Vehicle steering control method, vehicle steering control device, vehicle, and medium

Abstract

The application provides a vehicle steering control method, a vehicle steering control device, a vehicle and a medium, and relates to the field of auxiliary driving. The method comprises the following steps: in the case that the vehicle starts the auxiliary driving function, if it is detected that the driver is in a hands-off state, obtaining the expected steering torque of the vehicle and the driving condition; obtaining the adjustment coefficient corresponding to the driving condition based on the driving condition; obtaining the torque correction weight corresponding to the current time length based on the power function constructed by the adjustment coefficient and the current time length, the current time length being used to represent the time length between the current time and the time when it is detected that the driver is in the hands-off state, and the adjustment coefficient being used as the index of the power function; obtaining the target steering torque at the current time based on the expected steering torque and the torque correction weight corresponding to the current time length, and the target steering torque being used for auxiliary steering control of the vehicle. The method can control the steering of the vehicle, so as to improve the driving experience of the user.

Description

Technical Field

[0001] This application relates to the field of driver assistance systems, and more specifically, to a vehicle steering control method, a vehicle steering control device, a vehicle, and a medium in the field of driver assistance systems. Background Technology

[0002] With the widespread adoption of intelligent driving systems, human-machine collaborative driving has become a common interaction mode. In human-machine collaborative driving scenarios, when the system detects that the driver's hands are off the steering wheel, it needs to switch vehicle control from the driver to the intelligent driving system. This process relies on the torque adjustment of the electronic power steering system. During the switch from driver control to intelligent driving system control, existing vehicle steering control strategies suffer from a poor driving experience for the driver.

[0003] Therefore, how to control the vehicle's steering to improve the user's driving experience is an urgent problem to be solved. Summary of the Invention

[0004] This application provides a vehicle steering control method, a vehicle steering control device, a vehicle, and a medium. The method enables steering control of a vehicle to improve the user's driving experience.

[0005] Firstly, a vehicle steering control method is provided, the method comprising: When the vehicle's driver assistance function is activated, if it is detected that the driver is in a hands-free state, the vehicle's expected steering torque and driving conditions are obtained. Based on the driving conditions, the corresponding adjustment coefficients are obtained; Based on the power function constructed using the adjustment coefficient and the current duration, the torque correction weight corresponding to the current duration is obtained. The current duration is used to represent the duration between the current moment and the moment when the driver is detected to be in a hands-free state. The adjustment coefficient serves as the exponent of the power function. Based on the torque correction weight corresponding to the expected steering torque and the current duration, the target steering torque at the current moment is obtained, and the target steering torque is used to assist the vehicle's steering control.

[0006] In the above technical solution, when the driver assistance function is activated and the driver is detected to be in a hands-free state, a corresponding adjustment coefficient is determined based on the vehicle's driving conditions. Using this adjustment coefficient as the exponent and the current duration of the hands-free state as the variable, a power function is constructed to obtain the torque correction weight. This torque correction weight is then used to correct the desired steering torque, resulting in the target steering torque corresponding to the current duration, which is then used for vehicle assisted steering control. This allows for differentiated adjustment of the steering torque rate with hands-free duration based on different driving conditions, avoiding the problems of component jamming or vibration caused by step torque adjustment, and the poor adaptability of single-rule torque adjustment under various conditions. It enables smooth and gradual adjustment of assisted steering control in a hands-free state, ensuring smooth steering control under different driving conditions and improving the user's driving experience.

[0007] Furthermore, when the adjustment coefficient corresponding to the driving conditions is determined to be between 0 and 1, the corresponding target output torque exhibits a non-linear smooth transition. Compared to the single linear torque adjustment rule in existing technologies, this solution can quickly increase the target steering torque in the initial stage of driver hands-off control, promptly compensating for the control gap caused by the driver taking their hands off the wheel and quickly correcting the vehicle's posture. In the later stage of sustained hands-off control, the target steering torque is controlled to slowly approach the desired steering torque, avoiding sudden changes in steering force and stiff steering wheel correction caused by a continuous and significant increase in torque. This makes the vehicle steering adjustment process smoother and gentler, meeting the user's perception of steering force and further enhancing the user's driving experience.

[0008] In conjunction with the first aspect, in some possible implementations, the method also includes: Based on the vehicle speed, a target duration is determined. The target duration indicates the time required for the vehicle's steering torque to adjust to the desired steering torque. The target duration is negatively correlated with the vehicle speed. Based on the power function constructed using the adjustment coefficient and the current duration, the torque correction weight corresponding to the current duration is obtained, including: Based on the current duration and the target duration, the percentage of time corresponding to the current duration is obtained; The torque correction weight corresponding to the current duration is obtained by constructing a power function based on the adjustment coefficient and the duration ratio, with the duration ratio serving as the base of the power function.

[0009] In the above technical solution, a target duration negatively correlated with vehicle speed is obtained for steering torque adjustment. Then, the torque correction weight corresponding to the current duration is determined by using the ratio of the current duration to the target duration as the base of a power function. A longer torque adjustment duration is used at low speeds, resulting in smoother changes in steering torque; a shorter adjustment duration is used at high speeds, quickly completing steering torque correction and responding promptly to the vehicle's lateral control needs. This avoids the risk of lag in steering response when the vehicle is released from control at high speeds, balancing the smoothness and timeliness of steering control under different speed conditions, making the vehicle's steering torque correction process more closely aligned with the vehicle's dynamic driving characteristics.

[0010] Combining the first aspect and the above implementation methods, in some possible implementation methods, the target steering torque at the current moment is obtained based on the torque correction weight corresponding to the desired steering torque and the current duration, including: The torque difference is obtained based on the desired steering torque and the lower limit of the steering torque; Based on the torque difference and the torque correction weight corresponding to the current duration, the torque adjustment amount corresponding to the current duration is obtained; Based on the torque adjustment amount corresponding to the current duration and the lower limit of the steering torque, the target steering torque at the current moment is obtained.

[0011] In the above technical solution, the torque adjustment amount is determined by combining the torque difference between the desired steering torque and the lower limit of the steering torque, as well as the torque correction weight. Then, the target steering torque is obtained based on the torque adjustment amount and the lower limit of the steering torque. The lower limit of the steering torque ensures basic steering safety in the hands-free state. By combining the torque correction weight to determine the adjustment amount in real time, the steering torque smoothly transitions from the base value to the desired steering torque. The steering torque change is continuous and without abrupt changes. This can accurately adapt to the steering assistance needs under different hands-free durations, effectively correct the vehicle posture, and avoid problems such as vehicle vibration and stiff steering wheel correction caused by large torque fluctuations. It balances the accuracy and stability of steering control in assisted driving hands-free scenarios, further improving the user's driving experience.

[0012] In combination with the first aspect and the above implementation methods, in some possible implementations, the method further includes: Obtain the vehicle's driving parameters, including vehicle speed, yaw rate, and lateral deviation of the vehicle relative to the lane lines; The desired steering torque is obtained based on the vehicle's driving parameters.

[0013] In the above technical solution, by collecting driving parameters such as vehicle speed, yaw rate, and lateral deviation of the vehicle relative to the lane line, the corresponding expected steering torque is determined. This makes the expected steering torque more closely match the real-time driving state of the vehicle and the lane departure trend, thereby improving the accuracy of the expected steering torque. When determining the target steering torque based on the more accurate expected steering torque, the accuracy of the target steering torque can be further improved, thus achieving smooth and precise steering control of the vehicle.

[0014] Combining the first aspect and the above implementation methods, in some possible implementation methods, the desired steering torque is obtained based on the vehicle's driving parameters, including: Based on the vehicle speed, the first weighting coefficient corresponding to the yaw rate and the second weighting coefficient corresponding to the lateral deviation are obtained; The first steering torque is obtained based on the yaw rate and the first weighting coefficient; The second steering torque is obtained based on the lateral deviation and the second weighting coefficient; The desired steering torque is obtained based on the first steering torque and the second steering torque.

