Power-assisted steering force control method and device and vehicle

Abstract

The invention relates to the field of vehicle steering control, and particularly discloses a power-assisted steering force control method and device and a vehicle. The method comprises the steps that vehicle state parameters of a target vehicle are obtained, and dimension adjustment factors corresponding to parameter values of all the vehicle state parameters are determined; determining a preset weight factor group corresponding to the target vehicle based on each vehicle state parameter; determining a power-assisted adjustment factor corresponding to the current vehicle state parameter based on the dimension adjustment factor and a corresponding preset weight factor; and determining the power-assisted torque of the power-assisted steering motor based on the power-assisted adjustment factor and the basic power-assisted steering force. The requirements of a driver on steering operation under different driving conditions can be met, and the stability and safety of the vehicle and the comfort of the driver are improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle steering control, and in particular to a method and device for controlling steering assist force, and a vehicle. Background Art

[0002] The current levels of steering wheel power assistance are mostly divided into "comfort", "sport" and "light". After the driver selects the steering mode on the vehicle computer, the corresponding steering power assistance mode is executed.

[0003] The inventors discovered that the current power steering force is fixed across different modes, resulting in significant differences in the user's steering experience under different road conditions, impacting the driving experience. Therefore, designing an intelligent control strategy to meet the driver's steering needs under different driving conditions is an urgent challenge in the power steering field. Summary of the Invention

[0004] In view of the above problems, the present disclosure provides a method, device, computer-readable storage medium, and vehicle that overcome the above problems or at least partially solve the above problems. The technical solutions are as follows:

[0005] A method for controlling steering assist force, comprising: obtaining vehicle state parameters of a target vehicle, the vehicle state parameters including at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; determining dimensional adjustment factors corresponding to parameter values ​​of respective vehicle state parameters; based on respective vehicle state parameters, determining a preset weight factor group corresponding to the target vehicle, the preset weight factor group including preset weight factors corresponding to respective vehicle state parameters; based on the dimensional adjustment factors and the corresponding preset weight factors, determining an assist adjustment factor corresponding to the current vehicle state parameter; and based on the assist adjustment factor and a basic steering assist force, determining an assist torque of a steering assist motor.

[0006] This application sets the weight factors corresponding to each vehicle state parameter based on the influence of each vehicle state parameter on the steering assist force under different driving conditions of the target vehicle, and determines the dimensional adjustment factor corresponding to each weight factor according to the size of the vehicle state parameter, and then calculates the assist torque of the steering assist click, so that the target vehicle has an appropriate amount of steering assist force under different driving conditions. Compared with the current fixed steering assist force and speed-variable steering assist force, it can better adapt to different driving conditions and driving scenarios, and will greatly improve the stability and safety of the vehicle and the comfort of the driver.

[0007] Optionally, determining the dimensional adjustment factors corresponding to the parameter values ​​of each vehicle state parameter specifically includes: determining a pre-calibrated dimensional adjustment factor table corresponding to each vehicle state; and determining the dimensional adjustment factors corresponding to the vehicle state parameters in the dimensional adjustment factor table based on the parameter values ​​of the vehicle state parameters.

[0008] By calibrating the dimensional adjustment factors corresponding to the parameter values ​​of different vehicle state parameters in advance, the sizes of the dimensional adjustment factors corresponding to different vehicle state parameters can be quickly determined, thereby accelerating the response speed of the target vehicle when adjusting the steering assist.

[0009] Optionally, the determining of the preset weight factor group corresponding to the target vehicle based on each vehicle state parameter specifically includes: obtaining a weight reference parameter, the weight reference parameter including at least one of road curvature, steering angle change rate, ambient temperature, lateral acceleration and yaw angular velocity; determining that each vehicle state parameter and the weight reference parameter meet a preset weight condition; using the preset weight factor group corresponding to the preset weight condition as the preset weight factor group corresponding to the target vehicle; the preset weight condition includes at least one of the following conditions: a first preset weight condition that the vehicle speed is lower than a first speed threshold and the steering angle change rate is higher than the first change rate threshold; a second preset weight condition that the vehicle speed is higher than a second speed threshold and the lateral acceleration is lower than the first acceleration threshold; a third preset weight condition that the road curvature is higher than the preset curvature threshold and the yaw angular velocity is higher than the second acceleration threshold; a fourth preset weight condition that the road adhesion coefficient is less than the first preset threshold and the temperature is lower than the first temperature threshold; a fifth preset weight condition that the load is greater than a preset percentage threshold and the vehicle speed change amplitude within a preset time period is lower than the third speed threshold.

[0010] This application provides different weight factors corresponding to various working conditions. When the vehicle state parameters and weight reference parameters meet the corresponding preset weight conditions, the corresponding weight factors are used when calculating the assist torque, so that the final assist torque value is more in line with different driving conditions and improves the driver's driving experience.

[0011] Optionally, the power assist adjustment factor corresponding to the current vehicle state parameter is determined based on the dimensional adjustment factor and the corresponding preset weight factor, specifically including: multiplying the dimensional adjustment factor corresponding to the target vehicle state parameter with the corresponding preset weight factor to obtain the dimensional power assist adjustment factor corresponding to the target vehicle state parameter; and taking the sum of the dimensional power assist adjustment factors corresponding to each vehicle state parameter as the power assist adjustment factor corresponding to the current vehicle state parameter.

[0012] By weighted calculation of the power assist adjustment factor, the vehicle state parameters and the impact of the vehicle state on the steering assist can be combined to determine the most appropriate power assist torque output for the target vehicle under different driving conditions.

[0013] Optionally, after determining the power steering torque of the power steering motor, the method also includes: determining that the steering wheel angle of the target vehicle is higher than a preset threshold; obtaining vehicle motion parameters of the target vehicle, the vehicle motion parameters including vehicle speed, wheelbase, center of mass height, wheelbase, and actual steering wheel speed; based on the vehicle motion parameters, determining the maximum steering wheel speed of the target vehicle in a critical rollover state.

