Slope Determination Method, Device, New Energy Vehicle, and Storage Medium

Abstract

The present application discloses a slope determination method, device, new energy vehicle, and storage medium, relating to the technical field of new energy vehicles. The method includes: determining a first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed; when it is determined to output the first slope, obtaining a second slope; the second slope is determined based on the wheel-end driving force, vehicle speed, and filtered actual longitudinal acceleration of the vehicle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration; determining a fusion factor for fusing the first slope and the second slope; and determining the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor. By using this method, the accuracy of the determined slope can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicles, and particularly to a method and device for determining a slope, a new energy vehicle, and a storage medium. Background Art

[0002] With the increasing update of vehicle technologies (such as new energy vehicles), it is very necessary to improve the safety of driving vehicles. During the process of driving a vehicle, the vehicle control unit can determine the slope of the road surface where the vehicle is currently located in real time based on the dynamic principle. However, the slope determined by this method may be inaccurate, which may lead to a reduction in the overall vehicle driving performance.

[0003] Therefore, how to improve the accuracy of the determined slope has become an urgent problem to be solved. Summary of the Invention

[0004] Embodiments of the present application provide a method and device for determining a slope, a new energy vehicle, and a storage medium, which can improve the accuracy of the determined slope.

[0005] In a first aspect, an embodiment of the present application provides a method for determining a slope, the method including:

[0006] Determining a first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed;

[0007] When it is determined to output the first slope, obtaining a second slope; the second slope is determined based on the wheel-end driving force, the vehicle speed, and the filtered actual longitudinal acceleration of the vehicle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration;

[0008] Determining a fusion factor for fusing the first slope and the second slope;

[0009] Determining the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor.

[0010] In one of the embodiments, determining a fusion factor for fusing the first slope and the second slope includes: obtaining the wheel-end torque of the vehicle, and determining the wheel-end driving force change rate based on the wheel-end torque of the vehicle; looking up a table based on the wheel-end driving force change rate to obtain the fusion factor for fusing the first slope and the second slope.

[0011] In one embodiment, the fusion factor is used to characterize the first weight corresponding to the first slope; based on the change rate of the wheel-end driving force, the fusion factor for fusing the first slope and the second slope is obtained by looking up a table, including: normalizing the change rate of the wheel-end driving force to obtain the normalized change rate of the wheel-end driving force; based on the normalized change rate of the wheel-end driving force, looking up the table to obtain the first weight corresponding to the first slope, and based on the first weight, determining the second weight corresponding to the second slope; based on the first slope, the second slope, and the fusion factor, determining the target slope of the road surface where the vehicle is located, including: based on the first slope, the second slope, the first weight, and the second weight, determining the target slope of the road surface where the vehicle is located.

[0012] In one embodiment, the method further includes: activating the slope update flag when the following conditions are met: the vehicle speed is less than or equal to a preset vehicle speed threshold; the current gear of the vehicle is the forward gear; the opening of the vehicle's brake pedal is 0; the change rate of the vehicle speed is greater than a preset vehicle speed change rate threshold; the steering wheel angle of the vehicle is less than a preset steering wheel angle threshold; the wheel-end state of each wheel in the vehicle is in a stable state; the vehicle speed jerk within the first preset time period is less than a preset vehicle speed jerk threshold; wherein, when the slope update flag is activated, it is determined that the first slope is allowed to be output.

[0013] In one embodiment, the method further includes: determining the slip ratio corresponding to each wheel based on the wheel speed and the vehicle speed of each wheel in the vehicle; obtaining the wheel acceleration corresponding to each wheel by differentiating the wheel speed of each wheel in the vehicle; for each wheel, when the slip ratio corresponding to the wheel is less than or equal to a preset slip ratio threshold and the wheel acceleration corresponding to the wheel is less than or equal to a preset wheel acceleration threshold, it is determined that the wheel-end state of the wheel is in a stable state.

[0014] In one embodiment, determining the first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle includes: obtaining the actual longitudinal acceleration of the vehicle by differentiating the vehicle speed of the vehicle; based on the actual longitudinal acceleration, the wheel-end driving force, the vehicle speed, and the force balance principle of the vehicle on the current ramp, determining a first intermediate value; inputting the first intermediate value into a preset slope calculation model to obtain the first slope of the road surface where the vehicle is located.

[0015] In one embodiment, the second slope is determined by the following method: obtaining the actual longitudinal acceleration of the vehicle by differentiating the vehicle speed of the vehicle; filtering the actual longitudinal acceleration to filter out the fluctuation information in the actual longitudinal acceleration to obtain the filtered actual longitudinal acceleration; based on the filtered actual longitudinal acceleration, the wheel-end driving force, the vehicle speed, the force balance principle of the vehicle on the current ramp, and the least squares method, determining a second intermediate value; inputting the second intermediate value into a preset slope calculation model to obtain the second slope.

[0016] In one embodiment, the method further includes: obtaining a slope change rate by taking the derivative based on a target slope; determining a target slope correction factor when the slope change rate is greater than a preset slope change rate threshold; determining a slope change gradient by looking up a table based on the target slope, and determining the final slope of the road surface where the vehicle is located based on the slope change gradient, the target slope correction factor, and the final slope corresponding to the previous cycle of the current cycle, and updating the target slope based on the final slope.

[0017] In one embodiment, when the slope change rate is greater than a preset slope change rate threshold, determining a target slope correction factor includes: when the slope change rate is greater than a preset slope change rate threshold, determining an average value and a root mean square value of the absolute values of multiple slope change rates within a preset time period; obtaining the target slope correction factor corresponding to the average value and the root mean square value based on a target correspondence relationship; the target correspondence relationship includes the correspondence relationship between multiple combinations of average values and root mean square values and multiple slope correction factors; wherein, the slope correction factor is positively correlated with the average value in the combination, and the slope correction factor is positively correlated with the root mean square value in the combination.

[0018] In a second aspect, an embodiment of the present application provides a slope determination device, which includes:

[0019] A determination module, configured to determine a first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed;

[0020] An acquisition module, configured to acquire a second slope when it is determined to output the first slope; the second slope is determined based on the wheel-end driving force, the vehicle speed, and the filtered actual longitudinal acceleration of the vehicle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration;

[0021] The determination module is further configured to determine a fusion factor for fusing the first slope and the second slope;

[0022] The determination module is further configured to determine the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor.

[0023] In a third aspect, an embodiment of the present application provides a new energy vehicle, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of the method in the first aspect are implemented.

[0024] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method in the first aspect are implemented.

[0025] In a fifth aspect, the present application further provides a computer program product, including a computer program which, when executed by a processor, implements the steps of the method according to the first aspect above.