[0015] In the above technical solution, the weighting coefficients corresponding to the vehicle's yaw rate and lateral deviation are dynamically adapted based on the vehicle speed. The steering torque is obtained by combining these two parameters with their corresponding weighting coefficients, and then fused to obtain the target steering torque. Under different vehicle speed conditions, the system can automatically prioritize vehicle attitude correction or lane departure correction, avoiding the problem that a single weighting coefficient cannot adapt to different vehicle speed scenarios. This makes the desired steering torque more suitable for steering control requirements at different vehicle speeds.

[0016] In combination with the first aspect and the above implementation methods, in some possible implementations, the method further includes: Obtain vehicle model information; Based on vehicle model information, determine the range of adjustment coefficients; Based on driving conditions, the corresponding adjustment coefficients are obtained, including: Based on the driving conditions, the adjustment coefficient corresponding to the driving conditions is obtained from the adjustment coefficient range.

[0017] In the above technical solution, the adjustment coefficient range is first dynamically matched according to the vehicle model information, and then the corresponding adjustment coefficient is selected from the adjustment coefficient range according to the real-time driving conditions of the vehicle to improve the adaptability of the adjustment coefficient with the vehicle model and driving conditions. Then, when the target steering torque is further determined according to the adjustment coefficient, the auxiliary steering control needs of different vehicle models under different driving conditions can be met, thereby improving the driving experience of the vehicle under different driving conditions.

[0018] In combination with the first aspect and the above implementation methods, in some possible implementations, the method further includes: Obtain the driver's hand torque; When the hand torque is less than the hand torque threshold and the duration reaches the preset duration, it is determined that the driver is in a hands-free state.

[0019] In the above technical solution, the driver's hand torque is used as the core detection indicator. A dual-condition judgment is made by combining a hand torque threshold and a preset duration to avoid misjudgments or missed judgments caused by invalid interference scenarios such as the driver briefly releasing their hand or slight shaking of the vehicle or hand. The subsequent adaptive steering torque control logic is only triggered when the driver's hand torque is consistently below the hand torque threshold and completely removed from steering wheel control. This improves the accuracy of identifying the hands-free state and avoids useless intervention in non-real hands-free scenarios, ensuring the precision of the assisted steering control triggering.

[0020] Secondly, a vehicle steering control device is provided, the device comprising: The acquisition module is used to acquire the vehicle's expected steering torque and driving conditions when the vehicle's driver assistance function is activated and the driver is detected to be in a hands-free state. The processing module is used to obtain the adjustment coefficient corresponding to the driving condition based on the driving condition; to obtain the torque correction weight corresponding to the current duration based on the power function constructed by the adjustment coefficient and the current duration, where the current duration represents the duration between the current moment and the moment when the driver is detected to be in a hands-free state, and the adjustment coefficient serves as the exponent of the power function; and to obtain the target steering torque at the current moment based on the desired steering torque and the torque correction weight corresponding to the current duration, where the target steering torque is used to perform auxiliary steering control on the vehicle.

[0021] In conjunction with the second aspect, in some possible implementations, the processing module is also used to determine a target duration based on the vehicle speed. The target duration indicates the duration for adjusting the vehicle's steering torque to the desired steering torque, and the target duration is negatively correlated with the vehicle speed. Based on the current duration and the target duration, the duration percentage corresponding to the current duration is obtained. Based on the power function constructed from the adjustment coefficient and the duration percentage, the torque correction weight corresponding to the current duration is obtained, and the duration percentage is used as the base of the power function.

[0022] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the processing module is also used to obtain the torque difference based on the desired steering torque and the lower limit of steering torque; obtain the torque adjustment amount corresponding to the current duration based on the torque difference and the torque correction weight corresponding to the current duration; and obtain the target steering torque at the current moment based on the torque adjustment amount corresponding to the current duration and the lower limit of steering torque.

[0023] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the acquisition module is also used to acquire the vehicle's driving parameters, including vehicle speed, yaw rate and lateral deviation of the vehicle relative to the lane line; the processing module is also used to obtain the desired steering torque based on the vehicle's driving parameters.

[0024] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the processing module is further configured to obtain a first weighting coefficient corresponding to the yaw rate and a second weighting coefficient corresponding to the lateral deviation based on the vehicle speed; obtain a first steering torque based on the yaw rate and the first weighting coefficient; obtain a second steering torque based on the lateral deviation and the second weighting coefficient; and obtain a desired steering torque based on the first steering torque and the second steering torque.

[0025] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the acquisition module is also used to acquire vehicle model information; determine the adjustment coefficient range based on the model information; and the processing module is also used to obtain the adjustment coefficient corresponding to the driving condition from the adjustment coefficient range based on the driving condition.

[0026] In combination with the second aspect and the above implementation methods, in some possible implementation methods, the acquisition module is also used to acquire the driver's hand torque; the processing module is also used to determine that the driver is in a hands-free state when the hand torque is less than the hand torque threshold and the duration reaches the preset duration.

[0027] Thirdly, a vehicle is provided, including a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, causing the vehicle to perform the methods described in the first aspect or any possible implementation thereof.

[0028] Fourthly, a computer program product is provided, comprising: computer program code, which, when run on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof.

[0029] Fifthly, a computer-readable storage medium is provided that stores computer program code, which, when executed on a computer, causes the computer to perform the methods described in the first aspect or any possible implementation thereof. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a system architecture diagram of a vehicle provided in an embodiment of this application; Figure 2 This is a schematic flowchart of a vehicle steering control method provided in an embodiment of this application; Figure 3 This is a schematic flowchart of another vehicle steering control method provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of a vehicle steering control device provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application. Detailed Implementation

[0032] The technical solutions in this application will be clearly and thoroughly described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in the text is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

[0033] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0034] With the continuous implementation of policies for the intelligent connected vehicle industry and the gradual improvement of the autonomous driving regulatory system, Level 2 to Level 3 intelligent driving technologies are becoming increasingly widespread, and human-machine co-driving interaction scenarios have become the norm for vehicle operation. As the core actuator for lateral control of the vehicle, the smoothness of the steering torque control of the electric power steering system (EPS) directly affects the driving experience of the entire vehicle user and the safety of human-vehicle co-driving.

[0035] In current technologies, mainstream control schemes often employ either a step torque output or a single, uniform linear torque transition strategy when the driver takes their hands off the wheel and lateral control of the vehicle needs to be transferred to the autonomous driving system. Both of these traditional approaches have significant drawbacks: a sudden increase in torque can easily lead to steering wheel jerking and power steering motor vibration; a single linear transition with a constant rate of change cannot simultaneously meet the dual requirements of rapid response in low-torque ranges and smooth convergence in high-torque ranges. Furthermore, because human perception of torque changes is non-linear—sensitive to small torque changes but less perceptible to large torque changes close to the target value—the linear torque control strategy cannot match the user's perceptual characteristics. During the process of taking their hands off the wheel, the driver will clearly feel a sudden jerk of the steering wheel or steering play, resulting in low driving comfort in human-machine co-driving scenarios and negatively impacting the user's driving experience.

[0036] In view of the technical problems existing in the above-mentioned technologies, this application provides a vehicle steering control method, a vehicle steering control device, a vehicle, and a medium. When the vehicle's assisted driving function is activated, if the driver is detected to be in a hands-free state, the method acquires the vehicle's desired steering torque and driving conditions. Then, based on the driving conditions, it obtains an adjustment coefficient corresponding to the driving conditions. Combining the adjustment coefficient with a power function constructed from the current duration, it obtains a torque correction weight corresponding to the current duration, where the current duration represents the time between the current moment and the moment the driver is detected to be in a hands-free state, and the adjustment coefficient serves as the exponent of the power function. Subsequently, based on the desired steering torque and the torque correction weight corresponding to the current duration, it obtains the target steering torque for the current moment, which is used for assisted steering control of the vehicle. This method can construct a power function using an adjustment coefficient matched to the driving conditions, thereby obtaining a torque correction weight to correct the vehicle's steering torque, achieving assisted steering control of the vehicle. This allows the steering torque to smoothly transition to the desired steering torque, avoiding the shock problems caused by step control, and improving the user's driving experience.

