compensation method includes:

[0006] Obtain the basic friction compensation torque;

[0007] The adaptive friction compensation torque is determined based on the steering wheel torque signal and the basic friction compensation torque.

[0008] When the basic friction compensation torque and the adaptive friction compensation torque meet the preset conditions, the steering mechanism is controlled to work according to the adaptive friction compensation torque.

[0009] Preferably, obtaining the basic friction compensation torque includes:

[0010] Acquire steering wheel speed signal, steering wheel torque signal, and vehicle speed signal;

[0011] The basic friction compensation torque is obtained based on the steering wheel rotation speed signal and the vehicle speed signal.

[0012] Preferably, obtaining the basic friction compensation torque based on the steering wheel rotation speed signal and the vehicle speed signal includes:

[0013] Based on the steering wheel rotation speed signal, the first friction compensation torque and the direction of friction force are determined;

[0014] Based on the vehicle speed signal, determine the vehicle speed friction gain and vehicle speed friction limit;

[0015] The basic friction compensation torque is obtained based on the first friction compensation torque, the friction force direction, the vehicle speed friction gain, and the vehicle speed friction limit.

[0016] Preferably, obtaining the basic friction compensation torque based on the first friction compensation torque, the friction force direction, the vehicle speed friction gain, and the vehicle speed friction limit includes:

[0017] The second friction compensation torque is determined based on the first friction compensation torque, the direction of the friction force, and the vehicle speed friction gain;

[0018] The amplitude of the second friction compensation torque is limited by the vehicle speed friction limit to obtain the basic friction compensation torque.

[0019] Preferably, the step of limiting the amplitude of the second friction compensation torque using the vehicle speed friction limiter to obtain the basic friction compensation torque includes:

[0020] If the second friction compensation torque is within the vehicle speed friction limit, then the second friction compensation torque is determined as the basic friction compensation torque;

[0021] If the second friction compensation torque is not within the vehicle speed friction limit, then the basic friction compensation torque is determined based on the vehicle speed friction limit.

[0022] Preferably, determining the adaptive friction compensation torque based on the steering wheel torque signal and the basic friction compensation torque includes:

[0023] When the vehicle is in active self-centering mode, the steering wheel torque signal and the calibration torque signal are used to perform trend calculations to determine the target change trend value;

[0024] Determine the target gain coefficient based on the target change trend value;

[0025] The adaptive friction compensation torque is determined based on the target gain coefficient and the basic friction compensation torque.

[0026] Preferably, the step of performing trend calculation on the steering wheel torque signal and the calibrated torque signal to determine the target change trend value includes:

[0027] When the vehicle is in active self-centering mode, the current trend value of the steering wheel torque signal is determined based on the steering wheel torque signal and the calibration torque signal.

[0028] The current trend value is determined as the target trend value.

[0029] Preferably, the step of performing trend calculation on the steering wheel torque signal and the calibrated torque signal to determine the target change trend value includes:

[0030] Based on the steering wheel torque signal and the calibration torque signal, determine the current trend value corresponding to the steering wheel torque signal;

[0031] Based on all the current trend values ​​corresponding to this active recovery condition, determine the average trend value;

[0032] The current trend error is determined based on the current trend value and the average trend value.

[0033] If the current trend error is less than the trend error threshold, then the current trend value is determined as the target trend value.

[0034] If the current trend error is not less than the trend error threshold, then the average trend value is determined as the target trend value.

[0035] Preferably, determining the target gain coefficient based on the target change trend value includes:

[0036] The original gain coefficient corresponding to the target change trend value is determined by querying the trend gain mapping table based on the target change trend value.

[0037] The original gain coefficient is subjected to amplitude limitation to determine the target gain coefficient.

[0038] Preferably, the step of limiting the amplitude of the original gain coefficient to determine the target gain coefficient includes:

[0039] If the original gain coefficient is less than the preset gain coefficient limit, then the original gain coefficient is determined as the target gain coefficient;

[0040] If the original gain coefficient is not less than the preset gain coefficient limit, then the target gain coefficient is determined according to the gain coefficient limit.

[0041] Preferably, when the basic friction compensation torque and the adaptive friction compensation torque meet preset conditions, controlling the steering mechanism to operate according to the adaptive friction compensation torque includes:

[0042] The target compensation torque error is determined based on the basic friction compensation torque and the adaptive friction compensation torque.

[0043] If the target compensation torque error is not within the compensation torque error threshold, the steering mechanism is controlled to work according to the adaptive friction compensation torque.

[0044] Preferably, if the target compensation torque error is not within the compensation torque error threshold, then controlling the steering mechanism to operate according to the adaptive friction compensation torque includes:

[0045] If the target compensation torque error is not within the compensation torque error threshold, then the current vehicle operating condition is obtained;

[0046] If the current vehicle operating condition is a safe operating condition, then the steering mechanism is controlled to operate according to the adaptive friction compensation torque.

[0047] Preferably, the current vehicle operating condition is determined based on the steering wheel angle signal and the steering wheel torque signal.

[0048] Preferably, the safe operating condition is the condition where the absolute value of the steering wheel angle signal is less than a preset angle threshold and the absolute value of the steering wheel torque signal is less than a preset torque threshold.

[0049] An on-board controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described electric power steering compensation method.

[0050] A steering system includes the aforementioned onboard controller and a steering mechanism connected to the onboard controller.

[0051] A vehicle including the aforementioned steering system.

[0052] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described electric power steering compensation method.

[0053] The aforementioned electric power steering compensation method, controller, steering system, vehicle, and medium, after obtaining the basic friction compensation torque, adaptively adjust the basic friction compensation torque based on the steering wheel torque signal, making the adaptive friction compensation torque related to the aging degree of the steering mechanism; when the basic friction compensation torque and the adaptive friction compensation torque meet preset conditions, the steering mechanism is controlled to work according to the adaptive friction compensation torque, making the friction compensation torque of the steering mechanism related to the aging degree of the steering mechanism, which helps to ensure smooth and comfortable steering, thereby ensuring driving stability and safety. Attached Figure Description

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

[0055] Figure 1 This is a flowchart of an electric power steering compensation method according to an embodiment of the present invention;

[0056] Figure 2 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0057] Figure 3 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0058] Figure 4 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0059] Figure 5 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0060] Figure 6 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0061] Figure 7 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0062] Figure 8 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0063] Figure 9 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0064] Figure 10This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0065] Figure 11 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention;

[0066] Figure 12 This is another flowchart of the electric power steering compensation method in one embodiment of the present invention. Detailed Implementation

[0067] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] The electric power steering compensation method provided in this embodiment of the invention can be applied to an on-board controller, which is a controller installed on a vehicle, specifically a controller on a vehicle equipped with an electric power steering system (EPS). It can be a controller dedicated to steering control or a controller that integrates other functions.

