Road slope estimation method and device, computer device and storage medium

Abstract

This application relates to a road slope estimation method, apparatus, computer equipment, and storage medium. The method includes: obtaining a first slope estimate based on vehicle tire pressure information; obtaining a second slope estimate based on a first acceleration and a second acceleration of the vehicle; the first acceleration is obtained by an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's travel speed; obtaining a first weighting coefficient corresponding to the first slope estimate based on the travel speed, the first acceleration, and the second acceleration, and determining a second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient; and performing a weighted summation of the first slope estimate and the second slope estimate based on the first weighting coefficient and the second weighting coefficient to obtain a target slope estimate. This method can improve the accuracy of road slope estimation.

Description

Technical Field

[0001] This application relates to the field of autonomous driving technology, and in particular to a road slope estimation method, apparatus, computer equipment, storage medium, and computer program product. Background Technology

[0002] Road gradient, as one of the important parameters of vehicle driving status, has important practical significance for vehicle safety, stability and fuel economy control.

[0003] In related technologies, vehicle dynamics models are typically used, and corresponding state observers are designed to estimate road slope. However, the modeling process of vehicle dynamics models is complex, involves many formulas, and the calculation accuracy depends on a large number of given parameters. Errors are prone to occur during the calculation process, resulting in low accuracy of road slope estimation. Summary of the Invention

[0004] Therefore, it is necessary to provide a road slope estimation method, apparatus, computer equipment, computer-readable storage medium, and computer program product that can improve the accuracy of road slope estimation in response to the above-mentioned technical problems.

[0005] Firstly, this application provides a method for estimating road slope, including:

[0006] Based on the vehicle's tire pressure information, obtain the first slope estimate;

[0007] A second slope estimate is obtained based on the vehicle's first and second accelerations; the first acceleration is obtained through an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's speed.

[0008] Based on the driving speed, the first acceleration, and the second acceleration, obtain the first weighting coefficient corresponding to the first slope estimate, and determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0009] The target slope estimate is obtained by weighting and summing the first and second slope estimates based on the first and second weighting coefficients.

[0010] In one embodiment, obtaining a first slope estimate based on the vehicle's tire pressure information includes:

[0011] Obtain the average tire pressure of the front axle tires and the average tire pressure of the rear axle tires of the vehicle;

[0012] The product of the third weighting factor and the average tire pressure of the front axle tires is used as the first weighting tire pressure; the third weighting factor is determined based on the load ratio of the front axle tires.

[0013] The product of the fourth weighting factor and the average tire pressure of the rear axle tires is used as the second weighting tire pressure; the fourth weighting factor is determined based on the load ratio of the rear axle tires.

[0014] The ratio of the first weighted tire pressure to the second weighted tire pressure is taken as the target pressure ratio.

[0015] Based on the target pressure ratio and the preset slope function, obtain the first slope estimate.

[0016] In one embodiment, the slope function is constructed as follows:

[0017] Based on the preset slope range and slope step value, obtain multiple slope test values;

[0018] Obtain the test pressure ratio of the vehicle under various slope test values;

[0019] A slope function is constructed based on the test values ​​of each slope and the corresponding test pressure ratio.

[0020] In one embodiment, a slope function is constructed based on each slope test value and the corresponding test pressure ratio, including:

[0021] Using the least squares method, a linear fit is performed on each slope test value and the corresponding test pressure ratio to obtain the slope function.

[0022] In one embodiment, obtaining a second gradient estimate based on a first acceleration and a second acceleration of the vehicle includes:

[0023] The difference between the first acceleration and the second acceleration is obtained as the intermediate acceleration;

[0024] The initial slope estimate is obtained based on the ratio of intermediate acceleration to gravitational acceleration.

[0025] The initial slope estimate is filtered by a low-pass filter to obtain the second slope estimate.

[0026] In one embodiment, obtaining the first weighting coefficient corresponding to the first slope estimate based on the driving speed, the first acceleration, and the second acceleration includes:

[0027] When the driving speed is less than the speed threshold, the first weighting coefficient is obtained based on the driving speed and the preset first weighting function;

[0028] When the driving speed is not less than the speed threshold and the target acceleration is greater than the acceleration threshold, the first weighting coefficient is obtained based on the target acceleration and the preset second weighting function; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration.

[0029] When the driving speed is not less than the speed threshold and the target acceleration is not greater than the acceleration threshold, the first weighting coefficient is zero.

[0030] Secondly, this application also provides a road slope estimation device, comprising:

[0031] The first estimation module is used to obtain the first slope estimate based on the vehicle's tire pressure information;

[0032] The second estimation module is used to obtain a second slope estimate based on the vehicle's first acceleration and second acceleration; the first acceleration is obtained through an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's travel speed.

