Rear wheel steering control method, electronic equipment and vehicle

Abstract

The invention relates to the field of vehicle control, in particular to a rear wheel steering control method, electronic equipment and a vehicle. The method comprises the steps that the speed change rate of a vehicle is determined; the original rear wheel steering control quantity is determined according to the vehicle speed, the original rear wheel steering control quantity is corrected and adjusted through the speed change rate, and the target rear wheel steering control quantity is obtained; and performing rear wheel steering control according to the target rear wheel steering control quantity. The speed change rate can represent the change condition of the vehicle speed, so that after the original rear wheel steering control quantity is determined according to the vehicle speed, the original rear wheel steering control quantity is corrected through the speed change rate, and the obtained target rear wheel steering control quantity is more accurate and can better adapt to the change of the vehicle speed; therefore, the rear wheel steering can be accurately controlled according to the target rear wheel steering control quantity, and the running stability of the vehicle is ensured.

Description

Technical Field

[0001] The present application relates to the field of vehicle control technology, and in particular to a rear-wheel steering control method, electronic equipment, and a vehicle. Background Art

[0002] Currently, rear wheel steering control is generally performed by relying on vehicle speed to determine rear wheel steering control parameters, thereby controlling rear wheel steering.

[0003] However, there may be driving conditions where the vehicle speed is unstable. In such conditions, the rear wheel steering determined by the vehicle speed will be unstable, thus affecting the vehicle's driving. Summary of the Invention

[0004] In view of this, the purpose of this application is to propose a rear-wheel steering control method, electronic equipment and vehicle to solve the problem that the rear-wheel steering parameters currently determined based on vehicle speed are not accurate enough.

[0005] Based on the above objectives, the present application provides a rear wheel steering control method, comprising:

[0006] determining the rate of change of the vehicle's speed;

[0007] determining an original rear wheel steering control amount according to the vehicle speed, and correcting and adjusting the original rear wheel steering control amount using the speed change rate to obtain a target rear wheel steering control amount;

[0008] Rear-wheel steering control is performed according to the target rear-wheel steering control amount.

[0009] Based on the same inventive concept, the present application also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the method described above when executing the computer program.

[0010] Based on the same inventive concept, the present application also provides a vehicle, comprising the electronic device as described above.

[0011] As can be seen from the above, the rear-wheel steering control method, electronic device and vehicle provided by the present application will determine the speed change rate of the vehicle, and the speed change rate can characterize the change in vehicle speed. In this way, after the original rear-wheel steering control amount is determined according to the vehicle speed, since the original rear-wheel steering control amount may be affected by the change in vehicle speed and there is a deviation, it is necessary to use the speed change rate to correct it, so that the obtained target rear-wheel steering control amount is more accurate and more adaptable to changes in vehicle speed. In this way, the rear-wheel steering can be accurately controlled according to the target rear-wheel steering control amount to ensure the stability of vehicle driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in this application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are merely embodiments of this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0013] Figure 1 This is a flowchart of a rear wheel steering control method according to an embodiment of the present application;

[0014] Figure 2 This is a structural block diagram of a rear wheel steering control device according to an embodiment of the present application;

[0015] Figure 3 This is a schematic structural diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and advantages of this application more clear, this application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0017] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] Glossary:

[0019] TCS: Traction Control System, traction control system, also known as traction control system.

[0020] ABS: antilock brake system, anti-lock braking system.

[0021] VDC: Vdc vehicle running dynamic control system, vehicle running dynamic control system.

[0022] EPS: Electric Power Steering, electric power steering system.

[0023] Based on the description of the above background technology, in the related art, corresponding rear wheel steering control parameters (eg, the ratio of the front wheel and rear wheel steering angles) are generally determined only according to the vehicle speed.

[0024] This method has little deviation for driving conditions with small speed changes (stable vehicle driving), but for conditions with large speed changes (unstable speed), if the control parameters of the rear-wheel steering are still determined according to this traditional method, the control parameters of the rear-wheel steering will vary greatly, which may easily cause the vehicle to yaw unexpectedly or become unstable and roll over.

[0025] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0026] The embodiment of the present application proposes a rear wheel steering control method, such as Figure 1 As shown, including:

[0027] Step 101: Determine the speed change rate of the vehicle.

[0028] In specific implementations, the speed change rate is used to characterize the speed change trend. The speed change rate can be a positive value (indicating acceleration), a negative value (indicating deceleration), or zero (indicating a constant speed). The speed change rate can be calculated based on a vehicle speed curve, obtained using an acceleration sensor, or modified based on the vehicle's driving conditions.

[0029] Step 102 : determining an original rear-wheel steering control amount according to the vehicle speed, and correcting and adjusting the original rear-wheel steering control amount using the speed change rate to obtain a target rear-wheel steering control amount.

[0030] In specific implementation, the vehicle speed is first determined, and the average of the two lower wheel speeds is taken as the vehicle speed during vehicle driving conditions, and the average of the two higher wheel speeds is taken as the vehicle speed during vehicle braking conditions.

[0031] The vehicle's control system includes an original rear-wheel steering control module. This original rear-wheel steering control module includes a rear-wheel steering control curve. By inputting the vehicle speed into the original rear-wheel steering control module, an original rear-wheel steering control variable can be calculated based on the rear-wheel steering control curve. Alternatively, the original rear-wheel steering control variable corresponding to the vehicle speed can be directly retrieved from a rear-wheel steering control table within the original rear-wheel steering control module. The original rear-wheel steering control variable includes the initially calculated front and rear wheel steering angle control ratio.

[0032] If the corresponding speed change rate deviates significantly from zero, indicating a significant speed change, the original rear-wheel steering control variable will be corrected significantly, and the target rear-wheel steering control variable obtained after correction will tend to be stable. The target rear-wheel steering control variable includes the final front and rear wheel angle control ratio.

[0033] Step 103: Perform rear-wheel steering control according to the target rear-wheel steering control amount.

[0034] In specific implementation, if the target rear-wheel steering control amount is the front-to-rear wheel angle control ratio, the angle that the vehicle needs to deflect can be determined based on the steering signal received from the steering wheel, and then the rear wheel steering angle can be calculated based on the front-to-rear wheel angle control ratio in the target rear-wheel steering control amount, and the rear wheel steering can be controlled based on the rear wheel steering angle.

[0035] Through the above scheme, the vehicle's speed change rate can be determined, and the speed change rate can characterize the change in vehicle speed. In this way, after the original rear-wheel steering control amount is determined according to the vehicle speed, since the original rear-wheel steering control amount may be affected by the change in vehicle speed and there is a deviation, it is necessary to use the speed change rate to correct it, so that the obtained target rear-wheel steering control amount is more accurate and more adaptable to the change in vehicle speed. In this way, the rear-wheel steering can be accurately controlled according to the target rear-wheel steering control amount to ensure the stability of vehicle driving.

[0036] In some embodiments, step 101 includes:

[0037] Step 1011 : Obtain the vehicle speed, and determine the acceleration (eg, dVcomp) based on the vehicle speed.

