A road slope estimation method and device, an electronic device, and a readable storage medium

Abstract

The application relates to the field of new energy vehicles, and provides a road slope estimation method and device, electronic equipment and a readable storage medium. The method comprises the following steps: if current wheel speed characteristics meet a first hub mode activation condition, current acceleration characteristics meet a second hub mode activation condition, and current yaw characteristics meet a third hub mode activation condition, it is determined that a target vehicle is in a hub mode activation state; when the target vehicle is in the hub mode activation state and a longitudinal acceleration sensor is in an effective state, the current driving road slope of the target vehicle is estimated based on the longitudinal acceleration; when the target vehicle is in the hub mode activation state and the longitudinal acceleration sensor is in an ineffective state, the current driving road slope of the target vehicle is determined as a zero slope. The application can guarantee the rationality of road slope estimation in the hub mode, and avoid a series of problems such as abnormal vehicle torque control and vehicle mode control caused by unreasonable estimation of the road slope.

Description

Technical Field

[0001] This application relates to the field of new energy vehicles, and in particular to a method, apparatus, electronic device and readable storage medium for estimating road slope. Background Technology

[0002] Estimating road gradient has always been a core and challenging aspect of vehicle state parameter estimation. Accurately identifying whether a vehicle is in active wheel-turning mode, and achieving a reasonable estimation of road gradient while in active wheel-turning mode, are crucial to ensuring the success of wheel-turning tests.

[0003] If it is not possible to accurately identify whether the vehicle is in the active state of the swivel mode and to make a reasonable estimate of the road slope in the active state of the swivel mode, it will lead to a series of problems such as abnormal vehicle torque control and vehicle mode control. Summary of the Invention

[0004] In view of this, embodiments of this application provide a road slope estimation method, device, electronic device, and readable storage medium to provide a solution that can accurately identify whether a vehicle is in a hub mode activation state and reasonably estimate the road slope in the hub mode activation state, so as to avoid a series of problems such as abnormal vehicle torque control and vehicle mode control.

[0005] A first aspect of this application provides a road slope estimation method, including:

[0006] Collect vehicle status parameters of the target vehicle, including wheel speed, lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate of each wheel of the target vehicle.

[0007] The current wheel speed characteristics are determined based on the wheel speeds of each wheel of the target vehicle; the current acceleration characteristics are determined based on the lateral and longitudinal accelerations; and the current yaw characteristics are determined based on the steering wheel angle and yaw rate.

[0008] If the current wheel speed feature meets the preset first hub mode activation condition, the current acceleration feature meets the preset second hub mode activation condition, and the current yaw feature meets the preset third hub mode activation condition, then the target vehicle is determined to be in the hub mode activation state.

[0009] When the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an active state, the current road slope of the target vehicle is estimated based on the longitudinal acceleration collected by the longitudinal acceleration sensor.

[0010] When the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an invalid state, the current road gradient of the target vehicle is determined to be zero.

[0011] A second aspect of this application provides a road slope estimation device, comprising:

[0012] The parameter acquisition module is configured to acquire vehicle status parameters of the target vehicle, including wheel speed, lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate of each wheel of the target vehicle.

[0013] The feature determination module is configured to determine the current wheel speed feature based on the wheel speed of each wheel of the target vehicle, determine the current acceleration feature based on the lateral acceleration and longitudinal acceleration, and determine the current yaw feature based on the steering wheel angle and yaw rate.

[0014] The state determination module is configured to determine that the target vehicle is in the wheel rotation mode activation state if the current wheel speed feature meets the preset first wheel rotation mode activation condition, the current acceleration feature meets the preset second wheel rotation mode activation condition, and the current yaw feature meets the preset third wheel rotation mode activation condition.

[0015] The slope estimation module is configured to estimate the current road slope of the target vehicle based on the longitudinal acceleration collected by the longitudinal acceleration sensor when the target vehicle is in the active state of the wheel mode and the longitudinal acceleration sensor is in an active state.

[0016] The slope determination module is configured to determine that the current road slope of the target vehicle is zero when the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an invalid state.

[0017] A third aspect of this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-described method.

[0018] A fourth aspect of this application provides a readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described method.

