Gradient determination method and device, new energy automobile and storage medium

Abstract

The invention discloses a gradient determination method and device, a new energy automobile and a storage medium, and relates to the technical field of new energy automobiles. The method comprises the following steps: determining a first gradient based on a wheel end driving force and an actual longitudinal acceleration of a vehicle; the actual longitudinal acceleration is determined based on vehicle speed; acquiring a second gradient under the condition of determining to output the first gradient; the second gradient 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 fluctuation information in the actual longitudinal acceleration; determining a fusion factor for fusing the first gradient and the second gradient; and based on the first gradient, the second gradient and the fusion factor, determining a target gradient of the road surface where the vehicle is located. By adopting the method, the accuracy of the determined gradient can be improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a slope determination method, device, new energy vehicle and storage medium. Background Art

[0002] With the continuous updating of vehicle technology (such as new energy vehicles), it is very necessary to improve the safety of driving vehicles. In the process of driving a vehicle, the vehicle controller can determine the slope of the road the vehicle is currently on in real time based on the principle of dynamics. However, the slope determined by this method may be inaccurate, which may lead to a decrease in the driving performance of the vehicle.

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

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

[0005] In a first aspect, an embodiment of the present application provides a slope determination method, the method comprising:

[0006] 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;

[0007] 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;

[0008] determining a blending factor for blending the first slope and the second slope;

[0009] 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.

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

[0011] In one embodiment, a fusion factor is used to characterize a first weight corresponding to a 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, a first weight corresponding to the first slope is obtained by looking up a table, and based on the first weight, a second weight corresponding to the second slope is determined; based on the first slope, the second slope and the fusion factor, a target slope of the road surface on which the vehicle is located is determined, including: based on the first slope, the second slope, the first weight and the second weight, the target slope of the road surface on which the vehicle is located is determined.

[0012] In one of the embodiments, the method also 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 vehicle's current gear is a forward gear; the vehicle's brake pedal opening is 0; the vehicle's speed change rate is greater than a preset vehicle speed change rate threshold; the vehicle's steering wheel angle 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's 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.

[0013] In one of the embodiments, the method further includes: determining the slip rate corresponding to each wheel based on the wheel speed of each wheel in the vehicle and the vehicle speed; deriving the wheel acceleration corresponding to each wheel based on the wheel speed of each wheel in the vehicle; for each wheel, 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, determining that the wheel end state of the wheel is in a stable state.

[0014] In one embodiment, a first slope is determined based on the wheel-end driving force and actual longitudinal acceleration of the vehicle, including: based on the vehicle speed, deriving the actual longitudinal acceleration 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 slope, determining a first intermediate value; inputting the first intermediate value into a preset slope calculation model to obtain a first slope of the road surface on which the vehicle is located.

[0015] In one embodiment, the second slope is determined in the following manner: based on the vehicle speed, deriving the actual longitudinal acceleration 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, wheel-end driving force, vehicle speed, the force balance principle of the vehicle on the current slope 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 of the embodiments, the method further includes: based on the target slope, taking a derivative 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, looking up a table to determine a slope change gradient, and based on the slope change gradient, the target slope correction factor, and the final slope corresponding to a previous cycle of the current cycle, determining a final slope of the road surface on which the vehicle is located, and updating the target slope based on the final slope.

[0017] In one of the embodiments, when the slope change rate is greater than a preset slope change rate threshold, a target slope correction factor is determined, including: when the slope change rate is greater than the preset slope change rate threshold, an average value and a root mean square value of the absolute values ​​of multiple slope change rates within a preset time period are determined; based on a target correspondence relationship, a target slope correction factor corresponding to the average value and the root mean square value is obtained; the target correspondence relationship 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.

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

[0019] 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;

[0020] an acquisition module, for acquiring 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;

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

[0022] The determination module is also used to determine the target slope of the road surface on which 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, wherein the memory stores a computer program, and the processor implements the steps of the method of the first aspect when executing the computer program.

[0024] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the method of the first aspect when the computer program is executed by a processor.