[0038] In a specific implementation, the acceleration (e.g., dVcomp) can be directly used as the velocity change rate to perform the subsequent steps 102 and 103. However, the acceleration (e.g., dVcomp) may deviate from the normal range due to being too large or too small. Therefore, in order to further normalize the acceleration (e.g., dVcomp), the following steps 1012 to 1014 will be executed.

[0039] Step 1012: Obtain an upper acceleration limit value (eg, dVDmax) and a lower acceleration limit value (eg, dVBmin).

[0040] In a specific implementation, the acceleration upper limit value (eg, dVDmax) and the acceleration lower limit value (eg, dVBmin) may be pre-set according to the actual conditions of the vehicle, or may be calculated according to the vehicle speed under different working conditions.

[0041] Step 1013: Determine the lowest value between the acceleration upper limit value and the acceleration.

[0042] During specific implementation, the acceleration (eg, dVcomp) is compared with an upper limit of acceleration (eg, dVDmax), and the lowest value (eg, min(dVDmax, dVcomp)) is selected.

[0043] Step 1014: Determine the maximum value between the minimum value and the acceleration lower limit value as the velocity change rate.

[0044] In practice, the minimum value is compared with the lower acceleration limit (e.g., dVBmin), and the maximum value is selected as the velocity change rate. The resulting velocity change rate is within the normal range (e.g., [dVBmin, dVDmax]), and the subsequent steps 102 to 103 are performed based on this velocity change rate.

[0045] Through the above scheme, the acceleration upper limit and the acceleration lower limit can be used to correct the obtained acceleration, ensuring that the final speed change rate conforms to the normal range from the acceleration lower limit to the acceleration upper limit, avoiding the situation where the speed change rate is too large or too small, affecting the subsequent rear-wheel steering control.

[0046] In some embodiments, step 1011 includes:

[0047] Step 10111: Differentiate the vehicle speed to obtain an initial acceleration.

[0048] In specific implementation, the vehicle speed can be differentiated according to the obtained vehicle speed. However, the initial acceleration obtained by the differentiation is not accurate enough, so it is necessary to use a second-order filter to filter and smooth the initial acceleration obtained by differentiation to obtain a more accurate initial acceleration.

[0049] Step 10112: Obtain the sensor value detected by the acceleration sensor.

[0050] In a specific implementation, the vehicle is equipped with one or more acceleration sensors for detecting vehicle acceleration. If there is only one acceleration sensor, the acceleration result detected by the acceleration sensor is directly used as the sensor value. If there are multiple acceleration sensors, the average of the multiple acceleration results is calculated as the sensor value. If there are more than four acceleration sensors, the maximum and minimum values of the at least four acceleration results are removed, and then the average value is calculated as the sensor value.

[0051] Step 10113: In response to the sensor value being greater than or equal to the sensor threshold, compare the absolute value of the sensor value and the absolute value of the initial acceleration, whichever is smaller, as the acceleration.

[0052] In specific implementation, if the sensor value is greater than or equal to the sensor threshold, it proves that the sensor value may be too large, so it is necessary to compare the absolute values corresponding to the sensor value and the initial acceleration, and select the smaller value of the two as the acceleration. This way, the obtained acceleration is more accurate.

[0053] Alternatively, in step 10114, in response to the sensor value being less than a sensor threshold, the sensor value is used as the acceleration.

[0054] In a specific implementation, if the sensor value is less than the sensor threshold, it proves that the sensor value is within the normal value range and the sensor value is relatively accurate, so the sensor value is selected as the acceleration.

[0055] Through the above scheme, the initial acceleration calculated using the vehicle speed and the sensor value detected by the acceleration sensor can be used as the acceleration, whichever is closest to the actual value, to ensure that the selected acceleration is more accurate.

[0056] In some embodiments, the process of determining the acceleration upper limit includes:

[0057] Step A1: Under the driving condition, obtain the wheel driving force (e.g., FD), wind resistance constant (e.g., K), transmission efficiency factor (e.g., B), vehicle mass (e.g., m), and slope acceleration (e.g., a slope ).

[0058] In step A2, the wind resistance constant is multiplied by the square of the vehicle speed to obtain a first product (eg, K*V2).

[0059] Step A3: Subtract the first product from the wheel driving force to obtain a first power (e.g., FD-K*V 2 ).

[0060] Step A4: multiply the first power by the transmission efficiency factor and then divide the result by the vehicle mass to obtain a first acceleration value (for example, (FD-K*V 2 )*B / m).

[0061] Step A5: Subtract the gradient acceleration from the first acceleration value to obtain an initial upper limit value (e.g., (FD-K*V 2 )*B / ma slope ).

[0062] Step A6: The initial upper limit value and the first set value (for example, 0) are compared with the larger value (for example, max(0, [(FD-K*V 2 )*B / ma slope ])), as the acceleration upper limit value.

[0063] Through the above scheme, the acceleration upper limit value obtained by using the above steps A1 to A5 under the driving condition is the maximum acceleration that can be achieved within the normal range in accordance with the vehicle's own conditions. The obtained acceleration upper limit value is more compatible with the vehicle itself, ensuring the accuracy of the acceleration upper limit value.

[0064] In some embodiments, the process of determining the lower acceleration limit includes:

[0065] Step B1, under braking conditions, obtain wheel braking force (e.g., FB), wind resistance constant (e.g., K), transmission efficiency factor (e.g., B), vehicle mass (e.g., m), and slope acceleration (e.g., a slope ).

[0066] Step B2: multiply the wind resistance constant by the square of the vehicle speed to obtain a second product (for example, K*V 2 ).

[0067] Step B3, using the wheel braking force plus the second product to obtain a second power (for example, FB+K*V 2 ).

[0068] Step B4: multiply the second power by the transmission efficiency factor and then divide the result by the vehicle mass to obtain a second acceleration value (for example, (FB+K*V 2 )*B / m).

[0069] Step B5: derive an initial lower limit value (e.g., (FB+K*V)) by adding the second acceleration value to the slope acceleration. 2 )*B / m+a slope ).

[0070] Step B6: The smaller value (for example, min(0, [(FB+K*V 2 )*B / m+a slope ])), as the lower limit value of acceleration.

[0071] Through the above scheme, the acceleration lower limit value obtained by using the above steps B1 to B5 under braking conditions is the minimum acceleration that can be achieved within the normal range in accordance with the vehicle's own conditions. The obtained acceleration lower limit value is more compatible with the vehicle itself, ensuring the accuracy of the acceleration lower limit value.

[0072] In some embodiments, after step 101, the method further includes:

[0073] Step 101 ′: determine the vehicle speed, retrieve a modified speed change rate corresponding to the vehicle speed and the speed change rate, and replace the speed change rate with the modified speed change rate.

[0074] In a specific implementation, in order to increase the accuracy of the speed change rate, a table of various vehicle speeds and the corrected speed change rates corresponding to various speed change rates is pre-stored.

[0075] The table specifically includes the following: the value of the speed of the vehicle, the value of the speed change rate, and the corresponding modified speed change rate. The table can also include the value of the speed change rate of the vehicle, the value of the speed of the vehicle, and the corresponding modified speed change rate.