[0019] Compared with the prior art, the beneficial effects of this application embodiment include at least the following: by comprehensively determining whether the target vehicle is currently in the active state of the wheel rotation mode based on three dimensions of vehicle state parameters: wheel speed characteristics (wheel speed of each wheel), vehicle acceleration characteristics (including lateral acceleration and longitudinal acceleration), and vehicle steering characteristics (including steering wheel angle and yaw rate); if it is determined that the vehicle is in the active state of the wheel rotation mode, the current road gradient of the target vehicle is further determined by combining the effective / ineffective state of the longitudinal acceleration sensor, which can ensure the rationality of the road gradient estimation in the wheel rotation mode, ensure that the various performances of the vehicle can be stably performed during the wheel rotation test, and avoid a series of problems such as abnormal vehicle torque control and vehicle mode control caused by unreasonable estimation of road gradient. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating a road slope estimation method provided in an embodiment of this application;

[0022] Figure 2 This is a flowchart illustrating another road slope estimation method provided in an embodiment of this application;

[0023] Figure 3 This is a schematic diagram of the structure of a road slope estimation device provided in an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0025] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0026] The new energy vehicles in this application embodiment refer to vehicles that use new energy sources (non-traditional petroleum and diesel energy) and possess advanced technologies. These vehicles employ new power systems that can effectively reduce vehicle emissions, minimize environmental impact, and improve energy efficiency. The new energy vehicles in this application embodiment include, but are not limited to, the following types of vehicles: electric vehicles (EVs), battery electric vehicles (BEVs), fuel cell electric vehicles (FCEVs), plug-in hybrid electric vehicles (PHEVs), and hybrid electric vehicles (HEVs).

[0027] A road slope estimation method and apparatus according to an embodiment of this application will now be described in detail with reference to the accompanying drawings.

[0028] Figure 1 This is a flowchart illustrating a road slope estimation method provided in an embodiment of this application. Figure 1 The road gradient estimation method can be executed by the vehicle controller of a new energy vehicle, or by a server (such as a cloud server). Figure 1 As shown, this road slope estimation method may specifically include the following steps:

[0029] Step S101: Collect vehicle status parameters of the target vehicle. The vehicle status parameters include wheel speed, lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate of each wheel of the target vehicle.

[0030] In this embodiment of the application, the wheel speed and steering wheel angle of each wheel of the target vehicle can be monitored in real time by the vehicle controller of the new energy vehicle; and information such as longitudinal acceleration, lateral acceleration and yaw rate can be collected by the inertial navigation sensor mounted on the target vehicle.

[0031] Step S102: Determine the current wheel speed characteristics based on the wheel speeds of each wheel of the target vehicle, determine the current acceleration characteristics based on the lateral and longitudinal acceleration, and determine the current yaw characteristics based on the steering wheel angle and yaw rate.

[0032] Step S103: If the current wheel speed feature meets the preset first hub mode activation condition, the current acceleration feature meets the preset second hub mode activation condition, and the current yaw feature meets the preset third hub mode activation condition, then the target vehicle is determined to be in the hub mode activation state.

[0033] Step S104: When the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an active state, estimate the current road slope of the target vehicle based on the longitudinal acceleration collected by the longitudinal acceleration sensor.

[0034] The target vehicle being in the active state of the hub mode means that the target vehicle has entered the preset hub mode "activation" flag. In practical applications, the flag indicating that the target vehicle has entered the active state of the hub mode can be preset to 1, and the flag indicating that the target vehicle has entered the inactive state of the hub mode can be preset to 0.

[0035] For example, assuming the current wheel speed characteristic meets the preset first hub mode activation condition, the current acceleration characteristic meets the preset second hub mode activation condition, and the current yaw characteristic meets the preset third hub mode activation condition, then the target vehicle is determined to be in a hub mode activated state. At this time, the target vehicle enters the hub mode activated state, and its flag bit displays "1". If at least one of the above-mentioned first, second, and third hub mode activation conditions is not met, then the target vehicle enters the hub mode deactivated state, and its flag bit displays "0".

[0036] Step S105: When the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an invalid state, determine that the current driving road slope of the target vehicle is zero.

[0037] When the target vehicle is in the active state of the wheel-turning mode, the traditional road slope estimation method is based on the longitudinal acceleration and longitudinal reference speed of the vehicle. However, this road slope estimation method will cause the road slope to change with the derivative of the target vehicle speed, so that the estimated road slope is inconsistent with the road slope estimated under the actual wheel-turning condition, which can easily lead to a series of abnormal problems such as vehicle torque control and vehicle mode control.

[0038] The technical solution provided in this application improves the traditional road slope estimation method. When the target vehicle is in the active state of the wheel-turning mode and the longitudinal acceleration sensor is in an effective state, only the longitudinal acceleration collected by the longitudinal acceleration sensor is used to estimate the current road slope of the target vehicle. When the longitudinal acceleration sensor is in an ineffective state, zero slope is directly used to replace the current road slope of the target vehicle. This can ensure the rationality of the road slope estimation in the wheel-turning mode, ensure that the vehicle's various performances can be stably performed during the wheel-turning test, and avoid a series of problems such as abnormal vehicle torque control and vehicle mode control caused by unreasonable estimation of road slope.