[0026] In the above slope determination method, device, new energy vehicle, and storage medium, the new energy vehicle (hereinafter simply referred to as the vehicle) can determine a first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed; when it is determined to output the first slope, a second slope is obtained; the second slope is determined based on the wheel-end driving force, vehicle speed, and filtered actual longitudinal acceleration of the vehicle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration; a fusion factor for fusing the first slope and the second slope is determined; based on the first slope, the second slope, and the fusion factor, the target slope of the road surface where the vehicle is located is determined. By using this method, the vehicle can implement real-time slope calculation based on the wheel-end driving force and the actual longitudinal acceleration to obtain the first slope of the road surface where the vehicle is located; and when it is determined to output the first slope, a second slope determined based on the wheel-end driving force, vehicle speed, and filtered actual longitudinal acceleration is obtained. Since the accuracy of the filtered actual longitudinal acceleration is higher, the accuracy of the determined second slope is higher. Therefore, by fusing the first slope and the second slope, not only can the slope of the road surface where the vehicle is located be determined in real time, but also the accuracy of the determined slope can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 is a schematic flowchart of a slope determination method provided by an embodiment of the present application;

[0029] Figure 2 is a schematic flowchart of another slope determination method provided by an embodiment of the present application;

[0030] Figure 3 is a schematic structural diagram of a slope determination device provided by an embodiment of the present application;

[0031] Figure 4 is a schematic structural diagram of a new energy vehicle provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] To make the objectives, technical solutions and advantages of this application more clear and understandable, the following further elaborates on this application in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely used to explain this application and are not used to limit this application.

[0033] The following elaborates on the slope determination method provided by the embodiments of this application.

[0034] Please refer to Figure 1 , Figure 1 which is a schematic flowchart of a slope determination method provided by the embodiments of this application. This method can be executed by the vehicle controller. As Figure 1 shown, this slope determination method may include but is not limited to the following steps:

[0035] S101. Determine the first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed.

[0036] Optionally, the vehicle speed of the vehicle can be monitored in real time by the vehicle controller or determined by the vehicle controller based on the motor speed of the vehicle, and no limitation is imposed here.

[0037] Optionally, when the vehicle controller determines the vehicle speed based on the motor speed of the vehicle, the following formula (1) can be used.

[0038] (1)

[0039] In formula (1), V represents the vehicle speed (unit: km / h); n represents the motor speed; r represents the tire radius (unit: meter); i represents the speed ratio; μ is the conversion coefficient from speed to vehicle speed.

[0040] Among them, the wheel-end driving force can be determined by the vehicle controller based on the wheel-end torque. The wheel-end torque refers to the torque applied to the vehicle wheels, which is usually transmitted from the motor to the wheels through the transmission system. Optionally, the wheel-end torque can be obtained by the vehicle controller in real time or periodically.

[0041] In an alternative embodiment, determining the first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle can be based on the wheel-end driving force, the actual longitudinal acceleration, and the force balance principle of the vehicle on the current ramp to determine the first slope.

[0042] In some embodiments, the force balance principle of the vehicle on the current ramp can be achieved based on the ramp resistance, rolling resistance, air resistance, and acceleration resistance.

[0043] Among them, the ramp resistance refers to the force that hinders the vehicle's forward movement when the vehicle is traveling on a ramp, which is generated by the component force of gravity along the ramp direction. Specifically, when the vehicle is traveling on an inclined ramp, its own gravity will generate two component forces. One is the component force perpendicular to the ramp, which is used to balance the supporting force of the ground; the other is the component force along the ramp direction, which is the ramp resistance. When the vehicle is going uphill, the ramp resistance is opposite to the vehicle's traveling direction and hinders the vehicle's forward movement. The vehicle needs to overcome this ramp resistance to move upward; when going downhill, the ramp resistance is in the same direction as the vehicle's traveling direction and will cause the vehicle to have a tendency to accelerate and slide downward.

[0044] Among them, the rolling resistance refers to the force that hinders the vehicle's forward movement during the vehicle's traveling process, which is generated by the interaction between the tire and the road surface.

[0045] Among them, the acceleration resistance refers to the force that hinders the increase in the vehicle's speed during the vehicle's acceleration process. Or rather, the acceleration resistance refers to the sum of various forces that need to be overcome to increase the vehicle's speed when the vehicle is accelerating.

[0046] Among them, the air resistance refers to the force that the air exerts on the vehicle to hinder its forward movement when the vehicle is moving in the air.

[0047] Among them, the force balance principle of the vehicle on the current ramp can be that the wheel-end driving force of the vehicle is equal to the sum of the ramp resistance, rolling resistance, air resistance, and acceleration resistance. Optionally, the wheel-end driving force can be determined by the vehicle control unit based on the wheel-end torque of the vehicle.

[0048] Optionally, during the vehicle's traveling process, the vehicle control unit can obtain multiple state information of the vehicle in real time or periodically, such as vehicle speed, acceleration, etc. After that, the vehicle control unit can determine the air resistance and acceleration resistance corresponding to the vehicle currently based on one or more of the multiple state information. Among them, the air resistance is related to the vehicle speed and the frontal area, and the acceleration resistance is related to the acceleration. And since both the ramp resistance and the rolling resistance are related to the slope, the vehicle control unit can inversely deduce the slope of the road surface where the vehicle is currently located (i.e., the first slope) based on the wheel-end torque, vehicle speed, and the force balance principle of the vehicle on the current ramp.

[0049] S102. When the first slope is determined to be output, obtain the second slope; the second slope is determined based on the wheel-end driving force, vehicle speed, and the filtered actual longitudinal acceleration of the vehicle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration.

[0050] Optionally, the determination method of the vehicle speed can refer to the description in the foregoing step S101, and will not be elaborated here.

[0051] Optionally, during vehicle driving, the vehicle controller can obtain multiple state information of the vehicle in real time or periodically, such as vehicle speed, the gear position where the vehicle is currently located, the opening degree of the vehicle's brake pedal, etc.; afterwards, the vehicle controller can determine whether to activate the slope update flag bit based on one or more of the multiple state information, and in the case of determining to activate the slope update flag bit, allow the output of the first slope, and in the case of outputting the first slope, obtain the second slope.

[0052] Optionally, the vehicle controller can filter the fluctuation information in the actual longitudinal acceleration of the vehicle in real time or periodically to obtain the filtered actual longitudinal acceleration, and determine the second slope based on the filtered actual acceleration, wheel-end driving force, vehicle speed, and force balance principle.

[0053] S103. Determine the fusion factor for fusing the first slope and the second slope.

[0054] Optionally, during vehicle driving, the vehicle controller can obtain at least one state information of the vehicle in real time or periodically, such as the wheel-end torque of the vehicle; afterwards, the vehicle controller can determine the target parameter based on one or more of the at least one state information, such as the wheel-end driving force change rate, and determine the fusion factor for fusing the first slope and the second slope by looking up a table based on the target parameter. Among them, the above-mentioned table includes the corresponding relationships between multiple target parameters and multiple fusion factors. Optionally, the table can be a table preset in the vehicle controller, or a table preset in a certain database and readable by the vehicle controller, etc., which is not limited here.

[0055] S104. Determine the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor.

