Vehicle steering performance index determination method, vehicle steering limit hardness judgment method, storage medium and electronic equipment

Abstract

The invention discloses a vehicle steering performance index determination method, a vehicle steering limit hardness judgment method, a storage medium and electronic equipment, and the vehicle steering performance index determination method comprises the following steps: obtaining a steering wheel rotation angle and torque curve of a vehicle in a set rotation angle interval; segmenting the steering wheel angle and torque curve, and obtaining the curve gradient and the curve dispersion of each segment of curve; and determining a vehicle steering performance index according to the curve gradient and the curve dispersion of each section of curve. According to the method, a steering wheel rotation angle and torque curve is obtained from test data obtained through a steering performance objective test, then analysis is carried out through the curve gradient and the curve dispersion of each section of curve, and data indexes of the torque changing along with the steering wheel rotation angle in a left-turn area, a right-turn area and a middle-position area during vehicle steering are obtained; therefore, the subjective feeling of the driver during steering of the vehicle is reflected.

Description

Technical Field

[0001] The invention relates to the field of vehicle steering, and in particular to a method for determining a vehicle steering performance index, a method for determining the softness or hardness of a vehicle steering limit, a storage medium and an electronic device. Background Art

[0002] Objective testing of a car's steering performance is an important part of ensuring vehicle safety and maneuverability. Through a series of scientific and systematic testing methods, the vehicle's steering performance is evaluated to ensure that the vehicle has good maneuverability and safety during driving.

[0003] However, there is a large difference between the objective test indicators of steering performance testing and the driver's subjective feelings, and the degree of fit between the two is low; the objective test indicators of the test cannot reflect the driver's subjective feelings. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for determining a vehicle steering performance index, which aims to convert the test data obtained from an objective test of the steering performance into a data index that can reflect the driver's subjective feelings, thereby improving the fit between the subjective and objective indicators, thereby facilitating the development of vehicle models with user needs as the target and designing products with better steering performance.

[0005] To achieve the above object, the present invention proposes a method for determining a vehicle steering performance index, the method comprising:

[0006] Obtain the steering wheel angle and torque curve of the vehicle within the set angle range;

[0007] Divide the steering wheel angle and torque curve into segments, and obtain the curve gradient and curve discreteness of each segment of the curve;

[0008] The vehicle steering performance index is determined according to the curve gradient and curve discreteness of each curve segment.

[0009] Optionally, segmenting the steering wheel angle and torque curve comprises:

[0010] According to the comparison relationship between the steering wheel angle, the first set angle and the second set angle, the steering wheel angle and torque curve are divided into a left turn area, a right turn area and a middle area; wherein the first set angle is smaller than the second set angle;

[0011] The steering wheel angle and torque curve is divided into six sections according to the positional relationship between the steering wheel angle and torque curve in the left-turn area, the right-turn area and the middle area.

[0012] Optionally, dividing the steering wheel angle and torque curve into a left-turn area, a right-turn area and a middle area according to a comparison relationship between the steering wheel angle and the first set angle and the second set angle comprises:

[0013] If the steering wheel angle is less than or equal to the first set angle, the steering wheel angle is divided into a left turn area;

[0014] If the steering wheel angle is greater than the first set angle and less than or equal to the second set angle, dividing the steering wheel angle into a middle area;

[0015] If the steering wheel angle is greater than the second set angle, the steering wheel angle is divided into a right turn area.

[0016] Optionally, obtaining the curve gradient and the curve discreteness of each curve segment includes:

[0017] Get the discreteness of each curve segment;

[0018] Use straight lines to fit each segment of the curve;

[0019] The slope value of the straight line corresponding to each segment of the curve is obtained, and the slope value is used as the curve gradient of the segment of the curve.