[0069] In one embodiment, such as Figure 1 As shown, an electric power steering compensation method is provided, and the method is illustrated using an on-board controller as an example. The method includes the following steps:

[0070] S101: Obtain the basic friction compensation torque;

[0071] S102: Determine the adaptive friction compensation torque based on the steering wheel torque signal and the basic friction compensation torque;

[0072] S103: When the basic friction compensation torque and the adaptive friction compensation torque meet the preset conditions, control the steering mechanism to work according to the adaptive friction compensation torque.

[0073] Among them, the basic friction compensation torque is the value determined by calculating the friction compensation torque based on the real-time collected measured vehicle data.

[0074] As an example, in step S101, during vehicle operation, for example, when the vehicle is in an active self-centering state, the on-board controller can acquire real-time measured vehicle data transmitted by the bus or other sensors; then, it uses a pre-set basic friction compensation torque calculation logic to calculate the measured vehicle data and obtain the calculated basic friction compensation torque. The basic friction compensation torque calculation logic here is a pre-set processing logic for calculating the basic friction compensation torque, which can be a processing logic found in existing technologies.

[0075] As an example, in step S102, after acquiring the basic friction compensation torque, the vehicle controller can analyze the steering wheel torque signal to determine the change in friction force due to structural aging, and based on this change, determine the target gain coefficient that needs to be adjusted for the basic friction compensation torque; then, based on the target gain coefficient, the basic friction compensation torque is adjusted to obtain the amplified adaptive friction compensation torque, so that the adaptive friction compensation torque is related to the aging degree of the steering mechanism, and when the steering mechanism is controlled based on the adaptive friction compensation torque, the steering system can be ensured to be smooth and comfortable.

[0076] Among them, the preset conditions are pre-set conditions used to evaluate whether adaptive compensation can be performed.

[0077] As an example, in step S103, after acquiring the basic friction compensation torque and the adaptive friction compensation torque respectively, the vehicle controller can evaluate whether the preset conditions are met based on the basic friction compensation torque and the adaptive friction compensation torque. When the preset conditions are met, the steering mechanism is controlled to work based on the adaptive friction compensation torque, that is, when the preset conditions are met, the adaptive friction compensation torque is determined as the target friction compensation torque, and the steering mechanism is controlled to work based on the target friction compensation torque. When the preset conditions are not met, the steering mechanism is controlled to work based on the basic friction compensation torque, that is, when the preset conditions are not met, the basic friction compensation torque is determined as the target friction compensation torque, and the steering mechanism is controlled to work based on the target friction compensation torque.

[0078] In this example, after determining the target friction compensation torque, the vehicle controller can determine the corresponding target control current based on the target friction compensation torque, so as to control the steering mechanism motor to work based on the target control current. In this example, the vehicle controller can combine the determined target friction compensation torque with other compensation torques or assist torques to form a basic assist, and send it to the steering mechanism motor control module in the form of a command to control the rotation of the steering mechanism motor, which then acts on the steering mechanism to provide steering assistance to the driver.

[0079] In one example, the steering mechanism is controlled to operate based on the target friction compensation torque, including: (1) determining the base assist based on the target friction compensation torque; (2) determining the assist control current based on the base assist; and (3) determining the target control current based on the assist control current and the motor feedback current, and controlling the steering mechanism to operate based on the target control current.

[0080] As an example, when determining the target friction compensation torque, the vehicle controller can determine its friction compensation assist based on the target friction compensation torque. Then, the resultant force of the friction compensation assist, the basic torque assist, the active self-centering assist, the yaw damping and the inertia compensation assist is determined as the basic assist.

[0081] As an example, after determining the basic assist, the vehicle controller can determine the corresponding assist control current based on the basic assist. Specifically, it can determine the assist control current corresponding to the basic assist by looking up a table or other control methods based on the basic assist.

[0082] As an example, the vehicle controller determines the power assist control current at a specific moment. Initially, this power assist control current can be set as the target control current to control the steering mechanism motor. During the rotation of the steering mechanism motor, a motor feedback current is output. After the initial moment, the power assist control current is compared with the motor feedback current from the steering mechanism motor, and a new target control current is output. Based on this new target control current, the steering mechanism motor is controlled so that the motor output force equals the torque corresponding to the basic power assist, thus achieving steering control. In this example, the vehicle controller outputs the target control current to control the motor rotation, and the motor feedback current is used by the motor controller for feedback control to prevent the motor from outputting excessive or insufficient torque, thus preventing uncontrollable torque.

[0083] In this embodiment, after obtaining the basic friction compensation torque, the basic friction compensation torque is adaptively adjusted based on the steering wheel torque signal, so that the adaptive friction compensation torque is related to the aging degree of the steering mechanism. When the basic friction compensation torque and the adaptive friction compensation torque meet the preset conditions, the steering mechanism is controlled to work according to the adaptive friction compensation torque, so that the friction compensation torque of the steering mechanism is related to the aging degree of the steering mechanism, which helps to ensure the smooth and comfortable steering of the steering mechanism, thereby ensuring the stability and safety of driving operation.

[0084] In one embodiment, such as Figure 2 As shown, step S101, which is to obtain the basic friction compensation torque, includes:

[0085] S201: Acquire steering wheel speed signal, steering wheel torque signal, and vehicle speed signal;

[0086] S202: Obtain the basic friction compensation torque based on the steering wheel speed signal and vehicle speed signal.

[0087] The steering wheel speed signal refers to the real-time acquired signal reflecting the steering wheel speed, which can be represented by ω. The steering wheel torque signal refers to the real-time acquired signal reflecting the steering wheel torque, which can be represented by T. The vehicle speed signal refers to the real-time acquired vehicle speed signal, which can be represented by V.

[0088] As an example, in step S201, during vehicle operation, for example, when the vehicle is in active self-centering mode, the vehicle controller can acquire the steering wheel speed signal ω and steering wheel torque signal T sent by the torque angle sensor installed on the vehicle, and acquire measured vehicle data such as the vehicle speed signal V sent by the bus, so as to perform friction torque compensation processing based on these measured vehicle data. Generally, a torque angle sensor is arranged on the steering shaft of the vehicle steering system, which can be, but is not limited to, a Tas sensor. This torque angle sensor can collect the steering wheel angle signal A, perform differential processing on the steering wheel angle signal A to obtain the steering wheel speed signal ω; then, according to the relationship between power, speed, and torque, the steering wheel speed signal ω can be analyzed to obtain the steering wheel torque signal T, and the steering wheel speed signal ω and steering wheel torque signal T are sent to the vehicle controller. In this example, the steering wheel speed signal ω, steering wheel torque signal T, and vehicle speed signal V are all signals that need to be collected during vehicle operation, which can be directly called in the friction torque compensation process without the need for additional sensors for measurement, which helps to save costs.