[0014] Optionally, the maximum steering wheel speed of the target vehicle is determined based on the vehicle motion parameters, specifically including: determining the static lateral acceleration of the target vehicle in a critical rollover state based on the wheelbase and the center of mass height; using the static lateral acceleration as the maximum lateral acceleration of the target vehicle in a dynamic state; determining the curve radius based on the maximum lateral acceleration, the vehicle speed, and the actual steering wheel speed; determining the front wheel angle of the target vehicle based on the curve radius and the wheelbase; determining the maximum steering wheel angle of the target vehicle based on the front wheel angle and the transmission ratio; and determining the maximum steering wheel speed based on the maximum steering wheel angle. In order to prevent the vehicle from rolling over, the present application calculates the steering wheel speed corresponding to the critical conditions of the vehicle rolling over, so that the power assist motor can monitor the steering wheel speed during the vehicle's driving process, thereby reducing the probability of the vehicle rolling over, thereby improving the stability of the vehicle at high speeds and the comfort of the driver at low speeds.

[0015] Optionally, after determining the assist torque of the power steering motor based on the assist adjustment factor and the basic steering assist force, the method further includes: receiving an assist torque adjustment instruction from the driver, and obtaining the current vehicle state parameters of the target vehicle, the current preset weight factor group, and the sample vehicle state parameters corresponding to the current preset weight factor group; determining whether there is a difference state parameter between the current vehicle state parameter and the sample vehicle state parameter, the difference of which is higher than a preset threshold; if the difference state parameter exists, adjusting and recording the preset weight factor corresponding to the difference state parameter in the preset weight factor group based on the assist torque adjustment instruction; if the difference state parameter does not exist, adjusting and recording the basic steering assist force corresponding to the current vehicle state parameter based on the assist torque adjustment instruction.

[0016] This application obtains the driver's active adjustment instructions, analyzes the driver's active adjustment reasons, and adjusts and records the weight factor or basic steering assist force. When encountering the same working conditions again, the recorded weight factor and basic steering assist force can be used to make the assist torque output by the power motor closer to the driver's driving habits, so as to meet the driver's personalized needs and improve the driver's driving experience.

[0017] Optionally, before determining the assist torque of the power steering motor based on the assist adjustment factor and the basic steering assist force, the method also includes: receiving an instruction to change the seat position in the target vehicle; if the seat position templates corresponding to different drivers do not include the changed seat position, determining the seat adjustment distance between the changed seat position and each seat position template; and adjusting the basic steering assist force based on the seat adjustment distance.

[0018] Optionally, the basic steering assist force is adjusted based on the seat adjustment distance, specifically including: if there is a seat position template whose seat adjustment distance with the changed seat position is lower than a preset distance threshold, obtaining the driver's body data corresponding to the seat position template; the body data includes: torso length data and arm length data; based on the driver's body data and the changed seat position, adjusting the basic steering assist force; if there is no seat position template whose seat adjustment distance with the changed seat position is lower than a preset distance threshold, initializing the basic steering assist force.

[0019] This application compares the seat position with the driving habits and determines whether to change the driver by monitoring the seat position, so as to change the basic steering assist force according to the different seat positions, thereby outputting a more appropriate assist torque based on the physical data of different drivers. On the premise of ensuring that the assist torque is closer to the driving habits, it avoids the large gap between the actual output assist torque and the required assist torque due to the change of driver.

[0020] Optionally, after determining the assist torque of the power steering motor based on the assist adjustment factor and the basic steering assist force, the method further includes: obtaining the road surface change section and the corresponding road adhesion coefficient set of the target vehicle within a preset time period in the future based on the current navigation path; determining the predicted time point when the target vehicle will arrive at the road surface change section based on the position coordinates of the road surface change section and the current vehicle speed; determining the assist torque prediction value of the target vehicle within the road surface change section based on the road adhesion coefficient set; adjusting the assist torque of the power steering motor based on the predicted time point and the assist torque prediction value, so that the target vehicle slowly adjusts the current assist torque to the assist torque prediction value within a preset distance before reaching the road surface change section.

[0021] By accessing the navigation system and obtaining road conditions in advance, the corresponding power-assisting torque after the road section changes can be calculated in advance, and then the power-assisting torque of the power-assisting motor can be slowly adjusted in advance before entering the road section with road changes. This can prevent the driver from being unable to adapt to the sudden change in power-assisting torque. At the same time, putting the calculation process in advance can shorten the reaction time after entering the road section with road changes and improve the driver's driving experience.

[0022] The present application also provides a vehicle control device, which includes: a parameter acquisition module, which acquires vehicle state parameters of a target vehicle, wherein the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; a dimension adjustment factor module, which determines the dimension adjustment factors corresponding to the parameter values ​​of each vehicle state parameter; a preset weight factor module, which determines the preset weight factor group corresponding to the target vehicle based on each vehicle state parameter and the current working condition of the target vehicle; a power assist adjustment factor module, which determines the power assist adjustment factor corresponding to the current vehicle state parameter based on the dimension adjustment factor and the corresponding preset weight factor; and a power assist torque output module, which determines the power assist torque of the power steering motor based on the power assist adjustment factor and the basic steering assist force.

[0023] The present application also provides a vehicle, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute: obtaining vehicle state parameters of a target vehicle, the vehicle state parameters including at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; determining dimension adjustment factors corresponding to the parameter values ​​of each vehicle state parameter; determining a preset weight factor group corresponding to the target vehicle based on each vehicle state parameter and the current operating condition of the target vehicle; determining a power assist adjustment factor corresponding to the current vehicle state parameter based on the dimension adjustment factor and the corresponding preset weight factor; and determining the power assist torque of the power steering motor based on the power assist adjustment factor and the basic steering assist force.

[0024] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present disclosure. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0026] Figure 1 A schematic flow chart of a method for controlling steering assist force provided in an embodiment of the present application is shown;

[0027] Figure 2 A schematic structural diagram of a steering assist force control device provided in an embodiment of the present application is shown;

[0028] Figure 3 A schematic diagram of a steering assist force control device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. The technical solutions provided by the various embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0030] The current levels of steering wheel power assistance are mostly divided into "comfort", "sport" and "light". After the driver selects the steering mode on the vehicle computer, the corresponding steering power assistance mode is executed.

[0031] The inventors discovered that the current steering assist is fixed in different modes and cannot be adjusted to actual driving conditions. This can significantly impact the user's steering experience under different road conditions, affecting the driving experience. For example, at low speeds, steering is difficult; to improve the driving experience, the steering assist should be more sensitive. At high speeds, steering is easy; to prevent the vehicle from turning too sharply, the steering assist should be slower.

[0032] Therefore, how to design an intelligent control strategy to meet the steering operation needs of drivers in different driving conditions is an urgent problem to be solved in the field of power steering.