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

[0026] The above-mentioned slope determination method, device, new energy vehicle and storage medium, the new energy vehicle (hereinafter referred to as the vehicle) can determine the first slope based on the wheel-end driving force and actual longitudinal acceleration of the vehicle; the actual longitudinal acceleration is determined based on the vehicle speed; when the first slope is determined to be output, 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 of the vehicle; the filtered actual longitudinal acceleration is obtained after filtering the fluctuation information in the actual longitudinal acceleration; determine the fusion factor for fusing the first slope and the second slope; based on the first slope, the second slope and the fusion factor, determine the target slope of the road surface on which the vehicle is located. By adopting this method, the vehicle can realize 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 on which the vehicle is located; and when determining to output the first slope, obtain the second slope determined based on the wheel-end driving force, the vehicle speed and the actual longitudinal acceleration after filtering. Since the accuracy of the actual longitudinal acceleration after filtering 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 on which 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 drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 is a flow chart of a slope determination method provided in an embodiment of the present application;

[0029] Figure 2 is a flow chart of another slope determination method provided in an embodiment of the present application;

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

[0031] Figure 4 It is a structural schematic diagram of a new energy vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] The slope determination method provided in the embodiment of the present application is described below.

[0034] See also Figure 1 , Figure 1 is a flow chart of a slope determination method provided in an embodiment of the present application. The method can be executed by a vehicle controller. Figure 1 As shown, the slope determination method may include but is not limited to the following steps:

[0035] S101. Determine 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.

[0036] Optionally, the vehicle speed may be monitored in real time by the vehicle controller, or may be determined by the vehicle controller based on the motor speed of the vehicle, which is not limited here.

[0037] Optionally, when the vehicle controller determines the vehicle speed based on the motor speed of the vehicle, the following formula (1) may 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; and μ is the conversion coefficient from speed to vehicle speed.

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

[0041] In an optional embodiment, the vehicle controller determines the first slope based on the vehicle's wheel-end driving force and actual longitudinal acceleration. The first slope may be determined based on the vehicle's wheel-end driving force, actual longitudinal acceleration and the force balance principle of the vehicle on the current slope.

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

[0043] Among them, ramp resistance refers to the force that hinders the vehicle's forward movement due to the component of gravity along the ramp direction when the vehicle is driving on a ramp. Specifically, when a vehicle is driving on an inclined ramp, its own gravity will generate two components, one is the component perpendicular to the ramp, which is used to balance the support force of the ground; the other is the component along the ramp direction, which is the ramp resistance. When the vehicle is going uphill, the ramp resistance is opposite to the direction of the vehicle's travel, hindering the vehicle's forward movement. The vehicle needs to overcome the ramp resistance to move up; when going downhill, the ramp resistance is in the same direction as the vehicle's travel, which will cause the vehicle to have a tendency to accelerate downhill.

[0044] Among them, rolling resistance refers to the force that hinders the vehicle's progress due to the interaction between the tires and the road surface during the vehicle's driving.

[0045] Among them, acceleration resistance refers to the force that hinders the vehicle from increasing its speed during the acceleration process. In other words, acceleration resistance refers to the sum of various forces that hinder the acceleration of the vehicle that need to be overcome in order to increase the speed of the vehicle when the vehicle is accelerating.

[0046] Among them, air resistance refers to the force exerted by the air on the vehicle that hinders its forward movement when the vehicle moves in the air.

[0047] The force balance principle of the vehicle on the current ramp may 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 may be determined by the vehicle controller based on the wheel end torque of the vehicle.

[0048] Optionally, during the driving process of the vehicle, the vehicle controller can obtain multiple status information of the vehicle in real time or periodically, such as vehicle speed, acceleration, etc., and then the vehicle controller can determine the current corresponding air resistance and acceleration resistance of the vehicle based on one or more of the multiple status information. Among them, air resistance is related to vehicle speed and frontal area, and acceleration resistance is related to acceleration. Since ramp resistance and rolling resistance are both related to the slope, the vehicle controller can reversely deduce the slope of the current road surface (i.e., the first slope) of the vehicle based on the wheel end torque, vehicle speed, and the force balance principle of the vehicle on the current slope.

[0049] S102. When the first slope is determined to be output, a second slope is obtained; 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.

[0050] Optionally, the method for determining the vehicle speed may refer to the description in the aforementioned step S101, which will not be repeated here.