[0076] Through the above solution, a more accurate correction speed change rate is obtained according to the vehicle speed and the speed change rate, thereby avoiding the inaccuracy of the original speed change rate.

[0077] In some embodiments, step 102 includes:

[0078] Step 1021 , obtaining a speed correction value of a previous cycle, and correcting the speed correction value of the previous cycle using the speed change rate to obtain a current speed correction value.

[0079] In specific implementation, the speed correction value V of the previous cycle T-1 is T-1 Yes: Speed correction value V for period T-2 T-2 Add the speed change rate dVcor of one cycle T-1 T-1 The initial value of the speed correction value is the speed value detected by the speed sensor when the vehicle starts.

[0080] Thus, the current speed correction value V T The calculation formula is: V T =V T-1 +dVcor T .

[0081] Step 1022: Determine a first rear-wheel steering control value corresponding to the current speed correction value, and a second rear-wheel steering control value obtained by correcting the original rear-wheel steering control value using a correction relationship factor.

[0082] In specific implementation, the rear wheel steering control curve formula Ratio=f(V) is pre-stored, where V is the vehicle speed, f() is the rear wheel steering control curve function, and Ratio is the front and rear wheel angle control ratio.

[0083] The current speed correction value V T As V input to the rear wheel steering control curve formula to obtain the first rear wheel steering control amount (for example, f(V T)). Based on the speed change rate (e.g., dV), a corresponding correction factor (e.g., G(dV), where G() is the correction function and the larger the absolute value of dV, the smaller G(dV)) is determined. The second rear-wheel steering control variable (e.g., G(dV)*f(V)) can then be calculated.

[0084] As a preferred embodiment, the rear wheel steering control curve formula Ratio=f(V) is divided into the following cases:

[0085] (1) When driving at low speed (for example, speed V < 40 km / h), the rear wheel steering control curve is:

[0086] Ratio=-k*(1-V / V low ), where k is a proportional coefficient less than or equal to 1, V is the vehicle speed, V low It is the upper speed limit for low-speed driving.

[0087] Rear wheel steering angle direction: opposite to the front wheel (counter steering); purpose: to reduce the turning radius, improve the vehicle's flexibility, and facilitate parking and low-speed turning; curve characteristics: as the vehicle speed increases, the rear wheel steering angle gradually decreases.

[0088] (2) When driving at medium speed (for example, vehicle speed 40 km / h ≤ V < 80 km / h), the rear wheel steering control curve is:

[0089] Ratio=k*(VV min ) / (V mid -V min ), where k is a proportional coefficient less than or equal to 1, V is the vehicle speed, V min is the lower speed limit of the vehicle under medium speed driving, V mid It is the upper limit for medium speed driving.

[0090] Rear wheel steering angle direction: gradually transitions to the same as the front wheels (steering in the same direction); purpose: improve vehicle stability and reduce the risk of skidding; curve characteristics: the rear wheel steering angle gradually changes from counter-steering to zero, and then transitions to steering in the same direction.

[0091] (3) When driving at high speed (for example, vehicle speed V ≥ 80 km / h), the rear wheel steering control curve is:

[0092] Ratio=k*V / V max , where k is the proportional coefficient less than or equal to 1, V is the vehicle speed, V max The maximum design speed of the vehicle.

[0093] Rear wheel steering angle direction: the same as the front wheels (steering in the same direction); purpose: to improve stability at high speeds and reduce body roll and yaw; curve characteristics: the rear wheel steering angle gradually increases with increasing vehicle speed, but the increase is small.

[0094] Step 1023: In response to determining that the original rear-wheel steering control amount is greater than or equal to a set limit, the minimum value of the first rear-wheel steering control amount and the second rear-wheel steering control amount is selected as the target rear-wheel steering control amount.

[0095] In a specific implementation, the corresponding set limit is generally set to 0. If the original rear wheel steering control value (e.g., Ratio) ≥ the set limit 0, it proves that the front and rear wheel steering angles are in the same direction. At this time, in order to balance the front and rear wheel steering angles, the minimum value of the first rear wheel steering control value and the second rear wheel steering control value obtained in step 1022 is selected (e.g., min(f(V T ), G(dV)*f(V))).

[0096] Alternatively, in step 1024, in response to the original rear-wheel steering control amount being less than the set limit, the maximum value of the first rear-wheel steering control amount and the second rear-wheel steering control amount is selected as the target rear-wheel steering control amount.

[0097] In a specific implementation, the original rear wheel steering control value (e.g., Ratio) is less than the set limit of 0, indicating that the front and rear wheel steering angles are in opposite directions. In order to avoid imbalance caused by a large difference in the opposite direction of the front wheel steering angle, the maximum value (e.g., min(f(V T ), G(dV)*f(V))).

[0098] Through the above scheme, the speed correction value obtained in the previous cycle can be corrected using the obtained speed change rate, ensuring that the current speed correction value obtained is more accurate. In addition, the scheme of this embodiment will also reasonably screen the first rear wheel steering control amount and the second rear wheel steering control amount obtained based on the size of the original rear wheel steering control amount, which can effectively ensure the stability of vehicle driving.

[0099] In some embodiments, the execution of step 103 further includes:

[0100] Step 1031, in response to the activation of at least one of the traction control function (e.g., TCS), the anti-lock braking function (e.g., ABS), and the dynamic control function (e.g., VDC), during the activation period, the rear-wheel steering control is continuously performed using the target rear-wheel steering control amount corresponding to the activation time point.

[0101] In practice, activating any of the traction control, anti-lock braking, and dynamic control functions may cause a sudden change in vehicle speed. Consequently, the speed change rate determined during activation may be inaccurate, and consequently, the target rear-wheel steering control variable determined based on this speed change rate may also be inaccurate. To avoid this, the target rear-wheel steering control variable corresponding to the activation time is frozen during the activation period, and the target rear-wheel steering control variable is not recalculated. The target rear-wheel steering control variable corresponding to the activation time is maintained during the activation period, ensuring that the vehicle is not affected by the sudden change in vehicle speed during the activation period and that normal rear-wheel steering control is maintained.

[0102] Step 1032: Determine when the activation ends or a predetermined time period after the activation ends, and redetermine the target rear-wheel steering control amount to perform rear-wheel steering control.

[0103] In specific implementation, after the activation of the above-mentioned triggered function is completed, or after a predetermined period of time after the activation is completed, the new target rear-wheel steering control amount can be determined again according to the implementation process of the above-mentioned steps 101 and 102, and the vehicle can be controlled to obtain the target rear-wheel steering control amount corresponding to the activation time point, and according to the calibrated slope, it can be restored to the new target rear-wheel steering control amount to continue the rear-wheel steering control.

[0104] The time period after activation is completed (for example, 0.1s, 0.2s, or 0.3s) is counted, and a predetermined number of time periods are used as a predetermined time period; or a period of time (for example, 1s) is set as a predetermined time period.