[0056] In an optional implementation manner, the vehicle controller determines the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor, which can be to input the first slope, the second slope, and the fusion factor into a preset slope fusion calculation model to obtain the target slope of the road surface where the vehicle is located.

[0057] In the embodiments of the present application, the vehicle controller can determine the first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed; when it is determined to output the first slope, the second slope is obtained; the second slope is determined based on the wheel-end driving force, the vehicle speed, and the filtered actual longitudinal acceleration; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration; a fusion factor for fusing the first slope and the second slope is determined; based on the first slope, the second slope, and the fusion factor, the target slope of the road surface where the vehicle is located is determined. By using this method, the vehicle can calculate the slope in real time based on the wheel-end driving force and the actual longitudinal acceleration to obtain the first slope of the road surface where the vehicle is located; and when it is determined to output the first slope, the second slope determined based on the wheel-end driving force, the vehicle speed, and the filtered actual longitudinal acceleration is obtained. Since the accuracy of the filtered actual longitudinal acceleration is higher, the accuracy of the determined second slope is higher. Therefore, by fusing the first slope and the second slope, not only can the slope of the road surface where the vehicle is located be determined in real time, but also the accuracy of the determined slope can be improved.

[0058] In an alternative embodiment, Figure 1 In the slope determination method shown, when the vehicle controller determines the first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle, it may include: obtaining the actual longitudinal acceleration of the vehicle by taking the derivative based on the vehicle speed; determining a first intermediate value based on the actual longitudinal acceleration, the wheel-end driving force, the vehicle speed, and the force balance principle of the vehicle on the current ramp; and inputting the first intermediate value into a preset slope calculation model to obtain the first slope of the road surface where the vehicle is located.

[0059] In some embodiments, the wheel-end driving force can be determined by the vehicle controller based on the wheel-end torque and the tire rolling radius of the vehicle. Optionally, when the vehicle controller determines the wheel-end driving force based on the wheel-end torque and the tire rolling radius of the vehicle, the following formula (2) can be used.

[0060] (2)

[0061] In formula (2), F x represents the wheel-end driving force; T x represents the wheel-end torque; r represents the tire rolling radius.

[0062] In some embodiments, the force balance principle of the vehicle on the current ramp can be expressed as the following formula (3).

[0063] (3)

[0064] In formula (3), F x represents the wheel-end driving force; f空气 represents air resistance; f 加速 represents acceleration resistance; f 坡道 represents ramp resistance; f 滚动 represents rolling resistance.

[0065] Optionally, when the vehicle controller determines the first intermediate value based on the actual longitudinal acceleration, wheel-end driving force, vehicle speed, and the force balance principle of the vehicle on the current ramp, the following formulas (4) to (7) can be used.

[0066] (4)

[0067] (5)

[0068] (6)

[0069] (7)

[0070] In formulas (4) to (7), F x represents the wheel-end driving force (unit: Newton (N)), denoted as A; B represents the sum of the air resistance f 空气 (unit: N) and the acceleration resistance f 加速 (unit: N); m represents the vehicle mass (unit: kilogram); a x represents the actual longitudinal acceleration (unit: m / s 2 ); ρ represents the constant 1.2258; C d represents the air resistance coefficient; A1 represents the frontal area of the vehicle (unit: square meter (m 2 )); V x represents the vehicle speed (unit: km / h); C represents the sum of the ramp resistance f 坡道 (unit: N) and the rolling resistance f 滚动 (unit: N), that is, the first intermediate value; g represents the gravitational acceleration (unit: m / s 2 ); represents the first slope; f represents the rolling resistance coefficient.

[0071] In some embodiments, when the vehicle controller inputs the first intermediate value into a preset slope calculation model to obtain the first slope of the road surface where the vehicle is located, the following formula (8) can be used.

[0072] (8)

[0073] In formula (8), represents the first slope of the road surface where the vehicle is located (unit: degree); represents the first intermediate value; m represents the vehicle mass (unit: kg); g represents the acceleration due to gravity (unit: m / s 2 ); f represents the rolling resistance coefficient.

[0074] In this implementation, the vehicle controller accurately determines the first slope of the road surface where the vehicle is located through dynamic calculations.

[0075] In an alternative implementation, Figure 1 In the slope determination method shown, the second slope can be determined by the vehicle controller in the following manner: Based on the vehicle speed, the actual longitudinal acceleration of the vehicle is obtained by differentiation; the actual longitudinal acceleration is filtered to filter out the fluctuation information in the actual longitudinal acceleration, obtaining the filtered actual longitudinal acceleration; based on the filtered actual longitudinal acceleration, the wheel-end driving force, the vehicle speed, the force balance principle of the vehicle on the current ramp, and the least squares method, a second intermediate value is determined; the second intermediate value is input into a preset slope calculation model to obtain the second slope.

[0076] In some embodiments, when the vehicle controller filters the actual longitudinal acceleration to filter out the fluctuation information in the actual longitudinal acceleration and obtains the filtered actual longitudinal acceleration, it can be based on a pre-set low-pass filter to filter the fluctuation information in the actual longitudinal acceleration to obtain the filtered actual longitudinal acceleration. Since there may be fluctuation information in the actual longitudinal acceleration, therefore, the vehicle controller filters the possible fluctuation information in the actual longitudinal acceleration based on the pre-set low-pass filter, and a more accurate actual longitudinal acceleration can be obtained.

[0077] Optionally, when the vehicle controller filters the fluctuation information in the actual longitudinal acceleration based on the pre-set low-pass filter to obtain the filtered actual longitudinal acceleration, the following formula (9) can be used.

[0078] (9)

[0079] In formula (9), represents the filtered actual longitudinal acceleration, which is also denoted as in some subsequent embodiments; γ represents the filtering coefficient; represents the filtered actual longitudinal acceleration at the previous moment; represents the input actual longitudinal acceleration.

[0080] Optionally, when the vehicle controller determines the second intermediate value based on the filtered actual longitudinal acceleration, wheel-end driving force, vehicle speed, the force balance principle of the vehicle on the current ramp, and the least squares method, it can first determine the initial intermediate value based on the filtered actual longitudinal acceleration, wheel-end driving force, vehicle speed, and the force balance principle of the vehicle on the current ramp, and then calculate the second intermediate value based on the least squares method.

[0081] Optionally, when the vehicle controller determines the initial intermediate value based on the filtered actual longitudinal acceleration, wheel-end driving force, vehicle speed, and the force balance principle of the vehicle on the current ramp (as shown in the foregoing formula (3)), the following formulas (10) to (13) can be used.

[0082] (10)

[0083] (11)

[0084] (12)

[0085] (13)

[0086] In formulas (10) to (13), F x represents the wheel-end driving force (unit: N), denoted as ; represents the sum of the acceleration resistance and the air resistance ; m represents the vehicle mass (unit: kg); represents the filtered actual longitudinal acceleration (unit: m / s 2 ); represents the constant 1.2258; C d represents the air resistance coefficient; A1 represents the frontal area of the vehicle (unit: square meter); V x represents the vehicle speed (unit: km / h); represents the sum of the ramp resistance and the rolling resistance , that is, the initial intermediate value; g represents the gravitational acceleration (unit: m / s 2 ); represents the second slope; f represents the rolling resistance coefficient.