[0037] Figure 1 This is a system architecture diagram of a vehicle provided in an embodiment of this application. Figure 1As shown, the system architecture of vehicle 100 includes an electric power steering system 101 and an intelligent driving system 102. When vehicle 100 is driving on the road, in order to improve the driving stability and safety of vehicle 100, the driver can activate the driver assistance functions provided by the intelligent driving system 102. These driver assistance functions may include lane keeping assist (LKA), lane centering control (LCC), automatic lane change assist (ALC), cornering intelligent steering assist, and emergency steering assist (ESA), which are related to vehicle lateral control. When the above driver assistance functions are activated, the electric power steering system 101 needs to output steering torque to achieve steering control of vehicle 100. During the collaborative control process of human-machine co-driving, the system will allocate steering control authority according to the driver's hand contact status. When the driver's hands are detected on the steering wheel, the steering torque actively input by the driver is used as the main control quantity. The intelligent driving system only provides a small correction torque, which does not counteract the human hand operation, making the driver's driving feel more natural. When the driver's hands are completely off the wheel, the control of the vehicle 100 is switched to the intelligent driving system, which outputs the desired steering torque. The electric power steering system 101 completes the vehicle's steering control according to the desired steering torque.

[0038] The following is combined Figures 2 to 3 The vehicle steering control method provided in the embodiments of this application will be described in detail.

[0039] Figure 2 This is a schematic flowchart illustrating a vehicle steering control method provided in an embodiment of this application. It should be understood that this method can be applied to a vehicle; or, to a processor in a vehicle; or, to a chip within a processor in a vehicle.

[0040] For example, such as Figure 2 As shown, the method includes: S201. When the vehicle's driver assistance function is activated, if it is detected that the driver is in a hands-free state, the vehicle's desired steering torque and driving conditions are obtained.

[0041] It should be noted that in the vehicle steering control method provided in this application embodiment, the assisted driving function is specifically used to indicate assisted driving functions involving lateral control of the vehicle, such as lane keeping assist, lane centering control, automatic lane change assist, intelligent cornering assist, and emergency steering assist. When the above assisted driving functions are activated, it is necessary to control the steering of the vehicle's wheels.

[0042] For example, the vehicle's activated driver assistance functions are detected. If the activated driver assistance functions include lateral control-related driver assistance functions, the driver's steering wheel grip status is monitored during vehicle operation to determine whether the driver is in a hands-free state. If the driver is determined to be in a hands-free state, the vehicle's desired steering torque and driving conditions are acquired.

[0043] In one implementation, the vehicle's driving conditions can be determined based on driving parameters such as vehicle speed and road conditions. For example, driving conditions can be divided into low-speed driving conditions, medium-speed driving conditions, and high-speed driving conditions based on vehicle speed; or, driving conditions can be divided into congested crawling conditions, highway driving conditions, and normal driving conditions based on road conditions.

[0044] It should be noted that the above classification of driving conditions is only an example. For further information on the classification of driving conditions, please refer to the relevant descriptions in the following embodiments. This application does not impose any specific limitations on the classification of driving conditions.

[0045] In one implementation, the process of detecting whether the driver is in a hands-free state may include: acquiring the driver's hand torque; and determining that the driver is in a hands-free state when the hand torque is less than a hand torque threshold and the duration reaches a preset duration.

[0046] Among them, the duration refers to the duration during which the hand torque is less than the hand torque threshold.

[0047] For example, a hand torque threshold and a preset duration are pre-set. The hand torque threshold, also known as the driver's hands-off detection torque threshold, is used to determine whether the driver's hands have left the steering wheel. For instance, the hand torque threshold can be set to 0.25 N·m. The preset duration, also known as the vibration duration or hands-off anti-shake detection delay, is used to filter out high-frequency hand torque vibrations and prevent false triggering of the assisted steering control. For instance, the preset duration can be set to 0.2 seconds. The hand torque threshold and the preset duration together constitute the filtering logic for driver hands-off detection.

[0048] For example, during vehicle operation, the torque sensor built into the EPS monitors the driver's hand torque in real time. When the driver's hand torque is detected to be less than a hand torque threshold, and the duration is greater than or equal to a preset duration, it is determined that the driver is in a hands-free state.

[0049] It should be understood that when the driver's hand torque is greater than or equal to the hand torque threshold, it indicates that the driver is holding the steering wheel normally, and thus the driver is in a hands-free state. When the driver's hand torque is less than the hand torque threshold for a duration less than the preset duration, there may be signal noise caused by road bumps or slight movements of the driver's hands. In this case, the driver is not in an effective hands-free state, and thus the driver is in a hands-free state.

[0050] Optionally, the calibration range for the hand torque threshold can be 0.2~0.5 N·m, and the calibration range for the preset duration can be 0.15~0.3 s. Further, the corresponding hand torque threshold and preset duration can be determined based on the vehicle type.

[0051] For example, for family passenger vehicles, a larger hand torque threshold and a longer preset duration can be set; for sports vehicles, a smaller hand torque threshold and a shorter preset duration can be set.

[0052] In this embodiment, the driver's hand torque is used as the core detection indicator. A dual-condition judgment is made by combining a hand torque threshold and a preset duration to avoid misjudgments or missed judgments caused by invalid interference scenarios such as the driver briefly releasing their hand or slight shaking of the vehicle or hand. The subsequent adaptive steering torque control logic is only triggered when the driver's hand torque is consistently below the hand torque threshold and completely removed from steering wheel control. This improves the accuracy of identifying the hands-free state and avoids useless intervention in non-real hands-free scenarios, ensuring the precise triggering of the assisted steering control.

[0053] In one implementation, the process of determining the vehicle’s current desired steering torque may include: acquiring the vehicle’s driving parameters, including vehicle speed, yaw rate, and lateral deviation of the vehicle relative to the lane line. The desired steering torque is obtained based on the vehicle's driving parameters.

[0054] Among them, the yaw rate of a vehicle refers to the rate at which the vehicle rotates around its vertical axis, which reflects the tendency of the vehicle body to yaw; the lateral deviation of the vehicle relative to the lane line refers to the lateral distance between the vehicle's center of gravity or the front of the vehicle and the center line of the lane.

[0055] For example, during vehicle operation, the vehicle speed, yaw rate, and lateral deviation of the vehicle relative to the lane line are acquired in real time; then, by combining the above multi-dimensional driving parameters, the desired steering torque required for the current vehicle steering control is matched.

[0056] Optionally, the vehicle speed can be collected by the vehicle's wheel speed sensors, the vehicle's yaw rate can be collected by the gyroscope or electronic stability control (ESC) system, and the lane lines can be identified and the lateral deviation of the vehicle relative to the lane lines can be calculated by the vehicle's forward-facing camera.

[0057] Alternatively, the process of determining the desired steering torque can be performed by the vehicle's intelligent driving system or the vehicle's lateral control system.

[0058] In this embodiment, by collecting driving parameters such as vehicle speed, yaw rate, and lateral deviation of the vehicle relative to the lane line, the corresponding desired steering torque is determined, making the desired steering torque more closely match the real-time driving state of the vehicle and the lane departure trend, thereby improving the accuracy of the desired steering torque. When the target steering torque is determined based on the more accurate desired steering torque, the accuracy of the target steering torque can be further improved, thereby achieving smooth and precise steering control of the vehicle.

[0059] In one implementation, the process of obtaining the desired steering torque based on the vehicle's driving parameters may specifically include: Based on the vehicle speed, the first weighting coefficient corresponding to the yaw rate and the second weighting coefficient corresponding to the lateral deviation are obtained; The first steering torque is obtained based on the yaw rate and the first weighting coefficient; The second steering torque is obtained based on the lateral deviation and the second weighting coefficient; The desired steering torque is obtained based on the first steering torque and the second steering torque.

[0060] For example, the required lateral control varies depending on the vehicle's speed range. Therefore, by combining the vehicle speed, a first weighting coefficient corresponding to the yaw rate and a second weighting coefficient corresponding to the lateral deviation can be obtained. Then, by combining the yaw rate and the first weighting coefficient, a first steering torque matching the current yaw rate is obtained; simultaneously, by combining the lateral deviation and the second weighting coefficient, a second steering torque matching the current lateral deviation is obtained. Finally, by summing the first and second steering torques, the desired steering torque matching the vehicle's current driving state can be obtained.