[0033] The acquisition module is used to acquire the first weighting coefficient corresponding to the first slope estimate based on the driving speed, the first acceleration, and the second acceleration, and to determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0034] The weighting module is used to perform a weighted summation of the first slope estimate and the second slope estimate based on the first weighting coefficient and the second weighting coefficient to obtain the target slope estimate.

[0035] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0036] Based on the vehicle's tire pressure information, obtain the first slope estimate;

[0037] A second slope estimate is obtained based on the vehicle's first and second accelerations; the first acceleration is obtained through an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's speed.

[0038] Based on the driving speed, the first acceleration, and the second acceleration, obtain the first weighting coefficient corresponding to the first slope estimate, and determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0039] The target slope estimate is obtained by weighting and summing the first and second slope estimates based on the first and second weighting coefficients.

[0040] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0041] Based on the vehicle's tire pressure information, obtain the first slope estimate;

[0042] A second slope estimate is obtained based on the vehicle's first and second accelerations; the first acceleration is obtained through an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's speed.

[0043] Based on the driving speed, the first acceleration, and the second acceleration, obtain the first weighting coefficient corresponding to the first slope estimate, and determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0044] The target slope estimate is obtained by weighting and summing the first and second slope estimates based on the first and second weighting coefficients.

[0045] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0046] Based on the vehicle's tire pressure information, obtain the first slope estimate;

[0047] A second slope estimate is obtained based on the vehicle's first and second accelerations; the first acceleration is obtained through an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's speed.

[0048] Based on the driving speed, the first acceleration, and the second acceleration, obtain the first weighting coefficient corresponding to the first slope estimate, and determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0049] The target slope estimate is obtained by weighting and summing the first and second slope estimates based on the first and second weighting coefficients.

[0050] The aforementioned road slope estimation method, apparatus, computer equipment, storage medium, and computer program product first obtain a first slope estimate based on the vehicle's tire pressure information, and then obtain a second slope estimate based on the vehicle's first and second accelerations. Next, based on the driving speed, the first acceleration, and the second acceleration, a first weighting coefficient corresponding to the first slope estimate is obtained. Based on the first weighting coefficient, a second weighting coefficient corresponding to the second slope estimate is determined. Finally, based on the first and second weighting coefficients, the first and second slope estimates are weighted and summed to obtain the target slope estimate. This allows for road slope estimation with fewer sensor parameters, thereby improving the accuracy of road slope estimation. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying 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.

[0052] Figure 1 This is a diagram illustrating the application environment of the road slope estimation method in one embodiment;

[0053] Figure 2 This is a flowchart illustrating a road slope estimation method in one embodiment;

[0054] Figure 3 This is a flowchart illustrating the road slope estimation method in another embodiment;

[0055] Figure 4 This is a structural block diagram of a road slope estimation device in one embodiment;

[0056] Figure 5 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0058] The road slope estimation method provided in this application embodiment can be applied to, for example, Figure 1 In the application environment shown, terminal 102 communicates with server 104 via a network. A data storage system can store the data that server 104 needs to process. The data storage system can be integrated onto server 104, or it can be located in the cloud or on other network servers. Terminal 102 can be, but is not limited to, a smart vehicle-mounted device. Server 104 can be implemented using a standalone server or a server cluster consisting of multiple servers.

[0059] In one exemplary embodiment, such as Figure 2 As shown, a road slope estimation method is provided, which can be applied to... Figure 1 Taking terminal 102 as an example, the explanation includes the following steps:

[0060] S202: Obtain the first slope estimate based on the vehicle's tire pressure information.

[0061] Tire pressure information refers to the internal air pressure value of the tires.

[0062] Optionally, after the vehicle is powered on, the terminal first obtains the tire pressure information of each tire through the tire pressure sensor installed on each tire.

[0063] Since the center of gravity of a vehicle will shift to different degrees when it is on different slopes, which will have different effects on the tire pressure of the front axle and the tire pressure of the rear axle, the first slope estimate can be obtained based on the tire pressure of the front axle and the tire pressure of the rear axle.

[0064] In one alternative implementation, a first slope estimate can be obtained based on the change in front axle tire pressure relative to an initial tire pressure setting and the change in rear axle tire pressure relative to the initial tire pressure setting.

[0065] S204: Obtain a second slope estimate based on the vehicle's first and second accelerations; the first acceleration is obtained through an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's speed.

[0066] The directions of the first and second accelerations are aligned with the longitudinal direction of the vehicle.

[0067] Optionally, in addition to obtaining the first slope estimate, the terminal obtains the first acceleration through an acceleration sensor and the vehicle's speed from the CAN bus. Based on the first derivative of the speed, the second acceleration is obtained. Then, based on the first acceleration, the second acceleration, and gravitational acceleration, the second slope estimate is obtained.

[0068] S206: Based on the driving speed, the first acceleration, and the second acceleration, obtain the first weighting coefficient corresponding to the first slope estimate, and determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0069] Optionally, after obtaining the first slope estimate and the second slope estimate, the terminal determines the current operating condition of the vehicle based on the driving speed, the first acceleration and the second acceleration, and obtains the first weighting coefficient corresponding to the first slope estimate according to the weighting coefficient determination method corresponding to different operating conditions.