[0087] It should be noted that since the filtered actual longitudinal acceleration is used in this embodiment, new parameters , and are introduced to represent the relevant calculation results to distinguish from the foregoing embodiments.

[0088] Optionally, when calculating the second intermediate value based on the least squares method with a forgetting factor, the vehicle controller may use the following formulas (14) to (16).

[0089] (14)

[0090] (15)

[0091] (16)

[0092] In formulas (14) to (16), represents the estimated value of the second intermediate value after the k-th iteration; represents the estimated value of the second intermediate value after the (k - 1)-th iteration; L(k) represents the gain; A(k) represents the wheel-end driving force after the k-th iteration; B(k) represents the sum of the acceleration resistance and the air resistance after the k-th iteration; P(k) represents the error covariance after the k-th iteration; P(k - 1) represents the error covariance after the (k - 1)-th iteration; λ represents the forgetting factor; k ∈ [1, K], and K is a preset value.

[0093] Among them, the estimated value of the intermediate value obtained after the first iteration is the initial intermediate value; the (which can also be denoted as ) obtained after the K-th iteration is the second intermediate value calculated using the least squares method.

[0094] Optionally, after the vehicle controller calculates the second intermediate value including the slope information through the least squares method with a forgetting factor , the second intermediate value can be input into a preset slope calculation model, such as formula (17) below, to determine the second slope of the road surface where the vehicle is located.

[0095] (17)

[0096] In formula (17), represents the second slope of the road surface where the vehicle is located (unit: degree); represents the second intermediate value obtained based on the least squares method; m represents the vehicle mass (unit: kilogram); g represents the gravitational acceleration (unit: m / s 2 ); f represents the rolling resistance coefficient.

[0097] In this implementation, the vehicle controller filters the actual longitudinal acceleration to obtain a more accurate actual longitudinal acceleration, and combines the least squares method to accurately determine the second slope of the road surface where the vehicle is located.

[0098] In an alternative embodiment, Figure 1 In the slope determination method shown, the vehicle control unit determines a fusion factor for fusing the first slope and the second slope, which may include: obtaining the wheel-end torque of the vehicle, and determining the change rate of the wheel-end driving force based on the wheel-end torque of the vehicle; based on the change rate of the wheel-end driving force, looking up a table to obtain the fusion factor for fusing the first slope and the second slope.

[0099] In some embodiments, the vehicle control unit determines the change rate of the wheel-end driving force based on the wheel-end torque of the vehicle, which may include: determining the wheel-end driving force based on the wheel-end torque and the tire rolling radius of the vehicle; obtaining the change rate of the wheel-end driving force by taking the derivative of the wheel-end driving force. Optionally, the vehicle control unit may determine the wheel-end driving force based on the wheel-end torque and the tire rolling radius of the vehicle using the above formula (2).

[0100] In some embodiments, the fusion factor is used to represent the first weight corresponding to the first slope; the vehicle control unit looks up a table to obtain the fusion factor for fusing the first slope and the second slope based on the change rate of the wheel-end driving force, which may include: performing a normalization process on the change rate of the wheel-end driving force to obtain a normalized change rate of the wheel-end driving force; based on the normalized change rate of the wheel-end driving force, looking up a table to obtain the first weight corresponding to the first slope, and determining the second weight corresponding to the second slope based on the first weight; the vehicle control unit determines the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor, which may include: determining the target slope of the road surface where the vehicle is located based on the first slope, the second slope, the first weight, and the second weight.

[0101] Wherein, if the change rate of the wheel-end driving force is greater than a preset driving force change rate threshold, it indicates that the driver's driving behavior is in an emergency motion demand. In this case, the vehicle control unit may determine that the vehicle is in an unsteady state phase. At this time, the vehicle control unit may assign a heavier weight to the first slope to determine the target slope of the road surface where the vehicle is located more based on the first slope. If the change rate of the wheel-end driving force is less than or equal to the preset driving force change rate threshold, it indicates that the driver's driving behavior is in a non-emergency motion demand. In this case, the vehicle control unit may determine that the vehicle is in a steady state phase. At this time, the vehicle control unit may assign a heavier weight to the second slope to determine the target slope of the road surface where the vehicle is located more based on the second slope.

[0102] Optionally, the above-mentioned table may be a table preset in the vehicle control unit (denoted as the first correspondence table), or a table preset in a certain database and readable by the vehicle control unit (denoted as the first correspondence table), etc., which is not limited herein. Exemplarily, the first correspondence table may be as shown in Table 1 below.

[0103] Table 1 First correspondence table

[0104]

[0105] As can be seen from Table 1 above, the greater the change rate of the wheel-end driving force after normalization, the greater the determined fusion factor, that is, the first weight corresponding to the first slope, indicating that the vehicle controller pays more attention to using the first slope to determine the target slope of the road surface where the vehicle is located; conversely, the smaller the change rate of the wheel-end driving force after normalization, the smaller the determined fusion factor, that is, the first weight corresponding to the first slope, indicating that the vehicle controller pays more attention to using the second slope to determine the target slope of the road surface where the vehicle is located.

[0106] In some embodiments, when the vehicle controller determines the target slope of the road surface where the vehicle is located based on the first slope, the second slope, the first weight, and the second weight, the following formula (18) can be used.

[0107] (18)

[0108] In formula (18), represents the target slope of the road surface where the vehicle is located (unit: degree); represents the first slope of the road surface where the vehicle is located (unit: degree); represents the second slope of the road surface where the vehicle is located (unit: degree); represents the first weight (which can also be called the fusion factor); represents the second weight.

[0109] In this implementation, the vehicle controller can simply and quickly determine the fusion factor for fusing the first slope and the second slope by looking up a table. Thus, based on the first slope, the second slope, and the fusion factor, a high-precision slope estimation can be achieved, that is, the accuracy of the determined slope can be improved.

[0110] In an alternative implementation, Figure 1 in the slope determination method shown, the vehicle controller can also activate the slope update flag when the following conditions are met: the vehicle speed is less than or equal to the preset vehicle speed threshold; the current gear of the vehicle is the forward gear; the opening of the vehicle's brake pedal is 0; the vehicle speed change rate is greater than the preset vehicle speed change rate threshold; the steering wheel angle of the vehicle is less than the preset steering wheel angle threshold; the wheel-end state of each wheel in the vehicle is in a stable state; the vehicle speed jerk within the first preset time period is less than the preset vehicle speed jerk threshold; where, when the slope update flag is activated, it is determined that the first slope is allowed to be output.