[0061] For example, the process of determining the desired steering torque can be expressed as the following formula: (Formula 1); In the above formula one, Used to indicate the vehicle's desired steering torque. Used to represent the yaw rate of a vehicle. Used to represent yaw rate The corresponding first weight coefficient, Used to indicate lateral deviation. Used to represent lateral deviation The corresponding second weighting coefficient.

[0062] For example, after obtaining the vehicle speed, the first weighting coefficient and the second weighting coefficient can be obtained according to the mapping relationship between the vehicle speed and the weighting coefficient; then, by substituting the vehicle's current yaw rate and lateral deviation into the above formula one, the desired steering torque can be obtained.

[0063] For example, when the vehicle speed is in the high-speed range, such as when the speed is greater than 60 km / h, the second weighting coefficient can be increased to enhance the lane keeping ability during high-speed driving; when the vehicle speed is in the medium-low speed range, the first weighting coefficient and the second weighting coefficient can be balanced to take into account both the vehicle's steering smoothness and lane keeping ability.

[0064] In one implementation, due to the hardware limitations of the EPS motor, the torque it can output is limited to a certain range. After calculating the desired steering torque matching the current driving state according to Formula 1 above, the desired steering torque can be adjusted according to the range limitation of the EPS to ensure that the desired steering torque is within the normal output torque range of the EPS, and this value is used as the target value that needs to be achieved in the vehicle steering torque control process.

[0065] In this embodiment, the steering torque is obtained by combining the weighting coefficients corresponding to the vehicle's speed-dynamic adaptation yaw rate and lateral deviation, and then fusing these two parameters with their corresponding weighting coefficients to obtain the target steering torque. Under different vehicle speed conditions, the system can automatically prioritize vehicle attitude correction or lane deviation correction, avoiding the problem that a single weighting coefficient cannot adapt to different vehicle speed scenarios, thus making the desired steering torque more suitable for steering control requirements at different vehicle speeds.

[0066] S202. Based on the driving conditions, obtain the adjustment coefficient corresponding to the driving conditions.

[0067] For example, the need for assisted steering control of a vehicle varies under different driving conditions, thus requiring the determination of the corresponding adjustment coefficient based on the current driving conditions of the vehicle when the driver takes their hands off the wheel.

[0068] For example, the adjustment coefficient can specifically be a nonlinear power smoothing coefficient, that is, the exponent term in a power function, used to adjust the curvature of the change in vehicle steering torque. In this embodiment, the adjustment coefficient takes values ​​in the range of (0,1) to achieve nonlinear smooth adjustment of steering torque.

[0069] In one implementation, an adjustment coefficient matching the current driving conditions is determined by a preset mapping relationship between driving conditions and adjustment coefficients.

[0070] For example, if the driving condition is low speed, the corresponding adjustment coefficient is determined to be 0.38; if the driving condition is medium speed, the corresponding adjustment coefficient is determined to be 0.45; and if the driving condition is high speed, the corresponding adjustment coefficient is determined to be 0.52.

[0071] In another implementation, the process of determining the current driving condition of the vehicle may include: obtaining the vehicle model information; Based on vehicle model information, determine the range of adjustment coefficients; Based on driving conditions, the corresponding adjustment coefficients are obtained, including: Based on the driving conditions, the adjustment coefficient corresponding to the driving conditions is obtained from the adjustment coefficient range.

[0072] For example, different vehicle models and different driving parameters reflect different vehicle driving conditions. By combining vehicle model information and driving parameters, the current driving conditions of the vehicle can be analyzed.

[0073] For example, when the vehicle model information indicates that the vehicle is of type 1, the adjustment coefficient range is determined as the first range. The vehicle of type 1 may include micro electric vehicles, urban commuter cars and entry-level family passenger cars, etc. The corresponding first range can be a small range of values ​​in the range of [0.35, 0.42]. The power function curve constructed based on the adjustment coefficient in this range has a large climbing range, which controls the torque to climb rapidly in the initial stage and the torque to converge slowly in the later stage.

[0074] For example, when the vehicle model information indicates that the vehicle is of type two, the adjustment coefficient range is determined as the second range. The second type of vehicle may include compact vehicles, mid-size family fuel passenger cars or hybrid passenger cars, etc. The corresponding second range can be a value range of [0.43, 0.48] that is slightly in the middle. The power function curve constructed based on the adjustment coefficient in this range has a balanced climbing ratio, which controls the initial torque to climb quickly and controls the later torque to converge smoothly, taking into account both steering response and smoothness.

[0075] For example, when the vehicle model information indicates that the vehicle is of type three, the adjustment coefficient range is determined to be the third range. The third type of vehicle may include performance vehicles such as sports sedans, sports utility vehicles (SUVs), and light commercial vehicles. The corresponding third range can be a relatively large range of values ​​in the range of [0.49, 0.60]. The power function curve constructed based on the adjustment coefficient in this range tends to change linearly, thereby slowing down the initial torque ramp-up rate and minimizing the torque gradient change throughout the entire range.

[0076] After obtaining the adjustment coefficient range based on the vehicle model information, the adjustment coefficient that matches the current driving conditions is further obtained by combining the current driving conditions of the vehicle.

[0077] In one implementation, the vehicle's driving conditions can be determined based on the vehicle's speed, and the rules for classifying driving conditions differ for different vehicle models.

[0078] For example, for the first type of vehicle, its applicable operating conditions are mostly low-speed urban scenarios. The classification of its driving conditions according to vehicle speed can include: low-speed crawling conditions (vehicle speed 0 ≤ v ≤ 10 km / h), urban low-to-medium speed conditions (vehicle speed 10 < v ≤ 60 km / h), and urban medium-speed conditions (vehicle speed 60 < v ≤ 80 km / h). Low-speed crawling conditions can include scenarios such as maneuvering in residential areas, crawling in congested traffic, and low-speed U-turns, for which a smaller adjustment coefficient within the first interval [0.35, 0.42] can be selected, such as 0.36. Urban low-to-medium speed conditions can include scenarios such as following other vehicles on urban roads and low-speed cruising on ring roads, for which an intermediate adjustment coefficient within the first interval [0.35, 0.42] can be selected, such as 0.39. Urban medium-speed conditions can include scenarios such as driving on urban expressways, for which a larger adjustment coefficient within the first interval [0.35, 0.42] can be selected, such as 0.42.

[0079] For example, for the second type of vehicle, its applicable operating conditions include all speed scenarios. The classification of driving conditions according to vehicle speed can include: low-speed urban driving conditions (0≤v≤60km / h), conventional medium-speed driving conditions (60<v≤120km / h), and high-speed driving conditions (greater than 120km / h). Low-speed urban driving conditions can include scenarios such as urban congestion and U-turns in urban areas, corresponding to a smaller adjustment coefficient within the second interval [0.43, 0.48], for example, 0.43; conventional medium-speed driving conditions can include scenarios such as driving on national highways, highway cruising, and driving in the middle of a ring road, corresponding to a medium adjustment coefficient within the second interval [0.43, 0.48], for example, 0.45; high-speed driving conditions can include scenarios such as long-distance highway cruising, corresponding to a larger adjustment coefficient within the second interval [0.43, 0.48], for example, 0.47.

[0080] For example, for the third type of vehicle, to adapt to the requirements of high-speed dynamic driving and stable steering when carrying cargo, the driving conditions can be divided according to vehicle speed as follows: low-speed urban driving conditions (0≤v≤60km / h), conventional medium-speed driving conditions (60<v≤100km / h), and high-speed driving conditions (greater than 100km / h). Low-speed urban driving conditions can include scenarios such as city driving, and a smaller adjustment coefficient within the third interval [0.49,0.60] can be selected, for example, 0.50; conventional medium-speed driving conditions can include scenarios such as conventional overtaking and constant-speed cruising, and a medium adjustment coefficient within the third interval [0.49,0.60] can be selected, for example, 0.54; high-speed driving conditions can include scenarios such as high-speed lane changes and high-speed overtaking, and a larger adjustment coefficient within the third interval [0.49,0.60] can be selected, for example, 0.59.

