A method, device, computer device, and storage medium for calculating road slope

Abstract

The present application relates to a road slope calculation method, device, computer device, and storage medium. The method includes obtaining vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction; obtaining the maximum wheel acceleration and the minimum wheel acceleration, and the vehicle acceleration. According to the sensed acceleration and the maximum wheel acceleration, determining the sensed limited state of the vehicle, and determining the original slope value when the vehicle is in the sensed limited state. Based on the original slope value and the first slope output value at the previous moment, obtaining the second slope output value at the current moment by weighting, so as to control the vehicle based on the second slope output value. By using the method of the present application, the problem of inaccurate slope estimation in the prior art can be improved.

Description

Technical Field

[0001] This application relates to the technical field of vehicle control, and particularly to a road slope calculation method, device, computer device, and storage medium. Background Art

[0002] On the basis of ensuring power performance and economic performance, new energy vehicles can adapt to various driving environments. In order to enable them to cope with various working conditions, there are more requirements for the road condition adaptability of new energy vehicles. The main interference factors in the vehicle driving environment include road slope changes, air resistance changes, vehicle mass changes, and so on. Among them, the change of road slope has a particularly obvious impact on the vehicle driving condition.

[0003] Currently, the estimation of the slope signal mainly calculates the component of the vehicle gravity in the slope direction according to the acceleration sensor signal and the acceleration of the vehicle body according to the kinematic model, so as to estimate the slope. This method can achieve good performance when the vehicle is stationary or moving at a constant speed. However, when the vehicle is driving, due to the changing road conditions, the vehicle speed is often affected by the road conditions, which in turn affects the estimation accuracy of the slope. Summary of the Invention

[0004] Based on this, a road slope calculation method, device, computer device, and storage medium are provided to improve the problem of inaccurate slope estimation in the prior art.

[0005] On the one hand, a road slope calculation method is provided, and the method includes:

[0006] Obtain vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction;

[0007] Obtain the maximum wheel acceleration and the minimum wheel acceleration according to the wheel speeds of each wheel, and obtain the vehicle acceleration of the whole vehicle according to the vehicle speed of the whole vehicle;

[0008] Judge the sensed limited state of the vehicle according to the sensed acceleration and the maximum wheel acceleration, including: when the sensed acceleration is greater than zero, and the maximum wheel acceleration is less than or equal to zero, it is determined as the uphill limited state; when the sensed acceleration is less than or equal to zero, and the maximum wheel acceleration is greater than or equal to zero, it is determined as the downhill limited state;

[0009] Determine the original slope value when the vehicle is in a sensing-limited state, including: when in an uphill-limited state, determine the larger value between the first slope value and the second slope value as the original slope value; when in a downhill-limited state, determine the smaller value between the first slope value and the third slope value as the original slope value; wherein, based on the vehicle kinematic model, the first slope value is obtained according to the vehicle acceleration and the sensed acceleration, the second slope value is obtained according to the maximum wheel acceleration and the sensed acceleration, and the third slope value is obtained according to the minimum wheel acceleration and the sensed acceleration;

[0010] Based on the original slope value and the first slope output value at the previous moment, obtain the second slope output value at the current moment by weighting, so as to control the vehicle based on the second slope output value.

[0011] In one embodiment, after determining the sensing-limited state of the vehicle, it further includes:

[0012] When the acceleration sensor is in a normal state, determine the first slope value as the original slope value, so as to obtain the second slope output value by weighting.

[0013] In one embodiment, the obtaining the second slope output value at the current moment by weighting includes:

[0014] Obtain the original slope values at multiple historical moments, and obtain the original slope mean value through mean filtering;

[0015] Based on the original slope mean value and the first slope output value, obtain the second slope output value by weighting.

[0016] In one embodiment, before obtaining the second slope output value at the current moment by weighting, it further includes:

[0017] According to the comparison between the vehicle parameters and the corresponding preset thresholds, judge the driving scenario of the vehicle, and the driving scenario includes a static scenario, a dynamic scenario, and a state transition scenario;

[0018] Determine the weighting coefficient of the first slope output value from a preset first correspondence according to the driving scenario, wherein the weighting coefficient in the static scenario is less than the weighting coefficient corresponding to the dynamic scenario, and the weighting coefficient corresponding to the dynamic scenario is less than the weighting coefficient in the state transition scenario.