[0089] As an example, in step S202, the vehicle controller can use a pre-set basic friction compensation torque calculation logic to calculate the calculated basic friction compensation torque based on the two input parameters: the real-time collected steering wheel speed signal ω and the vehicle speed signal V. Since the compensation value of the friction torque is correlated with the motor speed, and the steering mechanism in the steering system is mechanically connected to the steering wheel, the motor speed and the steering wheel speed signal ω are positively correlated. Therefore, calculating the basic friction compensation torque requires the steering wheel speed signal ω as an input parameter. Because the steering mechanism has a larger friction torque when the vehicle is traveling at low speeds and a smaller friction torque when the vehicle is traveling at high speeds, calculating the basic friction compensation torque requires the vehicle speed signal V as an input parameter. In this example, the basic friction compensation torque calculation logic is a pre-determined logic based on the correlation between the friction torque and the steering wheel speed signal ω and the vehicle speed signal V. It uses the steering wheel speed signal ω and the vehicle speed signal V as input parameters and determines the corresponding friction torque calculation logic through table lookup or mathematical operations. The calculation process is simple and convenient.

[0090] For example, a friction compensation torque can be determined by looking up a table or performing other conversion processes based on the steering wheel speed signal ω. Then, the determined friction compensation torque can be adjusted in real time using the vehicle speed signal V to obtain the basic friction compensation torque. This ensures that the determined basic friction compensation torque is related not only to the steering wheel speed signal ω but also to the vehicle speed signal V, so as to adapt to the different needs of the vehicle at low speeds or high speeds, which helps to ensure the driving stability and safety of the vehicle.

[0091] In this embodiment, the steering wheel speed signal, steering wheel torque signal, and vehicle speed signal are collected by the vehicle's existing hardware, eliminating the need for additional sensors to measure the relevant data and helping to save costs. Based on the steering wheel speed signal and vehicle speed signal, the basic friction compensation torque is obtained, making the basic friction compensation torque related not only to the steering wheel speed but also to the vehicle speed. This can adapt to different needs of low-speed or high-speed driving, helping to ensure the driving's handling stability and safety.

[0092] In one embodiment, such as Figure 3 As shown, step S202, which involves obtaining the basic friction compensation torque based on the steering wheel speed signal and vehicle speed signal, includes:

[0093] S301: Determine the first friction compensation torque and the direction of friction force based on the steering wheel speed signal;

[0094] S302: Determine the vehicle speed friction gain and vehicle speed friction limit based on the vehicle speed signal;

[0095] S303: Obtain the basic friction compensation torque based on the first friction compensation torque, the direction of friction force, the vehicle speed friction gain, and the vehicle speed friction limit.

[0096] The first friction compensation torque refers to the friction compensation torque directly determined based on the steering wheel speed signal ω, and can be represented by WheelSpdCtor. The friction force direction refers to the direction corresponding to the friction force determined based on the steering wheel speed signal ω, and can be represented by SingWheelSpd.

[0097] As an example, in step S301, after acquiring the steering wheel speed signal ω, the vehicle controller can process the steering wheel speed signal ω according to a pre-set speed-friction compensation torque mapping function to quickly determine the first friction compensation torque WheelSpdCtor corresponding to the steering wheel speed signal ω; or, the vehicle controller can query a pre-set speed-friction compensation torque mapping table based on the first friction compensation torque WheelSpdCtor to quickly determine the first friction compensation torque WheelSpdCtor corresponding to the steering wheel speed signal ω. Since the compensation value of friction torque is correlated with the motor speed, and the steering mechanism in the steering system is mechanically connected to the steering wheel, the motor speed and the steering wheel speed signal ω are positively correlated. That is, the compensation value of friction torque is positively correlated with the steering wheel speed signal ω. Based on this positive correlation, a speed-friction compensation torque mapping function or a speed-friction compensation torque mapping table is constructed in advance. This allows for function calculation or table lookup based on the steering wheel speed signal ω to quickly determine the corresponding first friction compensation torque, WheelSpdCtor. Correspondingly, the vehicle controller can also determine the steering wheel rotation direction from the steering wheel speed signal ω, then determine the steering force direction based on the determined steering wheel rotation direction, and further determine the corresponding friction force direction, SingWheelSpd. Since the function calculation or table lookup process for the steering wheel speed signal ω is generally based on the absolute value of the steering wheel speed signal ω, the calculated first friction compensation torque WheelSpdCtor does not include the direction of friction. Therefore, it is necessary to determine the corresponding friction direction SingWheelSpd based on the steering wheel speed signal ω.

[0098] Among them, the vehicle speed friction gain FCGaid refers to the coefficient used to adjust the gain of the friction compensation torque based on the vehicle speed signal V, and can be represented by FCGaid. The vehicle speed friction limit FCLimit refers to the threshold value used to limit the amplitude of the friction compensation torque based on the vehicle speed signal V.

[0099] As an example, in step S302, after acquiring the vehicle speed signal V, the vehicle controller can process the vehicle speed signal V according to a pre-set vehicle speed-friction gain mapping function to quickly determine the vehicle speed friction gain FCGaid corresponding to the vehicle speed signal V. Alternatively, the vehicle controller can query a pre-set vehicle speed-friction gain mapping table based on the vehicle speed signal to quickly determine the vehicle speed friction gain FCGaid corresponding to the vehicle speed signal V. Since the steering mechanism has a large friction torque when the vehicle is traveling at low speed and a small friction torque when the vehicle is traveling at high speed, it can be seen that the friction torque and the vehicle speed signal V have a negative correlation. Based on this negative correlation, a vehicle speed-friction gain mapping function or a vehicle speed-friction gain mapping table is constructed in advance so that the corresponding vehicle speed friction gain FCGaid can be quickly determined by performing function calculation or table lookup based on the vehicle speed signal V. This allows for the use of the vehicle speed friction gain FCGaid to adjust the gain of the first friction compensation torque WheelSpdCtor determined based on the steering wheel rotation speed signal ω, thereby achieving real-time adjustment of the friction compensation torque based on the vehicle speed signal V.