[0081] In this embodiment, the adjustment coefficient range is first dynamically matched according to the vehicle model information, and then the corresponding adjustment coefficient is selected from the adjustment coefficient range according to the real-time driving conditions of the vehicle to improve the adaptability of the adjustment coefficient to the vehicle model and driving conditions. Then, when the target steering torque is further determined according to the adjustment coefficient, the auxiliary steering control needs of different vehicle models under different driving conditions can be met, thereby improving the driving experience of the vehicle under different driving conditions.

[0082] S203. Based on the power function constructed by the adjustment coefficient and the current duration, the torque correction weight corresponding to the current duration is obtained. The current duration is used to represent the duration between the current moment and the moment when the driver is detected to be in a hands-free state. The adjustment coefficient is used as the exponent of the power function.

[0083] For example, when it is detected that the driver is in a hands-free state, a timer is started. This timer is used to count the duration after the driver has taken his hands off the wheel. That is, the initial time when the driver is detected to be in a hands-free state is 0, and the duration of the timer is 0. Then, the duration between the current time and the initial time can be obtained based on the current time and the initial time, which is the current duration.

[0084] For example, after obtaining the adjustment coefficient that matches the current driving conditions of the vehicle, the adjustment coefficient corresponding to the driving conditions is used as the exponent of the power function. The power function is constructed by combining it with the current duration, and the torque correction weight corresponding to the current duration is obtained based on the power function.

[0085] In one implementation, a target duration is determined based on the vehicle speed. The target duration is used to indicate the time required for the vehicle's steering torque to adjust to the desired steering torque. The target duration is negatively correlated with the vehicle speed. The process of obtaining the torque correction weight corresponding to the current duration based on the power function constructed from the adjustment coefficient and the current duration can specifically include: Based on the current duration and the target duration, the percentage of time corresponding to the current duration is obtained; The torque correction weight corresponding to the current duration is obtained by constructing a power function based on the adjustment coefficient and the duration ratio, with the duration ratio serving as the base of the power function.

[0086] For example, the need for steering control varies depending on the vehicle's speed range. Therefore, a target duration can be determined based on the vehicle's speed. This target duration, also known as the torque transition duration, indicates the allowable time for adjusting the vehicle's steering torque to the desired steering torque; that is, the transition from the current steering torque to the desired steering torque needs to be completed within the target duration.

[0087] For example, when the vehicle speed is greater than 60 km / h, the risk of lateral drift is high due to the relatively fast vehicle speed. In this case, a shorter target duration (e.g., 0.4s) can be determined to allow the EPS to quickly establish steering torque adjustment, promptly suppress vehicle drift, ensure lane centering response speed, and avoid safety hazards caused by prolonged ineffective steering. When the vehicle speed is less than 60 km / h, the driver is more sensitive to changes in steering wheel torque. In this case, a longer target duration (e.g., 0.8s) can be determined. By extending the transition time, the rate of change in steering torque is slowed down, the abrupt feel caused by changes in steering torque is weakened, the smoothness of steering control is improved, and the quality of low-speed steering is enhanced.

[0088] After obtaining the target duration matching the vehicle speed, the ratio of the current duration to the target duration is calculated to obtain the duration percentage. This duration percentage indicates the current stage of the steering torque control process; the closer the duration percentage is to 0, the earlier the control is in progress, and the closer it is to 1, the later the control is in progress. Then, a power function is constructed using this duration percentage as the base and the adjustment coefficient as the exponent. This power function yields the torque correction weight corresponding to the current duration.

[0089] In one implementation, the power function can be expressed as: Where t represents the current duration, Used to indicate the target duration, This represents the percentage of time spent. This is used to represent the adjustment coefficient. Based on this power function, the torque correction weight for each moment during the assisted steering control process after the driver takes their hands off the wheel can be obtained.

[0090] For example, taking a target duration of 0.4s and an adjustment coefficient of 0.45, at the initial moment when the driver is detected to be in a hands-free state, t=0, the corresponding torque correction weight is 0; when t=0.1, the torque correction weight is... ≈0.54; when t=0.2, the torque correction weight is ≈0.73; when t=0.3, the torque correction weight is ≈0.88; when t=0.4, the torque correction weight is =1.

[0091] In this embodiment, a target duration negatively correlated with the vehicle speed is obtained for steering torque adjustment. Then, the torque correction weight corresponding to the current duration is determined by using the ratio of the current duration to the target duration as the base of a power function. A longer torque adjustment duration is applied at low speeds, resulting in smoother steering torque changes; a shorter adjustment duration is applied at high speeds, quickly completing steering torque correction and responding promptly to the vehicle's lateral control needs. This avoids the risk of lag in steering response when the vehicle is released from control at high speeds, balancing the smoothness and timeliness of steering control under different speed conditions, making the steering torque correction process more closely aligned with the vehicle's dynamic driving characteristics.

[0092] S204. Based on the torque correction weight corresponding to the desired steering torque and the current duration, the target steering torque at the current moment is obtained. The target steering torque is used for auxiliary steering control of the vehicle.

[0093] For example, a power function constructed using the current duration and adjustment coefficient is used to obtain the torque correction weight corresponding to the current duration. Then, the desired steering torque can be corrected based on this torque correction weight to obtain the target steering torque at the current moment. After obtaining the target steering torque, it can be sent to the EPS (Electrical Power Steering) to control the EPS to output the target steering torque, thus achieving assisted steering control of the vehicle when the driver is in a hands-free state.

[0094] In one implementation, the process of obtaining the target steering torque at the current moment based on the torque correction weight corresponding to the desired steering torque and the current duration may specifically include: The torque difference is obtained based on the desired steering torque and the lower limit of the steering torque; Based on the torque difference and the torque correction weight corresponding to the current duration, the torque adjustment amount corresponding to the current duration is obtained; Based on the torque adjustment amount corresponding to the current duration and the lower limit of the steering torque, the target steering torque at the current moment is obtained.

[0095] For example, when the driver holds the steering wheel, the intelligent driving system will output a smaller steering torque, that is, the lower limit of steering torque. As the minimum effective output torque, this lower limit of steering torque can ensure that the motor can be driven immediately to produce perceptible steering assistance when the controller issues a torque command, avoiding the problem of the steering wheel feeling floaty and loose at the beginning of the hand-off switching.

[0096] For example, by combining the current vehicle's desired steering torque and the lower limit of steering torque, the torque difference between the two is calculated. This torque difference indicates the torque required to achieve the desired steering torque based on the lower limit of steering torque adjustment, which is the torque that the vehicle needs to further increase. Then, based on the torque difference and the torque correction weight corresponding to the current duration, the torque adjustment amount corresponding to the current duration can be calculated. Finally, based on the torque adjustment amount and the lower limit of steering torque, the target steering torque corresponding to the current moment can be obtained.

[0097] Optionally, the lower limit of steering torque can also be referred to as the lower limit torque of human-machine co-driving, indicating the lowest torque after intelligent driving is suppressed during human-machine co-driving, that is, the minimum steering assistance torque allowed to be output by the EPS motor. This lower limit of steering torque can be calibrated according to different vehicle models. The lower the lower limit of steering torque, the less noticeable the reverse resistance, torque shock, or abrupt pulling will be felt when the driver re-grips the steering wheel and applies hand torque to intervene in control, and the interaction between the hand and the steering wheel will be smoother and gentler.

[0098] For example, for the first type of vehicle mentioned above, its body is light, its steering damping is low, and it is sensitive to torque changes at low speeds. Therefore, the calibration range of the lower limit of steering torque can be a relatively small value, such as 0.3~0.5 N·m. For the second type of vehicle mentioned above, the calibration range of the lower limit of steering torque can be a medium value, such as 0.5~0.8 N·m, which can take into account both smooth low-speed driving in urban areas and the safety requirements for preventing deviation at high speeds, and is applicable to the entire speed range. For the third type of vehicle mentioned above, the calibration range of the lower limit of steering torque can be a relatively large value, such as 0.8~1.2 N·m, to meet the stability requirements in sports scenarios or cargo-carrying scenarios.