[0105] Since the speed change rate may still be relatively large after the activation is completed, in this embodiment, the target rear-wheel steering control amount is preferably re-determined after a predetermined period of time after the activation is completed.

[0106] Through the above scheme, after any of the functions that are likely to cause sudden changes in vehicle speed, such as traction control, anti-lock braking function and dynamic control function, is activated, the rear-wheel steering control is performed using the target rear-wheel steering control amount corresponding to the activation time point, which can ensure that the vehicle's rear-wheel steering is not affected by sudden changes in vehicle speed, so that the vehicle's rear-wheel steering can operate accurately and smoothly.

[0107] The following describes the rear wheel steering control method of the present application with a specific embodiment, and the execution process is as follows:

[0108] 1. Calculate vehicle speed V:

[0109] The vehicle speed V is calculated as the average of the two lower wheel speeds during driving conditions and the average of the two higher wheel speeds during braking conditions.

[0110] 2. Calculate the velocity change rate dV:

[0111] (1) Calculate the differential of the vehicle speed V and perform a second-order filter to obtain the initial acceleration of the vehicle.

[0112] (2) Monitor the sensor value asesor of the vehicle acceleration sensor. When the absolute value of asensor is greater than the sensor threshold value TBD, compare the smaller value between asensor and the absolute value of the initial acceleration and use it as the acceleration dVcomp. When the absolute value of asensor is less than the sensor threshold value TBD, use asesor as the acceleration dVcomp.

[0113] (3) Determine the upper and lower limits of acceleration based on the vehicle's kinematic dynamics:

[0114] When driving, set the upper limit dVDmax = max(0,[(FD-K*V*V)*B / m-aslope]), where FD is the wheel driving force, K is the wind resistance constant, B is the transmission efficiency factor, m is the vehicle mass, and aslope is the slope acceleration value.

[0115] During braking, set the lower limit dVBmin=min(0,[(FB+K*V*V)*B / m+aslope]), where FB is the wheel braking force.

[0116] (4) Based on the above, the speed change rate dV = max(dVBmin, min(dVDmax, dVcomp)).

[0117] 3. Design a two-dimensional continuous lookup table with V and dV as input, and output the corrected speed change rate dVcor (the higher the V and the higher the absolute value of dV, the smaller the output dVcor).

[0118] 4. Assume that the original rear wheel steering control curve equation is Ratio = f(V), where Ratio is the front and rear wheel angle control ratio and V is the vehicle speed.

[0119] Based on the above equation, a new rear-wheel steering control curve equation (i.e., the equation for the target rear-wheel steering control amount RatioNew) is designed as follows:

[0120] When Ratio≥0, RatioNew=min(f(V T ),G(dV)*f(V));

[0121] When Ratio<0, RatioNew=max(f(V T ),G(dV)*f(V)).

[0122] Among them, the speed correction value V of the current cycle T T =V T-1Add the velocity change rate dVcor of the current cycle T T Calculated, that is, V T =V T-1 +dVcor T , where V T-1 =V T-2 +dVcor T-1 G(dV) is a correction function related to dV. The larger the absolute value of dV, the smaller G(dV).

[0123] 5. After TCS (traction control function), ABS (anti-lock braking function), or VDC (dynamic direction control function) is activated, the RatioNew corresponding to the activation time is obtained and frozen. During the activation period, RatioNew is continuously used for rear-wheel steering control. After activation is terminated and maintained for a predetermined number of periods, a new RatioNew is recalculated and restored to the new RatioNew at the calibrated slope from the RatioNew corresponding to the activation time.

[0124] During the process of performing rear-wheel steering control according to the target rear-wheel steering control amount (i.e., the ratio of the front and rear wheel steering angles) in step 103, the rear wheels and the front wheels are generally controlled in opposite directions when traveling at low speeds (e.g., vehicle speed ≤ 40 km / h). Since the front and rear wheels rotate in opposite directions at low speeds, the front wheels may move away from the roadside shoulder while the rear wheels collide with the roadside shoulder, which may easily cause scratches and damage to the rear tires of the vehicle.

[0125] A specific embodiment will be described below with respect to the above situation, as follows:

[0126] Step 201: determine whether the wheel has moved to the road shoulder and obtain a determination result.

[0127] During specific implementation, the camera can be used to collect and analyze real-time images of each wheel to determine whether each wheel has moved to the shoulder of the road (that is, there is a risk of collision with the shoulder of the road). If so, the corresponding judgment result is yes; if not, the corresponding judgment result is no.

[0128] It is also possible to determine whether each wheel has moved to the shoulder of the road (i.e., there is a risk of collision with the shoulder of the road) by detecting various control parameters when the wheels are turned. If so, the corresponding judgment result is yes; if not, the corresponding judgment result is no.

[0129] As a preferred embodiment, the vehicle is a vehicle with active rear-wheel steering control. When traveling at a low speed (for example, the vehicle speed is ≤40km / h), the vehicle steering control is performed by rotating the front and rear wheels in opposite directions. At this time, the front wheels will move away from the road shoulder and the rear wheels will move to the road shoulder (that is, collide with the road shoulder). The corresponding judgment result is yes.

[0130] Step 202 : In response to the judgment result being yes, determining a target direction of the road shoulder relative to the wheel, and restraining the wheel from turning toward the target direction.

[0131] In practice, if the judgment result is yes, proving that the wheel has contacted the curb, it is necessary to determine whether the wheel in contact with the curb is the front wheel or the rear wheel, and determine the azimuth position of the curb relative to the wheel as the target direction (for example, to the left or right of the rear wheel). In this way, to prevent the wheel from continuing to turn in the target direction and scraping against the curb, the wheel will be automatically controlled to suppress the steering angle in the target direction, causing the wheel to continuously reduce the steering operation in the target direction, thereby achieving the goal of suppressing the wheel's steering angle in the target direction.

[0132] Through the above scheme, when it is determined that the wheel moves to the shoulder and collides with the shoulder, the target direction of the shoulder relative to the wheel can be determined. In this way, the vehicle can automatically control the wheel to suppress rotation in the target direction in time, so that the wheel can be adjusted in time when it collides with the shoulder, and the wheel will not continue to collide with the shoulder, avoiding the situation where the wheel is scratched and damaged due to continuous collision with the shoulder. Since the vehicle automatically implements the process of suppressing the wheel from turning in the target direction, the process has a faster transient response speed. Compared with the method of manual control through prompts, it can save the time of human reaction and operation, and reduce the duration of the wheel's collision with the shoulder. In addition, the scheme of the present application does not require the vehicle to set up additional hardware. It can directly identify whether the wheel has collided with the shoulder based on the vehicle's own hardware, and then execute the corner suppression process after determining that there has been a collision with the shoulder. The operation is simple and convenient.

[0133] In some embodiments, the wheel is a rear wheel; step 201 includes:

[0134] Step 2011, during the process of steering the rear wheels, detecting whether there is a road shoulder when the rear wheels are turning, and obtaining a judgment result.

[0135] In specific implementation, this embodiment mainly focuses on the process of road shoulder monitoring of the rear wheels, and is specifically applied to vehicles with active rear wheel steering control.