[0100] Accordingly, after acquiring the vehicle speed signal V, the vehicle controller can process the vehicle speed signal V according to a pre-set vehicle speed-friction limit mapping function to quickly determine the corresponding vehicle speed friction limit FCLimit. Alternatively, the vehicle controller can query a pre-set vehicle speed-friction limit mapping table based on the vehicle speed signal to quickly determine the corresponding vehicle speed friction limit FCLimit. Friction torque is negatively correlated with vehicle speed signal V. When friction torque is high, active steering results in steering sluggishness and poor feel; during active return-to-center, the return force is insufficient, hindering return to center. Conversely, when friction torque is low, overshoot is likely to increase during return-to-center. Therefore, friction torque needs to be within a specific range to ensure vehicle safety and handling stability. Thus, a vehicle speed-friction limit mapping function or table can be pre-constructed. Based on the vehicle speed signal V, function calculations or table lookups can quickly determine the corresponding vehicle speed friction limit FCLimit. This FCLimit allows for amplitude limitation of the friction compensation torque based on the vehicle speed signal V, ensuring vehicle safety and handling stability. Generally, the magnitude of the vehicle speed friction limit FCLimit is determined through calibration and comprehensive consideration of driving safety.

[0101] As an example, in step S303, after acquiring the first friction compensation torque WheelSpdCtor and the friction direction SingWheelSpd corresponding to the steering wheel rotation speed signal ω, and acquiring the vehicle speed friction gain FCGaid and the vehicle speed friction limit FCLimit corresponding to the vehicle speed signal V, the vehicle controller can calculate and process the input parameters such as the first friction compensation torque WheelSpdCtor, the friction direction SingWheelSpd, the vehicle speed friction gain FCGaid, and the vehicle speed friction limit FCLimit based on the pre-set basic friction compensation torque determination logic to determine its output basic friction compensation torque. For example, the vehicle controller can adjust the gain of the first friction compensation torque WheelSpdCtor based on the vehicle speed friction gain FCGaid, and then use the vehicle speed friction limit FCLimit to limit the amplitude of the friction compensation torque after the gain adjustment to obtain the magnitude of the basic friction compensation torque; and obtain the direction of the basic friction compensation torque based on the friction direction SingWheelSpd.

[0102] In this embodiment, the steering wheel rotation speed signal ω determines its corresponding first friction compensation torque and friction direction, and the corresponding vehicle speed friction gain FCGaid and vehicle speed friction limit FCLimit are determined based on the vehicle speed signal. The vehicle speed friction gain FCGaid is used to adjust the gain of the first friction compensation torque, and the vehicle speed friction limit FCLimit is used to limit the amplitude of the friction compensation torque after the gain adjustment. This allows for real-time adjustment of the friction compensation torque determined based on the steering wheel rotation speed signal ω according to the vehicle speed signal V. The determined basic friction compensation torque is related not only to the steering wheel rotation speed signal ω but also to the vehicle speed signal V, so as to adapt to the different needs of the vehicle at low speed or high speed, which is beneficial to ensuring the driving stability and safety of the vehicle.

[0103] In one embodiment, such as Figure 4 As shown, step S303, which involves obtaining the basic friction compensation torque based on the first friction compensation torque, the direction of friction force, the vehicle speed friction gain, and the vehicle speed friction limit, includes:

[0104] S401: Determine the second friction compensation torque based on the first friction compensation torque, the direction of friction force, and the friction gain at vehicle speed;

[0105] S402: The amplitude of the second friction compensation torque is limited by the vehicle speed friction limiter to obtain the basic friction compensation torque.

[0106] As an example, in step S401, after the vehicle controller acquires the first friction compensation torque WheelSpdCtor and the friction direction SingWheelSpd corresponding to the steering wheel speed signal ω, and acquires the vehicle speed friction gain FCGaid corresponding to the vehicle speed signal V, it can determine the second friction compensation torque as the product of the first friction compensation torque WheelSpdCtor, the friction direction SingWheelSpd, and the vehicle speed friction gain FCGaid. That is, the second friction compensation torque refers to the friction compensation torque after determining the direction based on the friction direction SingWheelSpd, and adjusting the gain of the first friction compensation torque WheelSpdCtor determined based on the steering wheel speed signal ω using the vehicle speed friction gain FCGaid. It can be understood as the value after adjusting the gain of the friction compensation torque based on the vehicle speed signal V.

[0107] As an example, in step S402, after determining the second friction compensation torque, the vehicle controller can limit the amplitude of the second friction compensation torque according to the vehicle speed friction limit FCLimit corresponding to the vehicle speed signal V, so as to ensure that the final output basic friction compensation torque is within the safe range defined by the vehicle speed friction limit FCLimit corresponding to the vehicle speed signal V, which helps to ensure driving safety.

[0108] In this embodiment, the first friction compensation torque WheelSpdCtor, determined based on the steering wheel rotation speed signal ω, is adjusted using the vehicle speed friction gain FCGaid, which is determined based on the vehicle speed signal V, to determine the second friction compensation torque. This allows for real-time adjustment of the friction compensation torque based on the vehicle speed signal V, ensuring driving safety and handling stability. The second friction compensation torque is limited using the vehicle speed friction limit FCLimit, which is determined based on the vehicle speed signal V, to ensure that its output base friction compensation torque is within a pre-set safety range, thus contributing to ensuring driving safety and handling stability.

[0109] In one embodiment, such as Figure 5 As shown, step S402, which involves limiting the amplitude of the second friction compensation torque using vehicle speed friction limiting to obtain the basic friction compensation torque, includes:

[0110] S501: If the second friction compensation torque is within the vehicle speed friction limit, then the second friction compensation torque shall be determined as the basic friction compensation torque.

[0111] S502: If the second friction compensation torque is not within the vehicle speed friction limit, then the basic friction compensation torque is obtained based on the vehicle speed friction limit.

[0112] Among them, the vehicle speed friction limit is the limit range of its friction compensation torque determined based on the vehicle speed signal V, including the lower limit of the vehicle speed friction compensation torque and the upper limit of the vehicle speed friction compensation torque. The lower limit of the vehicle speed friction compensation torque refers to the lower limit value of its friction compensation torque determined based on the vehicle speed signal V, and the upper limit of the vehicle speed friction compensation torque refers to the upper limit value of its friction compensation torque determined based on the vehicle speed signal V.

[0113] As an example, after acquiring the second friction compensation torque, the vehicle controller can compare the second friction compensation torque with the upper limit and lower limit of the vehicle speed friction compensation torque, so as to obtain the basic friction compensation torque based on the comparison result.

[0114] As an example, in step S501, when the second friction compensation torque is greater than or equal to the lower limit of the vehicle speed friction compensation torque and the second friction compensation torque is less than or equal to the upper limit of the vehicle speed friction compensation torque, the vehicle controller can determine that the second friction compensation torque has not exceeded its vehicle speed friction limit. The second friction compensation torque can be determined as the basic friction compensation torque, so that the final output basic friction compensation torque is within the safe and controllable vehicle speed friction limit, which helps to ensure the safety of vehicle driving and the stability of handling.