[0111] In some embodiments, the vehicle controller may also determine the slip ratio corresponding to each wheel based on the wheel speed and vehicle speed of each wheel in the vehicle; obtain the wheel acceleration corresponding to each wheel by taking the derivative based on the wheel speed of each wheel in the vehicle; for each wheel, when the slip ratio corresponding to the wheel is less than or equal to a preset slip ratio threshold and the wheel acceleration corresponding to the wheel is less than or equal to a preset wheel acceleration threshold, determine that the wheel end state of the wheel is in a stable state.

[0112] Optionally, when the vehicle controller determines the slip ratio corresponding to each wheel based on the wheel speed and vehicle speed of each wheel in the vehicle, the following formula (19) may be used.

[0113] (19)

[0114] In formula (19), S represents the slip ratio; V x represents the vehicle speed (unit: km / h); V wheel represents the wheel speed of the wheel (unit: km / h).

[0115] Exemplarily, assume that the preset slip ratio threshold is 20% and the preset wheel acceleration threshold is 20 m / s 2 , and assume that the slip ratio of the front left wheel of the vehicle is 25% and the wheel acceleration is 30 m / s 2 . In this case, the vehicle controller may determine that the slip ratio of 25% of the front left wheel of the vehicle is greater than the preset slip ratio threshold of 20%, and the wheel acceleration of 30 m / s 2 is greater than the preset wheel acceleration threshold of 20 m / s 2 . At this time, the vehicle controller may determine that the wheel end state of the front left wheel of the vehicle is in a stable state.

[0116] By adopting this implementation manner, the vehicle controller can simply and efficiently determine whether the slope update flag is activated, and when the slope update flag is activated, allow the output of the first slope. Thus, it is beneficial to subsequently determine the target slope of the road surface where the vehicle is located.

[0117] In an alternative implementation manner, the vehicle controller may determine the slope change rate based on the target slope; when the slope change rate is less than or equal to a preset slope change rate threshold, use the target slope as the final slope of the road surface where the vehicle is located; when the slope change rate is greater than the preset slope change rate threshold, correct the target slope to obtain the final slope of the road surface where the vehicle is located. That is to say, Figure 1In the slope determination method shown above, the vehicle controller can also derive the slope change rate based on the target slope; when the slope change rate is greater than the preset slope change rate threshold, determine the target slope correction factor; based on the target slope, look up the table to determine the slope change gradient, and based on the slope change gradient, the target slope correction factor, and the final slope corresponding to the previous cycle of the current cycle, determine the final slope of the road surface where the vehicle is located, and update the target slope based on the final slope.

[0118] In some embodiments, when the vehicle controller determines the target slope correction factor when the slope change rate is greater than the preset slope change rate threshold, it may include: when the slope change rate is greater than the preset slope change rate threshold, determine the average value and the root mean square value of the absolute values of multiple slope change rates within a preset time period; based on the target correspondence, obtain the target slope correction factor corresponding to the average value and the root mean square value; the target correspondence includes the correspondence between multiple combinations of average values and root mean square values and multiple slope correction factors; wherein, the slope correction factor is positively correlated with the average value in the combination, and the slope correction factor is positively correlated with the root mean square value in the combination.

[0119] Optionally, the target correspondence can be a table preset in the vehicle controller (denoted as the second correspondence table), or a table preset in a certain database and readable by the vehicle controller (denoted as the second correspondence table), etc., which is not limited here. Among them, the table includes the correspondence between multiple combinations of average values and root mean square values and multiple slope correction factors, the slope correction factor is positively correlated with the average value in the combination, and the slope correction factor is positively correlated with the root mean square value in the combination. Exemplarily, the second correspondence table can be shown in Table 2 below.

[0120] Table 2 Second Correspondence Table

[0121]

[0122] Since the average value of the slope change rate within the preset time period is small, it indicates that the current road conditions are mainly gentle slopes; the root mean square value of the slope change rate within the preset time period is small, indicating that the proportion of gentle slopes is relatively high. Therefore, as can be seen from Table 2, when the average value of the slope change rate within the preset time period is smaller and the root mean square value is smaller, the determined target slope correction factor is smaller. By looking up the table, the target slope correction factor can be determined simply and efficiently.

[0123] In some embodiments, the vehicle controller determines the gradient change rate by looking up a table based on the target gradient. It can look up Table 3 below based on the target gradient to determine the gradient change rate. Table 3 includes the corresponding relationships between multiple gradients and gradient change rates. Optionally, Table 3 can be a table preset in the vehicle controller (denoted as the third correspondence table), or a table preset in a certain database and readable by the vehicle controller (denoted as the third correspondence table), which is not limited here.

[0124] Table 3 Third Correspondence Table

[0125]

[0126] As can be seen from Table 3, the smaller the gradient, the smaller the determined gradient change rate. The smaller the gradient indicates a higher possibility of a smaller actual gradient change rate. Therefore, the gradient change rate is smaller. By looking up the table, the gradient change rate can be determined simply and efficiently.

[0127] In some embodiments, when the vehicle controller determines the final gradient of the road surface where the vehicle is located based on the gradient change rate, the target gradient correction factor, and the final gradient corresponding to the previous cycle of the current cycle, the following formula (20) can be used.

[0128] (20)

[0129] In formula (20), represents the final gradient of the road surface where the vehicle is located; represents the final gradient corresponding to the previous cycle of the current cycle; represents the gradient change rate; represents the target gradient correction factor.

[0130] Adopting this implementation method, when the vehicle controller determines that the gradient change rate is greater than the preset gradient change rate threshold based on the target gradient of the road surface where the vehicle is located, it can determine the gradient change rate and the gradient change rate based on the target gradient, and determine the target gradient correction factor based on the gradient change rate. Then, based on the gradient change rate, the target gradient correction factor, and the final gradient corresponding to the previous cycle of the current cycle, it determines the final gradient of the road surface where the vehicle is located, and updates the target gradient based on the final gradient. In this way, the accuracy of the gradient of the road surface where the vehicle is located can be further improved.

[0131] Next, in combination with Figure 2 , the overall process of the gradient determination method provided by the embodiments of the present application will be elaborated. Please refer to Figure 2 , Figure 2It is a schematic flowchart of another slope determination method provided by an embodiment of the present application, and this method can be executed by a vehicle controller. As Figure 2 shown, this slope determination method may include but is not limited to the following steps.

[0132] S201. Monitor the vehicle speed, wheel speed, gear position, vehicle mass, brake pedal, steering wheel angle, and wheel end torque in real time.

[0133] S202. Calculate the actual longitudinal acceleration of the vehicle based on the vehicle speed.

[0134] In an alternative embodiment, the determination method of the vehicle speed may also refer to the description in the foregoing step S101, and details will not be elaborated here.

[0135] In an alternative embodiment, the vehicle controller can obtain the actual longitudinal acceleration of the vehicle by taking the derivative of the vehicle speed, that is , where a x represents the actual longitudinal acceleration of the vehicle (unit: m / s 2 ); V x represents the vehicle speed (unit: km / h).