[0099] In this embodiment, the torque adjustment amount is determined by combining the torque difference between the desired steering torque and the lower limit of the steering torque, as well as the torque correction weight. Then, the target steering torque is obtained based on the torque adjustment amount and the lower limit of the steering torque. The lower limit of the steering torque ensures basic steering safety during hands-free driving. By combining the torque correction weight with real-time adjustment, the steering torque smoothly transitions from the base value to the desired steering torque, with continuous and abrupt changes. This accurately adapts to steering assistance needs under different hands-free driving durations, effectively correcting vehicle posture, while avoiding problems such as vehicle vibration and stiff steering wheel correction caused by large torque fluctuations. It balances the accuracy and smoothness of steering control in hands-free driving scenarios, further enhancing the user's driving experience.

[0100] In one implementation, the process of obtaining the target steering torque at the current moment based on the torque adjustment amount corresponding to the current duration and the lower limit of the steering torque may specifically include: The target steering torque at the current moment is obtained based on the following formula: (Formula 2); In Formula 2 above, t represents the current duration. Used to indicate the target steering torque at the current moment. Used to indicate the lower limit of steering torque. Used to indicate the amount of torque adjustment corresponding to the current duration. Used to indicate the desired steering torque. Used to indicate the target duration, Used to represent adjustment coefficients.

[0101] For example, the moment when the driver's hands are detected is the initial moment of the assisted steering control. ; then, based on this initial moment With the current moment The current duration can be calculated. The calculation obtained by combining the above formula two is as follows: It can be expressed as the target steering torque corresponding to the current time t, or it can be expressed as the current moment. The corresponding target steering torque.

[0102] For example, the target steering torque obtained based on Formula 2 above is always between the lower limit of steering torque and the desired steering torque. Based on the power function algorithm, torque adjustment can ensure that the torque change always shows a unidirectional increasing trend without decline, overshoot, or oscillation during the vehicle's assisted steering control process, achieving a non-linear smooth transition of steering torque and avoiding the problem of the steering wheel swaying back and forth.

[0103] In one implementation, normalizing Formula 2 yields Formula 3: (Formula 3); In Formula 3 above, x represents the normalized time, and the value of x ranges from [0,1]. y represents the percentage of the normalized torque increment. Used to represent adjustment coefficients.

[0104] For example, the normalized time is equivalent to the time ratio between the current duration and the target duration, used to indicate the stage at which the current moment is in the entire assisted steering control process; the normalized torque increment ratio is used to represent the ratio of the torque increment output at the current moment to the total torque increment throughout the entire process, which is also the torque difference between the expected steering torque and the lower limit of the steering torque.

[0105] For example, using the adjustment coefficient Taking 0.45 as an example. When the normalized time x=0, the proportion of normalized torque increment y is 0, indicating that in the initial stage of assisted steering control, the initial lower limit of steering torque is used as the target steering torque, waiting for the adjustment value to reach the desired steering torque. When the normalized time x=0.2, the proportion of normalized torque increment y is 48.5%, rapidly increasing the steering torque in the initial stage of steering control to eliminate the control gap of the steering wheel after the driver takes their hands off the wheel. When the normalized time x=0.4, the proportion of normalized torque increment y is 66.2%, and the growth slope of the steering torque gradually decreases. When the normalized time x=0.6, the proportion of normalized torque increment y is 79.5%, and the steering torque enters a gentle convergence range. When the normalized time x=0.8, the proportion of normalized torque increment y is 90.4%, and in the later stage of assisted steering control, the steering torque slowly matches the desired steering torque. When the normalized time x=1, the normalized torque increment ratio y is 100%, and the vehicle's target steering torque smoothly reaches the desired steering torque, realizing non-linear smooth adjustment of the steering torque.

[0106] In this embodiment, a calculation formula integrates the lower limit of steering torque, desired steering torque, duration ratio, and adjustment coefficients corresponding to different driving conditions to achieve precise calculation of the target steering torque. This formula utilizes the power function characteristic to achieve non-linear, progressive adjustment of steering torque. It can adjust the rate of increase of steering torque according to the adjustment coefficients for different driving conditions, ensuring a smooth transition of steering torque from the lower limit to the desired steering torque after the driver releases their hands, while also accurately matching the steering control requirements of different driving conditions, thus improving the user experience of the assisted steering control function.

[0107] In one implementation, during the process of assisting the vehicle's steering control based on the target steering torque, if the driver's hand torque is detected to be greater than or equal to the hand torque threshold, that is, when the driver changes from a hands-free state to a hands-free state, the current assisting steering control is immediately interrupted, the target steering torque is set to the lower limit of the steering torque, and the human-machine co-driving state is re-entered, so that the driver can take the lead in steering the vehicle.

[0108] In summary, in this embodiment, when the driver assistance function is activated and the driver is detected to be in a hands-free state, a corresponding adjustment coefficient is determined based on the vehicle's driving conditions. Using this adjustment coefficient as the exponent and the current duration of the hands-free state as the variable, a power function is constructed to obtain the torque correction weight. This torque correction weight is then used to correct the desired steering torque, resulting in the target steering torque corresponding to the current duration, which is then used for vehicle assisted steering control. This allows for differentiated adjustment of the steering torque rate with hands-free duration based on different driving conditions, avoiding the problems of component jamming or vibration caused by step torque adjustment, and the poor adaptability of single-rule torque adjustment under various conditions. It enables smooth and gradual adjustment of assisted steering control in a hands-free state, ensuring smooth steering control under different driving conditions and improving the user's driving experience.

[0109] Furthermore, when the adjustment coefficient corresponding to the driving conditions is determined to be between 0 and 1, the corresponding target output torque exhibits a non-linear smooth transition. Compared to the single linear torque adjustment rule in existing technologies, this solution can quickly increase the target steering torque in the initial stage of driver hands-off control, promptly compensating for the control gap caused by the driver taking their hands off the wheel and quickly correcting the vehicle's posture. In the later stage of sustained hands-off control, the target steering torque is controlled to slowly approach the desired steering torque, avoiding sudden changes in steering force and stiff steering wheel correction caused by a continuous and significant increase in torque. This makes the vehicle steering adjustment process smoother and gentler, meeting the user's perception of steering force and further enhancing the user's driving experience.

[0110] Figure 3 This is a schematic flowchart illustrating another vehicle steering control method provided in an embodiment of this application. It should be understood that this method can be applied to a vehicle; or, to a processor in a vehicle; or, to a chip within a processor in a vehicle.

[0111] For example, such as Figure 3 As shown, the method includes: S301. Acquire the driver's hand torque when the vehicle's driver assistance function is activated.

[0112] Among them, driver assistance functions specifically include functions involving lateral control of the vehicle, such as lane keeping assist, lane centering control, automatic lane change assist, intelligent cornering assist, and emergency steering assist.

[0113] For example, when the vehicle's driver assistance function is activated, that is, when it enters the L2 or L3 level human-machine co-driving lateral control mode, the driver's hand torque T_hand on the steering wheel is collected in real time through the EPS in the vehicle.

[0114] S302. Determine whether the driver's hand torque is greater than or equal to the hand torque threshold; if yes, execute S303; if no, execute S304.

[0115] For example, after obtaining the driver's hand torque T_hand, the relationship between the hand torque T_hand and the hand torque threshold T_set is determined to determine whether the hand torque T_hand is greater than or equal to the hand torque threshold T_set.

[0116] The hand torque threshold can be set to 0.25 N·m, etc. Optionally, the hand torque threshold can be calibrated according to the vehicle model.

[0117] Alternatively, the implementation methods of S301 and S302 can be found in [reference needed]. Figure 2 The relevant description of S201 is not repeated here in the embodiments of this application.

[0118] S303. Correct the vehicle's steering using the lower limit of steering torque.

[0119] For example, if the driver's hand torque is greater than or equal to the hand torque threshold, i.e., T_hand≥T_set, it indicates that the driver is holding the steering wheel normally and the steering control of the vehicle is in the driver's hands. At this time, the vehicle can be slightly corrected according to the preset lower limit of steering torque to provide the driver with a small amount of steering resistance, thereby achieving basic correction. This improves the driver's driving experience and avoids the driver and steering wheel from fighting each other.

[0120] S304. Determine whether the duration has reached the preset duration; if yes, execute S305; if no, execute S301.

[0121] Among them, the duration refers to the duration during which the driver's hand torque is less than the hand torque threshold.