[0115] As an example, in step S502, when the second friction compensation torque is less than the lower limit of the vehicle speed friction compensation torque, or when the second friction compensation torque is greater than the upper limit of the vehicle speed friction compensation torque, the vehicle controller can determine that the second friction compensation torque exceeds its vehicle speed friction limit. The vehicle speed friction limit can be determined as the second friction compensation torque, that is, the lower limit or the upper limit of the vehicle speed friction compensation torque is determined as the basic friction compensation torque, so that the final output basic friction compensation torque is within the safe and controllable vehicle speed friction limit, which helps to ensure the safety of vehicle driving and the stability of handling.

[0116] In this embodiment, based on whether the second friction compensation torque is within the safe range defined by the lower limit and the upper limit of the vehicle speed friction compensation torque, it is determined that any one of the second friction compensation torque, the lower limit and the upper limit of the vehicle speed friction compensation torque is determined as the basic friction compensation torque. This ensures that the final output basic friction compensation torque is within the safe and controllable vehicle speed friction limit, which helps to ensure the safety and handling stability of vehicle driving.

[0117] In one embodiment, such as Figure 6 As shown, step S202, which involves determining the adaptive friction compensation torque based on the steering wheel torque signal and the basic friction compensation torque, includes:

[0118] S601: Perform trend calculations on the steering wheel torque signal and the calibration torque signal to determine the target change trend value;

[0119] S602: Determine the target gain coefficient based on the target's changing trend value;

[0120] S603: Determine the adaptive friction compensation torque based on the target gain coefficient and the basic friction compensation torque.

[0121] The calibration torque signal refers to the pre-calibrated torque signal of the steering wheel under active self-centering conditions. This calibration torque signal can be understood as the torque signal of the steering wheel under active self-centering conditions determined through calibration tests when the vehicle leaves the factory. The target change trend value refers to the trend value calculated based on the steering wheel torque signal, used to finally determine the target gain coefficient.

[0122] As an example, in step S601, when the vehicle is in active self-centering mode, the on-board controller can perform difference processing on the real-time acquired steering wheel torque signal T and the pre-set calibration torque signal to calculate the torque difference between the two, and determine the target trend value based on the calculated torque difference. Generally, when the vehicle is in active self-centering mode, the acquired steering wheel torque signal should remain unchanged or change little, and its value can intuitively reflect the magnitude of friction. Therefore, the real-time acquired steering wheel torque signal T and the pre-set calibration torque signal can be subjected to trend changes, so that the acquired target trend value can more intuitively reflect the change in friction due to structural aging.

[0123] The target gain coefficient refers to the coefficient used to adjust the gain of the basic friction compensation torque, which is determined based on the target change trend value.

[0124] As an example, in step S602, after obtaining the target trend value, the vehicle controller can perform a lookup operation based on the target trend value. Specifically, it queries a pre-set trend gain mapping table based on the target trend value to quickly determine the target gain coefficient that can be used for gain compensation. The trend gain mapping table is a pre-set mapping table that reflects the mapping relationship between the trend and the gain coefficient.

[0125] As an example, in step S603, after determining the target gain coefficient, the vehicle controller can use the target gain coefficient to adjust the gain of the basic friction compensation torque to determine the adaptive friction compensation torque. In this example, the vehicle controller can determine the adaptive friction compensation torque by multiplying the target gain coefficient and the basic friction compensation torque.

[0126] In this embodiment, the vehicle controller determines the target change trend value reflecting the friction force due to structural aging based on the steering wheel torque signal T and the calibrated torque signal. Then, it determines the corresponding target gain coefficient based on the target change trend value, so that the target gain coefficient matches its structural aging condition. The target gain coefficient is then used to adjust the gain of the basic friction compensation torque to obtain the amplified adaptive friction compensation torque. This makes the adaptive friction compensation torque related to the aging degree of the steering mechanism, which helps to ensure that the friction compensation assist determined based on it can ensure the smooth and comfortable steering of the steering system.

[0127] In one embodiment, such as Figure 7 As shown, step S601, which involves performing trend calculations on the steering wheel torque signal and the calibration torque signal to determine the target change trend value, includes:

[0128] S701: Determine the current trend value of the steering wheel torque signal based on the steering wheel torque signal and the calibration torque signal;

[0129] S702: Determine the current trend value as the target trend value.

[0130] As an example, in step S701, when the vehicle is in active self-centering mode, the on-board controller can perform difference processing on the real-time acquired steering wheel torque signal T and the pre-set calibration torque signal, and determine the torque difference between the steering wheel torque signal T and the calibration torque signal as the current trend value corresponding to the steering wheel torque signal collected at the current moment. In this example, when the vehicle is in active self-centering mode, the on-board controller can perform difference processing on the steering wheel torque signal T corresponding to the start or end of self-centering and the pre-set calibration torque signal, and determine the difference between the two as the current trend value.

[0131] As an example, in step S702, the vehicle controller, after acquiring the current trend value corresponding to each steering wheel torque signal, can directly determine this current trend value as the target trend value, ensuring the efficiency of target trend value determination and helping to improve overall efficiency. Since the current trend value corresponding to the steering wheel torque signal acquired at each current moment reflects the change in friction force due to structural aging at that moment, and the duration of this active return-to-center operation is relatively short, the change in friction force due to structural changes during this period is not significantly different. Therefore, the current trend value can be directly determined as the target trend value to simplify the calculation steps and help improve processing efficiency.

[0132] In this embodiment, when the vehicle is in active self-centering mode, the current trend value calculated from the steering wheel torque signal and the calibration torque signal collected at the current moment is directly determined as the target trend value to simplify the calculation steps and help improve processing efficiency.

[0133] In one embodiment, such as Figure 8 As shown, step S601, which involves performing trend calculations on the steering wheel torque signal and the calibration torque signal to determine the target change trend value, includes:

[0134] S801: Determine the current trend value of the steering wheel torque signal based on the steering wheel torque signal and the calibration torque signal;

[0135] S802: Determine the average trend value based on all current trend values ​​corresponding to this active recovery condition;

[0136] S803: Determine the current trend error based on the current trend value and the average trend value;

[0137] S803: If the current trend error is less than the trend error threshold, then the current trend value is determined as the target trend value.

[0138] S805: If the current trend error is not less than the trend error threshold, then the average trend value is determined as the target trend value.

[0139] Among them, the trend error threshold is a pre-set threshold used to assess whether there are any abnormalities in the trend error.

[0140] As an example, in step S801, when the vehicle is in active return-to-center mode, the on-board controller can perform difference processing between the real-time acquired steering wheel torque signal T and the pre-set calibration torque signal, and determine the torque difference between the steering wheel torque signal T and the calibration torque signal as the current trend value corresponding to the steering wheel torque signal collected at the current moment.