[0136] S203. Determine the wheel end driving force based on the wheel end torque.

[0137] In an alternative embodiment, the vehicle controller can determine the wheel end driving force based on the wheel end torque and the tire rolling radius by using the foregoing formula (2).

[0138] In some embodiments, after the vehicle controller determines the wheel end driving force, it can also perform a delay process on the wheel end driving force. In this way, the problem that the actual longitudinal acceleration lags behind the wheel end driving force can be solved.

[0139] Optionally, the delay period can be formulated by the vehicle controller based on the relationship between the wheel end driving force and the actual longitudinal acceleration. Exemplarily, since the wheel end driving force and the actual acceleration follow Newton's second law F = ma, where F represents the wheel end driving force, m represents the vehicle mass, and a represents the actual longitudinal acceleration, therefore, the vehicle controller can use F = ma as the dynamic model for describing the longitudinal motion of the vehicle. Then, by theoretically analyzing the above dynamic model using historical wheel end driving force data and historical actual longitudinal acceleration data, the response function of the longitudinal acceleration when the wheel end driving force changes can be solved, and thus the inherent delay characteristics of the system can be obtained.

[0140] Optionally, when the vehicle controller performs a delay process on the wheel end driving force, it can determine the response time corresponding to the actual longitudinal acceleration based on the determined wheel end driving force; use this response time as the delay period, and perform a delay process on the wheel end driving force based on this delay period.

[0141] Exemplarily, assume that the vehicle controller determines that the response time corresponding to the actual longitudinal acceleration is 10 s. Then, the vehicle controller may use this 10-s response time as the delay period and delay the wheel-end driving force by 10 s before applying it to the wheel to propel the vehicle forward.

[0142] S204. Determine a first slope based on the wheel-end driving force and the actual longitudinal acceleration.

[0143] In an alternative embodiment, the vehicle controller may determine the first slope based on the wheel-end driving force and the actual longitudinal acceleration by using the above formulas (3) to (8).

[0144] S205. Calculate the wheel-end state of each wheel based on the wheel speed, vehicle speed, and wheel acceleration.

[0145] In an alternative embodiment, the vehicle controller may determine that the wheel-end is in an unstable state when it determines that all of the following conditions are met: (1) the slip ratio is greater than a preset slip ratio threshold; (2) the wheel acceleration is greater than a preset wheel acceleration threshold.

[0146] That is to say, the vehicle controller may determine that the wheel-end state of a wheel is in a stable state when it determines that the slip ratio corresponding to the wheel is less than or equal to the preset slip ratio threshold and the wheel acceleration corresponding to the wheel is less than or equal to the preset wheel acceleration threshold.

[0147] Optionally, the slip ratio corresponding to the wheel may be determined by the vehicle controller based on the wheel speed and vehicle speed of the wheel by using the above formula (19); the wheel acceleration corresponding to the wheel may be obtained by the vehicle controller by taking the derivative of the wheel speed of the wheel, i.e., , where represents the wheel acceleration of the wheel, represents the wheel speed of the wheel.

[0148] S206. Judge the slope update flag bit based on the vehicle speed, gear position, brake pedal, vehicle speed change rate, steering wheel angle, wheel-end state, and vehicle speed jerk, and allow the output of the first slope when it is determined that the slope update flag bit is activated.

[0149] In an alternative embodiment, the vehicle controller may determine that the slope update flag is activated when all of the following conditions are met: (1) the vehicle speed is less than or equal to a preset vehicle speed threshold; (2) the gear is in the forward gear (D gear); (3) the brake pedal is not depressed, i.e., the opening of the brake pedal is 0; (4) the vehicle speed change rate is greater than a preset vehicle speed change rate threshold; (5) the steering wheel angle is less than a preset steering wheel angle threshold; (6) the wheel end state of each wheel is not in an unstable state, i.e., the wheel end state of each wheel is in a stable state; (7) the vehicle speed jerk within a preset time period is less than a preset vehicle speed jerk threshold.

[0150] S207. When it is determined that the first slope is allowed to be output, determine the first slope and output it, and when the first slope is output, obtain the second slope; the second slope is determined based on the wheel end driving force, vehicle speed, filtered actual longitudinal acceleration, and force balance principle of the vehicle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration.

[0151] In an alternative embodiment, the second slope may be determined by the vehicle controller using the above formulas (10) to (17).

[0152] S208. Based on the first slope, the second slope, and the fusion factor, determine the target slope of the road surface where the vehicle is located.

[0153] S209. Based on the target slope, determine the slope change gradient and the slope change rate.

[0154] In an alternative embodiment, for the vehicle controller to determine the slope change gradient based on the target slope, it may look up the slope change gradient from the above Table 3 based on the target slope.

[0155] In an alternative embodiment, for the vehicle controller to determine the slope change rate based on the target slope, it may take the derivative of the target slope to obtain the slope change rate, i.e., , where represents the slope change gradient, represents the target slope of the road surface where the vehicle is located.

[0156] S210. When the slope change rate is greater than a preset slope change rate threshold, determine the average value and the root mean square value of the absolute values of multiple slope change rates within a preset time period, and obtain the target slope correction factor corresponding to the average value and the root mean square value based on the target correspondence.

[0157] Among them, the target correspondence includes the correspondence between multiple combinations of average values and root mean square values and multiple slope correction factors; among them, the slope correction factor is positively correlated with the average value in the combination, and the slope correction factor is positively correlated with the root mean square value in the combination. Exemplarily, the target correspondence can be as shown in Table 2 above. The vehicle controller can look up Table 2 based on the average value and root mean square value of the absolute values of multiple slope change rates within a preset time period to obtain the target slope correction factor.

[0158] In an alternative implementation, the vehicle controller can use the target slope as the final slope of the road surface where the vehicle is located when the slope change rate is less than or equal to the preset slope change rate threshold.

[0159] S211. Determine the final slope of the road surface where the vehicle is located based on the slope change gradient, the target slope correction factor, and the final slope corresponding to the previous cycle of the current cycle, and update the target slope based on the final slope.

[0160] In an alternative implementation, the vehicle controller can use the above formula (20) to determine the final slope of the road surface where the vehicle is located based on the slope change gradient, the target slope correction factor, and the final slope corresponding to the previous cycle of the current cycle.

[0161] In the embodiment of the present application, the vehicle controller can perform real-time slope dynamics calculation based on the wheel-end driving force, the actual longitudinal acceleration, and the force balance principle of the vehicle on the current ramp to obtain the first slope of the road surface where the vehicle is located; and when it is determined to output the first slope, obtain the second slope determined based on the wheel-end driving force, the vehicle speed, the filtered actual longitudinal acceleration, and the force balance principle. Since the accuracy of the filtered actual longitudinal acceleration is higher, the accuracy of the determined second slope is higher. Therefore, by fusing the first slope and the second slope, not only can the slope of the road surface where the vehicle is located be determined in real time, but also the accuracy of the determined slope can be improved. Further, when the vehicle controller determines that the slope change rate is greater than the preset slope change rate threshold based on the target slope of the road surface where the vehicle is located, it determines the slope change gradient and the slope change rate based on the target slope, determines the target slope correction factor based on the slope change rate, and then determines the final slope of the road surface where the vehicle is located based on the slope change gradient, the target slope correction factor, and the final slope corresponding to the previous cycle of the current cycle. Finally, it updates the target slope based on the final slope. In this way, the accuracy of the slope of the road surface where the vehicle is located can be further improved.

