Steering assist control method, system, vehicle, storage medium, and electronic device

Abstract

This application discloses a steering assist control method, system, vehicle, storage medium, and electronic device. By introducing a load signal and co-processing it with the vehicle speed signal, the steering assist control is expanded from a single dimension dependent solely on vehicle speed to a dual-dimensional adaptive adjustment of load and vehicle speed. This solves the problem of unstable steering feel when unloaded and heavy when fully loaded in commercial vehicles due to large load variations. By sensing the load in real time and dynamically adjusting the assist curve, the vehicle provides a consistent, linear, and predictable steering feel to the driver across the entire speed range (from low-speed maneuvering to high-speed cruising), regardless of whether the vehicle is unloaded, fully loaded, or under other intermediate load conditions. This improves driving comfort, reduces driver fatigue, and significantly enhances driving safety by increasing the vehicle's directional stability under various loads.

Description

Technical Field

[0001] This application belongs to the field of vehicle technology, specifically relating to a steering assist control method, system, vehicle, storage medium, and electronic device. Background Technology

[0002] As a crucial transportation tool, the load on a truck directly affects the front axle load, thus altering the front axle alignment parameters and causing significant differences in steering torque. Currently, the control strategies of Electric Power Steering (EPS) systems are typically based on fixed calibrations, making it difficult to adapt to different operating conditions from unloaded to fully loaded. If the power steering setting is biased towards unloaded conditions, the EPS output torque is higher, resulting in lighter steering when unloaded. However, when fully loaded, the increased resistance of the steering system leads to relatively insufficient power steering, resulting in heavy steering torque, driver fatigue, and reduced comfort. Conversely, if the power steering setting is biased towards fully loaded conditions, the steering wheel center-holding force is insufficient when unloaded, making the vehicle prone to a "floating" phenomenon during high-speed straight-line driving, reducing handling stability and affecting driving safety.

[0003] In existing technologies, EPS control largely relies on signals such as vehicle speed and steering angle for power assist adjustment, but it fails to effectively incorporate load state parameters and cannot identify changes in the vehicle's actual load in real time. Therefore, under different load conditions, the system struggles to dynamically adjust its power assist characteristics, resulting in inconsistent steering feel, which affects both driving comfort and safety. Thus, frequent changes in vehicle operating load place higher demands on the adaptive capabilities of the steering system, requiring further improvements in steering consistency, stability, and comfort under different load and speed conditions. Summary of the Invention

[0004] This application provides a steering assist control method, system, vehicle, storage medium, and electronic device that solves at least one of the aforementioned technical problems.

[0005] The technical solution adopted in this application is as follows: A steering assist control method, applied to a vehicle equipped with an electric power steering system, the method comprising: Determine the no-load required torque and the full-load assist torque; Acquire vehicle speed signals and load signals characterizing the vehicle's load-bearing status; The acquired load signal is compared with a preset first threshold and a preset second threshold, wherein the preset first threshold is less than the preset second threshold; If the load signal indicates that the current load is not higher than the preset first threshold, the no-load required torque is output. If the load signal indicates that the current load is not lower than the preset second threshold, the full-load assist torque is output. If the load signal indicates that the current load is higher than the preset first threshold and lower than the preset second threshold, the target assist torque is calculated by a compensation function based on the full-load assist torque, the current load signal, and the current vehicle speed signal; wherein the target assist torque increases with the increase of the current load signal and decreases with the increase of the current vehicle speed signal. Output the target assist torque.

[0006] As an optional embodiment, the load signal is acquired by a height valve located on the front axle of the vehicle, and the load signal is set as the opening percentage of the height valve.

[0007] Preferably, the unloaded torque requirement is obtained through performance data calibration based on factors such as vehicle handling stability and ride comfort, with an adhesion coefficient of 0.85 on a conventional road surface.

[0008] Preferably, the full-load assist torque ( ) is calculated using the following formula: ; in: The unloaded torque requirement is obtained through vehicle performance calibration. This refers to the worm gear transmission ratio. This refers to the steering gear ratio.

[0009] Preferably, the compensation function is: ; Wherein: T Req The full-load assist torque is given by x, where x is the current load signal value, v is the current vehicle speed, and V is the current speed. max k represents the vehicle's actual maximum speed. v This is a calibrable vehicle speed influence coefficient.