[0070] Then, based on the first weighting coefficient, the second weighting coefficient corresponding to the second slope estimate is determined. The specific calculation method is as follows:

[0071] k2 = 1 - k1

[0072] Where k1 represents the first weighting coefficient and k2 represents the second weighting coefficient.

[0073] S208: Based on the first weighting coefficient and the second weighting coefficient, the first slope estimate and the second slope estimate are weighted and summed to obtain the target slope estimate.

[0074] Optionally, after determining the first weighting coefficient and the second weighting coefficient, the terminal performs a weighted summation of the first slope estimate and the second slope estimate based on the first weighting coefficient and the second weighting coefficient to obtain the target slope estimate. The specific calculation method is as follows:

[0075]

[0076] Where θ1 represents the first slope estimate and θ2 represents the second slope estimate. This represents the estimated target slope.

[0077] In the aforementioned road slope estimation method, a first slope estimate is obtained based on the vehicle's tire pressure information, and a second slope estimate is obtained based on the vehicle's first and second accelerations. Then, a first weighting coefficient corresponding to the first slope estimate is obtained based on the driving speed, the first acceleration, and the second acceleration. Based on the first weighting coefficient, a second weighting coefficient corresponding to the second slope estimate is determined. Finally, the first and second slope estimates are weighted and summed based on the first and second weighting coefficients to obtain the target slope estimate. In this way, road slope estimation can be completed with fewer sensor parameters, thereby improving the accuracy of road slope estimation.

[0078] In one embodiment, obtaining a first slope estimate based on the vehicle's tire pressure information includes: obtaining the average tire pressure of the front axle tires and the average tire pressure of the rear axle tires; using the product of a third weighting coefficient and the average tire pressure of the front axle tires as a first weighted tire pressure; the third weighting coefficient is determined based on the load ratio of the front axle tires; using the product of a fourth weighting coefficient and the average tire pressure of the rear axle tires as a second weighted tire pressure; the fourth weighting coefficient is determined based on the load ratio of the rear axle tires; using the ratio of the first weighted tire pressure and the second weighted tire pressure as a target pressure ratio; and obtaining the first slope estimate based on the target pressure ratio and a preset slope function.

[0079] The front and rear axles can be set according to the vehicle type. For example, for a three-axle vehicle, the axle closest to the front of the vehicle can be used as the front axle, and the other two axles can be used as the rear axles.

[0080] Taking a two-axle vehicle as an example, the axle closest to the front of the vehicle is designated as the front axle, and the other axle as the rear axle. Each axle is connected to two wheels. In obtaining the target pressure ratio, the terminal first calculates the average tire pressure of the front axle and the average tire pressure of the rear axle. The specific calculation method is as follows:

[0081]

[0082]

[0083] Where, p 11This indicates the tire pressure of the left front axle, p. 12 This indicates the tire pressure of the right-hand vehicle on the front axle, p1 represents the average tire pressure on the front axle, p 21 p represents the tire pressure of the left rear axle. 22 p1 indicates the tire pressure of the right-hand vehicle on the rear axle, and p2 indicates the average tire pressure on the rear axle.

[0084] Then, considering that some vehicles may use different models of wheels on the front and rear axles, and that the tire pressure of different models of wheels varies under different slopes, after obtaining the average tire pressure of the front axle and the average tire pressure of the rear axle, the terminal obtains the third weighting coefficient corresponding to the front axle tires and the fourth weighting coefficient corresponding to the rear axle tires according to the pre-set mapping relationship between the wheel load ratio and the weighting coefficient. The weighting is used to reduce the impact of different tire models on slope estimation.

[0085] Then, the terminal obtains the target pressure ratio based on the average tire pressure of the front axle, the average tire pressure of the rear axle, the third weighting coefficient, and the fourth weighting coefficient. The specific calculation method is as follows:

[0086] p3 = k3 × p1

[0087] p4 = k4 × p2

[0088]

[0089] Where k3 represents the third weighting coefficient, p3 represents the first weighted tire pressure, k4 represents the fourth weighting coefficient, p4 represents the second weighted tire pressure, and P represents the target pressure ratio.

[0090] After determining the target pressure ratio, the terminal obtains the first slope estimate based on the target pressure ratio and the preset slope function.

[0091] In this embodiment, the average front axle tire pressure and the average rear axle tire pressure are weighted separately, and the first slope estimate is obtained based on the weighted average front axle tire pressure and the average rear axle tire pressure. This can better measure the impact of slope on vehicle tire pressure, thereby improving the accuracy of the slope estimate.

[0092] In one embodiment, the slope function is constructed by: obtaining multiple slope test values ​​based on a preset slope range and slope step value; obtaining the test pressure ratio of the vehicle at each slope test value; and constructing the slope function based on each slope test value and the test pressure ratio corresponding to each slope test value.