[0020] Optionally, determining the vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment includes:

[0021] According to the curve gradients of the two curve segments in each area, the arithmetic mean is determined and taken as the average gradient value of the area, thereby obtaining the gradient value of the left-turn area, the gradient value of the right-turn area and the gradient value of the median area;

[0022] Obtain the difference and sum of the curve gradients of two curve segments in each region respectively;

[0023] The ratio of the difference to the sum is calculated, and the absolute value of the ratio is used as the gradient symmetry of the area where the corresponding curve is located, thereby obtaining the gradient symmetry of the left-turn area, the gradient symmetry of the right-turn area, and the gradient symmetry of the median area.

[0024] Optionally, the determining of the vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment further includes:

[0025] According to the left-turn area gradient value and the right-turn area gradient value, an arithmetic mean value is determined and used as an evaluation gradient value of the left / right turn torque change;

[0026] Get the difference and sum of the left-turn area gradient value and the right-turn area gradient value;

[0027] The ratio of the difference to the sum is calculated, and the absolute value of the ratio is used as the symmetry of the left / right turning torque change.

[0028] Optionally, the determining of the vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment further includes:

[0029] Subtracting the median area gradient value from the evaluation gradient value of the left / right turning torque change;

[0030] Calculating the ratio of the difference value to the median region gradient value, and using it as the relative difference value between the median and non-median moment gradients;

[0031] The arithmetic mean of the curve discreteness of each curve segment is calculated and used as the torque fluctuation of the vehicle.

[0032] The present invention also provides a method for determining the softness or hardness of a vehicle steering limit, the method comprising:

[0033] Obtain the vehicle's steering wheel angle and torque curve;

[0034] Use a cubic polynomial to fit the steering wheel angle and torque curve within a preset limit range;

[0035] Calculating the curvature radius value of the cubic polynomial fitting curve;

[0036] The hardness or softness of the vehicle steering limit is determined based on the comparison result of the curvature radius value and the set value.

[0037] The present invention further provides a storage medium, wherein a vehicle steering performance index determination program is stored on the storage medium, and when the vehicle steering performance index determination program is executed by a processor, the steps of the vehicle steering performance index determination method are implemented;

[0038] Alternatively, the storage medium stores a vehicle steering limit soft and hard judgment program, and when the vehicle steering limit soft and hard judgment program is executed by the processor, the steps of the vehicle steering limit soft and hard judgment method are implemented.

[0039] The present invention also provides an electronic device, which includes a processor and the storage medium.

[0040] The present invention discloses a method for determining a vehicle steering performance index, the method comprising: obtaining a steering wheel angle and torque curve of a vehicle within a set angle range; segmenting the steering wheel angle and torque curve, and obtaining the curve gradient and curve discreteness of each segment of the curve; and determining the vehicle steering performance index according to the curve gradient and curve discreteness of each segment of the curve. The present invention obtains a steering wheel angle and torque curve from test data obtained from an objective test of steering performance, and then analyzes the curve gradient and curve discreteness of each segment of the curve to obtain data indicators of the change of torque with the steering wheel rotation angle in the left turn area, the right turn area and the median area when the vehicle is turning, thereby reflecting the driver's subjective feelings when steering the vehicle; it is beneficial to target user needs in vehicle model development and design products with better steering performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0042] Figure 1 A schematic diagram of a flow chart of an embodiment of a method for determining a vehicle steering performance index according to the present invention;

[0043] Figure 2 A schematic flow chart of another embodiment of a method for determining a vehicle steering performance index according to the present invention;

[0044] Figure 3 A schematic flow chart of another embodiment of a method for determining a vehicle steering performance index according to the present invention;

[0045] Figure 4 A schematic flow chart of another embodiment of a method for determining a vehicle steering performance index according to the present invention;

[0046] Figure 5 A schematic flow chart of another embodiment of a method for determining a vehicle steering performance index according to the present invention;

[0047] Figure 6 A schematic diagram of a first steering wheel angle and steering wheel torque curve of an embodiment of a method for determining a vehicle steering performance index of the present invention;

[0048] Figure 7 This is a schematic diagram of a second steering wheel angle and steering wheel torque curve according to an embodiment of a method for determining a vehicle steering performance index of the present invention.