[0010] Preferably, the vehicle speed influence coefficient k v The range of values ​​for is 0 ≤ k v ≤1.

[0011] This application also includes a power steering control system, comprising: The preset torque determination module is used to determine the no-load required torque and the full-load assist torque; The signal acquisition module is used to acquire the vehicle speed signal and the load signal that characterizes the vehicle's load status. The comparison module is used to compare the acquired load signal with a preset first threshold and a preset second threshold; The enabling module is used to calculate the target assist torque based on the full-load assist torque, the current load signal, and the current vehicle speed signal when the load signal indicates that the current load is higher than the preset first threshold and lower than the preset second threshold. The output module is used to control the power steering system's power motor to output one of the unloaded required torque, the full-load power assist torque, and the target power assist torque.

[0012] This application also includes a vehicle comprising a power steering control system as described above, and a height valve for detecting the vehicle load status.

[0013] This application also includes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any of the preceding claims.

[0014] This application also includes an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as described in any of the preceding claims.

[0015] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows: This application's solution introduces "no-load demand torque," "full-load assist torque," and two preset load thresholds to divide the vehicle's load state into three typical conditions: "no-load," "full-load," and "intermediate load between the two." An optimal control strategy is matched for each condition. This solves the problem of the existing "either no-load or full-load" assist method. When the vehicle is in the set no-load or full-load state, the system directly outputs a precisely calibrated fixed torque, ensuring directional stability under no-load conditions and steering ease under full-load conditions, with a direct response. When the vehicle is in the common and frequently changing intermediate load state, the system activates an adaptive calculation mode. Based on the full-load reference torque, a compensation function is used to achieve a smooth transition of assist torque between no-load and full-load values. This allows the steering feel to change continuously and linearly with the actual load state of the vehicle, eliminating the unpleasant experience of "step" or "abrupt" steering feel caused by small changes in load. This provides the driver with good feel feedback, improves driving comfort and quality, and allows the driver to perceive the vehicle's status more accurately through the steering wheel, which is beneficial to improving active safety.

[0016] By introducing load signals and processing them in conjunction with vehicle speed signals, the steering assist control is expanded from a single dimension relying solely on vehicle speed to a dual-dimensional adaptive adjustment based on both load and vehicle speed. This solves the problem of unstable steering feel when unloaded and heavy when fully loaded in commercial vehicles due to large variations in load. By sensing the load in real time and dynamically adjusting the assist curve, the vehicle provides a consistent, linear, and predictable steering feel across the entire speed range (from low-speed maneuvering to high-speed cruising), regardless of whether it is unloaded, fully loaded, or under other intermediate load conditions. This improves driving comfort, reduces driver fatigue, and significantly enhances driving safety by increasing the vehicle's directional stability under various loads. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart of a control method in one embodiment of the present invention. Detailed Implementation

[0018] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0019] Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below. It should be noted that, unless otherwise specified, the embodiments of this application and the features thereof can be combined with each other.

[0020] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0021] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0023] This application provides a steering assist control method, applied to a vehicle equipped with an electric power steering system, the method comprising: Determine the no-load required torque and the full-load assist torque; Acquire vehicle speed signals and load signals characterizing the vehicle's load-bearing status; The acquired load signal is compared with a preset first threshold and a preset second threshold, wherein the preset first threshold is less than the preset second threshold; If the load signal indicates that the current load is not higher than the preset first threshold, the no-load required torque is output. If the load signal indicates that the current load is not lower than the preset second threshold, the full-load assist torque is output. If the load signal indicates that the current load is higher than the preset first threshold and lower than the preset second threshold, the target assist torque is calculated by a compensation function based on the full-load assist torque, the current load signal, and the current vehicle speed signal; wherein the target assist torque increases with the increase of the current load signal and decreases with the increase of the current vehicle speed signal. Output the target assist torque.

[0024] For new energy commercial vehicles with large variations in cargo weight, the front axle load differs significantly between unloaded and fully loaded states, resulting in substantial changes in the inherent resistance torque of the steering system. Existing EPS systems based on fixed calibration curves cannot cope with this variation and can only compromise by optimizing for either unloaded or fully loaded conditions, leading to the problem of "floating when unloaded and heavy when fully loaded."