[0051] Optionally, during the driving of the vehicle, the vehicle controller may obtain multiple status information of the vehicle in real time or periodically, such as the vehicle speed, the current gear position of the vehicle, the opening of the vehicle's brake pedal, etc.; thereafter, the vehicle controller may determine whether to activate the slope update flag based on one or more of the multiple status information, and if it is determined that the slope update flag is activated, it allows the output of the first slope, and when the first slope is output, the second slope is obtained.

[0052] Optionally, the vehicle controller may 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 a fusion factor for fusing the first slope and the second slope.

[0054] Optionally, during the driving of the vehicle, the vehicle controller may obtain at least one status information of the vehicle in real time or periodically, such as the wheel-end torque of the vehicle; thereafter, the vehicle controller may determine the target parameter based on one or more of the at least one status information, such as the wheel-end driving force change rate, and determine the fusion factor for fusing the first slope and the second slope based on the target parameter table lookup. Among them, the above-mentioned table includes the correspondence 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 database and readable by the vehicle controller, etc., which is not limited here.

[0055] S104: 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.

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

[0057] In the embodiment 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 the first slope is determined to be output, 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 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 on which the vehicle is located is determined. With this method, the vehicle can realize 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 on which the vehicle is located; and when the first slope is determined to be output, 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 the slope of the road surface on which the vehicle is located can be determined in real time, but also the accuracy of the determined slope can be improved.

[0058] In an optional embodiment, Figure 1 In the slope determination method shown, the vehicle controller determines the first slope based on the wheel-end driving force and actual longitudinal acceleration of the vehicle, which may include: based on the vehicle speed, deriving the actual longitudinal acceleration 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 slope, 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 on which the vehicle is located.

[0059] In some embodiments, the wheel end driving force may be determined by the vehicle controller based on the wheel end torque of the vehicle and the tire rolling radius. Optionally, the vehicle controller may use the following formula (2) to determine the wheel end driving force based on the wheel end torque of the vehicle and the tire rolling radius.

[0060] (2)

[0061] In formula (2), F x It 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 slope can be expressed as the following formula (3).

[0063] (3)

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

[0065] Optionally, the vehicle controller may use the following formulas (4) to (7) when determining 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 slope.

[0066] (4)

[0067] (5)

[0068] (6)

[0069] (7)

[0070] In formulas (4) to (7), F x It represents the wheel end driving force (unit: Newton (N)), recorded as A; B represents the air resistance f 空气 (Unit: N) and acceleration resistance f 加速 (unit: N) and m represents the total vehicle mass (unit: kg); a x It represents the actual longitudinal acceleration (unit: m / s 2 ); ρ represents the constant 1.2258; C d It represents the air resistance coefficient; A1 represents the windward area of ​​the vehicle (unit: square meters (m 2 ));V x represents the vehicle speed (unit: km / h); C represents the slope resistance f 坡道 (Unit: N) and rolling resistance f 滚动 (unit: N) is the sum of the first intermediate value; g represents the acceleration due to gravity (unit: m / s 2 ); It represents the first slope; f represents the rolling resistance coefficient.

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

[0072] (8)

[0073] In formula (8), It represents the first slope of the road where the vehicle is located (unit: degree); It represents the first intermediate value; m represents the mass of the vehicle (unit: kilogram); 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 on which the vehicle is located through dynamic calculations.

[0075] In an optional embodiment, 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 derived; the actual longitudinal acceleration is filtered 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, wheel-end driving force, vehicle speed, the force balance principle of the vehicle on the current slope 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 a second slope.

[0076] In some embodiments, the vehicle controller performs filtering processing on the actual longitudinal acceleration to filter out the fluctuation information in the actual longitudinal acceleration. When obtaining the filtered actual longitudinal acceleration, the fluctuation information in the actual longitudinal acceleration may be filtered based on a preset low-pass filter to obtain the filtered actual longitudinal acceleration. Since there may be fluctuation information in the actual longitudinal acceleration, the vehicle controller performs filtering processing on the fluctuation information that may exist in the actual longitudinal acceleration based on a preset low-pass filter to obtain a more accurate actual longitudinal acceleration.