[0049] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0052] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] Objective testing of a car's steering performance is an important part of ensuring vehicle safety and maneuverability. Through a series of scientific and systematic testing methods, the vehicle's steering performance is evaluated to ensure that the vehicle has good maneuverability and safety during driving. However, there is a large difference between the objective test indicators of steering performance testing and the driver's subjective feelings, and the fit between the two is low; the objective test indicators cannot reflect the driver's subjective feelings. For the driver, what he directly feels when the vehicle is turning is the force required to turn the steering wheel; and the smoothness of the change in the required force as the steering wheel angle changes.

[0055] The present invention proposes a method for determining a vehicle steering performance index, referring to Figure 1 , the vehicle steering performance index determination method comprises:

[0056] Step S10: Obtain the steering wheel angle and torque curve of the vehicle within a set angle range.

[0057] It should be noted that the angle range of the set turning angle interval can be symmetrical about 0°; this solution integrates the data of the vehicle steering test to obtain the vehicle's steering wheel angle and torque curve; in one example, the steering wheel turning angle and torque curve can be obtained when conducting a steering wheel center area experiment. In this step, the vehicle can be turned according to the steering wheel angle within the set turning angle interval, or the curve of the set turning angle interval segment can be intercepted from the original steering wheel angle and torque curve. The set turning angle interval is determined by the specific R&D personnel.

[0058] It should be noted that, due to the symmetry of the set turning angle range, the initial angle of the vehicle steering wheel is 0°; when the vehicle is turning, the steering wheel needs to be turned to one side first, then to the other side, and finally back to 0°. Due to the hysteresis of the steering wheel turning, the curves formed by the steering wheel turning and the rotation do not overlap. That is, each steering wheel angle corresponds to two torque values ​​within the set turning angle range.

[0059] Step S20: segment the steering wheel angle and torque curve, and obtain the curve gradient and curve discreteness of each segment of the curve.

[0060] Reference Figure 2 Specifically, in step S210, according to the comparison relationship between the steering wheel angle and the first set angle and the second set angle, the steering wheel angle and the torque curve are divided into a left turn area, a right turn area and a middle area; wherein the first set angle is smaller than the second set angle.

[0061] It is easy to understand that the steering wheel has three states, namely: left turn, maintaining neutral position and right turn. The steering wheel angle and torque curves corresponding to these three states may be different. Assuming that the neutral area is composed of the first set angle and the second set angle, the steering wheel angle can be compared with the first set angle and the second set angle.

[0062] The steering wheel angle and torque curve are divided into a left turn area, a right turn area and a middle area according to the comparison relationship between the steering wheel angle and the first set angle and the second set angle, including:

[0063] Reference Figure 3 , step S2110, if the steering wheel angle is less than or equal to the first set angle, the steering wheel angle is divided into a left turn area.

[0064] Step S2120: If the steering wheel angle is greater than the first set angle and less than or equal to the second set angle, the steering wheel angle is divided into a middle area.

[0065] Step S2130: If the steering wheel angle is greater than the second set angle, the steering wheel angle is divided into a right turn area.

[0066] The first set angle <0° < the second set angle. After determining the three regions, the steering wheel angle and torque curve is divided into three parts. Because each steering wheel angle corresponds to two torque values ​​within the set angle range of the steering wheel angle and torque curve, there are two curves in each region.

[0067] Step S220, dividing the steering wheel angle and torque curve into six sections according to the positional relationship between the steering wheel angle and torque curve in the left-turn area, the right-turn area and the middle area.

[0068] 6, the step of obtaining the curve gradient and the curve discreteness of each curve segment includes:

[0069] Get the discreteness of each curve segment;

[0070] Use straight lines to fit each segment of the curve;

[0071] The slope value of the straight line corresponding to each segment of the curve is obtained, and the slope value is used as the curve gradient of the segment of the curve.