[0162] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown in the direction of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or alternately with at least a part of other steps or steps or stages in other steps.

[0163] Based on the same inventive concept, an embodiment of the present application further provides a slope determination device for implementing the slope determination method described above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the slope determination device provided below can refer to the limitations on the slope determination method in the above text, and will not be repeated here.

[0164] Please refer to Figure 3 , Figure 3 which is a schematic structural diagram of a slope determination device provided by an embodiment of the present application. As Figure 3 shown, the slope determination device may include but is not limited to:

[0165] A determination module 301, configured to determine a first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed;

[0166] An acquisition module 302, configured to acquire a second slope when it is determined that the first slope is output; the second slope is determined based on the wheel-end driving force, the vehicle speed, and the filtered actual longitudinal acceleration of the vehicle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration;

[0167] The determination module 301 is further configured to determine a fusion factor for fusing the first slope and the second slope;

[0168] The determination module 301 is further configured to determine the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor.

[0169] In one embodiment, when the determination module 301 is used to determine the fusion factor for fusing the first slope and the second slope, it is specifically configured to: acquire the wheel-end torque of the vehicle, and determine the wheel-end driving force change rate based on the wheel-end torque of the vehicle; look up a table based on the wheel-end driving force change rate to obtain the fusion factor for fusing the first slope and the second slope.

[0170] In one embodiment, the fusion factor is used to characterize the first weight corresponding to the first slope. When the determination module 301 is configured to look up a table based on the change rate of the wheel-end driving force to obtain a fusion factor for fusing the first slope and the second slope, it is specifically configured to: perform normalization processing on the change rate of the wheel-end driving force to obtain a normalized change rate of the wheel-end driving force; based on the normalized change rate of the wheel-end driving force, look up a table to obtain the first weight corresponding to the first slope, and based on the first weight, determine the second weight corresponding to the second slope. When the determination module 301 is configured to determine the target slope of the road surface where the vehicle is located based on the first slope, the second slope, and the fusion factor, it is specifically configured to: determine the target slope of the road surface where the vehicle is located based on the first slope, the second slope, the first weight, and the second weight.

[0171] In one embodiment, the device further includes a processing module, and the processing module is configured to activate a slope update flag when the following conditions are met: the vehicle speed is less than or equal to a preset vehicle speed threshold; the gear in which the vehicle is currently located is a forward gear; the opening of the vehicle's brake pedal is 0; the change rate of the vehicle speed is greater than a preset vehicle speed change rate threshold; the steering wheel angle of the vehicle is less than a preset steering wheel angle threshold; the wheel-end state of each wheel in the vehicle is in a stable state; the vehicle speed jerk within a first preset time period is less than a preset vehicle speed jerk threshold. Wherein, when the slope update flag is activated, it is determined that the first slope is allowed to be output.

[0172] In one embodiment, the determination module 301 is further configured to determine the slip ratio corresponding to each wheel based on the wheel speed and the vehicle speed of each wheel in the vehicle; obtain the wheel acceleration corresponding to each wheel by taking the derivative of the wheel speed of each wheel in the vehicle. For each wheel, when the slip ratio corresponding to the wheel is less than or equal to a preset slip ratio threshold and the wheel acceleration corresponding to the wheel is less than or equal to a preset wheel acceleration threshold, it is determined that the wheel-end state of the wheel is in a stable state.

[0173] In one embodiment, when the determination module 301 is configured to determine the first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle, it is specifically configured to: obtain the actual longitudinal acceleration of the vehicle by taking the derivative of the vehicle speed; determine a first intermediate value based on the actual longitudinal acceleration, the wheel-end driving force, the vehicle speed, and the force balance principle of the vehicle on the current ramp; input the first intermediate value into a preset slope calculation model to obtain the first slope of the road surface where the vehicle is located.

[0174] In one embodiment, the determining module 301 is further configured to: derive the actual longitudinal acceleration of the vehicle based on the vehicle speed; perform a filtering process on the actual longitudinal acceleration to filter out the fluctuation information in the actual longitudinal acceleration, so as to obtain the filtered actual longitudinal acceleration; determine a second intermediate value based on the filtered actual longitudinal acceleration, the wheel-end driving force, the vehicle speed, the force balance principle of the vehicle on the current ramp, and the least squares method; and input the second intermediate value into a preset slope calculation model to obtain a second slope.

[0175] In one embodiment, the determining module 301 is further configured to: derive the slope change rate based on the target slope; determine a target slope correction factor when the slope change rate is greater than a preset slope change rate threshold; look up a table based on the target slope to determine the slope change gradient, and determine the final slope of the road surface where the vehicle is located based on the slope change gradient, the target slope correction factor, and the final slope corresponding to the previous cycle of the current cycle, and update the target slope based on the final slope.

[0176] In one embodiment, when the determining module 301 is configured to determine the target slope correction factor when the slope change rate is greater than the preset slope change rate threshold, it is specifically configured to: determine the average value and the root mean square value of the absolute values of multiple slope change rates within a preset time period when the slope change rate is greater than the preset slope change rate threshold; obtain the target slope correction factor corresponding to the average value and the root mean square value based on the target correspondence relationship; the target correspondence relationship includes the correspondence relationship between multiple combinations of average values and root mean square values and multiple slope correction factors; wherein, the slope correction factor is positively correlated with the average value in the combination, and the slope correction factor is positively correlated with the root mean square value in the combination.

[0177] Each module in the above slope determination device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the vehicle control device in software form, so that the processor can call and execute the operations corresponding to the above respective modules.

[0178] In an exemplary embodiment, a new energy vehicle is provided, and its internal structure diagram can be as Figure 4As shown in the figure. The new energy vehicle 400 includes a processor 401, a memory 402, an input / output interface 403, a communication interface 404, a display unit 405, and an input device 406. Among them, the processor 401, the memory 402, and the input / output interface 403 are connected through a system bus 407, and the communication interface 404, the display unit 405, and the input device 406 are connected to the system bus 407 through the input / output interface 403. Among them, the processor 401 of the new energy vehicle 400 is used to provide computing and control capabilities. The memory 402 of the new energy vehicle includes a non-volatile storage medium 4021 and an internal memory 4022. The non-volatile storage medium 4021 stores an operating system 4021a and a computer program 4021b. The internal memory 4022 provides an environment for the operation of the operating system 4021a and the computer program 4021b in the non-volatile storage medium 4021. The input / output interface 403 of the new energy vehicle 400 is used to exchange information between the processor 401 and external devices. The communication interface 404 of the new energy vehicle 400 is used to communicate with external terminals in a wired or wireless manner, and the wireless manner can be achieved through WIFI, a mobile cellular network, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it realizes a slope determination method. The display unit 4051 of the new energy vehicle is used to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the new energy vehicle can be a touch layer covered on the display screen, or a button, a trackball, or a touchpad set inside the new energy vehicle, etc.