[0122] For example, if it is determined that the driver's hand torque is less than the hand torque threshold, that is, T_hand < T_set, the duration is further compared with the preset duration to determine whether the duration has reached the preset duration.

[0123] For example, if the duration does not reach the preset duration, indicating that the driver has briefly released the hand, the system returns to S301 to continuously monitor the hand torque.

[0124] S305. Obtain the lower limit of steering torque, the desired steering torque, and the target duration.

[0125] For example, if the duration is determined to have reached a preset duration, it is confirmed that the driver is in a hands-free state. At this time, the lower limit of the vehicle's steering torque, the desired steering torque, and the target duration are obtained.

[0126] For example, the lower limit of steering torque can be a torque value preset according to the vehicle model; the desired steering torque is a torque value calculated by EPS in combination with the vehicle speed, yaw rate and lateral deviation of the vehicle relative to the lane line; the target duration is a duration matched according to the vehicle speed, and the target duration is used to indicate the allowable duration for the vehicle's steering torque to be adjusted to the desired steering torque.

[0127] Optionally, the process for determining the desired steering torque and target duration can be found in [reference needed]. Figure 2 The relevant descriptions of S201 and S203 are not repeated here in the embodiments of this application.

[0128] S306. Based on the lower limit of steering torque, the desired steering torque, and the target duration, the target steering torque is obtained using a nonlinear smoothing algorithm.

[0129] For example, after obtaining the vehicle's lower limit of steering torque, desired steering torque, and target duration, a nonlinear smoothing algorithm can be used to obtain the target steering torque at each moment during the assisted steering control process.

[0130] In one implementation, the nonlinear smoothing algorithm can be expressed by the following formula: ; Where t represents the current duration, Used to indicate the target steering torque at the current moment. Used to indicate the lower limit of steering torque. Used to indicate the desired steering torque. Used to indicate the target duration, Used to represent adjustment coefficients.

[0131] For example, based on the vehicle's driving conditions, determine the matching... , The value range is (0,1), and the corresponding steering torque adjustment curve is concave. The rate of change of the target steering torque shows a trend of being fast at first and then slow. The smaller the value, the faster the steering torque increases in the early stages of steering control, and the smoother the steering torque convergence in the later stages of control. The larger the value, the closer the steering torque adjustment curve becomes to linear, and the smoothness of steering control decreases.

[0132] In one implementation, =0.45 is used as the optimal calibration value. That is, for any working condition, the adjustment coefficient of 0.45 is used to determine the target steering torque at each moment in the steering control process. This is in line with the human body's perception of steering force, taking into account the agility in the early stage of torque transition and the smoothness in the later stage. It avoids the initial steering wheel control blank and the torque shock in the later stage, so that the steering wheel torque can be restored to the desired steering torque without feeling after the driver takes his hands off the wheel, thus improving the user's driving experience.

[0133] Alternatively, the implementation of S306 can be found in [reference needed]. Figure 2 The relevant descriptions of S202 and S203 are not repeated here in the embodiments of this application.

[0134] S307. Assisted steering control of the vehicle based on the target steering torque.

[0135] For example, after determining the target steering torque that matches the current state of the vehicle, the EPS is controlled to output the target steering torque to provide assisted steering control for the vehicle.

[0136] S308. Determine whether the driver's hand torque is greater than or equal to the hand torque threshold; if yes, execute S303; if no, execute S309.

[0137] For example, during the process of controlling the vehicle according to the target steering torque, the driver's hand torque is continuously monitored, and the relationship between the hand torque and the hand torque threshold is compared.

[0138] For example, if the driver's hand torque is greater than or equal to the hand torque threshold, indicating that the driver has re-engaged in vehicle control, S303 can be executed to correct the vehicle's steering torque to the lower limit of steering torque.

[0139] S309. Determine if the current duration has reached the target duration; if yes, execute S310; if no, execute S306.

[0140] For example, if the driver's hand torque is still less than the hand torque threshold, it indicates that the driver is still in a hands-free state. Then, it is determined whether the cumulative time after the assisted steering control is executed, that is, whether the current time has reached the target time.

[0141] For example, if the current duration has not reached the target duration, the target steering torque is continuously calculated iteratively in order to perform assisted steering control.

[0142] S310. The intelligent driving system calculates the target steering torque in real time and controls the vehicle's steering.

[0143] For example, if the duration of the assisted steering control reaches the target duration, it indicates that the smooth transition process of the steering torque has been completed. Then, the nonlinear smooth transition logic can be exited, and the intelligent driving system can calculate the steady-state target steering torque in real time based on the real-time vehicle speed, lateral deviation, and yaw rate, and switch to the conventional lateral closed-loop control mode, relying on the real-time steering torque to continuously control the vehicle's steering.

[0144] In summary, in this embodiment, after the vehicle's assisted driving function is activated, the driver's hand torque is continuously collected. The effective hands-free state of the driver is identified through a dual determination of the hand torque threshold and the duration of hands-free operation. In the hands-free state, a basic corrective torque is provided using the lower limit of steering torque to avoid the steering wheel feeling loose and unstable. In the hands-free state, a nonlinear smoothing algorithm is used to generate a gradually increasing target steering torque based on the lower limit of steering torque, the desired steering torque, and the target duration to assist in steering control of the vehicle. During the control process, the hand torque of the driver's intervention is monitored in real time. Once the driver is detected holding the steering wheel, the system immediately switches to a correction mode that only outputs the lower limit of steering torque. After the transition time is reached without driver intervention, the system switches to the conventional closed-loop control of the intelligent driving system to adjust the steering torque in real time. This scheme can smooth the steering torque by relying on a nonlinear power function transition curve when the driver takes their hands off the wheel, weakening the steering wheel pull and jerk caused by sudden torque changes, improving the smoothness of assisted steering control of the vehicle in the hands-free state, and enhancing the user's driving experience.

[0145] The above text combined Figures 1 to 3 The vehicle steering control method provided in the embodiments of this application is described in detail below; the following will be combined with Figure 4 and Figure 5 The apparatus embodiments of this application are described in detail below. It should be understood that the apparatus in the embodiments of this application can perform the various methods described in the foregoing embodiments of this application, that is, the specific working processes of the various products described below can be referred to the corresponding processes in the foregoing method embodiments.

[0146] Figure 4 This is a schematic diagram of the structure of a vehicle steering control device provided in an embodiment of this application.

[0147] For example, such as Figure 4 As shown, the vehicle steering control device 400 includes: The acquisition module 401 is used to acquire the vehicle's expected steering torque and driving conditions when the vehicle's assisted driving function is activated and the driver is detected to be in a hands-free state. The processing module 402 is used to obtain the adjustment coefficient corresponding to the driving condition based on the driving condition; to obtain the torque correction weight corresponding to the current duration based on the power function constructed by the adjustment coefficient and the current duration, where the current duration is used to represent the duration between the current moment and the moment when the driver is detected to be in a hands-free state, and the adjustment coefficient is used as the exponent of the power function; and to obtain the target steering torque at the current moment based on the desired steering torque and the torque correction weight corresponding to the current duration, where the target steering torque is used to perform auxiliary steering control on the vehicle.

[0148] In one possible implementation, the processing module 402 is further configured to determine a target duration based on the vehicle speed, wherein the target duration indicates the duration for adjusting the vehicle's steering torque to the desired steering torque, and the target duration is negatively correlated with the vehicle speed; based on the current duration and the target duration, the duration percentage corresponding to the current duration is obtained; and based on the power function constructed from the adjustment coefficient and the duration percentage, the torque correction weight corresponding to the current duration is obtained, wherein the duration percentage is used as the base of the power function.

[0149] In one possible implementation, the processing module 402 is further configured to obtain a torque difference based on the desired steering torque and the lower limit of the steering torque; obtain a torque adjustment amount corresponding to the current duration based on the torque difference and the torque correction weight corresponding to the current duration; and obtain the target steering torque at the current moment based on the torque adjustment amount corresponding to the current duration and the lower limit of the steering torque.

[0150] In one possible implementation, the acquisition module 401 is further configured to acquire the vehicle's driving parameters, including vehicle speed, yaw rate, and lateral deviation of the vehicle relative to the lane line; the processing module 402 is further configured to obtain the desired steering torque based on the vehicle's driving parameters.