[0136] The ratio of the front and rear wheel turning angles obtained during low speed (vehicle speed < 40km / h) is a negative value, that is, the direction of the front wheel turning angle is opposite to that of the rear wheel turning angle, which makes low-speed turning more flexible. Therefore, since the driver can control the front wheels better during the turning process, the front wheels are generally not prone to colliding with the curb. However, the rear wheels are difficult to control because the driver cannot see them. In addition, when the front and rear wheels are turned at low speed, the steering direction of the rear wheels is opposite to that of the front wheels, so it is easy for the rear tires to scrape the curb.

[0137] During vehicle steering control, the vehicle speed is used as input to determine the corresponding front and rear wheel steering angle ratio. The steering angle of the steering wheel then determines the corresponding front and rear wheel control angles. The front wheel angle is then sent to the front motor for front-wheel steering control. Simultaneously, the rear wheel angle is sent to the rear motor for rear-wheel steering control.

[0138] The above solution can avoid the rear wheel colliding with the shoulder during the rear wheel steering control process, and the rear wheel can suppress the turning angle in time to reduce the situation where the rear wheel scrapes the shoulder.

[0139] In some embodiments, step 2011 includes at least one of the following:

[0140] Step 20111: Detect the output motor torque of the rear wheel motor when the two rear wheels are at the same rotation angle and the same speed, and determine whether the output motor torque is greater than the torque upper limit value to obtain a first judgment result.

[0141] During specific implementation, it is determined that the two rear wheels are in the same turning angle and the same rotation speed condition, so that it can be determined that the steering of the two rear wheels is in a stable state.

[0142] Under this condition, the output motor torque of the rear wheel motor (for example, Mr) is detected. If the output motor torque is greater than the torque upper limit (for example, Mr>Mr Max ), and continues for a predetermined period of time (for example, for a predetermined number of operation cycles), proving that there is a shoulder on the rear wheel steering side at this time, the corresponding first judgment result is yes.

[0143] Otherwise, when the rear wheels perform normal steering, the output motor torque is less than or equal to the torque upper limit (for example, Mr≤Mr Max ), the corresponding first judgment result is no.

[0144] Step 20112: Determine the angle difference between the target rear wheel angle and the actual rear wheel angle, and determine whether the angle difference is greater than a angle difference threshold to obtain a second determination result.

[0145] In a specific implementation, the rear wheel target angle is a target angle value corresponding to the rear wheel determined according to the ratio of the front and rear wheel angles, and the rear wheel motor is controlled to perform rear wheel steering according to the rear wheel target angle:

[0146] If there is a shoulder, the rear wheels will be affected by the shoulder and unable to complete the turn. As a result, the actual rear wheel angle detected by the rear wheel angle sensor will deviate significantly from the target rear wheel angle, resulting in a larger difference between the two angles. This difference will exceed the angle difference threshold, and the corresponding second judgment result will be yes.

[0147] If the rear wheels are steering normally, the actual rear wheel angle detected by the rear wheel angle sensor deviates slightly from the rear wheel target angle, and the corresponding angle difference is relatively small. The angle difference will be less than or equal to the angle difference threshold, and the corresponding second judgment result will be no.

[0148] Step 20113: Detect the yaw rate difference between the desired yaw rate and the actual yaw rate, as well as the lateral rate difference between the desired lateral rate and the actual lateral rate, and determine whether at least one of the yaw rate difference and the lateral rate difference exceeds a corresponding design threshold, thereby obtaining a third determination result.

[0149] During specific implementation, a table is formed by presetting the expected yaw rate and the expected lateral rate corresponding to the vehicle speed and the front wheel steering angle.

[0150] Based on the real-time vehicle speed and front wheel steering angle, the desired yaw rate and desired lateral velocity of the vehicle are then determined through a table lookup. Steering control is then performed based on the desired yaw rate and desired lateral velocity. The vehicle is equipped with an acceleration sensor and a yaw rate sensor, which can detect the vehicle's actual yaw rate in real time. The actual lateral velocity is determined based on the vehicle's acceleration and yaw angle detected in real time by the acceleration sensor. The yaw rate difference between the desired yaw rate and the actual yaw rate, as well as the lateral rate difference between the desired lateral velocity and the actual lateral velocity, can then be calculated.

[0151] If the yaw angular velocity difference is greater than the yaw angular velocity threshold, and / or the lateral angular velocity difference is greater than the lateral angular velocity threshold, it can reflect that the rear wheels cannot steer normally, proving that there is a shoulder on the corresponding rear wheel steering side, and the third judgment result is yes.

[0152] If the yaw rate difference is less than or equal to the yaw rate threshold, and the lateral rate difference is less than or equal to the lateral rate threshold, it is determined that the rear wheel steering is normal steering and there is no road shoulder, and the third judgment result is no.

[0153] Step 20114, in response to the vehicle speed being lower than the vehicle speed threshold, receiving the action of alternating forward and reverse steering within a predetermined time period, determining the rear wheel motor output torque difference corresponding to the forward steering and reverse steering, judging whether the rear wheel motor output torque difference is greater than the torque threshold, and obtaining a fourth judgment result.

[0154] In specific implementation, when the vehicle speed is lower than the speed threshold, the vehicle is traveling at a low speed, and during the vehicle turning process, the driver may operate the steering wheel alternately in the forward direction (ie, clockwise) and the reverse direction (ie, counterclockwise).

[0155] During forward and reverse operation, the difference in rear wheel motor output torque corresponding to the forward and reverse directions is calculated when the angle or speed have the same absolute value.

[0156] If the rear wheel collides with a curb, the torque difference will be greater than the torque threshold, determining that there is a curb on the side where the rear wheel motor outputs a larger torque (for example, the positive direction corresponds to a larger output torque of the rear wheel motor, and there is a curb on the right side of the rear wheel; the positive direction corresponds to a larger output torque of the rear wheel motor, and there is a curb on the left side of the rear wheel), and the fourth judgment result is yes.

[0157] If the rear wheels do not collide with the curb, the torque difference is less than or equal to the torque threshold, and the fourth determination result is no.

[0158] The judgment result includes at least one of a first judgment result, a second judgment result, a third judgment result and a fourth judgment result.

[0159] Through the above scheme, the above four methods of determining whether there is a shoulder when the rear wheel is turned are provided, thereby providing a variety of choices. Specifically, you can choose from the four determination methods according to actual needs. You can choose one of them, or you can choose multiple of them for comprehensive judgment.

[0160] In some embodiments, the process of determining the upper limit of the torque includes:

[0161] Step I: Detect the drag distance of the front wheels when the two front wheels are at the same turning angle and the same speed.

[0162] During specific implementation, the driver's output torque Mdriver detected by the torque sensor on the steering wheel is obtained when the two front wheels are at the same turning angle and the same speed; the output torque converted to the wheel end by the EPS power assist motor is obtained, which is specifically output by the motor controller, and the output torque Meps corresponding to the output of the motor controller can be directly detected; the moment of inertia Jwheel of the front wheel control system around the vertical axis is retrieved; and the angular acceleration α of the front wheel rotation is also retrieved.