[0033] In this regard, Figure 1 This is a flow chart of a method for controlling steering assist force provided in one or more embodiments of this specification. The process can be executed by a computing device within a vehicle, and certain input parameters or intermediate results in the process can be manually adjusted to help improve accuracy.

[0034] The analysis method involved in the embodiments of the present application can be implemented by a terminal device or a server, and the present application does not impose any special restrictions on this. For ease of understanding and description, the following embodiments are described in detail using a server as an example.

[0035] It should be noted that the server can be a single device or a system composed of multiple devices, that is, a distributed server, and this application does not make any specific restrictions on this.

[0036] like Figure 1 As shown, an embodiment of the present application provides a method for controlling the steering assist force, including:

[0037] S101: Obtain vehicle state parameters of a target vehicle.

[0038] In this solution, steering assistance refers to steering wheel assistance, which means that the driver can turn the steering wheel with less force, thereby achieving an effort-saving effect. Taking into account the impact of actual vehicle speed, tire pressure, vehicle load, road adhesion, and steering angle and speed on the steering assistance force under different working conditions, this solution will use these factors as control factors to adjust the steering assistance force under different working conditions, and ensure vehicle safety in special scenarios such as insufficient tire pressure and low road adhesion. The above-mentioned vehicle state parameters can be understood as evaluation dimensions for determining the steering assistance force. The type of vehicle state parameters selected and the size of the state parameter values ​​will directly affect the steering assistance force.

[0039] S102: Determine the dimension adjustment factors corresponding to the parameter values ​​of each vehicle state parameter.

[0040] The steering assist torque calculated logically for the current vehicle is used as the base torque; vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed are used as adjustment factors for the base steering assist torque. These dimensional adjustment factors reflect the impact of a single vehicle state parameter on the base steering assist torque, and their magnitude is correlated with the value of the single vehicle state parameter.

[0041] In one embodiment, when determining the dimensionality adjustment factor, it is necessary to first determine a pre-calibrated dimensionality adjustment factor table corresponding to each vehicle state parameter value, and then determine the dimensionality adjustment factor corresponding to the vehicle state parameter value in the dimensionality adjustment factor table. In this process, the parameter value of the vehicle state parameter is used as input to the dimensionality adjustment factor table to determine the dimensionality adjustment factor corresponding to the vehicle state parameter value.

[0042] The values ​​of the dimension adjustment factors in each table can be determined through actual vehicle calibration. The specific values ​​of each dimension adjustment factor in the above dimension adjustment factor table can be filled in based on the tester's experience during the test. The following is an explanation of the value logic of each dimension adjustment factor during the test:

[0043] For the speed dimension adjustment factor, a low-speed threshold and a high-speed threshold can be set separately. When the actual vehicle speed is lower than the low-speed threshold, the target vehicle is in a low-speed driving state. When the actual vehicle speed is higher than the high-speed threshold, the target vehicle is in a high-speed driving state. When the actual vehicle speed is greater than the low-speed threshold but less than the high-speed threshold, the target vehicle is in a medium-speed driving state. Low speed, medium speed, and high speed correspond to different speed dimension adjustment factors, and the lower the speed, the larger the dimension adjustment factor. The purpose is to ensure easy steering at low speeds, steering flexibility and vehicle stability at medium speeds, and vehicle stability at high speeds. The speed dimension adjustment factor is output after judging the low, medium, and high speeds.

[0044] For example, the dimension adjustment factor table structure for different vehicle speeds is as follows. The specific values ​​need to be adjusted through calibration to improve accuracy:

[0045] Table 1 Dimension adjustment factors corresponding to different vehicle speeds

[0046] Vehicle speed (kph) 0 20 40 60 80 100 120 150 Vehicle speed dimension adjustment factor 1.5 1.3 1.1 1.0 0.9 0.8 0.7 0.5

[0047] For the tire pressure dimension adjustment factor, a normal tire pressure threshold can be set. When the actual tire pressure value is lower than this threshold, the tire pressure is judged to be insufficient. The difference between the actual tire pressure and the normal tire pressure threshold is used as the input for the one-dimensional lookup table. The larger the positive difference, the smaller the tire pressure dimension adjustment factor; the larger the negative difference, the larger the tire pressure dimension adjustment factor. The purpose is that when the tire pressure is insufficient, the contact area with the ground will increase, the friction will also increase, and the steering resistance will increase, requiring greater steering force. This can be used to calibrate the tire pressure dimension adjustment factor.

[0048] For example, the dimension adjustment factor table for different tire pressure differences is as follows:

[0049] Table 2 Dimension adjustment factors corresponding to different tire pressure differences

[0050] Tire pressure difference (bar) -0.3 -0.2 -0.1 0 +0.1 +0.2 +0.3 Tire pressure dimension adjustment factor 1.2 1.1 1.05 1.0 0.95 0.9 0.85

[0051] For the load dimension adjustment factor, the vehicle's unladen weight can be set as the judgment threshold. The absolute difference between the actual vehicle weight and the threshold is used as the input for a one-dimensional lookup table. The larger the difference, the larger the load dimension adjustment factor. The goal is to calibrate the load dimension adjustment factor based on the fact that as vehicle weight increases, tire-ground friction increases, resulting in greater steering resistance and the need for greater steering assist.

[0052] For example, the dimension adjustment factor table for different load differences is as follows:

[0053] Table 3 Dimension adjustment factors corresponding to different load differences

[0054] Load difference (kg) 0 100 200 300 Load dimension adjustment factor 1.0 1.1 1.2 1.3

[0055] For the adhesion coefficient dimensional adjustment factor, the current road adhesion coefficient is used as input for a one-dimensional lookup table. The lower the road adhesion coefficient, the smaller the adhesion coefficient dimensional adjustment factor, and vice versa. The goal is to calibrate the adhesion coefficient dimensional adjustment factor so that low-adhesion road surfaces, such as icy or slippery surfaces, have less steering resistance and require less power.

[0056] For example, the dimension adjustment factor table for different tire pressure differences is as follows:

[0057] Table 4 Dimension adjustment factors corresponding to different adhesion coefficients

[0058] Adhesion coefficient 0.3 0.5 0.7 0.9 1 Adhesion coefficient dimension adjustment factor 1.5 1.3 1.1 0.9 0.8

[0059] For the speed dimension adjustment factor, the steering wheel speed can be directly used as the input of the one-dimensional lookup table. The faster the speed, the larger the dimension adjustment factor. The purpose is that when the steering wheel speed is too fast, such as at a rapid speed, the steering assist needs to provide greater force to help the driver complete the steering smoothly. In this way, the speed dimension adjustment factor can be calibrated.