[0039] The technical solution provided in this application comprehensively determines whether the target vehicle is currently in a wheel-turning mode activation state by considering three dimensions of vehicle state parameters: wheel speed characteristics (wheel speed of each wheel), vehicle acceleration characteristics (including lateral acceleration and longitudinal acceleration), and vehicle steering characteristics (including steering wheel angle and yaw rate). If the vehicle is determined to be in a wheel-turning mode activation state, the current road gradient of the target vehicle is further determined by combining the effective / ineffective state of the longitudinal acceleration sensor. This ensures the rationality of the road gradient estimation in wheel-turning mode, guarantees the stable performance of all vehicle components during wheel-turning tests, and avoids a series of problems such as abnormal vehicle torque control and vehicle mode control caused by unreasonable road gradient estimation.

[0040] In some embodiments, the current wheel speed characteristics include the current wheel speed state, the current wheel speed difference, and the current wheel acceleration difference.

[0041] The current wheel speed characteristics are determined based on the wheel speeds of each wheel of the target vehicle, including:

[0042] Based on the wheel speed of each wheel of the target vehicle, determine the current wheel speed state of each wheel;

[0043] If all wheels of the target vehicle are currently in a non-slipping state, then find the target vehicle's current highest wheel speed and current lowest wheel speed.

[0044] Based on the current highest wheel speed and the current lowest wheel speed, calculate the current wheel speed difference and the current wheel acceleration difference of the target vehicle.

[0045] In some embodiments, determining the current wheel speed state of each wheel based on the wheel speed of each wheel of the target vehicle includes:

[0046] Calculate the wheel acceleration of each wheel based on the wheel speed of each wheel of the target vehicle;

[0047] Calculate the rate of change of wheel acceleration for each wheel based on the wheel acceleration of each wheel;

[0048] If the wheel acceleration of each wheel is less than the preset wheel acceleration threshold, and the wheel acceleration change rate is less than the preset change rate threshold, then the current wheel speed state of each wheel is determined to be a non-slip state.

[0049] As an example, suppose the target vehicle has four wheels: the left front wheel (first wheel), the right front wheel (second wheel), the left rear wheel (third wheel), and the right rear wheel (fourth wheel), where the wheel speed of the left front wheel is denoted as v. wheel_1 The wheel speed of the right front wheel is denoted as v. wheel_2 The wheel speed of the left rear wheel is denoted as v. wheel_3The wheel speed of the right rear wheel is denoted as v. wheel_4 .

[0050] Calculate the wheel acceleration of each wheel of the target vehicle according to formula (1):

[0051]

[0052] in, This represents the wheel acceleration of the i-th wheel, where i ranges from 1 to 4.

[0053] Calculate the rate of change of wheel acceleration of each wheel of the target vehicle according to formula (2):

[0054]

[0055] in, This represents the rate of change of wheel acceleration of the i-th wheel, where i ranges from 1 to 4.

[0056] The preset wheel acceleration threshold is generally set to 10 m / s². 2 The preset rate of change threshold is generally set to 60 m / s. 3 .

[0057] Next, based on the calculated wheel acceleration and rate of change of wheel acceleration of each wheel of the target vehicle, the wheel slip state is determined. The following is a detailed explanation using the left front wheel as an example: First, the wheel acceleration of the left front wheel is calculated according to the above formula (1). rate of change of wheel acceleration Then, determine the wheel acceleration. Is it less than the preset wheel acceleration threshold (e.g., 10 m / s²)? 2 ), and determine the rate of change of wheel acceleration. Is it less than the preset rate of change threshold (e.g., 60 m / s)? 3 If it is wheel acceleration Less than 10m / s 2 and the rate of change of wheel acceleration Less than 60m / s 3 This determines that the current wheel speed of the target vehicle's left front wheel is in a non-slipping state. If it is wheel acceleration... Greater than or equal to 10 m / s 2 and / or the rate of change of wheel acceleration ≥60m / s 3 Then it can be determined that the current wheel speed of the left front wheel of the target vehicle is in a slipping state.

[0058] Understandably, the method for determining the current wheel speed of the target vehicle's right front wheel, left rear wheel, and right rear wheel is the same as the method for determining the current wheel speed of the left front wheel, and will not be repeated here.

[0059] In one embodiment, the preset first hub mode activation condition may be: the current wheel speed state of each wheel is in a non-slipping state, the absolute value of the current wheel speed difference is less than a preset wheel speed difference threshold, and the absolute value of the current wheel acceleration difference is less than a preset wheel acceleration difference threshold.