[0025] This application's solution introduces "no-load demand torque," "full-load assist torque," and two preset load thresholds to divide the vehicle's load state into three typical conditions: "no-load," "full-load," and "intermediate load between the two." An optimal control strategy is matched for each condition. This solves the problem of the existing "either no-load or full-load" assist method. When the vehicle is in the set no-load or full-load state, the system directly outputs a precisely calibrated fixed torque, ensuring directional stability under no-load conditions and steering ease under full-load conditions, with a direct response. When the vehicle is in the common and frequently changing intermediate load state, the system activates an adaptive calculation mode. Based on the full-load reference torque, a compensation function is used to achieve a smooth transition of assist torque between no-load and full-load values. This allows the steering feel to change continuously and linearly with the actual load state of the vehicle, eliminating the unpleasant experience of "step" or "abrupt" steering feel caused by small changes in load. This provides the driver with good feel feedback, improves driving comfort and quality, and allows the driver to perceive the vehicle's status more accurately through the steering wheel, which is beneficial to improving active safety.

[0026] By introducing load signals and processing them in conjunction with vehicle speed signals, the steering assist control is expanded from a single dimension relying solely on vehicle speed to a dual-dimensional adaptive adjustment based on both load and vehicle speed. This solves the problem of unstable steering feel when unloaded and heavy when fully loaded in commercial vehicles due to large variations in load. By sensing the load in real time and dynamically adjusting the assist curve, the vehicle provides a consistent, linear, and predictable steering feel across the entire speed range (from low-speed maneuvering to high-speed cruising), regardless of whether it is unloaded, fully loaded, or under other intermediate load conditions. This improves driving comfort, reduces driver fatigue, and significantly enhances driving safety by increasing the vehicle's directional stability under various loads.

[0027] In one embodiment, the load signal is acquired by a height valve located on the front axle of the vehicle, and the load signal is set as the opening percentage of the height valve.

[0028] This solution provides a cost-effective and highly reliable method for acquiring load signals. Understandably, since height valves are already widely used in commercial vehicles, their existing signals can be utilized without the need for expensive additional sensors (such as direct axle load sensors), thus reducing system cost and complexity. Furthermore, representing the load as the percentage of opening monitored by the height valve makes signal processing simple and intuitive, facilitating controller identification and calculation, and enhancing the feasibility and robustness of the solution.

[0029] Specifically, in this embodiment, a height valve is added to the front axle to identify the vehicle's load capacity. When the detected opening is lower than a preset load threshold, the EPS motor outputs a small torque as under no-load conditions, which avoids excessive steering torque and a "floating" steering wheel. When the height valve opening is higher than the preset load threshold, the EPS motor outputs a large torque as under full load conditions, ensuring light and reliable steering performance and improving the overall vehicle handling stability and safety.

[0030] It should be noted that the preset first threshold can be determined based on the opening degree of the height valve when the vehicle is unloaded. In other methods, the acquisition of the current load signal is not limited to the opening degree of the height valve, but can also be the pressure signal of the air suspension, the strain gauge signal that directly measures the axle load, or other parameters that can reflect the vehicle load.

[0031] Preferably, the unloaded torque requirement is obtained through performance data calibration based on factors such as vehicle handling stability and ride comfort, with an adhesion coefficient of 0.85 on a conventional road surface.

[0032] By calibrating the data on a conventional road surface with an adhesion coefficient of 0.85, the final determined no-load torque requirement can take into account both handling stability and smoothness, laying a scientific and reliable foundation for the performance of the entire control system and avoiding performance deviations caused by subjective settings.

[0033] Furthermore, the full-load assist torque ( ) is calculated using the following formula: ; in: The no-load torque is obtained through vehicle performance calibration. This refers to the worm gear transmission ratio. This refers to the steering gear ratio.

[0034] As mentioned above, This is the unloaded torque requirement. This value is a basic mapping value obtained by calibrating a large amount of performance data on a normal road surface (such as a coefficient of adhesion of 0.85) based on targets such as vehicle handling stability and ride comfort.