[0060] For example, the dimension adjustment factor table for different tire pressure differences is as follows:

[0061] Table 5 Dimension adjustment factors corresponding to different steering wheel speeds

[0062] Steering wheel speed (° / s) 0 100 200 300 400 500 600 Speed ​​dimension adjustment factor 1.5 1.3 1.1 1.0 0.9 0.75 0.6

[0063] It should be noted that for different vehicles, the actual correspondence between the parameter values ​​of the above five vehicle state parameters and the dimensional adjustment factors needs to be calibrated on the actual vehicle. The above five tables are only used to illustrate the changing trends between the parameter values ​​of the five vehicle states and the dimensional adjustment factors.

[0064] S103: Determine a preset weight factor group corresponding to the target vehicle based on each vehicle state parameter and the current operating condition of the target vehicle.

[0065] Each dimensional adjustment factor is associated with a weighting factor, which represents the importance of each dimensional adjustment factor under different vehicle driving conditions. It should be noted that if the vehicle's dimensional adjustment factors are determined using the vehicle's speed, tire pressure, and vehicle load parameters, only the weighting factors corresponding to these three parameters will be generated when determining the weighting factor group.

[0066] In one embodiment, the preset weight factors corresponding to different vehicle driving conditions are different. Therefore, when determining the preset weight factor group of the target vehicle, it is necessary to obtain weight reference parameters that can reflect the current vehicle driving conditions to assist in determining whether each vehicle state parameter meets the preset weight conditions. When the current vehicle state parameters and weight reference parameters meet the preset weight conditions, the preset weight factor group corresponding to the preset weight conditions is used as the preset weight factor group corresponding to the target vehicle.

[0067] The following are examples of preset weight factors under several working conditions:

[0068] In the urban commuting driving scenario, the target vehicle's operating condition is a speed of less than 60 kph and a steering angle change rate greater than 5° / s. The weight factors corresponding to the adjustment factors of each dimension are: steering wheel speed 0.4, vehicle speed 0.3, load 0.1, tire pressure 0.1, and adhesion coefficient 0.1.

[0069] In the high-speed cruising driving scenario, the target vehicle's operating conditions are a speed greater than 80 kph and a lateral acceleration less than 0.3 g. The weighting factors can be set as: adhesion coefficient 0.35, speed 0.3, tire pressure 0.2, load 0.1, and steering wheel speed 0.05.

[0070] In the driving scenario of mountain roads, the operating condition of the target vehicle is that the road curvature is greater than 0.01 and the yaw angular velocity is greater than 10° / s; at this time, the weight factors of different dimensional adjustment factors for the modification can be set to: adhesion coefficient 0.4, steering wheel speed 0.3, load 0.2, vehicle speed 0.0, and tire pressure 0.05.

[0071] In the driving scenario on icy and snowy roads, the target vehicle's operating conditions are adhesion coefficient less than 0.3 and temperature less than 5°. At this time, the weight factors of different dimensional adjustment factors for the adjustment can be set to: adhesion coefficient 0.5, tire pressure 0.25, vehicle speed 0.1, steering wheel speed 0.1, and load 0.05.

[0072] In the heavy-load transportation driving scenario, the target vehicle's operating condition is that the load is greater than 80% of the rated weight, and the speed change amplitude within the preset time period is less than 10kph; at this time, the weight factors of different dimensional adjustment factors for the drink change can be set to: load 0.45, tire pressure 0.25, adhesion coefficient 0.2, vehicle speed 0.1, and steering wheel speed 0.

[0073] S104: Based on the dimension adjustment factor and the corresponding preset weight factor, determine the power assistance adjustment factor corresponding to the current vehicle state parameter.

[0074] After determining the adjustment factors of each dimension and the corresponding weight factors, the corresponding power adjustment factor of the current vehicle under the current working condition can be determined. Among them, the power adjustment factor can be calculated by weighting the adjustment factors of each dimension and the corresponding weight factors.

[0075] Specifically, if the dimensional adjustment factors corresponding to vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed are K1, K2, K3, K4, and K5 respectively, and the weight factors are X1, X2, X3, X4, and X5 respectively, then the power adjustment factor can be calculated by the following formula:

[0076] K corrn =K1*X1+K2*X2+K3*X3+K4*X4+K5*X5

[0077] in, To help regulate factors.

[0078] S105: Determine the power steering torque of the power steering motor based on the power steering adjustment factor and the basic power steering force.

[0079] Once the power assist adjustment factor and base steering assist force are known, the product of the power assist adjustment factor and base steering assist force can be used as the total assist torque output to the power steering motor. The base steering assist force can be related to the power assist mode selected by the user. Currently, the steering assist levels are generally divided into "Comfort," "Sport," and "Light," and different power assist modes correspond to different base steering assist forces.

[0080] The assist torque can be calculated using the following formula:

[0081] Tq=Tq Base *K corrn

[0082] Among them, Tq is the assist torque, Tq Base Basic steering assist.

[0083] In one embodiment, the present application also considers the risk of vehicle rollover caused by excessive steering wheel speed when the user turns. Therefore, it is necessary to regulate the steering wheel assist force based on the corresponding motion parameters of the target vehicle when turning, and control the steering wheel speed within a reasonable range to prevent the vehicle from rolling over. If the steering wheel angle of the target vehicle is higher than a preset threshold, it can be determined that the target vehicle is in a turning state, and the vehicle motion parameters of the target vehicle in the curve are obtained, wherein the vehicle motion parameters include parameters such as vehicle speed, wheelbase, center of mass height, wheelbase, actual steering wheel speed, etc.; based on the vehicle motion parameters, the maximum steering wheel speed per unit time of the target vehicle in the critical state of rollover can be determined, and then the maximum steering wheel speed can be sent to the steering power motor so that the power motor controls the steering wheel speed.