[0141] As an example, in step S802, after the vehicle controller obtains all current trend values ​​under the current active return-to-center condition, that is, after obtaining all current trend values ​​between the start time and the end time of the current active return-to-center, it calculates the average trend value by averaging all current trend values.

[0142] As an example, in step S803, the vehicle controller can perform difference processing on the current trend value and the average trend value, and determine the difference between the two as the current trend error, so as to evaluate whether the calculated current trend value is abnormal based on the current trend error, and then evaluate whether the corresponding steering wheel torque signal T has an error.

[0143] As an example, in step S804, the vehicle controller can compare the current trend error with a preset trend error threshold. If the current trend error is less than the trend error threshold, it can be determined that the current trend value corresponding to the current trend error is not abnormal. The current trend value can be determined as the target trend value, which can ensure that subsequent adaptive friction torque compensation is performed based on the normal current trend value, thus helping to ensure the driving safety and handling stability of the vehicle.

[0144] As an example, in step S805, the vehicle controller can compare the current trend error with a preset trend error threshold. If the current trend error is not less than the trend error threshold, it can be determined that the current trend value corresponding to the current trend error is abnormal. The average trend value can be determined as the target trend value, which can avoid subsequent adaptive friction torque compensation based on the abnormal current trend value, and helps to ensure the driving safety and handling stability of the vehicle.

[0145] In this embodiment, when the vehicle is in active self-centering mode, the current trend value is first calculated based on the steering wheel torque signal and calibration torque signal collected at the current moment. Then, based on all current trend values ​​collected during the entire active self-centering mode, the average trend value is determined. Based on the current trend value and the average trend value, the current trend error is determined. Based on the comparison between the current trend error and the trend error threshold, the current trend value or the average trend value is determined as the target trend value, so as to achieve the goal of balancing efficiency and ensuring the driving safety and handling stability of the vehicle.

[0146] In one embodiment, such as Figure 9 As shown, step S602, which involves determining the target gain coefficient based on the target change trend value, includes:

[0147] S901: Query the trend gain mapping table based on the target change trend value to determine the original gain coefficient corresponding to the target change trend value;

[0148] S902: Limit the amplitude of the original gain coefficient to determine the target gain coefficient.

[0149] As an example, in step S901, after obtaining the target trend value, the vehicle controller can perform a table lookup operation based on the target trend value. Specifically, it queries a pre-set trend gain mapping table based on the target trend value, and determines the gain coefficient corresponding to the target trend value in the trend gain mapping table as the original gain coefficient, thus ensuring the efficiency of obtaining the original gain coefficient. In this example, the original gain coefficient refers to the gain coefficient directly determined by querying the trend gain mapping table based on the target trend value.

[0150] As an example, in step S902, after the vehicle controller obtains the original gain coefficient corresponding to the target change trend value, it needs to limit the amplitude of the original gain coefficient in order to obtain the target gain coefficient within the safe range of the gain coefficient.

[0151] In this embodiment, the original gain coefficient obtained by looking up the target change trend value is a coefficient greater than or equal to 1. If the coefficient is too large, the adaptive friction compensation torque determined by adjusting the gain of the basic friction compensation torque using the coefficient will be too large, which will affect the driver's handling feel and interfere with the driver's normal driving. Therefore, it is necessary to limit the amplitude of the original gain coefficient in order to limit the amplitude of the subsequently determined adaptive friction compensation torque, which helps to ensure driving safety and handling stability based on the adaptive friction compensation torque for friction torque compensation.

[0152] In one embodiment, such as Figure 10 As shown, step S902, which involves limiting the amplitude of the original gain coefficient and determining the target gain coefficient, includes:

[0153] S1001: If the original gain coefficient is less than the preset gain coefficient limit, then the original gain coefficient is determined as the target gain coefficient.

[0154] S1002: If the original gain coefficient is not less than the preset gain coefficient limit, then determine the target gain coefficient according to the gain coefficient limit.

[0155] Among them, the gain coefficient limit is a pre-set threshold used to limit the amplitude of the gain coefficient.

[0156] As an example, in step S1001, after the vehicle controller obtains the original gain coefficient corresponding to the target change trend value, it can compare the original gain coefficient with the preset gain coefficient limit. If the original gain coefficient is less than the preset gain coefficient limit, it means that the original gain coefficient is within the safe range. The original gain coefficient can be determined as the target gain coefficient to ensure that the adaptive friction compensation torque determined by adjusting the gain of the basic friction compensation torque using the target gain coefficient is also within the safe range. This helps to ensure driving safety and handling stability based on friction torque compensation using adaptive friction compensation torque.

[0157] As an example, in step S1002, after the vehicle controller obtains the original gain coefficient corresponding to the target trend value, it can compare the original gain coefficient with the preset gain coefficient limit. If the original gain coefficient is not less than the preset gain coefficient limit, it means that the original gain coefficient is not within the safe range. If the gain is directly adjusted based on the original gain coefficient, the adaptive friction compensation torque after the gain adjustment will exceed the safe range. Therefore, the gain coefficient limit can be determined as the target gain coefficient to ensure that the adaptive friction compensation torque determined by adjusting the basic friction compensation torque using the target gain coefficient is also within the safe range. This helps to ensure the driving safety and handling stability of friction torque compensation based on the adaptive friction compensation torque.

[0158] In one embodiment, such as Figure 11 As shown, step S114, which involves determining the target friction compensation torque based on the basic friction compensation torque and the adaptive friction compensation torque, includes:

[0159] S1101: Determine the target compensation torque error based on the basic friction compensation torque and the adaptive friction compensation torque;

[0160] S1102: If the target compensation torque error is not within the compensation torque error threshold, the steering mechanism is controlled to work according to the adaptive friction compensation torque.

[0161] The target compensation torque error is the error value determined by error calculation based on the basic friction compensation torque and the adaptive friction compensation torque.

[0162] As an example, in step S1101, when the vehicle is in active self-alignment mode, the on-board controller can perform difference processing on the adaptive friction compensation torque and the basic friction compensation torque at each current moment to determine the measured compensation torque error corresponding to each current moment; the measured compensation torque error corresponding to each current moment can be determined as the target compensation torque error; or the average of all measured compensation torque errors between the start and end of this active self-alignment can be calculated, and the average of all measured compensation torque errors determined by this active self-alignment can be determined as the target compensation torque error; or a weighted calculation or other calculation can be performed on all measured compensation torque errors between the start and end of this active self-alignment, and the calculation result can be determined as the target compensation torque error.

[0163] Among them, the compensation torque error threshold is a pre-set threshold used to assess whether the compensation torque error has reached the severe aging standard.