[0072] It should be noted that in the steering wheel angle and torque curve, the torque is an analog quantity, and the torque fluctuates with the angle change. This fluctuation directly affects the driver's driving experience. The discreteness of the curve can represent the fluctuation amount of the torque during steering. The curve is not a linear curve; but refer to Figure 6, we can use straight lines to fit each segment of the curve and draw a line graph in the original image, which can clearly show the change of the curve. Figure 6 It can be obtained that the curve gradient of each curve segment is roughly the same. The slope value of the fitting straight line corresponding to each curve segment can be obtained first, and used as the curve gradient of the curve segment.

[0073] Step S30: determining a vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment.

[0074] It should be noted that the vehicle steering performance index can reflect the driver's subjective feelings, and reflect the size of the steering torque required when the steering wheel is turned, whether the torque change gradient is consistent, whether the left and right steering torques are symmetrical, and whether the steering torque changes smoothly.

[0075] Reference Figure 4 The method of determining the vehicle steering performance index according to the curve gradient and the curve discreteness of each curve segment includes:

[0076] Step S310: Determine the arithmetic mean value of the curve gradients of the two curve segments in each area and use it as the average gradient value of the area, thereby obtaining the left-turn area gradient value, the right-turn area gradient value and the median area gradient value.

[0077] Specifically, since the steering wheel angle and torque curve has three regions, they need to be calculated separately.

[0078] The calculation formula for the median regional gradient value is as follows:

[0079]

[0080] in, is the median regional gradient value, refer to Figure 6 , k2 is the curve gradient of the second curve, and k5 is the curve gradient of the fifth curve. k2 and k5 are the degree of change of the torque in the median area during forward rotation and reverse rotation, respectively. It indicates the degree of change of the overall torque in the median area. If the value is large, the torque required to rotate a certain angle is large, which makes people feel that the median torque is heavier and the median sense is stronger. If the value is small, the median torque is lighter and the median sense is vague.

[0081] The calculation formula for the left turn area gradient value is as follows:

[0082]

[0083] in, is the left turn area gradient value, refer to Figure 6 , k, is the curve gradient of the first segment of the curve, and k4 is the curve gradient of the fourth segment of the curve. It indicates the degree of change of the overall torque in the left-turn area. If the value is large, the non-neutral left-turn steering force will feel lighter. If the value is large, the non-neutral left-turn steering force will feel heavier.

[0084] The calculation formula for the gradient value of the right turn area is as follows:

[0085]

[0086] in, is the gradient value of the right-turn area, refer to Figure 6 , k3 is the curve gradient of the third segment of the curve, and k6 is the curve gradient of the sixth segment of the curve. It indicates the degree of torque change in the right-turn area as a whole. If the value is large, the non-neutral steering force for turning right will feel lighter. If the value is large, the non-neutral steering force for turning right will feel heavier.

[0087] Step S320: Obtain the difference and sum of the curve gradients of two segments of the curve in each region respectively.

[0088] Step S330, calculate the ratio of the difference to the sum, and use the absolute value of the ratio as the gradient symmetry of the area where the corresponding curve is located, thereby obtaining the gradient symmetry of the left-turn area, the gradient symmetry of the right-turn area, and the gradient symmetry of the median area.

[0089] The calculation formula of the median region gradient symmetry is as follows:

[0090]

[0091] in, is the gradient symmetry of the median area, k2 is the curve gradient of the second curve, and k5 is the curve gradient of the fifth curve. The gradient symmetry of the median area represents the consistency of the gradient of the torque change in the positive and negative directions of the steering wheel near the median.

[0092] The calculation formula for the left-turn region gradient symmetry is as follows:

[0093]

[0094] in, is the left-turn area gradient symmetry, k1 is the curve gradient of the first curve, and k4 is the curve gradient of the fourth curve. The left-turn area gradient symmetry represents the consistency of the gradient of the torque change in the positive and negative directions of the steering wheel when turning left. If the value of the left-turn area gradient symmetry is large, it will make people feel that the torque change gradients of turning outward and turning back when turning left are inconsistent, and there are some problems with the steering system.