[0084] Specifically, when calculating the maximum steering wheel speed, the static lateral acceleration of the target vehicle in the critical rollover state is first determined based on the wheelbase and center of mass height. The static lateral acceleration can be expressed by the following formula: Among them, a J is the static acceleration, g is the acceleration due to gravity, T is the wheelbase, and h is the center of mass height. The static lateral acceleration is then used as the maximum lateral acceleration of the target vehicle in a dynamic state to determine the curve radius based on the maximum lateral acceleration, vehicle speed, and actual steering wheel speed. The dynamic acceleration can be expressed as follows: where a Dis the dynamic acceleration, V is the actual vehicle speed, R is the curve radius, K is the safety factor, the initial calibration value can be set to 1, W is the actual steering wheel speed, W ref The reference steering wheel speed is set to 120° / s. After determining the curve radius, the front wheel turning angle of the target vehicle can be determined based on the curve radius and wheelbase. Specifically, the relationship between the curve radius and the front wheel turning angle can be expressed as: Where L is the wheelbase and α is the front wheel angle. Based on the front wheel angle and a fixed gear ratio, the target vehicle's maximum steering wheel angle, and thus the maximum steering wheel speed per unit time, can be determined. Once the maximum steering wheel speed and assist torque are determined, they are transmitted to the assist motor, which enforces the torque and speed limits.

[0085] In one embodiment, in addition to the aforementioned factors, different road conditions can also lead to different rollover conditions. To reduce the probability of rollover and increase the accuracy of the maximum steering wheel speed, the maximum steering wheel speed can be corrected based on the following two factors: the vehicle's center of gravity position and the road adhesion coefficient. Specifically, a correction factor can be pre-set based on the offset of the vehicle's center of gravity position and the road adhesion coefficient. After the maximum steering wheel speed is calculated, the maximum steering wheel speed is multiplied by the correction factor to obtain the corrected maximum steering wheel speed.

[0086] At the same time, the above-mentioned maximum steering wheel speed is only used to prevent the vehicle from rolling over. It does not lock the steering wheel when the steering wheel speed exceeds the above-mentioned maximum steering wheel speed. Instead, it reduces the steering assist force in the corresponding direction so that the driver needs more effort when turning the steering wheel, thereby alerting the driver that the current vehicle may roll over under the current driving conditions.

[0087] In one embodiment, due to individual driver needs, the driver may not be satisfied with the power assist torque output by the power assist motor. In this case, the driver can send a power assist torque adjustment command to the vehicle computer, such as "the steering wheel is too light." Specifically, the vehicle computer can receive the power assist torque adjustment command from the driver and obtain the current vehicle state parameters, the current preset weighting factor group, and the sample vehicle state parameters corresponding to the current preset weighting factor group. A determination is made as to whether there are differentiating state parameters between the current vehicle state parameters and the sample vehicle state parameters, each with a difference greater than a preset threshold. If there are differentiating state parameters, the vehicle computer adjusts and records the preset weighting factor corresponding to the differentiating state parameter in the preset weighting factor group based on the power assist torque adjustment command. If there are no differentiating state parameters, the vehicle computer adjusts and records the basic steering assist force corresponding to the current vehicle state parameter based on the power assist torque adjustment command. For example, after receiving the power assist torque adjustment command, the vehicle computer can analyze the driver's needs based on the power assist torque adjustment command, the current vehicle state parameters, and historical driving data. For example, if the vehicle state parameters in the historical driving data differ from the current vehicle state parameters, and the driver issues an adjustment command, it is assumed that the weighting factor corresponding to the differentiating state parameter needs to be adjusted. For example, if the current vehicle state parameters differ from historical driving data in terms of the road adhesion coefficient, and the road adhesion coefficient corresponding to the current vehicle state parameters is 1, while the road adhesion coefficient corresponding to the historical driving data is 0.7, and the power-assisted motor uses the weighting factor group corresponding to the historical driving data when outputting the power-assisted torque, and the driver sends a power-assisted torque adjustment command, then the weighting factor corresponding to the road adhesion coefficient within the weighting factor group is deemed to be inconsistent with the driver's driving needs. In this case, the weighting factor corresponding to the road adhesion coefficient can be adjusted based on the power-assisted torque adjustment command. If the current vehicle state parameters do not differ from the historical driving data, then the basic steering assist force in the power-assisted torque is deemed to be inconsistent with the driver's driving needs. In this case, the basic steering assist force corresponding to the current vehicle state parameters can be adjusted and recorded. It should be noted that when the same operating conditions are encountered again, the recorded weighting factors and basic steering assist force can be used to make the power-assisted torque output by the power-assisted motor more consistent with the driver's driving habits, thereby meeting the driver's personalized needs and improving the driver's driving experience.

[0088] In one embodiment, the server can be connected to the navigation system to determine the vehicle's turn entry time and turning radius in advance, thereby pre-setting the above calculation process and reducing the amount of calculation. This allows the steering wheel speed limit to be implemented immediately after entering the curve, thus preventing the driver from suddenly turning the steering wheel after entering the curve and causing the vehicle to roll over.

[0089] In one embodiment, the user's physical data can also be taken into account when setting the basic steering assist force. It is understood that drivers of different genders, weights, and arm lengths will have different arm and grip strengths. Therefore, a corresponding basic steering assist force can be generated based on the basic physical data input by the user. This physical data may include gender, age, weight, arm length, torso length, and other data. Based on the corresponding movement pattern, the basic steering assist force can be adjusted to suit the driver's physical condition.

[0090] Furthermore, since the amount of steering assist depends on the driving habits of different drivers, the corresponding steering assist should also be adjusted when the driver changes, ensuring that the new steering assist is tailored to the driver's habits. Of course, the steering assist values ​​for different drivers and their corresponding seat positions can be stored in the vehicle computer. This eliminates the need to calculate steering assist when the driver changes to a previous user. Specifically, seat position adjustment can be used to determine whether the driver has changed. Upon receiving a seat position change instruction in a target vehicle, if the seat position template corresponding to the different driver does not include the changed seat position, this indicates that the target vehicle has a new driver, that the driver has previously driven the target vehicle, or that their driving habits and physical data are not stored in the vehicle computer. In this case, the seat adjustment distance corresponding to the changed seat position and each seat position template can be determined, and the basic steering assist force can be adjusted based on the seat adjustment distance.

[0091] In one embodiment, while adjusting the base steering assist force, fine-tuning can also be performed by collecting driver feedback. For example, laser radars deployed around the vehicle can determine that the target vehicle is entering a relatively flat environment with few obstacles and no need for lane changes. The user's steering assist experience can then be questioned and recorded. This process can use voice recognition technology to identify user feedback and, based on the identified keywords, immediately adjust the power assist torque output by the power assist motor. It should be noted that after adjusting the power assist torque, the driver needs to be notified to prevent the driver from turning the steering wheel too far with the same amount of force. This notification can be made to the driver and passengers through voice notification, indicator light notification, vehicle computer display notification, and other methods.