[0035] The transmission ratio of the worm gear in the EPS system is a mechanical constant. The steering gear ratio is also a mechanical constant. By introducing the worm gear ratio and the steering gear ratio, the basic torque requirement obtained from the vehicle-level calibration is accurately converted to the torque required at the motor shaft end. This makes the entire control logic hierarchical and the physical meaning of the parameters clear, which is conducive to precise matching and calibration in practical applications, ensuring control accuracy and system response accuracy.

[0036] Based on the comparison between the current load signal and the preset load threshold, the system selects different assist torque mapping strategies. If the current load signal is lower than or equal to the preset load threshold, the system determines that the vehicle is in an unloaded or lightly loaded state. At this time, to ensure the stability of the steering wheel at high speeds and avoid the "floating" phenomenon, the controller will ignore the slight changes in the load signal and control the assist motor to output a relatively small fixed assist torque corresponding to the unloaded condition.

[0037] If the current load signal is higher than the preset load threshold, the vehicle is determined to be in a medium or full load state. At this time, the steering system resistance torque increases significantly, requiring greater assistance. The controller will enter adaptive adjustment mode, calculating the final target assistance torque based on the full-load assistance torque, the current load signal, and the current vehicle speed signal through a compensation function.

[0038] Preferably, the compensation function is: ; in: To provide the target torque, T Req The full-load assist torque (this is the maximum torque, corresponding to when the height valve is fully open and the vehicle speed is 0), x is the current load signal value, v is the current vehicle speed, and V max This refers to the vehicle's actual maximum speed. This is a calibrable vehicle speed influence coefficient.

[0039] Load compensation ensures that the power assist torque increases linearly with increasing load, directly offsetting the increased steering resistance torque due to increased load, ensuring light steering even when fully loaded. Speed ​​compensation ensures that the power assist torque decreases with increasing vehicle speed, consistent with traditional EPS functions, guaranteeing stability and safety of the steering wheel at high speeds. This method achieves the dual control objectives of "load-dependent gain" and "speed-dependent attenuation," realizing a linear proportional relationship between power assist torque and load. It features a simple structure, high computational efficiency, and low controller load. It also inherits mature speed-sensitive gain characteristics. The multiplication of these two features allows the load compensation effect to be modulated by vehicle speed. For example, at high speeds, even when fully loaded, the power assist will not be excessive, thus ensuring high-speed stability. This coupling relationship optimizes overall performance under all operating conditions.

[0040] Preferably, the vehicle speed influence coefficient The range of values ​​for is 0≤ ≤1. This coefficient is used to finely adjust the effect of vehicle speed on the assist torque. For example, through calibration, the system can provide sufficient assistance at low speeds to ensure ease of use, while significantly reducing assistance at high speeds to enhance road feel and directional stability. It provides clear and reasonable parameter boundaries for system tuning, ensuring the stability and safety of the control system. Value range: 0 ≤ A value of ≤1 avoids amplification effects or unstable positive feedback during vehicle speed gain adjustment, allowing engineers to perform flexible and precise calibration within this safe range according to different vehicle models and driving styles, in order to achieve the best balance between steering ease and directional stability.

[0041] Preferably, when the load signal indicates that the current load is lower than or equal to the preset first threshold, the power assist motor is controlled to output a fixed assist torque corresponding to the no-load condition, i.e., the no-load required torque. This is optimized for the specific no-load / light-load condition. When the load is lower than the preset first threshold, using a fixed, relatively small assist torque can effectively suppress the high-speed "floating" phenomenon caused by excessive assist, which is particularly beneficial for improving the directional stability of the vehicle when traveling at high speed in a straight line under no-load conditions.

[0042] Specifically, the EPS controller converts the final determined target assist torque, no-load demand torque, or full-load assist torque into a current command and sends it to the assist motor, driving the motor to output the corresponding assist torque and complete one control cycle.

[0043] This application also includes a power steering control system, comprising: A preset torque determination module is used to determine the no-load required torque and the full-load assist torque; The signal acquisition module is used to acquire the vehicle speed signal and the load signal that characterizes the vehicle's load status. The comparison module is used to compare the acquired load signal with a preset first threshold and a preset second threshold; The enabling module is used to calculate the target assist torque based on the full-load assist torque, the current load signal, and the current vehicle speed signal when the load signal indicates that the current load is higher than the preset first threshold and lower than the preset second threshold. The output module is used to control the power steering system's power motor to output one of the unloaded required torque, the full-load power assist torque, and the target power assist torque.