[0095] The calculation formula for the gradient symmetry of the right-turn region is as follows:

[0096]

[0097] in, is the right-turn area gradient symmetry, k3 is the curve gradient of the third curve, and k6 is the curve gradient of the sixth curve. The right-turn area gradient symmetry represents the consistency of the gradient of the torque change in the positive and negative directions of the steering wheel when turning right. If the value of the right-turn area gradient symmetry is large, it will make people feel that the torque change gradients for turning outward and turning back are inconsistent when turning right.

[0098] The present invention discloses a method for determining a vehicle steering performance index, the method comprising: obtaining a steering wheel angle and torque curve of a vehicle within a set angle range; segmenting the steering wheel angle and torque curve, and obtaining the curve gradient and curve discreteness of each segment of the curve; and determining the vehicle steering performance index according to the curve gradient and curve discreteness of each segment of the curve. The present invention obtains a steering wheel angle and torque curve from test data obtained from an objective test of steering performance, and then analyzes the curve gradient and curve discreteness of each segment of the curve to obtain data indicators of the change of torque with the steering wheel rotation angle in the left turn area, the right turn area and the median area when the vehicle is turning, thereby reflecting the driver's subjective feelings when steering the vehicle; it is beneficial to target user needs in vehicle model development and design products with better steering performance.

[0099] In one embodiment, determining the vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment further includes:

[0100] Step S340: Determine the arithmetic mean value of the left-turn area gradient value and the right-turn area gradient value and use it as the evaluation gradient value of the left / right turn torque change.

[0101] The calculation formula of the evaluation gradient value of the left / right turning torque change is as follows:

[0102]

[0103] in, is the evaluation gradient value of the left / right turning torque change, is the gradient value of the left-turn area, is the gradient value of the right-turn area. If the non-neutral steering force is smaller, the non-neutral steering force will feel lighter; If it is larger, the non-neutral steering force will feel heavier.

[0104] Step S350: Obtain the difference and sum of the left-turn area gradient value and the right-turn area gradient value.

[0105] Step S360: Calculate the ratio of the difference to the sum, and use the absolute value of the ratio as the symmetry of the left / right turning torque change.

[0106] The calculation formula of the symmetry of the left / right turning torque change is as follows:

[0107]

[0108] in, is the symmetry of left / right turning torque change, is the gradient value of the left-turn area, is the gradient value of the right-turn area. If it is larger, it will make people feel asymmetry between the left and right directions.

[0109] Reference Figure 5 The method of determining the vehicle steering performance index according to the curve gradient and the curve discreteness of each curve segment further includes:

[0110] Step S370: Subtract the median area gradient value from the evaluation gradient value of the left / right turning torque change.

[0111] Step S380, calculate the ratio of the difference value to the median region gradient value, and use it as the relative difference value between the median and non-median moment gradients.

[0112] Step S390: Calculate the arithmetic mean of the curve discreteness of each curve segment and use it as the torque fluctuation of the vehicle.

[0113] The calculation formula of the relative difference between the median and non-median moment gradients is as follows:

[0114]

[0115] in, is the relative difference between the median and non-median moment gradients, is the median regional gradient value, is the evaluation gradient value of the left / right turning torque change. If the value is large, the change from median to non-median moment will feel unnatural; If the value is smaller, the non-neutral torque gradient is larger and the steering force is heavier.

[0116] The calculation formula of the torque fluctuation amount of the vehicle is as follows:

[0117]

[0118] Among them, Δ1 is the discreteness of the first curve segment, Δ2 is the discreteness of the second curve segment, Δ3 is the discreteness of the third curve segment, Δ4 is ​​the discreteness of the fourth curve segment, Δ5 is the discreteness of the fifth curve segment, and Δ6 is the discreteness of the sixth curve segment. It is the torque fluctuation of the vehicle; if the value is large, people will feel that the steering force is not smooth and there are more burrs.