[0179] Those skilled in the art can understand that Figure 4 the structure shown in the figure is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the new energy vehicle to which the solution of the present application is applied. The specific new energy vehicle may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0180] In an exemplary embodiment, the present application provides a new energy vehicle, including a memory and a processor, and the memory stores a computer program; when the processor executes the computer program, it realizes the steps in the above-mentioned slope determination methods.

[0181] In an exemplary embodiment, the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by the processor, it realizes the steps in the above-mentioned slope determination methods.

[0182] In an exemplary embodiment, the present application provides a computer program product, including a computer program. When the computer program is executed by the processor, it realizes the steps in the above-mentioned slope determination methods.

[0183] It should be noted that the data involved in this application (including but not limited to wheel-end driving force, actual longitudinal acceleration, first slope, second slope, vehicle speed, integration factor, etc.) are all information and data authorized by users or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0184] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., and are not limited thereto. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., and are not limited thereto.

[0185] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0186] The above-described embodiments merely represent several implementation manners of this application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application shall be subject to the appended claims.

Claims

1. A slope determination method, characterized in that: The method comprises: Determining a first slope based on a wheel end driving force and an actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on a vehicle speed; In the case of determining to output the first slope, obtaining a second slope; the second slope is determined based on the wheel end driving force of the vehicle, the vehicle speed and the filtered actual longitudinal acceleration; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration; determining a fusion factor for fusing the first slope and the second slope; A target slope of the road surface on which the vehicle is located is determined based on the first slope, the second slope, and the fusion factor.

2. The method according to claim 1, characterized in that Determining a fusion factor for fusion of the first slope and the second slope includes: Acquiring the wheel end torque of the vehicle, and determining the wheel end driving force change rate based on the wheel end torque of the vehicle; Based on the wheel end driving force change rate, a fusion factor for fusing the first slope and the second slope is obtained by looking up a table.

3. The method according to claim 2, characterized in that The fusion factor is used to represent a first weight corresponding to the first slope; Based on the wheel end driving force change rate, a fusion factor for fusing the first slope and the second slope is obtained by looking up a table, including: Normalizing the wheel end driving force change rate to obtain a normalized wheel end driving force change rate; Based on the normalized wheel end driving force change rate, looking up a table to obtain a first weight corresponding to the first slope, and based on the first weight, determining a second weight corresponding to the second slope; Determining a target slope of the road surface on which the vehicle is located based on the first slope, the second slope, and the fusion factor includes: A target slope of the road surface on which the vehicle is located is determined based on the first slope, the second slope, the first weight, and the second weight.

4. The method according to claim 1, characterized in that: The method further comprises: The slope update flag is activated when the following conditions are met: The vehicle speed is less than or equal to a preset vehicle speed threshold; The current gear position of the vehicle is a forward gear position; The opening degree of the brake pedal of the vehicle is 0; The vehicle speed change rate of the vehicle is greater than a preset vehicle speed change rate threshold; The steering wheel angle of the vehicle is less than a preset steering wheel angle threshold; The wheel end state of each wheel in the vehicle is in a stable state; The vehicle speed jerk of the vehicle within the first preset time period is less than a preset vehicle speed jerk threshold; Wherein, when the slope update flag is activated, it is determined that the first slope is allowed to be output.

5. The method according to claim 4, characterized in that The method further comprises: Determining a slip ratio corresponding to each wheel based on the wheel speed of each wheel in the vehicle and the vehicle speed; Based on the wheel speed of each wheel in the vehicle, deriving the wheel acceleration corresponding to each wheel; For each of the wheels, when the slip rate corresponding to the wheel is less than or equal to a preset slip rate threshold, and the wheel acceleration corresponding to the wheel is less than or equal to a preset wheel acceleration threshold, it is determined that the wheel end state of the wheel is in a stable state.

6. The method according to claim 1, characterized in that Based on the wheel end driving force and the actual longitudinal acceleration of the vehicle, a first slope is determined, including: Based on the vehicle speed, deriving the actual longitudinal acceleration of the vehicle; Determining a first intermediate value based on the actual longitudinal acceleration, the wheel end driving force, the vehicle speed, and a force balance principle of the vehicle on the current slope; The first intermediate value is input into a preset slope calculation model to obtain a first slope of the road surface on which the vehicle is located.

7. The method according to claim 1, characterized in that The second slope is determined by: Based on the vehicle speed, deriving the actual longitudinal acceleration of the vehicle; Performing filtering processing on the actual longitudinal acceleration to filter fluctuation information in the actual longitudinal acceleration to obtain a filtered actual longitudinal acceleration; Determining a second intermediate value based on the filtered actual longitudinal acceleration, the wheel end driving force, the vehicle speed, the force balance principle of the vehicle on the current ramp, and the least squares method; The second intermediate value is input into a preset slope calculation model to obtain a second slope.

8. The method according to any one of claims 1 to 7, characterized in that: The method further comprises: Based on the target slope, deriving to obtain a slope change rate; When the slope change rate is greater than a preset slope change rate threshold, determining a target slope correction factor; Based on the target slope, a table is looked up to determine the slope change gradient, and based on the slope change gradient, the target slope correction factor, and the final slope corresponding to the previous cycle of the current cycle, the final slope of the road surface on which the vehicle is located is determined, and the target slope is updated based on the final slope.

9. The method according to claim 8, characterized in that When the slope change rate is greater than a preset slope change rate threshold, determining a target slope correction factor includes: When the slope change rate is greater than a preset slope change rate threshold, determining an average value and a root mean square value of the absolute values ​​of a plurality of the slope change rates within a preset time period; Based on the target correspondence, a target slope correction factor corresponding to the average value and the root mean square value is obtained; the target correspondence includes a correspondence between a combination of multiple average values ​​and root mean square values ​​and multiple slope correction factors; wherein the slope correction factor is positively correlated with the average value in the combination, and the slope correction factor is positively correlated with the root mean square value in the combination.

10. A slope determination device, characterized in that: The device comprises: A determination module, configured to determine a first slope based on a wheel end driving force and an actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration being determined based on a vehicle speed; an acquisition module, configured to acquire a second slope when the first slope is determined to be output; the second slope is determined based on the wheel end driving force of the vehicle, the vehicle speed and the filtered actual longitudinal acceleration; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration; The determining module is further used to determine a fusion factor for fusing the first slope and the second slope; The determination module is further used to determine a target slope of the road surface on which the vehicle is located based on the first slope, the second slope and the fusion factor.

11. A new energy vehicle, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

Images