[0093] Optionally, during the construction of the slope function, the terminal first obtains multiple slope test values ​​based on a preset slope range and slope step value. For example, if the slope range is [-10%, 10%] and the slope step value is 1%, the corresponding slope test values ​​are -10%, -9%, -8%, etc., and so on. A negative slope value indicates a downhill slope, and a positive slope value indicates an uphill slope.

[0094] Then, the test pressure ratio corresponding to the vehicle under different slope test values ​​in the test environment is obtained. The method of obtaining the test pressure ratio is the same as that of obtaining the target pressure ratio, and will not be repeated here.

[0095] Then, the terminal takes the slope test value as input and the test pressure ratio corresponding to the slope test value as output, and performs function fitting to obtain the constructed slope function θ1=f(P). The fitting method can be piecewise linear fitting, or linear fitting based on the least squares method, etc., without specific limitations here.

[0096] The constructed slope function can be randomly tested on slopes outside the preset slope range. When the measurement error meets a certain range, the final slope function is obtained; otherwise, more data sets are obtained to update the slope function.

[0097] In this embodiment, multiple slope test values ​​are obtained based on a preset slope range and slope step value, and the test pressure ratio of the vehicle at each slope test value is obtained. Then, based on each slope test value and the test pressure ratio corresponding to each slope test value, a slope function is constructed. A better slope function can be determined based on the measured data to estimate the slope value, thereby improving the accuracy of the slope estimate.

[0098] In one embodiment, obtaining a second slope estimate based on a first acceleration and a second acceleration of the vehicle includes: obtaining the difference between the first acceleration and the second acceleration as an intermediate acceleration; obtaining an initial slope estimate based on the ratio of the intermediate acceleration to the gravitational acceleration; and filtering the initial slope estimate using a low-pass filter to obtain the second slope estimate.

[0099] Optionally, after obtaining the first and second accelerations, the terminal substitutes these accelerations into the vehicle's longitudinal kinematics model to calculate the initial slope estimate. The specific calculation method is as follows:

[0100]

[0101] Among them, a senx Let a represent the first acceleration. x The second acceleration is represented by g, which represents the acceleration due to gravity, and θ is the acceleration due to gravity. init This represents the initial slope estimate.

[0102] In one alternative implementation, considering that road gradients are typically small, the calculation of the initial gradient estimate can be simplified as follows:

[0103]

[0104] After obtaining the initial slope estimate, considering that sensors such as accelerometers and velocity sensors are easily affected by environmental noise during data acquisition, resulting in high-frequency noise in the initial slope estimate, a low-pass filter is used to filter the initial slope estimate to obtain the second slope estimate. The low-pass filter formula is shown below:

[0105] x(k)=(1-α)θ init (k)+αx(k-1)

[0106] Where x(k-1) represents the output of the (k-1)th low-pass filter, α represents the filter coefficient, and θ init (k) represents the current sampled value of the initial slope estimate, and x(k) represents the output of the k-th low-pass filter.

[0107] In this embodiment, the difference between the first acceleration and the second acceleration is first obtained as the intermediate acceleration, and the initial slope estimate is obtained based on the ratio of the intermediate acceleration to the gravitational acceleration. Then, the initial slope estimate is filtered by a low-pass filter to obtain the second slope estimate. In this way, the calculation of the second slope estimate can be completed with fewer sensor parameters and the influence of noise is reduced, thereby improving the accuracy of the slope estimate.

[0108] In one embodiment, obtaining a first weighting coefficient corresponding to a first slope estimate based on the driving speed, a first acceleration, and a second acceleration includes: obtaining a first weighting coefficient based on the driving speed and a preset first weighting function when the driving speed is less than a speed threshold; obtaining a first weighting coefficient based on the target acceleration and a preset second weighting function when the driving speed is not less than a speed threshold and the target acceleration is greater than an acceleration threshold; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration; and the first weighting coefficient is zero when the driving speed is not less than a speed threshold and the target acceleration is not greater than an acceleration threshold.

[0109] Optionally, after obtaining the first and second slope estimates, the terminal first determines the relationship between the vehicle's speed and the speed threshold.

[0110] When the driving speed is less than a speed threshold, the terminal obtains a first weighting coefficient based on the driving speed and a preset first weighting function. In the first weighting function, k1 > 0.5 and k1 gradually approaches 1 as the driving speed decreases; when the driving speed is 0, k1 = 1. This allows for slope estimation even when the vehicle is stationary, broadening its applicability.

[0111] If the driving speed is greater than the speed threshold, the terminal continues to determine the absolute value of the difference between the first acceleration and the second acceleration, i.e. the target acceleration, and the relationship between the two acceleration thresholds.