[0119] The present invention also provides a method for determining the softness or hardness of a vehicle steering limit, the method comprising:

[0120] Obtain the vehicle's steering wheel angle and torque curve;

[0121] Use a cubic polynomial to fit the steering wheel angle and torque curve within a preset limit range;

[0122] Calculating the curvature radius value of the cubic polynomial fitting curve;

[0123] The hardness or softness of the vehicle steering limit is determined based on the comparison result of the curvature radius value and the set value.

[0124] It should be noted that the steering wheel has rotation angle limits, which are left limit angle and right limit angle; refer to Figure 7 The steering wheel is limited at about + / - 500°, and the torque in the limit interval increases sharply with the change of angle; the driver feels that the steering wheel is difficult to turn. If the torque in the limit interval increases too quickly, the driver will feel that the steering wheel suddenly cannot turn, and the lack of the process of feeling the torque increase makes the driver feel that the vehicle steering limit is hard. The angle range of the preset limit interval is determined by the R&D personnel according to the specific vehicle.

[0125] After fitting the steering wheel angle and torque curve within the preset limit range using a cubic polynomial, the curvature radius value of the fitting curve can be calculated according to the cubic polynomial to determine the change speed of the torque within the limit range. Figure 7 , c1 represents the fitting curve of the steering wheel rotating clockwise, and c2 represents the fitting curve of the steering wheel rotating counterclockwise. The curvature radii ρ1 and ρ2 of c1 and c2 are calculated by the curvature radius calculation formula, where the curvature radius formula is:

[0126]

[0127] Among them, y 1，2 Represents the cubic polynomial of curve c1 and curve c2 respectively, ρ 1，2 Respectively represent the curvature radii of curve c1 and curve c2.

[0128] Further, the minimum curvature radius of curve c1 and curve c2 is obtained:

[0129] ρ1，min =min(ρ1)

[0130] ρ 2，min =min(ρ2)

[0131] Among them, ρ 1，min is the minimum curvature radius of curve c1, ρ 2，min is the minimum radius of curvature of curve c2.

[0132] If 1，min If it is too small, it means that when turning clockwise, the limit force changes greatly and the steering limit is harder;

[0133] If 2，min If it is too small, it means that when turning counterclockwise, the limit force changes greatly and the steering limit is harder.

[0134] The minimum curvature radius of c1 and the minimum curvature radius of c2 can be compared with the set value respectively. If the minimum curvature radius is greater than the set value, it means that the steering limit corresponding to the minimum curvature radius is harder. The set value is determined by the R&D personnel.

[0135] The present invention further provides a storage medium, wherein a vehicle steering performance index determination program is stored on the storage medium, and when the vehicle steering performance index determination program is executed by a processor, the steps of the vehicle steering performance index determination method are implemented;

[0136] Alternatively, the storage medium stores a vehicle steering limit soft and hard judgment program, and when the vehicle steering limit soft and hard judgment program is executed by the processor, the steps of the vehicle steering limit soft and hard judgment method are implemented. The storage medium includes ROM, RAM, FLASH, floppy disk, CD or DVD, etc.

[0137] The present invention also provides an electronic device, the electronic device includes a processor and the storage medium. The specific steps of the vehicle steering performance index determination program or the vehicle steering limit soft and hard judgment program stored in the storage medium refer to the above embodiments. Since the electronic device adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here one by one.

[0138] The electronic device may be a vehicle controller, a vehicle steering detector or an electronic computer, etc.

[0139] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for determining a vehicle steering performance index, characterized in that: The vehicle steering performance index determination method comprises: Obtain the steering wheel angle and torque curve of the vehicle within the set angle range; Divide the steering wheel angle and torque curve into segments, and obtain the curve gradient and curve discreteness of each segment of the curve; The vehicle steering performance index is determined according to the curve gradient and curve discreteness of each curve segment.