[0077] Optionally, when the vehicle controller performs filtering processing on the fluctuation information in the actual longitudinal acceleration based on a preset low-pass filter to obtain the filtered actual longitudinal acceleration, the following formula (9) may be used.

[0078] (9)

[0079] In formula (9), It represents the actual longitudinal acceleration after filtering, which is also recorded as ;γ represents the filter coefficient; It represents the actual longitudinal acceleration after filtering at the previous moment; It represents the actual longitudinal acceleration of the input.

[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, 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, the vehicle controller may use the following formulas (10) to (13) when determining 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 slope (as shown in the above formula (3)).

[0082] (10)

[0083] (11)

[0084] (12)

[0085] (13)

[0086] In formulas (10) to (13), F x It represents the wheel end driving force (unit: N), recorded as ; It represents the acceleration resistance and air resistance The sum of ; m represents the mass of the vehicle (unit: kilogram); It represents the actual longitudinal acceleration after filtering (unit: m / s 2 ); represents the constant 1.2258; C d It represents the air resistance coefficient; A1 represents the frontal area of ​​the vehicle (unit: square meters); V x It indicates the vehicle speed (unit: km / h); It represents the slope resistance and rolling resistance The sum of the initial intermediate value; g represents the acceleration due to gravity (unit: m / s 2 ); It represents the second slope; f represents the rolling resistance coefficient.

[0087] It should be noted that since the actual longitudinal acceleration after filtering is used in this embodiment, a new parameter is introduced: , and To represent the relevant calculation results, so as to distinguish it from the aforementioned embodiment.

[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), It represents the estimated value of the second intermediate value after the kth iteration; It represents the estimated value of the second intermediate value after the k-1th 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-1th iteration; λ represents the forgetting factor; k∈[1, K], K is the preset value.

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

[0094] Optionally, the vehicle controller calculates a second intermediate value containing slope information by using a least squares method with a forgetting factor. Afterwards, the second intermediate value can be input into a preset slope calculation model, such as the following formula (17), to determine the second slope of the road surface on which the vehicle is located.

[0095] (17)

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

[0097] In this implementation, the vehicle controller obtains a more accurate actual longitudinal acceleration by filtering the actual longitudinal acceleration, and accurately determines the second slope of the road surface on which the vehicle is located by combining the least squares method.

[0098] In an optional embodiment, Figure 1 In the slope determination method shown, the vehicle controller 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 rate of change of the wheel-end driving force based on the wheel-end torque of the vehicle; based on the rate of change of the wheel-end driving force, looking up a table to obtain a fusion factor for fusing the first slope and the second slope.

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

[0100] In some embodiments, a fusion factor is used to characterize a first weight corresponding to a first slope; the vehicle controller obtains a fusion factor for fusing the first slope and the second slope based on the wheel-end driving force change rate by looking up a table, which may include: 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, obtaining a first weight corresponding to the first slope by looking up a table, and determining a second weight corresponding to the second slope based on the first weight; the vehicle controller determines 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, which may include: determining the target slope of the road surface on which the vehicle is located based on the first slope, the second slope, the first weight and the second weight.

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

[0102] Optionally, the table mentioned above may be a table preset in the vehicle controller (referred to as the first correspondence table), or a table preset in a database and readable by the vehicle controller (referred to as the first correspondence table), etc., which is not limited here. Exemplarily, the first correspondence table may be shown in Table 1 below.

[0103] Table 1 The first correspondence table

[0104]

[0105] It can be seen from Table 1 above that the greater the normalized wheel-end driving force change rate, the greater the determined fusion factor, that is, the first weight corresponding to the first slope, which indicates that the vehicle controller places more emphasis on using the first slope to determine the target slope of the road surface on which the vehicle is located; conversely, the smaller the normalized wheel-end driving force change rate, the smaller the determined fusion factor, that is, the first weight corresponding to the first slope, which indicates that the vehicle controller places more emphasis on using the second slope to determine the target slope of the road surface on which the vehicle is located.

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

[0107] (18)

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

[0109] In this embodiment, the vehicle controller can simply and quickly determine the fusion factor used to fuse 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, high-precision slope estimation can be achieved, thereby improving the accuracy of the determined slope.