[0112] When the driving speed is not less than the speed threshold and the target acceleration is greater than the acceleration threshold, considering that the second slope estimate may have a large error due to special road conditions, such as bumpy roads, the terminal obtains the first weighting coefficient based on the target acceleration and the preset second weighting function. In the second weighting function, k1 gradually approaches 0 as the target acceleration decreases.

[0113] When the driving speed is not less than the speed threshold and the target acceleration is not greater than the acceleration threshold, the first weighting coefficient is zero.

[0114] The details are as follows:

[0115]

[0116] Where f(v) represents the first weighting function, f(|a senx -a x |) represents the second weighting function, v ref Indicates the speed threshold, a ref This indicates the acceleration threshold.

[0117] In this embodiment, by determining the corresponding weighting coefficient of the slope estimate based on the different driving states of the vehicle, the target slope estimate can be determined by combining the first slope estimate and the second slope estimate based on the driving state of the vehicle, thereby improving the accuracy of the slope estimate.

[0118] In one embodiment, such as Figure 3 As shown, a road slope estimation method is provided, which includes the following steps:

[0119] S302: Obtain the average tire pressure of the front axle tires and the average tire pressure of the rear axle tires of the vehicle; multiply the third weighting coefficient and the average tire pressure of the front axle tires as the first weighted tire pressure; the third weighting coefficient is determined based on the load ratio of the front axle tires; multiply the fourth weighting coefficient and the average tire pressure of the rear axle tires as the second weighted tire pressure; the fourth weighting coefficient is determined based on the load ratio of the rear axle tires; the ratio of the first weighted tire pressure and the second weighted tire pressure is taken as the target pressure ratio; obtain the first slope estimate based on the target pressure ratio and the preset slope function.

[0120] S304: Obtain the difference between the first acceleration and the second acceleration as the intermediate acceleration; obtain the initial slope estimate based on the ratio of the intermediate acceleration to the gravitational acceleration; filter the initial slope estimate using a low-pass filter to obtain the second slope estimate.

[0121] S306: When the driving speed is less than the speed threshold, a first weighting coefficient is obtained based on the driving speed and a preset first weighting function; when the driving speed is not less than the speed threshold and the target acceleration is greater than the acceleration threshold, a first weighting coefficient is obtained based on the target acceleration and a preset second weighting function; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration; when the driving speed is not less than the speed threshold and the target acceleration is not greater than the acceleration threshold, the first weighting coefficient is zero.

[0122] S308: Determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0123] S310: Based on the first weighting coefficient and the second weighting coefficient, the first slope estimate and the second slope estimate are weighted and summed to obtain the target slope estimate.

[0124] The slope function is constructed by: obtaining multiple slope test values ​​based on a preset slope range and slope step value; obtaining the test pressure ratio of the vehicle at each slope test value; and performing linear fitting on each slope test value and the corresponding test pressure ratio using the least squares method to obtain the slope function.

[0125] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0126] Based on the same inventive concept, this application also provides a road slope estimation device for implementing the road slope estimation method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations of one or more road slope estimation device embodiments provided below can be found in the limitations of the road slope estimation method described above, and will not be repeated here.

[0127] In one exemplary embodiment, such as Figure 4 As shown, a road slope estimation device is provided, including: a first estimation module 410, a second estimation module 420, an acquisition module 430, and a weighting module 440, wherein:

[0128] The first estimation module 410 is used to obtain a first slope estimate based on the vehicle's tire pressure information.

[0129] The second estimation module 420 is used to obtain a second slope estimate based on the first acceleration and the second acceleration of the vehicle; the first acceleration is obtained by an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's travel speed.

[0130] The acquisition module 430 is used to acquire the first weighting coefficient corresponding to the first slope estimate based on the driving speed, the first acceleration, and the second acceleration, and to determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient.

[0131] The weighting module 440 is used to perform a weighted summation of the first slope estimate and the second slope estimate based on the first weighting coefficient and the second weighting coefficient to obtain the target slope estimate.

[0132] In one embodiment, the first estimation module 410 is further configured to obtain the average tire pressure of the front axle tires and the average tire pressure of the rear axle tires; multiply the third weighting coefficient and the average tire pressure of the front axle tires as the first weighted tire pressure; the third weighting coefficient is determined based on the load ratio of the front axle tires; multiply the fourth weighting coefficient and the average tire pressure of the rear axle tires as the second weighted tire pressure; the fourth weighting coefficient is determined based on the load ratio of the rear axle tires; the ratio of the first weighted tire pressure and the second weighted tire pressure is used as the target pressure ratio; and obtain a first slope estimate based on the target pressure ratio and a preset slope function.

[0133] In one embodiment, the first estimation module 410 is further configured to obtain multiple slope test values ​​based on a preset slope range and slope step value; obtain the test pressure ratio of the vehicle at each slope test value; and construct a slope function based on each slope test value and the test pressure ratio corresponding to each slope test value.