[0163] The calculation formula of the resistance torque Mf of the front wheel is: Mf=Mdriver+Meps-Jwheel*α.

[0164] Step II: Obtain the load ratio value of the front wheels and the rear wheels (i.e., the target rear wheel steering control amount in the above embodiment), multiply the load ratio value by the drag distance and then by the safety factor to obtain the torque upper limit value.

[0165] In specific implementation, the load ratio value K between the front and rear wheels can be obtained by inputting the corresponding rear wheel steering control curve formula according to the vehicle speed. Alternatively, the load ratio value directly calculated based on the vehicle speed can be corrected and adjusted in combination with the speed change rate to obtain the final load ratio value K between the front and rear wheels.

[0166] The upper limit of torque Mr Max The calculation formula is: Mr Max =K*Mf*g, where g is the safety factor (a calibrated value greater than 1).

[0167] Through the above scheme, an accurate resistance torque can be obtained, and then the resistance torque is combined with the load ratio of the front and rear wheels and the corresponding safety factor for multiplication to obtain a more accurate torque upper limit value, thereby ensuring that the output motor torque of the rear wheel motor is accurately judged on the shoulder based on the torque upper limit value to obtain the first judgment result.

[0168] In some embodiments, the judgment result further includes:

[0169] Step (1) determines a first judgment value corresponding to the first judgment result, a second judgment value corresponding to the second judgment result, a third judgment value corresponding to the third judgment result, and a fourth judgment value corresponding to the fourth judgment result.

[0170] In a specific implementation, if the first judgment result is yes, the corresponding first judgment value W is w1 (for example, 1); if the first judgment result is no, the corresponding first judgment value W is w2 (for example, 0).

[0171] If the second judgment result is yes, the corresponding second judgment value X is x1 (for example, 1), and if the second judgment result is no, the corresponding second judgment value X is x2 (for example, 0).

[0172] If the third judgment result is yes, the corresponding third judgment value Y is y1 (for example, 1); if the third judgment result is no, the corresponding third judgment value Y is y2 (for example, 0).

[0173] If the fourth judgment result is yes, the corresponding fourth judgment value Z is z1 (for example, 1); if the fourth judgment result is no, the corresponding fourth judgment value Z is z2 (for example, 0).

[0174] Step (2): performing weighted summation on the first judgment value, the second judgment value, the third judgment value and the fourth judgment value to obtain a total judgment value.

[0175] In a specific implementation, the calculation formula of the total judgment value is a1*W+a2*X+a3*Y+a4*Z, wherein a1, a2, a3 and a4 are weight values, and a1+a2+a3+a4=1.

[0176] Step (3) determines whether the total judgment value is greater than the comprehensive threshold value and obtains a comprehensive judgment result.

[0177] In specific implementations, a corresponding comprehensive threshold is pre-set. If the total judgment value is greater than the comprehensive threshold, it indicates that the rear wheel has collided with the curb, and the comprehensive judgment result is yes. If the total judgment value is less than or equal to the comprehensive threshold, it indicates that the rear wheel is steering normally and there has been no collision with the curb, and the comprehensive judgment result is no. This comprehensive judgment result can then be used as the judgment result to continue the process of step 202.

[0178] Through the above scheme, the above four road shoulder judgment results can be integrated to avoid the situation where any one of the judgments is inaccurate, thereby improving the accuracy of identifying whether the rear wheel collides with the road shoulder.

[0179] In some embodiments, the wheels are rear wheels; the process of performing road shoulder monitoring mainly targets rear wheels, and is specifically applied to vehicles with active rear wheel steering control.

[0180] The step 202 of suppressing the wheel from turning toward the target direction includes:

[0181] Step 2021: Receive the target steering angle value of the rear wheel, and continuously select the minimum value from the target steering angle value and the target steering angle value of the previous cycle to perform rear wheel steering control.

[0182] In practice, to effectively control the target steering angle for the rear wheels while simultaneously enabling rear-wheel steering, the system continuously takes the smaller of the currently received target angle and the target angle received in the previous cycle, and then performs rear-wheel steering control based on the smaller value. This continues until the vehicle's rear wheels are determined to have cleared the roadside collision, or until the minimum value reaches 0.

[0183] Through the above scheme, the rear wheel steering suppression processing is performed by continuously taking the smaller value of the target steering angle value currently received and the target steering angle value received in the previous cycle, which can ensure that the rear wheels of the vehicle can perform a smooth steering suppression process and avoid excessive suppression that causes vehicle instability.

[0184] As a preferred embodiment, the suppression method may also be to reduce the target turning angle value of the rear wheel according to a predetermined ratio, or to reduce it linearly.

[0185] In some embodiments, after step 202, the method further includes:

[0186] Step 203: Determine that the vehicle is traveling normally, and release the rotation angle restriction of the wheel toward the target direction.

[0187] In specific implementation, if the steering adjustment is made by continuously adjusting the wheel angle through corner suppression, so that after the vehicle is adjusted through steering, the collision between the wheel and the road shoulder is resolved, the corner suppression process will be released and the normal driving mode will be restored.

[0188] Through the above scheme, it is possible to ensure that the vehicle restrains the wheels from turning toward the target direction, so that the wheels no longer turn toward the shoulder, and the wheels gradually move away from the shoulder, so that normal driving can be restored. Then, the steering restraint is released to avoid continuing the steering restraint process and affecting the normal driving of the vehicle.

[0189] In some embodiments, determining that the vehicle is driving normally in step 203 includes:

[0190] Step 2031: Integrate the wheel speed to obtain an effective driving distance. In response to the effective driving distance being greater than a distance threshold, it is determined that the vehicle is driving normally.

[0191] In specific implementation, if the wheels hit the shoulder of the road, the vehicle will not be able to move normally. Therefore, after the corner suppression process, the effective driving distance of the vehicle will be determined based on the integral calculation of the wheel speed. If the effective driving distance is greater than the distance threshold, it proves that the vehicle can move normally, and it can be determined that the vehicle has returned to normal driving state.

[0192] And / or, in step 2032, the actual yaw angular velocity of the vehicle is integrated to obtain a vehicle rotation angle, and in response to the vehicle rotation angle being greater than a rotation angle threshold, it is determined that the vehicle is traveling normally.

[0193] During specific implementation, if the wheels hit the roadside, the vehicle will be stuck on the roadside and will not be able to swing laterally. Therefore, after the angle suppression process, the vehicle's rotation angle will be determined based on the integral calculation of the actual yaw angular velocity. If the rotation angle is greater than the rotation angle threshold, it proves that the vehicle can swing normally, and it can be determined that the vehicle has returned to normal driving state.

[0194] Through the above scheme, at least two schemes for judging whether the vehicle can drive normally are given, which meet diverse needs and can identify the normal driving of the vehicle from multiple aspects, avoiding the situation where the wheel angle suppression cannot be released in time due to inaccurate identification of the normal driving of the vehicle, thereby affecting the normal driving of the vehicle.