[0060] In some embodiments, the steps for determining whether the current wheel speed characteristic meets the preset first hub mode activation condition are as follows:

[0061] If it is determined that the current wheel speed state of each wheel is in a non-slipping state, then it is determined whether the current wheel speed difference is less than the preset wheel speed difference threshold, and whether the current wheel acceleration difference is less than the preset wheel acceleration difference threshold.

[0062] If the absolute value of the current wheel speed difference is less than the preset wheel speed difference threshold, and the absolute value of the current wheel acceleration difference is less than the preset wheel acceleration difference threshold, then the current wheel speed feature is determined to meet the preset first hub mode activation condition.

[0063] As an example, if the wheel acceleration and wheel acceleration change rate of each wheel of the target vehicle are calculated according to the above formulas (1) and (2), and it is determined that the current wheel speed state of each wheel is non-slipping based on the wheel acceleration and wheel acceleration change rate of each wheel, then the current highest wheel speed (i.e., maximum wheel speed value) and the current lowest wheel speed (i.e., minimum wheel speed value) of the four wheels of the target vehicle can be found.

[0064] Next, the current wheel speed difference of the target vehicle is calculated according to formula (3):

[0065] D speed_diff =max(v wheel_i )-min(v wheel_i (3)

[0066] Where max(v) wheel_i () represents the current maximum wheel speed, min(v) wheel_i ) represents the current minimum wheel speed, D speed_diff This indicates the current wheel speed difference.

[0067] The current wheel acceleration difference can be calculated using the following formula (4):

[0068]

[0069] Among them, a speed_diff This represents the difference in acceleration between the current wheels. This indicates the current lowest wheel acceleration. This indicates the current highest wheel acceleration.

[0070] If the absolute value of the current wheel speed difference is less than the preset wheel speed difference threshold (usually set to 0.5 m / s), and the absolute value of the current wheel acceleration difference is less than the preset wheel acceleration difference threshold (usually set to 0.5 m / s), then... 2 If the current wheel speed characteristic meets the preset first hub mode activation condition, then it is determined that the current wheel speed characteristic meets the preset first hub mode activation condition.

[0071] In some embodiments, the current acceleration characteristics include the current lateral acceleration difference and the current longitudinal acceleration difference.

[0072] The current acceleration characteristics are determined based on lateral and longitudinal acceleration, including:

[0073] Calculate the average lateral acceleration and average longitudinal acceleration of the target vehicle within a preset data collection period;

[0074] Calculate the current lateral acceleration difference of the target vehicle based on the mean lateral acceleration and the lateral acceleration.

[0075] Calculate the current longitudinal acceleration difference of the target vehicle based on the mean longitudinal acceleration and the longitudinal acceleration.

[0076] The preset sampling period is usually 50 periods, with each period having a sampling duration of 10ms and an overall sampling duration of 500ms.

[0077] As an example, multiple lateral acceleration values ​​(including 50 lateral acceleration values) and multiple longitudinal acceleration values ​​(including 50 longitudinal acceleration values) of the vehicle can be collected within 500ms using inertial navigation sensors installed on the target vehicle; then, the arithmetic mean of the 50 collected lateral acceleration values ​​is calculated to obtain the mean lateral acceleration; the arithmetic mean of the 50 collected longitudinal acceleration values ​​is calculated to obtain the mean longitudinal acceleration.

[0078] Next, calculate the current lateral acceleration difference of the target vehicle according to formula (4); calculate the current longitudinal acceleration difference of the target vehicle according to formula (5).

[0079]

[0080] Where, d later This represents the current lateral acceleration difference, a. later This represents the currently collected lateral acceleration. This represents the average lateral acceleration value collected within a preset acquisition period.

[0081]

[0082] Where, d long This represents the current longitudinal acceleration difference, a.long a long This represents the currently collected longitudinal acceleration. This represents the average longitudinal acceleration value of multiple longitudinal acceleration values ​​collected within a preset acquisition period.

[0083] In one embodiment, the preset second hub mode activation condition may be: the absolute value of the current lateral acceleration difference of the target vehicle is less than a preset lateral acceleration threshold, and the absolute value of the current longitudinal acceleration difference is less than a preset longitudinal acceleration threshold.

[0084] In some embodiments, the step of determining whether the current acceleration characteristic meets the preset second hub mode activation condition is as follows:

[0085] Determine whether the absolute value of the current lateral acceleration difference is less than a preset lateral acceleration threshold, and whether the absolute value of the current longitudinal acceleration difference is less than a preset longitudinal acceleration threshold;

[0086] If the absolute value of the current lateral acceleration difference is less than the preset lateral acceleration threshold, and the absolute value of the current longitudinal acceleration difference is less than the preset longitudinal acceleration threshold, then the current acceleration feature is determined to meet the preset second hub mode activation condition.