[0134] In one embodiment, the first estimation module 410 is further configured to perform linear fitting on each slope test value and the test pressure ratio corresponding to each slope test value according to the least squares method to obtain the slope function.

[0135] In one embodiment, the second estimation module 420 is further configured to obtain the difference between the first acceleration and the second acceleration as an intermediate acceleration; obtain an initial slope estimate based on the ratio of the intermediate acceleration to the gravitational acceleration; and filter the initial slope estimate using a low-pass filter to obtain a second slope estimate.

[0136] In one embodiment, the acquisition module 430 is further configured to: when the driving speed is less than a speed threshold, acquire a first weighting coefficient based on the driving speed and a preset first weighting function; when the driving speed is not less than a speed threshold and the target acceleration is greater than an acceleration threshold, acquire a first weighting coefficient based on the target acceleration and a preset second weighting function; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration; when the driving speed is not less than a speed threshold and the target acceleration is not greater than an acceleration threshold, the first weighting coefficient is zero.

[0137] The modules in the aforementioned road slope estimation device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0138] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 5As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a road slope estimation method. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0139] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0140] In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps: obtaining a first slope estimate based on tire pressure information of a vehicle; obtaining a second slope estimate based on a first acceleration and a second acceleration of the vehicle; the first acceleration is obtained by an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's driving speed; obtaining a first weighting coefficient corresponding to the first slope estimate based on the driving speed, the first acceleration, and the second acceleration, and determining a second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient; and performing a weighted summation of the first slope estimate and the second slope estimate based on the first weighting coefficient and the second weighting coefficient to obtain a target slope estimate.

[0141] In one embodiment, when the processor executes the computer program, it further performs the following steps: obtaining the average tire pressure of the front axle tires and the average tire pressure of the rear axle tires of the vehicle; multiplying a third weighting coefficient and the average tire pressure of the front axle tires as a first weighted tire pressure; the third weighting coefficient is determined based on the load ratio of the front axle tires; multiplying a fourth weighting coefficient and the average tire pressure of the rear axle tires as a second weighted tire pressure; the fourth weighting coefficient is determined based on the load ratio of the rear axle tires; the ratio of the first weighted tire pressure and the second weighted tire pressure is used as a target pressure ratio; and obtaining a first slope estimate based on the target pressure ratio and a preset slope function.

[0142] In one embodiment, when the processor executes the computer program, it further performs the following steps: obtaining multiple slope test values ​​based on a preset slope range and slope step value; obtaining the test pressure ratio of the vehicle at each slope test value; and constructing a slope function based on each slope test value and the test pressure ratio corresponding to each slope test value.

[0143] In one embodiment, when the processor executes the computer program, it further performs the following steps: according to the least squares method, it performs linear fitting on each slope test value and the test pressure ratio corresponding to each slope test value to obtain a slope function.

[0144] In one embodiment, when the processor executes the computer program, it further performs the following steps: obtaining the difference between the first acceleration and the second acceleration as an intermediate acceleration; obtaining an initial slope estimate based on the ratio of the intermediate acceleration to the gravitational acceleration; and filtering the initial slope estimate through a low-pass filter to obtain a second slope estimate.

[0145] In one embodiment, when the processor executes the computer program, it further performs the following steps: when the driving speed is less than a speed threshold, obtaining a first weighting coefficient based on the driving speed and a preset first weighting function; when the driving speed is not less than the speed threshold and the target acceleration is greater than the acceleration threshold, obtaining a first weighting coefficient based on the target acceleration and a preset second weighting function; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration; when the driving speed is not less than the speed threshold and the target acceleration is not greater than the acceleration threshold, the first weighting coefficient is zero.

[0146] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, it performs the following steps: obtaining a first slope estimate based on tire pressure information of a vehicle; obtaining a second slope estimate based on a first acceleration and a second acceleration of the vehicle; the first acceleration is obtained by an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's driving speed; obtaining a first weighting coefficient corresponding to the first slope estimate based on the driving speed, the first acceleration, and the second acceleration, and determining a second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient; and performing a weighted summation of the first slope estimate and the second slope estimate based on the first weighting coefficient and the second weighting coefficient to obtain a target slope estimate.

[0147] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the average tire pressure of the front axle tires and the average tire pressure of the rear axle tires of the vehicle; multiplying a third weighting coefficient and the average tire pressure of the front axle tires as a first weighted tire pressure; the third weighting coefficient is determined based on the load ratio of the front axle tires; multiplying a fourth weighting coefficient and the average tire pressure of the rear axle tires as a second weighted tire pressure; the fourth weighting coefficient is determined based on the load ratio of the rear axle tires; the ratio of the first weighted tire pressure and the second weighted tire pressure is used as a target pressure ratio; and obtaining a first slope estimate based on the target pressure ratio and a preset slope function.