[0092] It should be noted that the above-mentioned driving habit data, body data and dimension adjustment factor query table can be pre-stored in the storage device of the computer device. When the steering assist force needs to be adjusted, the computer device can select the above-mentioned driving habit data, body data and dimension adjustment factor query table from the storage device. Of course, when the user switches the vehicle to drive, the above-mentioned driving habit data, body data and dimension adjustment factor query table can be obtained from other external devices (such as the original vehicle). For example, the above-mentioned driving habit data, body data and dimension adjustment factor query table are stored in the cloud. When the steering assist force needs to be adjusted, the computer device can obtain the corresponding user's driving habit data, body data and dimension adjustment factor query table from the cloud. This embodiment does not limit the method of obtaining the above-mentioned data.

[0093] Furthermore, when adjusting the basic steering assist force based on the seat adjustment distance, it is necessary to consider whether there is a seat position template whose seat adjustment distance from the changed seat position is less than a preset distance threshold. If so, this indicates that the driver may have accidentally touched or adjusted the seat position, and the adjustment was small. At this point, a prompt may be displayed on the vehicle computer, asking whether to use the basic steering assist force corresponding to this seat position template. If the user selects yes, the basic steering assist force corresponding to this seat position template may be used as the current basic steering assist force. Alternatively, the basic steering assist force may be adjusted based on the current arm bending state of the driver. If the user selects no, or if there is no seat position template whose seat adjustment distance from the changed seat position is less than a preset distance threshold, an attempt may be made to obtain the user's basic body data and generate a corresponding basic steering assist force based on this basic body data. If the user does not provide basic body data, the basic steering assist force is initialized based on the power assist mode selected by the user.

[0094] When adjusting the basic steering assist force based on the relative position between the driver's palm and the steering wheel, the relative position between the palm and the steering wheel can be determined based on the user's basic body data, including torso length, arm length, and current seat position. Alternatively, the relative position between the user's palm and the steering wheel can be acquired using an image acquisition device installed in the target vehicle. After determining the relative position, a high-sensitivity sensor (such as an infrared sensor, pressure sensor, or capacitive sensor) mounted on the steering wheel can be activated to continuously monitor the contact position and force between the driver's palm and the steering wheel. Furthermore, when the palm is detected near the center of the steering wheel (normal grip), the basic steering assist force is not adjusted. When the palm moves toward the edge of the steering wheel (indicating that greater force may be required for quick steering or emergency evasive maneuvers), the basic steering assist force is gradually increased to reduce driver strain. When the palm approaches the edge of the steering wheel and the force increases (emergency maneuvers), or when the palm leaves the steering wheel (such as when shifting gears), the basic steering assist force is maintained at a minimum or temporarily disabled to prevent misoperation. When the arm is bent to a greater or lesser degree, the basic steering assist force is gradually increased to reduce driver strain. This application automatically adjusts the basic steering assist force by monitoring the palm position information in real time, thereby ensuring that the assist force matches the driver's needs.

[0095] In one embodiment, a sudden change in steering wheel power can easily cause driver discomfort and severe vehicle wobbling during driving. Since calculating the steering power requires a certain amount of time, a server can be connected to a navigation system. By obtaining advance information about the road ahead, the steering power caused by road section changes in a future time period can be calculated in advance, thereby avoiding the discomfort caused by road section changes. Specifically, based on the current navigation route, the target vehicle's road section with a road surface change and the corresponding road adhesion coefficient set within a preset future time period can be obtained. Then, based on the position coordinates of the road section with a current speed, the predicted time point at which the target vehicle will arrive at the road section with a road surface change can be determined. Then, based on the road adhesion coefficient set, a predicted power torque value for the target vehicle within the road section with a road surface change can be determined. Finally, the power torque can be slowly adjusted when the target vehicle is close to the road section with a road surface change, so that the power steering motor can output the appropriate power torque when the target vehicle enters the road section with a road surface change.

[0096] In one embodiment, when the target vehicle's body is in a swaying state, the sway can be mitigated by controlling the steering wheel direction. To facilitate driver adjustments, a corresponding steering assist force control strategy can be specified. Specifically, the vehicle's built-in accelerometer and gyroscope can be activated to collect real-time data on the vehicle's sway amplitude and direction. The steering assist force of the steering wheel can then be adjusted based on the sway amplitude and direction. For example, when the steering wheel's rotation direction aligns with the vehicle's sway, the assist torque can be reduced to prevent the driver from turning the steering wheel too lightly, potentially causing a rollover. When the steering wheel's rotation direction does not align with the vehicle's sway, the assist torque can be increased to encourage the driver to steer to the opposite side, thereby controlling the vehicle's tilt. It should be noted that the magnitude of the assist torque is related to the sway amplitude. The above process is briefly illustrated by citing several common operating conditions: When the vehicle experiences slight sway (such as on a slightly bumpy road), the steering assist can be appropriately increased to stabilize the vehicle's trajectory. When the vehicle shakes violently (such as in emergency avoidance, high-speed cornering, etc.), the power assist is automatically adjusted according to the direction of the shake. For example, when the vehicle deviates to one side due to crosswind, the power assist in the opposite direction is increased to resist the shake and ensure vehicle stability.

[0097] In one embodiment, when the steering wheel is being assisted, the steering wheel assist force can also be adjusted according to the driver's driving time and driving distance. For example, when the driver's driving time is too long or the driving distance is too long, the steering wheel assist force can be increased to save the driver's physical strength. At the same time, the server can also obtain the length of the navigation path before departure and adjust the steering wheel assist force based on the length of the navigation path. It is understandable that the longer the navigation path, the greater the physical burden on the driver, and the steering wheel assist force can be slightly increased throughout the journey. At the same time, if it is detected that the driver stops to rest during driving to relieve driving fatigue, the driver's assist feedback can be obtained before the target vehicle sets off again, and the steering wheel assist force can be adjusted accordingly.