[0110] In an optional embodiment, 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 vehicle's current gear is the forward gear; the vehicle's brake pedal opening is 0; the vehicle's speed change rate is greater than the preset vehicle speed change rate threshold; the vehicle's steering wheel angle 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's speed jerk within the first preset time period is less than the 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.

[0111] In some embodiments, the vehicle controller can also determine the slip rate corresponding to each wheel based on the wheel speed of each wheel in the vehicle and the vehicle speed; derive the wheel acceleration corresponding to each wheel based on the wheel speed of each wheel in the vehicle; for each wheel, 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, determine that the wheel end state of the wheel is in a stable state.

[0112] Optionally, the vehicle controller may use the following formula (19) to determine the slip rate corresponding to each wheel based on the wheel speed of each wheel and the vehicle speed.

[0113] (19)

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

[0115] For example, assuming that the preset slip rate threshold is 20%, the preset wheel acceleration threshold is 20m / s 2 , and assuming that the slip rate of the front left wheel of the vehicle is 25% and the wheel acceleration is 30m / s 2 In this case, the vehicle controller can determine that the slip rate of the vehicle's front left wheel corresponding to 25% is greater than the preset slip rate threshold of 20%, and the wheel acceleration is 30m / s 2 Greater than the preset wheel acceleration threshold of 20m / s 2 At this time, the vehicle controller can determine that the wheel end state of the front left wheel of the vehicle is in a stable state.

[0116] By adopting this implementation, 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 first slope to be output, thereby facilitating the subsequent determination of the target slope of the road on which the vehicle is located.

[0117] In an optional implementation, the vehicle controller can determine the slope change rate based on the target slope; when the slope change rate is less than or equal to the preset slope change rate threshold, the target slope is used as the final slope of the road on which the vehicle is located; when the slope change rate is greater than the preset slope change rate threshold, the target slope is corrected to obtain the final slope of the road on which the vehicle is located. In other words, Figure 1In the slope determination method shown, the vehicle controller can also derive the slope change rate based on the target slope; determine the target slope correction factor when the slope change rate is greater than a preset slope change rate threshold; based on the target slope, determine the slope change gradient by looking up the table, and determine the final slope of the road surface on which 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.

[0118] In some embodiments, the vehicle controller determines a target slope correction factor when the slope change rate is greater than a preset slope change rate threshold, which may include: when the slope change rate is greater than the preset slope change rate threshold, determining the average value and root mean square value of the absolute values ​​of multiple slope change rates within a preset time period; based on the target correspondence, obtaining the target slope correction factor corresponding to the average value and the root mean square value; 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.

[0119] Optionally, the target correspondence may be a table preset in the vehicle controller (recorded as the second correspondence table), or a table preset in a database and readable by the vehicle controller (recorded as the second correspondence table), etc., which is not limited here. Among them, the table includes the correspondence between a combination of multiple average values ​​and root mean square values ​​and a plurality of 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 may be shown in Table 2 below.

[0120] Table 2 Second correspondence table

[0121]

[0122] Since the average value of the slope change rate in the preset time period is small, it means that the current road conditions are mainly gentle slopes; the root mean square value of the slope change rate in the preset time period is small, which means that the proportion of gentle slopes is high. Therefore, it can be seen from Table 2 that the smaller the average value of the slope change rate in the preset time period and the smaller the root mean square value, the smaller the target slope correction factor is. 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 slope change gradient by looking up a table based on the target slope. The slope change gradient may be determined by looking up the following Table 3 based on the target slope. Table 3 includes a correspondence between multiple slopes and slope change gradients. Optionally, Table 3 may be a table preset in the vehicle controller (referred to as the third correspondence table), or a table preset in a database and readable by the vehicle controller (referred to as the third correspondence table), which is not limited here.

[0124] Table 3 The third correspondence table

[0125]

[0126] It can be seen from Table 3 that the smaller the slope, the smaller the determined slope change gradient. The smaller the slope, the higher the probability that the actual slope change rate is small, and therefore, the smaller the slope change gradient. By looking up the table, the slope change gradient can be determined simply and efficiently.

[0127] In some embodiments, the vehicle controller may use the following formula (20) to determine the final slope of the road surface on which 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.