[0044] By dividing the system into modules such as preset torque determination, signal acquisition, comparison, enabling, and output, the hardware architecture and division of labor for system implementation are clearly defined. This enables the intelligent control function to be efficiently and reliably integrated into the vehicle's electronic and electrical architecture, providing a clear path for system development, testing, and fault diagnosis.

[0045] This application also includes a vehicle comprising the steering assist control system as described above, and a height valve for detecting the vehicle's load status. The solution provided in this application enhances the adaptive intelligence level of the system, enabling the vehicle to become an organic whole capable of sensing its own state (load) and intelligently adjusting its performance, and further lays the foundation for precise lateral control in high-level autonomous driving functions.

[0046] This application also includes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method as described in any of the preceding claims.

[0047] This application also includes an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as described in any of the above embodiments.

[0048] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0049] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0050] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A steering assist control method, characterized in that, Applied to vehicles equipped with an electric power steering system, the method includes: Determine the no-load required torque and the full-load assist torque; Acquire vehicle speed signals and load signals characterizing the vehicle's load-bearing status; The acquired load signal is compared with a preset first threshold and a preset second threshold, wherein the preset first threshold is less than the preset second threshold; If the load signal indicates that the current load is not higher than the preset first threshold, the no-load required torque is output. If the load signal indicates that the current load is not lower than the preset second threshold, the full-load assist torque is output. If the load signal indicates that the current load is higher than the preset first threshold and lower than the preset second threshold, the target assist torque is calculated by a compensation function based on the full-load assist torque, the current load signal, and the current vehicle speed signal; wherein the target assist torque increases with the increase of the current load signal and decreases with the increase of the current vehicle speed signal. Output the target assist torque.

2. The method according to claim 1, characterized in that, The load signal is acquired by a height valve located on the front axle of the vehicle, and the load signal is set as the opening percentage of the height valve.

3. The method according to claim 1, characterized in that, The unloaded torque requirement is obtained through performance data calibration based on factors such as vehicle handling stability and ride comfort, with a coefficient of adhesion of 0.85 on a conventional road surface.

4. The method according to claim 1, characterized in that, The full-load assist torque ( ) is calculated using the following formula: ; in: The no-load required torque is obtained through vehicle performance calibration. This refers to the worm gear transmission ratio. This refers to the steering gear ratio.

5. The method according to claim 1, characterized in that, The compensation function is: ； Wherein: T Req The full-load assist torque is given by x, where x is the current load signal value, v is the current vehicle speed, and V is the current speed. max k represents the vehicle's actual maximum speed. v This is a calibrable vehicle speed influence coefficient.

6. The method according to claim 5, characterized in that, The vehicle speed influence coefficient k v The range of values ​​for is 0≤ ≤1.

7. A power steering control system, characterized in that, include: The preset torque determination module is used to determine the no-load required torque and the full-load assist torque; The signal acquisition module is used to acquire the vehicle speed signal and the load signal that characterizes the vehicle's load status. A comparison module is used to compare the acquired load signal with a preset first threshold and a preset second threshold; wherein the preset first threshold is less than the preset second threshold; An enabling module is configured to output the no-load required torque when the load signal indicates that the current load is not higher than the preset first threshold; and to output the full-load assist torque when the load signal indicates that the current load is not lower than the preset second threshold; and to calculate the target assist torque based on the full-load assist torque, the current load signal, and the current vehicle speed signal using a compensation function when the load signal indicates that the current load is higher than the preset first threshold and lower than the preset second threshold; wherein the target assist torque increases with the increase of the current load signal and decreases with the increase of the current vehicle speed signal. The output module is used to control the power steering system's power motor to output one of the unloaded required torque, the full-load power assist torque, and the target power assist torque.

8. A vehicle, characterized in that, It includes the steering assist control system as described in claim 7, and a height valve for detecting the vehicle load status.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 6.

10. An electronic device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method as described in any one of claims 1 to 6.

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