[0087] The preset lateral acceleration threshold can generally be set to 0.2 m / s². 2 The preset longitudinal acceleration threshold can generally be set to 0.3 m / s². 2 .

[0088] If d later The absolute value is less than the preset lateral acceleration threshold (e.g., 0.2 m / s²). 2 ), and d long The absolute value is less than the preset longitudinal acceleration threshold (e.g., 0.3 m / s²). 2 If the current acceleration characteristic satisfies the preset second hub mode activation condition, then it is determined that the current acceleration characteristic meets the preset second hub mode activation condition.

[0089] In some embodiments, the current yaw characteristic is used to characterize the vehicle's current steering characteristics, including the magnitude of the vehicle's yaw rate and the magnitude of the steering wheel angle. The preset activation condition for the third steering mode may be: the absolute value of the target vehicle's yaw rate is less than or equal to a preset yaw rate threshold, and the absolute value of the steering wheel angle is less than or equal to a preset steering angle threshold.

[0090] As an example, the steps to determine whether the current yaw feature meets the preset third hub mode activation condition are as follows:

[0091] Based on the target vehicle's steering wheel angle θ and the yaw rate ε collected by the inertial navigation sensor, vehicle steering feature recognition is performed. When the absolute value of the vehicle's steering wheel angle θ is greater than a preset angle threshold (generally set to 0.1 rad), and the absolute value of the yaw rate ε is greater than a preset yaw rate threshold (generally set to 0.1 rad / s), the target vehicle can be determined to be in a steering state. Specifically, when the vehicle's steering wheel angle θ is greater than the preset angle threshold (0.1 rad), and the absolute value of the vehicle's yaw rate ε is greater than the preset yaw rate threshold (0.1 rad / s), the vehicle can be determined to be in a left turn state. When the vehicle's steering wheel angle θ is less than -0.1 rad, and the absolute value of the vehicle's yaw rate ε is greater than 0.1 rad / s, the vehicle can be determined to be in a right turn state.

[0092] When the absolute value of the vehicle's steering wheel angle θ is less than or equal to a preset angle threshold (generally set to 0.1 rad), and the absolute value of the yaw rate ε is less than or equal to a preset yaw rate threshold (generally set to 0.1 rad / s), it can be determined that the target vehicle is currently in a straight-line state. At this time, the target vehicle's current yaw characteristic satisfies the preset third hub mode activation condition.

[0093] In some embodiments, when the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an active state, the current road slope of the target vehicle is estimated based on the longitudinal acceleration collected by the longitudinal acceleration sensor. Specifically, the road slope can be calculated using the following formula (7):

[0094]

[0095] in, Indicates the road slope, a M This represents the longitudinal acceleration, where g is the acceleration due to gravity.

[0096] In this embodiment of the application, when it is determined that the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in the effective state, the vehicle slope estimation strategy is automatically switched. The longitudinal acceleration collected by the longitudinal acceleration sensor is directly used and substituted into the above formula (7) to calculate the current road slope of the target vehicle. Finally, the calculation result is filtered to obtain the slope information of the target vehicle.

[0097] All of the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here.

[0098] Figure 2 This is a flowchart illustrating another road slope estimation method provided in an embodiment of this application.

[0099] like Figure 2As shown, firstly, the vehicle state parameters of the target vehicle are collected and processed. These parameters include the wheel speed signals, lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate of each wheel. Then, based on the wheel speed signals of each wheel, the current wheel speed characteristics are determined, and it is judged whether the current wheel speed characteristics meet the preset first wheel rotation mode activation conditions. Specifically, this includes: determining the stable state of the four-wheel wheel speeds (i.e., determining whether the current wheel speed state of each wheel of the vehicle is in a non-slipping state), determining the wheel speed deviation of the four wheels (i.e., determining whether the absolute value of the difference between the current highest and lowest wheel speeds among the vehicle's wheels is less than a preset wheel speed difference threshold), and determining the wheel speed acceleration deviation of the four wheels (i.e., determining whether the absolute value of the difference between the current highest and lowest wheel speeds among the vehicle's wheels is less than a preset wheel acceleration difference threshold). The system determines whether the vehicle's current acceleration characteristics meet the preset second hub mode activation conditions based on lateral and longitudinal acceleration features. Specifically, this includes: discrimination of longitudinal acceleration changes (i.e., determining whether the absolute value of the difference between the vehicle's current lateral acceleration and the average lateral acceleration within a preset acquisition period is less than a preset lateral acceleration threshold) and discrimination of longitudinal acceleration changes (i.e., determining whether the absolute value of the difference between the vehicle's current longitudinal acceleration and the average longitudinal acceleration within a preset acquisition period is less than a preset longitudinal acceleration threshold); and determines whether the vehicle's current yaw features meet the preset third hub mode activation conditions based on yaw features. Specifically, this includes: discrimination of yaw rate changes (i.e., determining whether the absolute value of the yaw rate is less than or equal to a preset yaw rate threshold) and discrimination of steering angle changes (i.e., determining whether the absolute value of the vehicle's steering wheel angle is less than or equal to a preset steering angle threshold). Subsequently, the discrimination results based on the wheel speed feature dimension, longitudinal and lateral acceleration dimension, and yaw angle dimension are fused to output a hub mode flag (for example, if the discrimination results of the above three dimensions are all satisfied, the output hub mode flag is in an active state); then, when the target vehicle is in the hub mode active state, the road slope calculation strategy is automatically switched to estimate the current road slope of the target vehicle by combining the effective / ineffective state of the longitudinal acceleration sensor.