[0164] As an example, in step S1102, after obtaining the target compensation torque error under the current active self-centering condition, the vehicle controller can compare the target compensation torque error with a pre-set compensation torque error threshold. If the target compensation torque error is within the compensation torque error threshold, it is determined that the frictional force of the steering mechanism does not change significantly, and the aging of the steering mechanism has not reached the severe aging standard. In this case, the steering mechanism is controlled according to the basic frictional compensation torque, that is, the basic frictional compensation torque is determined as the target frictional compensation torque, and the steering mechanism is controlled according to the target frictional compensation torque without the need for frictional compensation torque switching, which helps to ensure the handling stability of the steering system. Conversely, if the target compensation torque error is not within the compensation torque error threshold, it is determined that the frictional force of the steering mechanism changes significantly, and the aging of the steering mechanism has reached the severe aging standard. In this case, the steering mechanism is controlled according to the adaptive frictional compensation torque, that is, the adaptive frictional compensation torque is determined as the target frictional compensation torque, and the steering mechanism is controlled according to the target frictional compensation torque, so that the frictional compensation torque of the steering mechanism is related to the degree of aging of the steering mechanism, which helps to ensure the smoothness and comfort of steering, thereby ensuring driving handling stability and safety.

[0165] In this embodiment, the target compensation torque error is determined based on the basic friction compensation torque and the adaptive friction compensation torque. This target compensation torque error can effectively reflect the aging degree of the steering mechanism. When the target compensation torque error is not within the compensation torque error threshold, it can be determined that the friction force of the steering mechanism changes significantly, and the aging of the steering mechanism reaches the severe aging standard. At this time, the steering mechanism is controlled according to the adaptive friction compensation torque, so that the friction compensation torque of the steering mechanism is related to the aging degree of the steering mechanism, which helps to ensure the smooth and comfortable steering of the steering mechanism, thereby ensuring the driving stability and safety.

[0166] In one embodiment, such as Figure 12 As shown, step S1102, i.e., if the target compensation torque error is not within the compensation torque error threshold, then the steering mechanism is controlled to work according to the adaptive friction compensation torque, including:

[0167] S1201: If the target compensation torque error is not within the compensation torque error threshold, then obtain the current vehicle operating condition;

[0168] S1202: If the current vehicle operating condition is a safe operating condition, the steering mechanism will be controlled to operate according to the adaptive friction compensation torque.

[0169] As an example, in step S1201, if the target compensation torque error is not within the compensation torque error threshold, the vehicle controller can determine that the friction force of the steering mechanism has changed significantly, and its aging has reached the severe aging standard. At this time, the current vehicle data can be obtained through the bus. This current vehicle data refers to the vehicle data collected at the current moment. Then, the pre-set vehicle condition judgment logic is called to judge and process the real-time collected current vehicle data to determine its corresponding current vehicle condition. This current vehicle condition can be either a safe condition or an unsafe condition. Here, a safe condition refers to a condition where switching the friction compensation torque will not affect driving safety; conversely, an unsafe condition refers to a condition where switching the friction compensation torque will affect driving safety.

[0170] In one embodiment, the current vehicle operating condition is determined based on the steering wheel angle signal and the steering wheel torque signal; the safe operating condition is the condition where the absolute value of the steering wheel angle signal is less than a preset angle threshold and the absolute value of the steering wheel torque signal is less than a preset torque threshold.

[0171] The preset angle threshold is a pre-set threshold used to assess whether the angle is within a safe operating condition. This preset angle threshold can be set to 0 or a value close to 0. The preset torque threshold is a pre-set threshold used to assess whether the torque is within a safe operating condition. This preset torque threshold can be set to 0 or a value close to 0.

[0172] As an example, when the vehicle controller needs to assess the current vehicle operating condition, it can acquire current vehicle data such as the steering wheel angle signal A and the steering wheel torque signal T sent by the torque angle sensor installed on the vehicle. Then, it compares the absolute value of the steering wheel angle signal A with a preset angle threshold and the steering wheel torque signal T with a preset torque threshold to determine the current vehicle operating condition based on the comparison results. If the absolute value of both the steering wheel angle signal A and the absolute value of the steering wheel torque signal T are less than the preset angle threshold, the vehicle controller can determine that the steering wheel has returned to the center position or is close to the center position. The vehicle is not turning, and the external force / torque acting on the steering wheel is small or close to zero. In this case, if friction compensation torque switching is performed, the driver will not feel a sudden disappearance or increase in torque. Therefore, it will not affect driving stability and safety, and the current vehicle operating condition can be determined as a safe operating condition. Conversely, if the absolute value of the steering wheel angle signal A is not less than the preset angle threshold, or the absolute value of the steering wheel torque signal T is not less than the preset torque threshold, the vehicle controller can determine that the steering wheel has not been returned to the center position or is close to the center position, and that the vehicle is still in the process of turning. Alternatively, it can determine that the external force / torque acting on the steering wheel is large. In this case, if the friction compensation torque is switched, the driver will feel the torque suddenly disappear or increase. Therefore, it will affect the driving stability and safety, and the current vehicle operating condition can be determined to be an unsafe operating condition.

[0173] In this embodiment, the vehicle can be assessed for steering based on the steering wheel angle signal A and steering wheel torque signal T sent by the torque angle sensor installed on the vehicle, and it can be determined whether there is a large external force acting on the steering wheel. This determines whether the current vehicle operating condition is a safe or unsafe condition, and further determines whether it can be switched to adaptive friction compensation torque.

[0174] As an example, in step S1202, when the vehicle controller is in a safe operating condition, it indicates that switching from the original basic friction compensation torque to the adaptive friction compensation torque will not affect the driver's safe driving. At this time, the steering mechanism can be controlled according to the adaptive friction compensation torque, that is, the adaptive friction compensation torque is determined as the target friction compensation torque so that the steering mechanism can be controlled based on the target friction compensation torque. That is, the adaptive friction compensation torque will only be used for friction torque compensation when the vehicle is in a safe operating condition, which helps to ensure the handling stability of the steering system.

[0175] In this example, when the vehicle is in an unsafe condition, the onboard controller indicates that switching from the original basic friction compensation torque to the adaptive friction compensation torque would affect the driver's safe driving. At this time, the basic friction compensation torque is still set as the target friction compensation torque so that the steering mechanism is controlled based on the basic friction compensation torque. This continues until the vehicle enters a safe condition, at which point the steering mechanism is switched to be controlled based on the adaptive friction compensation torque. In other words, between the transition from an unsafe to a safe condition, the basic friction compensation torque is still used for friction torque compensation to avoid affecting the driving stability during steering.