[0098] In one embodiment, after the server is connected to the navigation system, it can obtain the number of lanes and vehicle density of the target vehicle in the current road section. The steering wheel steering assist force can then be adjusted based on the driver's driving habits, the number of lanes, and the vehicle density. For example, if the driver is accustomed to changing lanes to complete overtaking, and the current number of lanes is small and the vehicle density is moderate, and multiple lane changes do not cause danger, the steering wheel steering assist force in this road section can be appropriately increased to help the driver complete the lane change and overtaking. If the vehicle density is relatively high and frequent lane changes may cause a vehicle accident, the steering wheel assist force in this road section can be slightly increased to warn the driver to reduce the number of lane changes and ensure the driver's personal safety.

[0099] like Figure 2 As shown, the embodiment of the present application further provides a device for controlling the power steering force, comprising:

[0100] The parameter acquisition module 201 acquires vehicle state parameters of the target vehicle, where the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed.

[0101] The dimension adjustment factor module 202 determines the dimension adjustment factors corresponding to the parameter values ​​of each vehicle state parameter.

[0102] The preset weight factor module 203 determines a preset weight factor group corresponding to the target vehicle based on various vehicle state parameters and the current operating condition of the target vehicle.

[0103] The power assist adjustment factor module 204 determines a power assist adjustment factor corresponding to the current vehicle state parameter based on the dimension adjustment factor and the corresponding preset weight factor.

[0104] The power assist torque output module 205 determines the power assist torque of the power steering motor based on the power assist adjustment factor and the basic steering assist force.

[0105] like Figure 3 As shown, an embodiment of the present application further provides a steering assist force control device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to:

[0106] Obtain vehicle state parameters of the target vehicle, wherein the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; determine the dimensionality adjustment factors corresponding to the parameter values ​​of each vehicle state parameter; based on each vehicle state parameter and the current operating condition of the target vehicle, determine the preset weight factor group corresponding to the target vehicle; based on the dimensionality adjustment factor and the corresponding preset weight factor, determine the power assist adjustment factor corresponding to the current vehicle state parameter; based on the power assist adjustment factor and the basic steering assist force, determine the power assist torque of the power steering motor.

[0107] The present application also provides a non-volatile computer storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured as follows:

[0108] Obtain vehicle state parameters of the target vehicle, wherein the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; determine the dimensionality adjustment factors corresponding to the parameter values ​​of each vehicle state parameter; based on each vehicle state parameter and the current operating condition of the target vehicle, determine the preset weight factor group corresponding to the target vehicle; based on the dimensionality adjustment factor and the corresponding preset weight factor, determine the power assist adjustment factor corresponding to the current vehicle state parameter; based on the power assist adjustment factor and the basic steering assist force, determine the power assist torque of the power steering motor.

[0109] An embodiment of the present application further provides a vehicle, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to:

[0110] Obtain vehicle state parameters of the target vehicle, wherein the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; determine the dimensionality adjustment factors corresponding to the parameter values ​​of each vehicle state parameter; based on each vehicle state parameter and the current operating condition of the target vehicle, determine the preset weight factor group corresponding to the target vehicle; based on the dimensionality adjustment factor and the corresponding preset weight factor, determine the power assist adjustment factor corresponding to the current vehicle state parameter; based on the power assist adjustment factor and the basic steering assist force, determine the power assist torque of the power steering motor.

[0111] This embodiment can divide the vehicle into functional modules based on the above-described method example. For example, each functional module can be mapped to a specific function, or two or more functions can be integrated into a single processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used.

[0112] When functional modules are divided according to their functions, the vehicle may include a parameter acquisition module, a dimension adjustment factor module, a power assist adjustment factor module, a power assist torque output module, etc. It should be noted that all relevant details of the various steps involved in the above method embodiment can be referred to in the functional description of the corresponding functional modules and will not be repeated here.

[0113] The vehicle provided in this embodiment is used to implement the aforementioned method for controlling steering assist force, thereby achieving the same effect as the aforementioned implementation method. When an integrated unit is employed, the vehicle may include a processing module and a storage module. The processing module may be used to control and manage the vehicle's movements. The storage module may be used to support the vehicle's execution of program code and data.

[0114] The processing module may be a processor or controller that implements or executes various exemplary logic blocks, modules, and circuits disclosed herein. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processing (DSP) and a microprocessor, and the storage module may be a memory.

[0115] This embodiment also provides a computer-readable storage medium, which stores computer program code (including but not limited to disk storage, CD-ROM, optical storage, etc.). When the computer program code runs on a computer, the computer executes the above-mentioned related method steps to implement a steering assist force control method provided in the above embodiment.

[0116] This embodiment further provides a computer program product. When the computer program product is executed on a computer, the computer executes the above steps to implement the steering assist force control method provided in the above embodiment. The beneficial effects of the above embodiment can be referred to the beneficial effects of the corresponding method provided above and will not be repeated here.

[0117] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by 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.

[0118] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. In the description of this disclosure, it should be understood that if the terms "upper", "lower", "front", "back", "left" and "right" are used to indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the position or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation of this disclosure.

[0119] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. It should also be noted that the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, commodity, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, commodity, or device comprising the element.

[0120] The above are merely examples of the present disclosure and are not intended to limit the present disclosure. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure are intended to be included within the scope of the claims of the present disclosure.

Claims

1. A method for controlling steering assist force, characterized in that: include: Acquiring vehicle state parameters of the target vehicle, wherein the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; Determining a dimensionality adjustment factor corresponding to each parameter value of each vehicle state parameter, wherein the magnitude of the dimensionality adjustment factor is related to the magnitude of the parameter value of the single vehicle state parameter; Determining a preset weight factor group corresponding to the target vehicle based on each vehicle state parameter, the preset weight factor group including preset weight factors corresponding to each vehicle state parameter; Determining a power assist adjustment factor corresponding to a current vehicle state parameter based on the dimension adjustment factor and the corresponding preset weight factor; The power assist torque of the power steering motor is determined based on the power assist adjustment factor and the basic steering assist force.

2. The method according to claim 1, characterized in that The determining of the dimension adjustment factors corresponding to the parameter values ​​of the vehicle state parameters specifically includes: Determining a pre-calibrated dimension adjustment factor table corresponding to each vehicle state; Based on the parameter value of the vehicle state parameter, a dimension adjustment factor corresponding to the vehicle state parameter is determined in the dimension adjustment factor table.