[0100] The technical solution provided in this application, based on wheel speed characteristics, lateral and longitudinal acceleration, and yaw angle, can accurately identify whether the target vehicle is currently in a wheel-turning mode activation state. Simultaneously, when the target vehicle is in a wheel-turning mode activation state and the longitudinal acceleration sensor is active, the longitudinal acceleration collected by the longitudinal acceleration sensor is directly used to estimate the current road slope. Alternatively, when the target vehicle is in a wheel-turning mode activation state and the longitudinal acceleration sensor is inactive, zero slope is directly used to replace the current road slope. This avoids the calculation of the current road slope changing with the derivative of the target vehicle's speed, ensuring that the estimated road slope is consistent with the road slope estimated under actual wheel-turning conditions. This effectively avoids a series of abnormal problems in vehicle torque control and vehicle mode control.

[0101] The road slope estimation method provided in this application embodiment can reasonably and accurately estimate the current road slope when the vehicle is in the active state of the hub mode. The estimated result can be used as a reference for other control modules of the vehicle when formulating vehicle control strategies (such as torque control strategies), which is conducive to realizing more intelligent control of the vehicle and thus improving the user's driving experience.

[0102] The following are embodiments of the apparatus described in this application, which can be used to execute the embodiments of the method described in this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the method described in this application.

[0103] Figure 3 This is a schematic diagram of a road slope estimation device provided in an embodiment of this application. Figure 3 As shown, the road slope estimation device includes:

[0104] The parameter acquisition module 301 is configured to acquire vehicle status parameters of the target vehicle, including wheel speed, lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate of each wheel of the target vehicle.

[0105] The feature determination module 302 is configured to determine the current wheel speed feature based on the wheel speed of each wheel of the target vehicle, determine the current acceleration feature based on the lateral acceleration and longitudinal acceleration, and determine the current yaw feature based on the steering wheel angle and yaw rate.

[0106] The state determination module 303 is configured to determine that the target vehicle is in the wheel rotation mode activation state if the current wheel speed feature meets the preset first wheel rotation mode activation condition, the current acceleration feature meets the preset second wheel rotation mode activation condition, and the current yaw feature meets the preset third wheel rotation mode activation condition.

[0107] The slope estimation module 304 is configured to estimate the current road slope of the target vehicle based on the longitudinal acceleration collected by the longitudinal acceleration sensor when the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an active state.

[0108] The slope determination module 305 is configured to determine that the current road slope of the target vehicle is zero when the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an invalid state.

[0109] In some embodiments, the current wheel speed characteristics include the current wheel speed state, the current wheel speed difference, and the current wheel acceleration difference.

[0110] The aforementioned feature determination module 302 includes a wheel speed feature determination unit, configured to determine the current wheel speed feature based on the wheel speed of each wheel of the target vehicle.

[0111] The wheel speed characteristic determination unit includes:

[0112] The component is configured to determine the current wheel speed state of each wheel based on the wheel speed of the target vehicle.

[0113] The search component is configured to find the current highest wheel speed and the current lowest wheel speed of the target vehicle if the current wheel speed of each wheel of the target vehicle is in a non-slipping state.

[0114] The calculation component is configured to calculate the difference between the current wheel speed and the difference between the current wheel acceleration of the target vehicle based on the current highest wheel speed and the current lowest wheel speed.

[0115] In some embodiments, the determining component includes:

[0116] The first computing device is configured to calculate the wheel acceleration of each wheel based on the wheel speed of each wheel of the target vehicle.

[0117] The second computing device is configured to calculate the rate of change of wheel acceleration of each wheel based on the wheel acceleration of each wheel;

[0118] The device is configured to determine that if the wheel acceleration of each wheel is less than a preset wheel acceleration threshold and the wheel acceleration change rate is less than a preset change rate threshold, then the current wheel speed state of each wheel is determined to be a non-slip state.