[0176] Generally, after mechanical aging of the steering mechanism is detected and its adaptive friction compensation torque is calculated, directly switching from the basic friction compensation torque to the adaptive friction compensation torque during steering will cause the torque felt by the driver to suddenly disappear or increase, affecting driving safety. Therefore, the adaptive friction compensation torque should only be set as the target friction compensation torque and the steering mechanism should be controlled when the vehicle is in a safe operating condition. When the vehicle is in an unsafe operating condition, the basic friction compensation torque should be set as the target friction compensation torque and the steering mechanism should be controlled to ensure the driving stability and safety.

[0177] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0178] In one embodiment, an on-board controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the electric power steering compensation method described in the above embodiment, for example... Figure 1 As shown in S111-S115, or Figures 2 to 11 As shown in the figure, to avoid repetition, it will not be repeated here.

[0179] In one embodiment, a steering system is provided, including an on-board controller as described in the above embodiments and a steering mechanism connected to the on-board controller. The on-board controller can control the steering mechanism to operate according to the electric power steering compensation method described in the above embodiments, for example... Figure 1 As shown in S101-S103, or Figures 2 to 12 As shown in the figure, to avoid repetition, it will not be repeated here.

[0180] In one embodiment, a vehicle is provided that includes the steering system described in the above embodiments.

[0181] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When executed by a processor, the computer program implements the electric power steering compensation method described in the above embodiment, for example... Figure 1 As shown in S101-S103, or Figures 2 to 12 As shown in the figure, to avoid repetition, it will not be repeated here.

[0182] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0183] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0184] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An electric power steering compensation method, characterized in that, include: Obtain the basic friction compensation torque; The adaptive friction compensation torque is determined based on the steering wheel torque signal and the basic friction compensation torque. The adaptive friction compensation torque is related to the degree of aging of the steering mechanism; The target compensation torque error is determined based on the basic friction compensation torque and the adaptive friction compensation torque. If the target compensation torque error is not within the compensation torque error threshold, the steering mechanism is controlled to work according to the adaptive friction compensation torque.

2. The electric power steering compensation method as described in claim 1, characterized in that, The process of obtaining the basic friction compensation torque includes: Acquire steering wheel speed signal, steering wheel torque signal, and vehicle speed signal; The basic friction compensation torque is obtained based on the steering wheel rotation speed signal and the vehicle speed signal.

3. The electric power steering compensation method as described in claim 2, characterized in that, The step of obtaining the basic friction compensation torque based on the steering wheel rotation speed signal and the vehicle speed signal includes: Based on the steering wheel rotation speed signal, the first friction compensation torque and the direction of friction force are determined; Based on the vehicle speed signal, determine the vehicle speed friction gain and vehicle speed friction limit; The basic friction compensation torque is obtained based on the first friction compensation torque, the friction force direction, the vehicle speed friction gain, and the vehicle speed friction limit.

4. The electric power steering compensation method as described in claim 3, characterized in that, The step of obtaining the basic friction compensation torque based on the first friction compensation torque, the friction force direction, the vehicle speed friction gain, and the vehicle speed friction limit includes: The second friction compensation torque is determined based on the first friction compensation torque, the direction of the friction force, and the vehicle speed friction gain; The amplitude of the second friction compensation torque is limited by the vehicle speed friction limit to obtain the basic friction compensation torque.

5. The electric power steering compensation method as described in claim 4, characterized in that, The step of limiting the amplitude of the second friction compensation torque using the vehicle speed friction limiter to obtain the basic friction compensation torque includes: If the second friction compensation torque is within the vehicle speed friction limit, then the second friction compensation torque is determined as the basic friction compensation torque; If the second friction compensation torque is not within the vehicle speed friction limit, then the basic friction compensation torque is determined based on the vehicle speed friction limit.

6. The electric power steering compensation method as described in claim 1, characterized in that, The step of determining the adaptive friction compensation torque based on the steering wheel torque signal and the basic friction compensation torque includes: The steering wheel torque signal and the calibration torque signal are used to perform trend calculations to determine the target change trend value; Determine the target gain coefficient based on the target change trend value; The adaptive friction compensation torque is determined based on the target gain coefficient and the basic friction compensation torque.

7. The electric power steering compensation method as described in claim 6, characterized in that, The step of performing trend calculations on the steering wheel torque signal and the calibrated torque signal to determine the target change trend value includes: When the vehicle is in active self-centering mode, the current trend value of the steering wheel torque signal is determined based on the steering wheel torque signal and the calibration torque signal. The current trend value is determined as the target trend value.

8. The electric power steering compensation method as described in claim 6, characterized in that, The step of performing trend calculations on the steering wheel torque signal and the calibrated torque signal to determine the target change trend value includes: Based on the steering wheel torque signal and the calibration torque signal, determine the current trend value corresponding to the steering wheel torque signal; Based on all the current trend values ​​corresponding to this active recovery condition, determine the average trend value; The current trend error is determined based on the current trend value and the average trend value. If the current trend error is less than the trend error threshold, then the current trend value is determined as the target trend value. If the current trend error is not less than the trend error threshold, then the average trend value is determined as the target trend value.

9. The electric power steering compensation method as described in claim 6, characterized in that, Determining the target gain coefficient based on the target change trend value includes: The original gain coefficient corresponding to the target change trend value is determined by querying the trend gain mapping table based on the target change trend value. The original gain coefficient is subjected to amplitude limitation to determine the target gain coefficient.

10. The electric power steering compensation method as described in claim 9, characterized in that, The step of limiting the amplitude of the original gain coefficient to determine the target gain coefficient includes: If the original gain coefficient is less than the preset gain coefficient limit, then the original gain coefficient is determined as the target gain coefficient; If the original gain coefficient is not less than the preset gain coefficient limit, then the target gain coefficient is determined according to the gain coefficient limit.

11. The electric power steering compensation method as described in claim 1, characterized in that, If the target compensation torque error is not within the compensation torque error threshold, then controlling the steering mechanism to operate according to the adaptive friction compensation torque includes: If the target compensation torque error is not within the compensation torque error threshold, then the current vehicle operating condition is obtained; If the current vehicle operating condition is a safe operating condition, then the steering mechanism is controlled to operate according to the adaptive friction compensation torque.

12. The electric power steering compensation method as described in claim 11, characterized in that, The current vehicle operating condition is determined based on the steering wheel angle signal and the steering wheel torque signal; The safe operating condition is when the absolute value of the steering wheel angle signal is less than a preset angle threshold and the absolute value of the steering wheel torque signal is less than a preset torque threshold.

13. An on-board controller, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the electric power steering compensation method as described in any one of claims 1 to 12.

14. A steering system, characterized in that, It includes the vehicle controller as described in claim 13 and the steering mechanism connected to the vehicle controller.

15. A vehicle, characterized in that, Includes the steering system as described in claim 14.

16. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the electric power steering compensation method as described in any one of claims 1 to 12.

Images