[0148] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining multiple slope test values ​​based on a preset slope range and slope step value; obtaining the test pressure ratio of the vehicle at each slope test value; and constructing a slope function based on each slope test value and the test pressure ratio corresponding to each slope test value.

[0149] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: according to the least squares method, it performs linear fitting on each slope test value and the test pressure ratio corresponding to each slope test value to obtain a slope function.

[0150] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the difference between the first acceleration and the second acceleration as an intermediate acceleration; obtaining an initial slope estimate based on the ratio of the intermediate acceleration to the gravitational acceleration; and filtering the initial slope estimate through a low-pass filter to obtain a second slope estimate.

[0151] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: when the driving speed is less than a speed threshold, obtaining a first weighting coefficient based on the driving speed and a preset first weighting function; when the driving speed is not less than the speed threshold and the target acceleration is greater than the acceleration threshold, obtaining a first weighting coefficient based on the target acceleration and a preset second weighting function; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration; when the driving speed is not less than the speed threshold and the target acceleration is not greater than the acceleration threshold, the first weighting coefficient is zero.

[0152] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps:

[0153] Based on the vehicle's tire pressure information, a first slope estimate is obtained; based on the vehicle's first acceleration and second acceleration, a second slope estimate is obtained; the first acceleration is obtained through an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's speed; based on the speed, the first acceleration, and the second acceleration, a first weighting coefficient corresponding to the first slope estimate is obtained, and based on the first weighting coefficient, a second weighting coefficient corresponding to the second slope estimate is determined; based on the first weighting coefficient and the second weighting coefficient, the first slope estimate and the second slope estimate are weighted and summed to obtain the target slope estimate.

[0154] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the average tire pressure of the front axle tires and the average tire pressure of the rear axle tires of the vehicle; multiplying a third weighting coefficient and the average tire pressure of the front axle tires as a first weighted tire pressure; the third weighting coefficient is determined based on the load ratio of the front axle tires; multiplying a fourth weighting coefficient and the average tire pressure of the rear axle tires as a second weighted tire pressure; the fourth weighting coefficient is determined based on the load ratio of the rear axle tires; the ratio of the first weighted tire pressure and the second weighted tire pressure is used as a target pressure ratio; and obtaining a first slope estimate based on the target pressure ratio and a preset slope function.

[0155] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining multiple slope test values ​​based on a preset slope range and slope step value; obtaining the test pressure ratio of the vehicle at each slope test value; and constructing a slope function based on each slope test value and the test pressure ratio corresponding to each slope test value.

[0156] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: according to the least squares method, it performs linear fitting on each slope test value and the test pressure ratio corresponding to each slope test value to obtain a slope function.

[0157] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: obtaining the difference between the first acceleration and the second acceleration as an intermediate acceleration; obtaining an initial slope estimate based on the ratio of the intermediate acceleration to the gravitational acceleration; and filtering the initial slope estimate through a low-pass filter to obtain a second slope estimate.

[0158] In one embodiment, when the computer program is executed by the processor, it further performs the following steps: when the driving speed is less than a speed threshold, obtaining a first weighting coefficient based on the driving speed and a preset first weighting function; when the driving speed is not less than the speed threshold and the target acceleration is greater than the acceleration threshold, obtaining a first weighting coefficient based on the target acceleration and a preset second weighting function; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration; when the driving speed is not less than the speed threshold and the target acceleration is not greater than the acceleration threshold, the first weighting coefficient is zero.

[0159] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0160] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile 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. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0161] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 specification.

[0162] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for estimating road slope, characterized in that, The method includes: Based on the vehicle's tire pressure information, obtain the first slope estimate; A second slope estimate is obtained based on the first acceleration and the second acceleration of the vehicle; the first acceleration is obtained by an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's travel speed. Based on the driving speed, the first acceleration, and the second acceleration, obtain the first weighting coefficient corresponding to the first slope estimate, and determine the second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient. Based on the first weighting coefficient and the second weighting coefficient, the first slope estimate and the second slope estimate are weighted and summed to obtain the target slope estimate; The step of obtaining the first slope estimate based on the vehicle's tire pressure information includes: The average tire pressure of the front axle tires and the average tire pressure of the rear axle tires of the vehicle are obtained using the following formula: in, This indicates the tire pressure of the left front axle. This indicates the tire pressure of the right-hand tire on the front axle. This indicates the average tire pressure on the front axle. This indicates the tire pressure of the left rear axle. This indicates the tire pressure of the right rear axle. Indicates the average tire pressure on the rear axle; The product of the third weighting coefficient and the average tire pressure of the front axle tires is used as the first weighted tire pressure; the third weighting coefficient is determined based on the load-bearing ratio of the front axle tires; the product of the fourth weighting coefficient and the average tire pressure of the rear axle tires is used as the second weighted tire pressure; the fourth weighting coefficient is determined based on the load-bearing ratio of the rear axle tires; the ratio of the first weighted tire pressure to the second weighted tire pressure is used as the target pressure ratio. The formula is as follows: in, This represents the third weighting coefficient. Indicates the first weighted tire pressure. This represents the fourth weighting coefficient. This indicates the second weighted tire pressure. The target pressure ratio is represented; based on the target pressure ratio and a preset slope function, the first slope estimate is obtained; The step of obtaining the second gradient estimate based on the vehicle's first and second accelerations includes: The difference between the first acceleration and the second acceleration is obtained as the intermediate acceleration; based on the ratio of the intermediate acceleration to the gravitational acceleration, the initial slope estimate is obtained, as shown in the following formula: in, Indicates the first acceleration. Indicates the second acceleration. Represents gravitational acceleration. The initial slope estimate is represented by [value]. The second slope estimate is obtained by filtering the initial slope estimate using a low-pass filter. The low-pass filter formula is shown below: in, Indicates the first Output of the second low-pass filter Represents the filter coefficients. This represents the current sample value of the initial slope estimate. Indicates the first The output of the low-pass filter.