[0128] (20)

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

[0130] By adopting this implementation mode, the vehicle controller can determine the slope change gradient and the slope change rate based on the target slope when it is determined that the slope change rate is greater than a preset slope change rate threshold based on the target slope, and determine the target slope correction factor based on the slope change rate. Thereafter, the final slope of the road surface on which the vehicle is located is determined 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 the target slope is updated based on the final slope. In this way, the accuracy of the slope of the road surface on which the vehicle is located can be further improved.

[0131] Combine the following Figure 2 , the overall process of the slope determination method provided in the embodiment of the present application is described. Figure 2 , Figure 2FIG. 1 is a flow chart of another slope determination method provided in an embodiment of the present application, which can be executed by a vehicle controller. Figure 2 As shown, the 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 optional implementation, the method for determining the vehicle speed may also refer to the description in the aforementioned step S101, which will not be repeated here.

[0135] In an optional implementation, the vehicle controller may obtain the actual longitudinal acceleration of the vehicle by deriving the vehicle speed, that is, , where a x It represents the actual longitudinal acceleration of the vehicle (unit: m / s 2 ); V x It indicates the vehicle speed (unit: km / h).

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

[0137] In an optional implementation, the vehicle controller may determine the wheel end driving force based on the wheel end torque and the tire rolling radius using the aforementioned formula (2).

[0138] In some embodiments, after determining the wheel-end driving force, the vehicle controller may also perform delay processing on the wheel-end driving force, so as to solve the problem that the actual longitudinal acceleration lags behind the wheel-end driving force.

[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. For example, 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, the vehicle controller can use F=ma as a dynamic model for describing the longitudinal motion of the vehicle. After that, by using the historical wheel-end driving force data and the historical actual longitudinal acceleration data to perform theoretical analysis on the above dynamic model, the response function of the longitudinal acceleration when the wheel-end driving force changes can be solved, thereby obtaining the inherent delay characteristics of the system.

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

[0141] For example, assuming that the vehicle controller determines that the response time corresponding to the actual longitudinal acceleration is 10s, the vehicle controller can use the response time of 10s as a delay period and apply the wheel-end driving force to the wheels with a delay of 10s 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 optional implementation, the vehicle controller may determine the first slope based on the wheel end driving force and the actual longitudinal acceleration 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 optional embodiment, the vehicle controller may determine that the wheel end is in an unstable state when all of the following conditions are met: (1) the slip rate is greater than a preset slip rate threshold; (2) the wheel acceleration is greater than a preset wheel acceleration threshold.

[0146] That is to say, the vehicle controller can determine that the wheel end state of the wheel is in a stable state when it is determined that 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.

[0147] Optionally, the slip rate corresponding to the wheel can be determined by the vehicle controller based on the wheel speed and vehicle speed using the above formula (19); the wheel acceleration corresponding to the wheel can be obtained by the vehicle controller by derivation of the wheel speed, that is, ,in, It represents the wheel acceleration. Indicates the wheel speed.

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

[0149] In an optional embodiment, the vehicle controller may determine that the slope update flag is activated when it is determined that 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 the forward gear (D gear); (3) the brake pedal is not depressed, that is, the brake pedal opening 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, that is, 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, the first slope is determined and output, and when the first slope is output, a second slope is obtained; the second slope is determined based on the wheel-end driving force of the vehicle, the vehicle speed, the filtered actual longitudinal acceleration, and the force balance principle; the filtered actual longitudinal acceleration is obtained by filtering the fluctuation information in the actual longitudinal acceleration.

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

[0152] S208: 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.

[0153] S209: Determine the slope change gradient and the slope change rate based on the target slope.

[0154] In an optional implementation, the vehicle controller determines the slope change gradient based on the target slope, and may obtain the slope change gradient by searching the above Table 3 based on the target slope.

[0155] In an optional implementation, the vehicle controller determines the slope change rate based on the target slope, which may be obtained by taking the derivative of the target slope, that is, ,in, It represents the slope change gradient. It indicates the target slope of the road on which 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 root mean square value of the absolute values ​​of multiple slope change rates within a preset time period, and based on the target corresponding relationship, obtain a target slope correction factor corresponding to the average value and the root mean square value.