[0119] In some embodiments, the steps for determining whether the current wheel speed characteristic meets the preset first hub mode activation condition are as follows:

[0120] If it is determined that the current wheel speed state of each wheel is in a non-slipping state, then it is determined whether the absolute value of the current wheel speed difference is less than the preset wheel speed difference threshold, and whether the absolute value of the current wheel acceleration difference is less than the preset wheel acceleration difference threshold.

[0121] If the absolute value of the current wheel speed difference is less than the preset wheel speed difference threshold, and the absolute value of the current wheel acceleration difference is less than the preset wheel acceleration difference threshold, then the current wheel speed feature is determined to meet the preset first hub mode activation condition.

[0122] In some embodiments, the current acceleration feature includes the current lateral acceleration difference and the current longitudinal acceleration difference. The feature determination module 302 described above includes an acceleration feature determination unit configured to determine the current acceleration feature based on the lateral acceleration and the longitudinal acceleration.

[0123] The acceleration characteristic determination unit includes:

[0124] The mean calculation component is configured to calculate the mean lateral acceleration and mean longitudinal acceleration of the target vehicle within a preset collection period;

[0125] The first difference calculation component is configured to calculate the current lateral acceleration difference of the target vehicle based on the mean lateral acceleration and the lateral acceleration.

[0126] The second difference calculation component is configured to calculate the current longitudinal acceleration difference of the target vehicle based on the mean longitudinal acceleration and the longitudinal acceleration.

[0127] In some embodiments, the step of determining whether the current acceleration characteristic meets the preset second hub mode activation condition is as follows:

[0128] Determine whether the current lateral acceleration difference is less than a preset lateral acceleration threshold, and whether the current longitudinal acceleration difference is less than a preset longitudinal acceleration threshold;

[0129] If the absolute value of the current lateral acceleration difference is less than the preset lateral acceleration threshold, and the absolute value of the current longitudinal acceleration difference is less than the preset longitudinal acceleration threshold, then the current acceleration feature is determined to meet the preset second hub mode activation condition.

[0130] In some embodiments, the slope estimation module 304 includes an estimation unit configured to estimate the road slope of the road currently being traveled by the target vehicle based on longitudinal acceleration, specifically by calculating the road slope using the following formula:

[0131]

[0132] in, Indicates the road slope, a MThis represents the longitudinal acceleration, where g is the acceleration due to gravity.

[0133] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0134] Figure 4 This is a schematic diagram of the electronic device 4 provided in an embodiment of this application. Figure 4 As shown, the electronic device 4 of this embodiment includes: a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, it implements the steps in the various method embodiments described above. Alternatively, when the processor 401 executes the computer program 403, it implements the functions of each module / unit in the various device embodiments described above.

[0135] Electronic device 4 can be a desktop computer, laptop, handheld computer, cloud server, or other electronic device. Electronic device 4 may include, but is not limited to, processor 401 and memory 402. Those skilled in the art will understand that... Figure 4 This is merely an example of electronic device 4 and does not constitute a limitation on electronic device 4. It may include more or fewer components than shown, or different components.

[0136] The processor 401 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0137] The memory 402 can be an internal storage unit of the electronic device 4, such as a hard disk or RAM of the electronic device 4. The memory 402 can also be an external storage device of the electronic device 4, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc., equipped on the electronic device 4. The memory 402 can also include both internal and external storage units of the electronic device 4. The memory 402 is used to store computer programs and other programs and data required by the electronic device.

[0138] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0139] If integrated modules / units are implemented as software functional units and sold or used as independent products, they can be stored in a readable storage medium (e.g., a computer-readable storage medium). Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program may include computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. A computer-readable storage medium may include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carriers, telecommunications, and software distribution media, etc.

[0140] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for estimating road slope, characterized in that, include: Collect vehicle status parameters of the target vehicle, including wheel speed, lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate of each wheel of the target vehicle; The current wheel speed characteristics are determined based on the wheel speeds of each wheel of the target vehicle; the current acceleration characteristics are determined based on the lateral and longitudinal accelerations; and the current yaw characteristics are determined based on the steering wheel angle and yaw rate. If the current wheel speed feature meets the preset first hub mode activation condition, the current acceleration feature meets the preset second hub mode activation condition, and the current yaw feature meets the preset third hub mode activation condition, then the target vehicle is determined to be in a hub mode activation state. When the target vehicle is in the active hub mode and the longitudinal acceleration sensor is active, the current road gradient of the target vehicle is estimated based on the longitudinal acceleration collected by the longitudinal acceleration sensor. Specifically, the road gradient is calculated using the following formula: ;in, Indicates the road slope. This represents the longitudinal acceleration, where g is the acceleration due to gravity. When the target vehicle is in the active state of the hub mode and the longitudinal acceleration sensor is in an invalid state, the current road gradient of the target vehicle is determined to be zero.