[0195] As a preferred embodiment, the specific method for determining whether the vehicle is driving normally can be determined according to at least one of the above steps 20111 to 20114, or steps (1) to (3). When the corresponding judgment result (the first judgment result, the second judgment result, the third judgment result, the fourth judgment result or the comprehensive judgment result) is determined to be no, it is considered that the vehicle is driving normally.

[0196] It should be noted that the method of the embodiment of the present application can be performed by a single device, such as a computer or server. The method of this embodiment can also be applied in a distributed scenario and performed by multiple devices working together. In such a distributed scenario, one of the multiple devices may only perform one or more steps of the method of the embodiment of the present application, and the multiple devices will interact with each other to complete the method.

[0197] It should be noted that the above description is limited to some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in an order different from that described in the above embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0198] Based on the same inventive concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides a rear-wheel steering control device.

[0199] refer to Figure 2 , the device comprises:

[0200] A speed change rate determination module 21 is configured to determine a speed change rate of the vehicle;

[0201] a correction and adjustment module 22 configured to determine an original rear-wheel steering control amount according to the vehicle speed, and to correct and adjust the original rear-wheel steering control amount using the speed change rate to obtain a target rear-wheel steering control amount;

[0202] The rear-wheel steering control module 23 is configured to perform rear-wheel steering control according to the target rear-wheel steering control amount.

[0203] In some embodiments, the speed change rate determination module 21 includes:

[0204] an acceleration determining unit configured to obtain the vehicle speed and determine the acceleration based on the vehicle speed;

[0205] a limit value determination unit configured to determine an upper acceleration limit value and a lower acceleration limit value;

[0206] The comparison unit is configured to determine a lowest value between the acceleration upper limit value and the acceleration; and determine a maximum value between the lowest value and the acceleration lower limit value as the speed change rate.

[0207] In some embodiments, the acceleration determination unit is specifically configured to:

[0208] Differentiating the vehicle speed to obtain an initial acceleration;

[0209] Get the sensor value detected by the acceleration sensor;

[0210] In response to the sensor value being greater than or equal to a sensor threshold, comparing an absolute value of the sensor value and an absolute value of the initial acceleration, whichever is smaller, as the acceleration; or,

[0211] In response to the sensor value being less than a sensor threshold, the sensor value is used as the acceleration.

[0212] In some embodiments, the limit value determining unit is specifically configured to:

[0213] Under driving conditions, obtain wheel driving force, wind resistance constant, transmission efficiency factor, vehicle mass and slope acceleration;

[0214] Multiplying the wind resistance constant by the square of the vehicle speed to obtain a first product;

[0215] subtracting the first product from the wheel driving force to obtain a first power;

[0216] Multiplying the first power by the transmission efficiency factor and then dividing the result by the vehicle mass to obtain a first acceleration value;

[0217] subtracting the gradient acceleration from the first acceleration value to obtain an initial upper limit value;

[0218] The larger value between the initial upper limit value and the first set value is used as the acceleration upper limit value.

[0219] In some embodiments, the limit value determining unit is specifically configured to:

[0220] Under braking conditions, obtain wheel braking force, wind resistance constant, transmission efficiency factor, vehicle mass and slope acceleration;

[0221] multiplying the wind resistance constant by the square of the vehicle speed to obtain a second product;

[0222] Adding the second product to the wheel braking force to obtain a second power;

[0223] Multiplying the second power by the transmission efficiency factor and dividing the result by the vehicle mass to obtain a second acceleration value;

[0224] obtaining an initial lower limit value by adding the second acceleration value to the slope acceleration;

[0225] The smaller value between the initial lower limit value and the second set value is used as the acceleration lower limit value.

[0226] In some embodiments, the apparatus further comprises: a speed change rate correction module configured to:

[0227] After determining the speed change rate of the vehicle, the vehicle speed is determined, a modified speed change rate corresponding to the vehicle speed and the speed change rate is retrieved, and the speed change rate is replaced by the modified speed change rate.

[0228] In some embodiments, the correction and adjustment module 22 is specifically configured to:

[0229] Obtaining a speed correction value of a previous cycle, and correcting the speed correction value of the previous cycle using the speed change rate to obtain a current speed correction value;

[0230] determining a first rear-wheel steering control amount corresponding to the current speed correction value, and a second rear-wheel steering control amount obtained by correcting the original rear-wheel steering control amount using a correction relationship factor;

[0231] In response to determining that the original rear-wheel steering control amount is greater than or equal to a set limit, selecting the minimum value of the first rear-wheel steering control amount and the second rear-wheel steering control amount as the target rear-wheel steering control amount; or

[0232] In response to the original rear-wheel steering control amount being less than the set limit value, the maximum value of the first rear-wheel steering control amount and the second rear-wheel steering control amount is selected as the target rear-wheel steering control amount.

[0233] In some embodiments, the rear wheel steering control module 23 is specifically configured to:

[0234] In response to activation of at least one of a traction control function, an anti-lock braking function, and a dynamic control function, during the activation period, continuously performing rear-wheel steering control using a target rear-wheel steering control amount corresponding to the activation time point;

[0235] The activation is terminated or a predetermined time period after the activation is terminated is determined, and the target rear-wheel steering control amount is re-determined to perform rear-wheel steering control.

[0236] For the convenience of description, the above devices are described as being divided into various modules according to their functions. Of course, when implementing this application, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0237] The apparatus of the above embodiment is used to implement the corresponding method in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be described in detail here.

[0238] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any of the above embodiments when executing the program.

[0239] Figure 3 10 is a schematic diagram showing a more specific hardware structure of an electronic device provided in this embodiment. The device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are communicatively connected to each other within the device via the bus 1050.

[0240] The processor 1010 can be implemented using a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0241] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage devices, dynamic storage devices, etc. The memory 1020 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 1020 and is called and executed by the processor 1010.

[0242] The input / output interface 1030 is used to connect input / output modules to implement information input and output. The input / output modules can be configured as components within the device (not shown in the figure) or can be externally connected to the device to provide corresponding functions. Input devices may include a keyboard, mouse, touch screen, microphone, various sensors, etc., and output devices may include a display, speaker, vibrator, indicator light, etc.

[0243] The communication interface 1040 is used to connect to a communication module (not shown) to enable communication between the device and other devices. The communication module can communicate via a wired method (such as USB, network cable, etc.) or a wireless method (such as mobile network, WiFi, Bluetooth, etc.).

[0244] The bus 1050 comprises a path for transmitting information between the various components of the device (eg, the processor 1010 , the memory 1020 , the input / output interface 1030 , and the communication interface 1040 ).

[0245] It should be noted that although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040, and the bus 1050, in a specific implementation, the device may also include other components necessary for normal operation. In addition, it will be understood by those skilled in the art that the above device may only include the components necessary to implement the embodiments of this specification, and does not necessarily include all the components shown in the figure.

[0246] The electronic device of the above embodiment is used to implement the corresponding method in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be described in detail here.

[0247] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method described in any of the above embodiments.