[0151] In one possible implementation, the processing module 402 is further configured to: obtain a first weighting coefficient corresponding to the yaw rate and a second weighting coefficient corresponding to the lateral deviation based on the vehicle speed; obtain a first steering torque based on the yaw rate and the first weighting coefficient; obtain a second steering torque based on the lateral deviation and the second weighting coefficient; and obtain a desired steering torque based on the first steering torque and the second steering torque.

[0152] In one possible implementation, the processing module 402 is further configured to obtain the target steering torque at the current moment based on the following formula: ; Where t represents the current duration, Used to indicate the target steering torque at the current moment. Used to indicate the lower limit of steering torque. Used to indicate the amount of torque adjustment corresponding to the current duration. Used to indicate the desired steering torque. Used to indicate the target duration, Used to represent adjustment coefficients.

[0153] In one possible implementation, the acquisition module 401 is further configured to acquire vehicle model information; determine the adjustment coefficient range based on the model information; and the processing module 402 is further configured to obtain the adjustment coefficient corresponding to the driving condition from the adjustment coefficient range based on the driving condition.

[0154] In one possible implementation, the acquisition module 401 is further used to acquire the driver's hand torque; the processing module 402 is further used to determine that the driver is in a hands-free state when the hand torque is less than the hand torque threshold and the duration reaches a preset duration.

[0155] It should be noted that the aforementioned vehicle steering control device is implemented in the form of a functional unit. The term "module" here can be implemented in software and / or hardware, without specific limitations.

[0156] For example, a "module" can be a software program, a hardware circuit, or a combination of both that implements the above functions. The hardware circuit may include an application-specific integrated circuit (ASIC), electronic circuitry, a processor (e.g., a shared processor, a proprietary processor, or a group processor) and memory for executing one or more software or firmware programs, integrated logic circuitry, and / or other suitable components that support the described functions.

[0157] Therefore, the units of the various examples described in the embodiments of this application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0158] Figure 5 This is a schematic diagram of the structure of a vehicle provided in an embodiment of this application.

[0159] For example, such as Figure 5 As shown, the vehicle 100 includes a memory 501 and a processor 502. The memory 501 stores executable program code 503, and the processor 502 is used to call and execute the executable program code 503 to perform a vehicle steering control method.

[0160] Furthermore, embodiments of this application also protect an apparatus that may include a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code to perform a vehicle steering control method provided in embodiments of this application.

[0161] This embodiment can divide the device into functional modules based on the above method example. For example, each module can correspond to a separate function, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0162] When the functional modules are divided according to their respective functions, the device may also include an acquisition module, a processing module, etc. It should be noted that all relevant content of each step involved in the above method embodiments can be referenced to the functional description of the corresponding functional module, and will not be repeated here.

[0163] It should be understood that the device provided in this embodiment is used to execute the above-described vehicle steering control method, and therefore can achieve the same effect as the above-described implementation method.

[0164] When using an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module can be used to control and manage the vehicle's movements. The storage module can be used to support the vehicle in executing relevant program code.

[0165] The processing module may be a processor or a controller, which can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor may also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc., and the storage module may be a memory.

[0166] In addition, the device provided in the embodiments of this application may specifically be a chip, component or module. The chip may include a connected processor and a memory. The memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute a vehicle steering control method provided in the above embodiments.

[0167] This embodiment also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer, the computer executes the above-described related method steps to implement a vehicle steering control method provided in the above embodiment.

[0168] The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, Digital Video Discs (DVDs), Compact Disc Read-Only Memory (CD-ROMs), microdrives, and magneto-optical disks, read-only memory (ROMs), random access memory (RAMs), erasable programmable read-only memory (EPROMs), electrically erasable programmable read-only memory (EEPROMs), dynamic random access memory (DRAMs), video random access memory (VRAMs), flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0169] This embodiment also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned steps to implement a vehicle steering control method provided in the above embodiment.

[0170] In this embodiment, the device, computer-readable storage medium, computer program product, or chip are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0171] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0172] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0173] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A vehicle steering control method, characterized in that, The method includes: When the vehicle's driver assistance function is activated, if it is detected that the driver is in a hands-free state, the vehicle's expected steering torque and driving conditions are obtained. Based on the driving conditions, the adjustment coefficient corresponding to the driving conditions is obtained; Based on the power function constructed using the adjustment coefficient and the current duration, the torque correction weight corresponding to the current duration is obtained. The current duration is used to represent the duration between the current moment and the moment when the driver is detected to be in a hands-free state. The adjustment coefficient serves as the exponent of the power function. Based on the desired steering torque and the torque correction weight corresponding to the current duration, the target steering torque at the current moment is obtained, and the target steering torque is used to perform auxiliary steering control on the vehicle.

2. The method according to claim 1, characterized in that, The method further includes: Based on the vehicle speed, a target duration is determined. The target duration is used to indicate the duration for the vehicle's steering torque to adjust to the desired steering torque. The target duration is negatively correlated with the vehicle speed. The power function constructed based on the adjustment coefficient and the current duration yields the torque correction weight corresponding to the current duration, including: Based on the current duration and the target duration, the duration percentage corresponding to the current duration is obtained; Based on the adjustment coefficient and the duration ratio, a power function is constructed to obtain the torque correction weight corresponding to the current duration, and the duration ratio is used as the base of the power function.

3. The method according to claim 1, characterized in that, The step of obtaining the target steering torque at the current moment based on the torque correction weight corresponding to the desired steering torque and the current duration includes: Based on the desired steering torque and the lower limit of steering torque, the torque difference is obtained; Based on the torque difference and the torque correction weight corresponding to the current duration, the torque adjustment amount corresponding to the current duration is obtained; Based on the torque adjustment amount corresponding to the current duration and the lower limit of the steering torque, the target steering torque at the current moment is obtained.

4. The method according to any one of claims 1 to 3, characterized in that, The method further includes: The vehicle's driving parameters are obtained, including vehicle speed, yaw rate, and lateral deviation of the vehicle relative to the lane line. The desired steering torque is obtained based on the vehicle's driving parameters.

5. The method according to claim 4, characterized in that, The process of obtaining the desired steering torque based on the vehicle's driving parameters includes: Based on the vehicle speed, a first weighting coefficient corresponding to the yaw rate and a second weighting coefficient corresponding to the lateral deviation are obtained; The first steering torque is obtained based on the yaw rate and the first weighting coefficient; The second steering torque is obtained based on the lateral deviation and the second weighting coefficient; The desired steering torque is obtained based on the first steering torque and the second steering torque.

6. The method according to any one of claims 1 to 3, characterized in that, The method further includes: Obtain the vehicle model information; Based on the vehicle model information, determine the adjustment coefficient range; The step of obtaining the adjustment coefficient corresponding to the driving conditions based on the driving conditions includes: Based on the driving conditions, the adjustment coefficient corresponding to the driving conditions is obtained from the adjustment coefficient range.

7. The method according to any one of claims 1 to 3, characterized in that, The method further includes: Obtain the driver's hand torque; When the hand torque is less than the hand torque threshold and the duration reaches a preset duration, the driver is determined to be in the hands-free state.

8. A vehicle steering control device, characterized in that, The device includes: The acquisition module is used to acquire the vehicle's expected steering torque and driving conditions when the vehicle's assisted driving function is activated and the driver is detected to be in a hands-free state. The processing module is configured to: obtain an adjustment coefficient corresponding to the driving condition based on the driving condition; obtain a torque correction weight corresponding to the current duration based on a power function constructed from the adjustment coefficient and the current duration, wherein the current duration represents the duration between the current moment and the moment when the driver is detected to be in a hands-free state, and the adjustment coefficient serves as the exponent of the power function; and obtain a target steering torque at the current moment based on the desired steering torque and the torque correction weight corresponding to the current duration, wherein the target steering torque is used to perform auxiliary steering control on the vehicle.

9. A vehicle, characterized in that, The vehicles include: Memory, used to store executable program code; A processor for calling and running the executable program code from the memory, causing the vehicle to perform the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1 to 7.

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