2. The method according to claim 1, characterized in that, The current wheel speed characteristics include the current wheel speed state, the current wheel speed difference, and the current wheel acceleration difference; Determining the current wheel speed characteristics based on the wheel speeds of each wheel of the target vehicle includes: Based on the wheel speed of each wheel of the target vehicle, determine the current wheel speed state of each wheel; If the current wheel speed of each wheel of the target vehicle is in a non-slipping state, then find the current highest wheel speed and the current lowest wheel speed of the target vehicle. Based on the current highest wheel speed and the current lowest wheel speed, calculate the current wheel speed difference and the current wheel acceleration difference of the target vehicle.

3. The method according to claim 2, characterized in that, Based on the wheel speeds of each wheel of the target vehicle, the current wheel speed state of each wheel is determined, including: The wheel acceleration of each wheel is calculated based on the wheel speed of each wheel of the target vehicle. Calculate the rate of change of wheel acceleration for each wheel based on the wheel acceleration of each wheel; If the wheel acceleration of each wheel is less than the preset wheel acceleration threshold, and the wheel acceleration change rate is less than the preset change rate threshold, then the current wheel speed state of each wheel is determined to be a non-slip state.

4. The method according to claim 3, characterized in that, The steps to determine whether the current wheel speed characteristic meets the preset first hub mode activation condition are as follows: If it is determined that the current wheel speed state of each wheel is in a non-slipping state, then it is determined whether the absolute value of the current wheel speed difference is less than a preset wheel speed difference threshold, and whether the absolute value of the current wheel acceleration difference is less than a preset wheel acceleration difference threshold. If the absolute value of the current wheel speed difference is less than a preset wheel speed difference threshold, and the absolute value of the current wheel acceleration difference is less than a preset wheel acceleration difference threshold, then the current wheel speed feature is determined to meet the preset first hub mode activation condition.

5. The method according to claim 1, characterized in that, The current acceleration characteristics include the current lateral acceleration difference and the current longitudinal acceleration difference; Determining the current acceleration characteristics based on the lateral and longitudinal accelerations includes: Calculate the average lateral acceleration and average longitudinal acceleration of the target vehicle within a preset acquisition period; Based on the mean lateral acceleration and the lateral acceleration, calculate the current lateral acceleration difference of the target vehicle; The current longitudinal acceleration difference of the target vehicle is calculated based on the mean longitudinal acceleration and the longitudinal acceleration.

6. The method according to claim 5, characterized in that, The steps to determine whether the current acceleration characteristic meets the preset second hub mode activation condition are as follows: Determine whether the current lateral acceleration difference is less than a preset lateral acceleration threshold, and whether the current longitudinal acceleration difference is less than a preset longitudinal acceleration threshold; If the absolute value of the current lateral acceleration difference is less than a preset lateral acceleration threshold, and the absolute value of the current longitudinal acceleration difference is less than a preset longitudinal acceleration threshold, then the current acceleration feature is determined to meet the preset second hub mode activation condition.

7. A road slope estimation device, characterized in that, include: The parameter acquisition module is configured to acquire vehicle status parameters of the target vehicle, including wheel speed, lateral acceleration, longitudinal acceleration, steering wheel angle, and yaw rate of each wheel of the target vehicle. The feature determination module is configured to determine the current wheel speed feature based on the wheel speed of each wheel of the target vehicle, determine the current acceleration feature based on the lateral acceleration and longitudinal acceleration, and determine the current yaw feature based on the steering wheel angle and yaw rate. The state determination module is configured to determine that the target vehicle is in a wheel rotation mode activation state if the current wheel speed feature meets a preset first wheel rotation mode activation condition, the current acceleration feature meets a preset second wheel rotation mode activation condition, and the current yaw feature meets a preset third wheel rotation mode activation condition. The slope estimation module is configured to estimate the current road slope of the target vehicle based on the longitudinal acceleration collected by the longitudinal acceleration sensor when the target vehicle is in a hub-and-spoke mode and the longitudinal acceleration sensor is active. Specifically, the road slope is calculated using the following formula: ;in, Indicates the road slope. This represents the longitudinal acceleration, where g is the acceleration due to gravity. The slope determination module is configured to determine that the current road slope of the target vehicle is zero when the target vehicle is in a hub mode activation state and the longitudinal acceleration sensor is in an invalid state.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 6.

9. A readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 6.

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