2. The method for determining a vehicle steering performance index according to claim 1, characterized in that: The step of segmenting the steering wheel angle and torque curve comprises: According to the comparison relationship between the steering wheel angle, the first set angle and the second set angle, the steering wheel angle and torque curve are divided into a left turn area, a right turn area and a middle area; wherein the first set angle is smaller than the second set angle; The steering wheel angle and torque curve is divided into six sections according to the positional relationship between the steering wheel angle and torque curve in the left-turn area, the right-turn area and the middle area.

3. The method for determining a vehicle steering performance index according to claim 2, characterized in that: The steering wheel angle and torque curve are divided into a left turn area, a right turn area and a middle area according to the comparison relationship between the steering wheel angle and the first set angle and the second set angle, including: If the steering wheel angle is less than or equal to the first set angle, the steering wheel angle is divided into a left turn area; If the steering wheel angle is greater than the first set angle and less than or equal to the second set angle, dividing the steering wheel angle into a middle area; If the steering wheel angle is greater than the second set angle, the steering wheel angle is divided into a right turn area.

4. The method for determining a vehicle steering performance index according to claim 2, characterized in that: The step of obtaining the curve gradient and the curve discreteness of each curve segment includes: Get the discreteness of each curve segment; Use straight lines to fit each segment of the curve; The slope value of the straight line corresponding to each segment of the curve is obtained, and the slope value is used as the curve gradient of the segment of the curve.

5. The method for determining a vehicle steering performance index according to any one of claims 2 to 4, characterized in that: The method of determining the vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment includes: According to the curve gradients of the two curve segments in each area, the arithmetic mean is determined and taken as the average gradient value of the area, thereby obtaining the gradient value of the left-turn area, the gradient value of the right-turn area and the gradient value of the median area; Obtain the difference and sum of the curve gradients of two curve segments in each region respectively; The ratio of the difference to the sum is calculated, and the absolute value of the ratio is used as the gradient symmetry of the area where the corresponding curve is located, thereby obtaining the gradient symmetry of the left-turn area, the gradient symmetry of the right-turn area, and the gradient symmetry of the median area.

6. The method for determining a vehicle steering performance index according to claim 5, characterized in that: The method of determining the vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment also includes: According to the left-turn area gradient value and the right-turn area gradient value, an arithmetic mean value is determined and used as an evaluation gradient value of the left / right turn torque change; Get the difference and sum of the left-turn area gradient value and the right-turn area gradient value; The ratio of the difference to the sum is calculated, and the absolute value of the ratio is used as the symmetry of the left / right turning torque change.

7. The method for determining a vehicle steering performance index according to claim 6, characterized in that: The method of determining the vehicle steering performance index according to the curve gradient and the curve dispersion of each curve segment also includes: Subtracting the median area gradient value from the evaluation gradient value of the left / right turning torque change; Calculating the ratio of the difference value to the median region gradient value, and using it as the relative difference value between the median and non-median moment gradients; The arithmetic mean of the curve discreteness of each curve segment is calculated and used as the torque fluctuation of the vehicle.

8. A method for determining whether a vehicle's steering limit is soft or hard, characterized in that: The vehicle steering limit soft and hard judgment method comprises: Obtain the vehicle's steering wheel angle and torque curve; Use a cubic polynomial to fit the steering wheel angle and torque curve within a preset limit range; Calculating the curvature radius value of the cubic polynomial fitting curve; The hardness or softness of the vehicle steering limit is determined based on the comparison result of the curvature radius value and the set value.

9. A storage medium, characterized in that: The storage medium stores a vehicle steering performance index determination program, which, when executed by the processor, implements the steps of the vehicle steering performance index determination method according to any one of claims 1 to 7; Alternatively, the storage medium stores a vehicle steering limit soft and hard judgment program, and when the vehicle steering limit soft and hard judgment program is executed by the processor, the steps of the vehicle steering limit soft and hard judgment method as claimed in claim 8 are implemented.

10. An electronic device, characterized in that: The electronic device comprises a processor and the storage medium as claimed in claim 9.

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