2. The method according to claim 1, characterized in that, The slope function is constructed in the following ways: Based on the preset slope range and slope step value, obtain multiple slope test values; Obtain the test pressure ratio of the vehicle under various slope test values; The slope function is constructed based on the test values ​​of each slope and the test pressure ratio corresponding to each slope test value.

3. The method according to claim 2, characterized in that, The step of constructing the slope function based on each slope test value and the corresponding test pressure ratio includes: The slope function is obtained by performing linear fitting on each slope test value and the corresponding test pressure ratio using the least squares method.

4. The method according to claim 1, characterized in that, The step of obtaining the first weighting coefficient corresponding to the first slope estimate based on the driving speed, the first acceleration, and the second acceleration includes: When the driving speed is less than a speed threshold, the first weighting coefficient is obtained based on the driving speed and a preset first weighting function; When the driving speed is not less than the speed threshold and the target acceleration is greater than the acceleration threshold, the first weighting coefficient is obtained according to the target acceleration and a preset second weighting function; the target acceleration is the absolute value of the difference between the first acceleration and the second acceleration. When the driving speed is not less than the speed threshold and the target acceleration is not greater than the acceleration threshold, the first weighting coefficient is zero.

5. A road slope estimation device, characterized in that, The device includes: The first estimation module is used to obtain the first slope estimate based on the vehicle's tire pressure information; The second estimation module is used to obtain a second slope estimate based on the first acceleration and the second acceleration of the vehicle; the first acceleration is obtained by an acceleration sensor installed on the vehicle; the second acceleration is obtained based on the vehicle's travel speed. The acquisition module is used to acquire a first weighting coefficient corresponding to the first slope estimate based on the driving speed, the first acceleration, and the second acceleration, and to determine a second weighting coefficient corresponding to the second slope estimate based on the first weighting coefficient. The weighting module is used to perform a weighted summation of the first slope estimate and the second slope estimate based on the first weighting coefficient and the second weighting coefficient to obtain the target slope estimate. The step of obtaining the first slope estimate based on the vehicle's tire pressure information includes: The average tire pressure of the front axle tires and the average tire pressure of the rear axle tires of the vehicle are obtained using the following formula: in, This indicates the tire pressure of the left front axle. This indicates the tire pressure of the right-hand tire on the front axle. This indicates the average tire pressure on the front axle. This indicates the tire pressure of the left rear axle. This indicates the tire pressure of the right rear axle. Indicates the average tire pressure on the rear axle; The product of the third weighting coefficient and the average tire pressure of the front axle tires is used as the first weighted tire pressure; the third weighting coefficient is determined based on the load-bearing ratio of the front axle tires; the product of the fourth weighting coefficient and the average tire pressure of the rear axle tires is used as the second weighted tire pressure; the fourth weighting coefficient is determined based on the load-bearing ratio of the rear axle tires; the ratio of the first weighted tire pressure to the second weighted tire pressure is used as the target pressure ratio. The formula is as follows: in, This represents the third weighting coefficient. Indicates the first weighted tire pressure. This represents the fourth weighting coefficient. This indicates the second weighted tire pressure. The target pressure ratio is represented; based on the target pressure ratio and a preset slope function, the first slope estimate is obtained; The step of obtaining the second gradient estimate based on the vehicle's first and second accelerations includes: The difference between the first acceleration and the second acceleration is obtained as the intermediate acceleration; based on the ratio of the intermediate acceleration to the gravitational acceleration, the initial slope estimate is obtained, as shown in the following formula: in, Indicates the first acceleration. Indicates the second acceleration. Represents gravitational acceleration. The initial slope estimate is represented by [value]. The second slope estimate is obtained by filtering the initial slope estimate using a low-pass filter. The low-pass filter formula is shown below: in, Indicates the first Output of the second low-pass filter Represents the filter coefficients. This represents the current sample value of the initial slope estimate. Indicates the first The output of the low-pass filter.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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