3. The method according to claim 1, characterized in that The step of determining a preset weight factor group corresponding to the target vehicle based on each vehicle state parameter specifically includes: Obtaining a weight reference parameter, the weight reference parameter comprising at least one of road curvature, steering angle change rate, ambient temperature, lateral acceleration, and yaw rate; Determining that the vehicle state parameters and the weight reference parameters meet preset weight conditions; Using the preset weight factor group corresponding to the preset weight condition as the preset weight factor group corresponding to the target vehicle; The preset weight condition includes at least one of the following conditions: a first preset weight condition that the vehicle speed is lower than a first speed threshold and the steering angle change rate is higher than a first change rate threshold; a second preset weighting condition that the vehicle speed is higher than a second speed threshold and the lateral acceleration is lower than a first acceleration threshold; a third preset weighting condition that the road curvature is higher than a preset curvature threshold and the yaw rate is higher than a second acceleration threshold; a fourth preset weight condition that the road adhesion coefficient is less than the first preset threshold and the temperature is lower than the first temperature threshold; A fifth preset weight condition is that the load amount is greater than a preset percentage threshold, and the vehicle speed change amplitude within a preset time period is lower than a third speed threshold.

4. The method according to claim 1, wherein The determining of the power assist adjustment factor corresponding to the current vehicle state parameter based on the dimension adjustment factor and the corresponding preset weight factor specifically includes: Multiplying the dimension adjustment factor corresponding to the target vehicle state parameter by the corresponding preset weight factor to obtain the dimension power adjustment factor corresponding to the target vehicle state parameter; The sum of the dimensional power assist adjustment factors corresponding to the various vehicle state parameters is used as the power assist adjustment factor corresponding to the current vehicle state parameter.

5. The method according to claim 1, wherein After determining the power steering torque of the power steering motor, the method further includes: Determining that a steering wheel angle of the target vehicle is greater than a preset threshold; Obtaining vehicle motion parameters of the target vehicle, wherein the vehicle motion parameters include vehicle speed, wheelbase, center of mass height, wheelbase, and actual steering wheel speed; Based on the vehicle motion parameters, a maximum steering wheel speed of the target vehicle is determined.

6. The method according to claim 5, characterized in that Determining the maximum steering wheel speed of the target vehicle based on the vehicle motion parameter specifically includes: Determining a static lateral acceleration of the target vehicle in a critical rollover state based on the wheelbase and the center of mass height; Taking the static lateral acceleration as the maximum lateral acceleration of the target vehicle in a dynamic state; determining a curve radius based on the maximum lateral acceleration, the vehicle speed, and the actual steering wheel speed; Determining a front wheel turning angle of the target vehicle based on the curve radius and the wheelbase; Determining a maximum steering wheel angle of the target vehicle based on the front wheel angle and the gear ratio; The maximum steering wheel speed is determined based on the maximum steering wheel angle.

7. The method according to claim 1, characterized in that After determining the power steering torque of the power steering motor based on the power steering adjustment factor and the basic steering power steering force, the method further includes: receiving a power assist torque adjustment instruction from a driver, and obtaining a current vehicle state parameter of the target vehicle, a current preset weight factor group, and a sample vehicle state parameter corresponding to the current preset weight factor group; Determining whether there is a difference between the current vehicle state parameter and the sample vehicle state parameter, and whether the difference is greater than a preset threshold; If the distinguishing state parameter exists, adjusting and recording the preset weight factor corresponding to the distinguishing state parameter in the preset weight factor group based on the assist torque adjustment instruction; If the distinguishing state parameter does not exist, the basic steering assist force corresponding to the current vehicle state parameter is adjusted and recorded based on the assist torque adjustment instruction.

8. The method according to claim 1, characterized in that Before determining the power steering torque of the power steering motor based on the power steering adjustment factor and the basic power steering force, the method further includes: receiving a seat position change instruction in the target vehicle; If the seat position templates corresponding to different drivers do not include the changed seat position, determining the seat adjustment distances between the changed seat position and the seat position templates respectively corresponding to each seat position template; The basic steering assist force is adjusted based on the seat adjustment distance.

9. The method according to claim 8, characterized in that The adjusting of the basic steering assist force based on the seat adjustment distance specifically includes: If there is a seat position template whose seat adjustment distance from the modified seat position is less than a preset distance threshold, obtaining driver body data corresponding to the seat position template; the body data includes: torso length data and arm length data; adjusting the basic steering assist force based on the driver's physical data and the changed seat position; If there is no seat position template whose seat adjustment distance from the modified seat position is less than a preset distance threshold, the basic steering assist force is initialized.

10. The method according to claim 1, characterized in that After determining the power steering torque of the power steering motor based on the power steering adjustment factor and the basic steering power steering force, the method further includes: Based on the current navigation path, obtaining a road surface change section and a corresponding road adhesion coefficient set of the target vehicle within a preset time period in the future; Determining a predicted time point at which the target vehicle arrives at the road surface change section based on the position coordinates of the road surface change section and the current vehicle speed; Determining a predicted power assist torque value of the target vehicle in the road section with a road surface change based on the road adhesion coefficient set; Based on the predicted time point and the predicted power torque value, the power steering motor's power torque is adjusted so that the target vehicle slowly adjusts its current power torque to the predicted power torque value within a preset distance before reaching the road surface change section.

11. A device for controlling the power steering force, characterized in that: The device comprises: a parameter acquisition module for acquiring vehicle state parameters of the target vehicle, wherein the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; A dimension adjustment factor module determines the dimension adjustment factors corresponding to the parameter values ​​of each vehicle state parameter; A preset weight factor module is configured to determine a preset weight factor group corresponding to the target vehicle based on various vehicle state parameters and the current operating condition of the target vehicle; A power assist adjustment factor module, which determines a power assist adjustment factor corresponding to a current vehicle state parameter based on the dimension adjustment factor and a corresponding preset weight factor; The power assist torque output module determines the power assist torque of the power steering motor based on the power assist adjustment factor and the basic steering assist force.

12. A vehicle, characterized in that: include: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform: Acquiring vehicle state parameters of the target vehicle, wherein the vehicle state parameters include at least one of vehicle speed, tire pressure, vehicle load, road adhesion coefficient, and steering wheel speed; Determine the dimension adjustment factors corresponding to the parameter values ​​of each vehicle state parameter; Determining a preset weight factor group corresponding to the target vehicle based on each vehicle state parameter and the current operating condition of the target vehicle; Determining a power assist adjustment factor corresponding to a current vehicle state parameter based on the dimension adjustment factor and the corresponding preset weight factor; The power assist torque of the power steering motor is determined based on the power assist adjustment factor and the basic steering assist force.

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