[0248] The computer-readable media of this embodiment include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM, Parameter Random Access Memory), static random access memory (SRAM, Static Random-Access Memory), dynamic random access memory (DRAM, Dynamic Random Access Memory), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM, Electrically Erasable Programmable read only memory), flash memory or other memory technology, read-only compact disc read-only memory (CD-ROM, Compact Disc Read-Only Memory), digital versatile disc (DVD, Digital Video Disc) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0249] The computer instructions stored in the storage medium of the above embodiment are used to enable the computer to execute the method described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0250] Based on the same concept, corresponding to any of the above-mentioned embodiments, the present application also provides a computer program product, including computer program instructions. When the computer program instructions are run on a computer, the computer executes the method described in any of the above embodiments, which has the beneficial effects of the corresponding method embodiments and will not be repeated here.

[0251] Based on the same inventive concept, the present application further provides a vehicle including the rear-wheel steering control device or the electronic device described in the above embodiments. The beneficial effects of the embodiments of the corresponding rear-wheel steering control device or electronic device are not further described here.

[0252] It is understandable that before using the technical solutions of each embodiment of this application, the type, scope of use, usage scenarios, etc. of the personal information involved will be informed to the user in an appropriate manner, and the user's authorization will be obtained.

[0253] For example, in response to receiving a user's active request, a prompt message is sent to the user to clearly inform the user that the operation requested will require the acquisition and use of the user's personal information. Thus, the user can independently choose whether to provide personal information to the electronic device, application, server, storage medium, or other software or hardware that performs the operation of the technical solution of this application based on the prompt message.

[0254] As an optional but non-limiting implementation, in response to a user's active request, the prompt information may be sent to the user in the form of a pop-up window, in which the prompt information may be presented in text form. Furthermore, the pop-up window may also contain a selection control for the user to select "agree" or "disagree" to provide personal information to the electronic device.

[0255] It is understandable that the above notification and user authorization process are merely illustrative and do not constitute a limitation on the implementation of this application. Other methods that comply with relevant laws and regulations may also be applied to the implementation of this application.

[0256] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. Within the scope of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0257] In addition, for simplicity of description and discussion, and in order not to make the embodiment of the application difficult to understand, the known power supply / ground connection with integrated circuit (IC) chip and other components may or may not be shown in the accompanying drawings provided. In addition, the device can be shown in the form of a block diagram to avoid making the embodiment of the application difficult to understand, and this also takes into account the following fact, that is, the details of the embodiment of these block diagram devices are highly dependent on the platform to be implemented in the embodiment of the application (that is, these details should be fully within the scope of understanding of those skilled in the art). When specific details (for example, circuit) are set forth to describe exemplary embodiments of the application, it will be apparent to those skilled in the art that the embodiment of the application can be implemented without these specific details or when these specific details are changed. Therefore, these descriptions should be considered to be illustrative rather than restrictive.

[0258] Although the present invention has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those skilled in the art based on the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may utilize the embodiments discussed.

[0259] The embodiments of the present application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of this application.

Claims

1. A rear wheel steering control method, characterized in that: include: determining the rate of change of the vehicle's speed; determining an original rear wheel steering control amount according to the vehicle speed, and correcting and adjusting the original rear wheel steering control amount using the speed change rate to obtain a target rear wheel steering control amount; Rear-wheel steering control is performed according to the target rear-wheel steering control amount.

2. The method according to claim 1, wherein determining the rate of change of the vehicle speed comprises: obtaining the vehicle speed, and determining an acceleration based on the vehicle speed; Determine the upper and lower acceleration limits; Determining a lowest value between the acceleration upper limit value and the acceleration; The maximum value between the minimum value and the acceleration lower limit value is determined as the velocity change rate.

3. The method according to claim 2, wherein determining the acceleration based on the vehicle speed comprises: Differentiating the vehicle speed to obtain an initial acceleration; Get the sensor value detected by the acceleration sensor; In response to the sensor value being greater than or equal to a sensor threshold, comparing an absolute value of the sensor value and an absolute value of the initial acceleration, whichever is smaller, as the acceleration; or, In response to the sensor value being less than a sensor threshold, the sensor value is used as the acceleration.

4. The method according to claim 2, characterized in that The process of determining the acceleration upper limit value includes: Under driving conditions, obtain wheel driving force, wind resistance constant, transmission efficiency factor, vehicle mass and slope acceleration; Multiplying the wind resistance constant by the square of the vehicle speed to obtain a first product; subtracting the first product from the wheel driving force to obtain a first power; Multiplying the first power by the transmission efficiency factor and then dividing the result by the vehicle mass to obtain a first acceleration value; subtracting the gradient acceleration from the first acceleration value to obtain an initial upper limit value; The larger value between the initial upper limit value and the first set value is used as the acceleration upper limit value.

5. The method according to claim 2, characterized in that The process of determining the lower limit of acceleration includes: Under braking conditions, obtain wheel braking force, wind resistance constant, transmission efficiency factor, vehicle mass and slope acceleration; multiplying the wind resistance constant by the square of the vehicle speed to obtain a second product; Adding the second product to the wheel braking force to obtain a second power; Multiplying the second power by the transmission efficiency factor and dividing the result by the vehicle mass to obtain a second acceleration value; obtaining an initial lower limit value by adding the second acceleration value to the slope acceleration; The smaller value between the initial lower limit value and the second set value is used as the acceleration lower limit value.

6. The method according to claim 1, characterized in that After determining the speed change rate of the vehicle, the method further includes: The vehicle speed is determined, a modified speed change rate corresponding to the vehicle speed and the speed change rate is retrieved, and the speed change rate is replaced by the modified speed change rate.

7. The method according to claim 1, characterized in that The method of correcting and adjusting the original rear wheel steering control amount by using the speed change rate to obtain a target rear wheel steering control amount includes: Obtaining a speed correction value of a previous cycle, and correcting the speed correction value of the previous cycle using the speed change rate to obtain a current speed correction value; determining a first rear-wheel steering control amount corresponding to the current speed correction value, and a second rear-wheel steering control amount obtained by correcting the original rear-wheel steering control amount using a correction relationship factor; In response to determining that the original rear-wheel steering control amount is greater than or equal to a set limit, selecting the minimum value of the first rear-wheel steering control amount and the second rear-wheel steering control amount as the target rear-wheel steering control amount; or In response to the original rear-wheel steering control amount being less than the set limit value, the maximum value of the first rear-wheel steering control amount and the second rear-wheel steering control amount is selected as the target rear-wheel steering control amount.

8. The method according to claim 1, characterized in that The process of performing rear wheel steering control according to the target rear wheel steering control amount further includes: In response to activation of at least one of a traction control function, an anti-lock braking function, and a dynamic control function, during the activation period, continuously performing rear-wheel steering control using a target rear-wheel steering control amount corresponding to the activation time point; The activation is terminated or a predetermined time period after the activation is terminated is determined, and the target rear-wheel steering control amount is re-determined to perform rear-wheel steering control.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 8 is implemented.

10. A vehicle, characterized in that: The electronic device comprising claim 9.

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