[0157] The target correspondence relationship includes a correspondence relationship 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. Exemplarily, the target correspondence relationship may be as shown in Table 2 above, and the vehicle controller may 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 optional embodiment, the vehicle controller may use the target slope as the final slope of the road surface on which the vehicle is located when the slope change rate is less than or equal to a preset slope change rate threshold.

[0159] S211. Determine the final slope of the road on which 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 optional embodiment, the vehicle controller may determine the final slope of the road surface on which the vehicle is located using the above formula (20) 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 an embodiment of the present application, the vehicle controller can realize 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 slope to obtain a first slope of the road surface on which the vehicle is located; and when determining to output the first slope, obtain a 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 on which the vehicle is located be determined in real time, but also the accuracy of the determined slope can be improved. Furthermore, when the vehicle controller determines that the slope change rate is greater than a preset slope change rate threshold based on the target slope, it determines the slope change gradient and the slope change rate based on the target slope, and determines the target slope correction factor based on the slope change rate. Thereafter, the final slope of the road surface on which the vehicle is located is determined 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, the target slope is updated based on the final slope. In this way, the accuracy of the slope of the road surface on which the vehicle is located can be further improved.

[0162] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

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

[0164] See also Figure 3 , Figure 3 Schematic diagram of a slope determination device provided in an embodiment of the present application. Figure 3 As shown, the slope determination device may include but is not limited to:

[0165] A determination module 301 is used to determine 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;

[0166] The acquisition module 302 is used 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;

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

[0168] The determination module 301 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.

[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 used to: obtain 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; based on the wheel-end driving force change rate, look up the table 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 used to 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, it is specifically used to: normalize the wheel-end driving force change rate to obtain the normalized wheel-end driving force change rate; based on the normalized wheel-end driving force change rate, look up a table to obtain the first weight corresponding to the first slope, and determine the second weight corresponding to the second slope based on the first weight; when the determination module 301 is used to determine the target slope of the road surface on which the vehicle is located based on the first slope, the second slope and the fusion factor, it is specifically used to: determine the target slope of the road surface on which 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 also includes a processing module, which is used to activate 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 vehicle's current gear is a forward gear; the opening of the vehicle's brake pedal is 0; the vehicle's speed change rate is greater than a preset vehicle speed change rate threshold; the vehicle's steering wheel angle 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's 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 also used to determine the slip rate 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, derive the wheel acceleration corresponding to each wheel; for each wheel, 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, determine that the wheel end state of the wheel is in a stable state.

[0173] In one embodiment, when the determination module 301 is used to determine the first slope based on the wheel-end driving force and the actual longitudinal acceleration of the vehicle, it is specifically used to: derive the actual longitudinal acceleration of the vehicle based on 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 slope; input the first intermediate value into a preset slope calculation model to obtain the first slope of the road surface on which the vehicle is located.

[0174] In one embodiment, the determination module 301 is also used to: derive the actual longitudinal acceleration of the vehicle based on the vehicle speed; filter the actual longitudinal acceleration to filter out the fluctuation information in the actual longitudinal acceleration to obtain the filtered actual longitudinal acceleration; determine a 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 slope, and the least squares method; input the second intermediate value into a preset slope calculation model to obtain a second slope.

[0175] In one embodiment, the determination module 301 is also used to: based on the target slope, derive the slope change rate; when the slope change rate is greater than a preset slope change rate threshold, determine the target slope correction factor; based on the target slope, determine the slope change gradient by looking up a table, 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 on which the vehicle is located, and update the target slope based on the final slope.

[0176] In one embodiment, when the determination module 301 is used to determine the target slope correction factor when the slope change rate is greater than a preset slope change rate threshold, it is specifically used to: determine the average value and 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; 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 the 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.

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

[0178] In an exemplary embodiment, a new energy vehicle is provided, and its internal structure diagram can be as follows: Figure 4As shown. 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 an external device. The communication interface 404 of the new energy vehicle 400 is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be realized through WIFI, mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a slope determination method is implemented. 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 it can be a button, trackball or touchpad set in the new energy vehicle.

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

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

[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 a processor, the steps in the above-mentioned slope determination methods are implemented.

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

[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 the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0184] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and 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-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present 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), magnetic 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. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0185] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this application.

[0186] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached 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