[0019] In one embodiment, after judging the driving scenario of the vehicle according to the comparison between the vehicle parameters and the corresponding preset thresholds, it further includes:

[0020] When the driving scenario is a dynamic scenario, determining the sub - state in the dynamic scenario includes: obtaining the slip ratio of each wheel according to the vehicle speed of the whole vehicle and the wheel speeds of each vehicle, and determining the maximum slip ratio; obtaining the acceleration change rate of the vehicle according to the vehicle speed of the whole vehicle;

[0021] Determining the current sub - state according to the maximum slip ratio and / or the acceleration change rate;

[0022] Determining the weighting coefficient of the first slope output value from a preset second correspondence according to the sub - state, wherein in the second correspondence, the weighting coefficient has a positive correlation with both the maximum slip ratio and the acceleration change rate.

[0023] In one embodiment, determining the sub - state in the dynamic scenario according to the maximum slip ratio and / or the acceleration change rate includes:

[0024] Determining whether the current vehicle is in a spinning state or a non - spinning state according to the comparison between the maximum slip ratio and the slip ratio threshold;

[0025] When in the non - spinning state, determining the weighting coefficient from the second correspondence according to the range where the acceleration change rate is located;

[0026] When in the spinning state, determining the weighting coefficient in the spinning state from the second correspondence.

[0027] In one embodiment, before weighting to obtain the second slope output value at the current moment, it includes:

[0028] When in the sensing - limited state, determining the weighting coefficient of the first slope output value according to a preset third correspondence.

[0029] On the other hand, a road slope calculation device is provided, and the device includes:

[0030] An acquisition module, configured to acquire vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction;

[0031] A first calculation module, configured to obtain the maximum wheel acceleration and the minimum wheel acceleration according to the wheel speeds of each wheel, and obtain the vehicle's overall acceleration according to the vehicle speed of the whole vehicle;

[0032] A judgment module, configured to judge the sensed limited state of the vehicle according to the sensed acceleration and the maximum wheel acceleration, including: when the sensed acceleration is greater than zero and the maximum wheel acceleration is less than or equal to zero, it is determined as an uphill limited state; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, it is determined as a downhill limited state;

[0033] A second calculation module, configured to determine the original slope value when the vehicle is in a sensed limited state, including: when in an uphill limited state, determining the larger value of the first slope value and the second slope value as the original slope value; when in a downhill limited state, determining the smaller value of the first slope value and the third slope value as the original slope value; wherein, based on the vehicle kinematic model, the first slope value is obtained according to the vehicle acceleration and the sensed acceleration, the second slope value is obtained according to the maximum wheel acceleration and the sensed acceleration, and the third slope value is obtained according to the minimum wheel acceleration and the sensed acceleration;

[0034] An output module, configured to obtain the second slope output value at the current moment by weighting according to the original slope value and the first slope output value at the previous moment, so as to control the vehicle based on the second slope output value.

[0035] On the other hand, a computer device is provided, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the method are implemented.

[0036] A computer-readable storage medium is also provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method are implemented.

[0037] For the above road slope calculation method, device, computer device and storage medium, according to the sensed acceleration and the maximum wheel acceleration, the sensed limited state of the vehicle is judged. When the sensed acceleration of the sensor is positive but the maximum wheel acceleration is equal to zero or even negative, it is judged that the vehicle is in a special uphill state. At this time, the estimated slope signal value should not be less than the angle value calculated according to the maximum wheel acceleration and the sensed acceleration according to the kinematic model. Therefore, a minimum limit is placed on the original slope value; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, it is judged that the vehicle is in a special downhill state. At this time, the estimated slope signal value should not be greater than the angle value calculated according to the minimum wheel acceleration and the sensed acceleration according to the kinematic model. Therefore, a maximum limit is placed on the original slope value. By adopting the above limit output method, the influence of road conditions on the vehicle is excluded, the slope value is approximated to the true slope, and the accuracy of slope estimation is improved. Description of the Drawings

[0038] Figure 1 is the vehicle kinematic model under ideal conditions;

[0039] Figure 2 is the schematic diagram of the acceleration sensor sensing when the vehicle is going uphill;

[0040] Figure 3 is the schematic flowchart of the road slope calculation method in an embodiment;

[0041] Figure 4 is the structural block diagram of the road slope calculation device in an embodiment;

[0042] Figure 5 is the internal structure diagram of a computer device in an embodiment. Detailed implementation manners

[0043] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0044] The road surface estimation parameters of vehicle movement are the basis of automotive kinematics research. As one of the most important reference input information for functions such as the vehicle's power output and range extension control, the slope signal has a crucial impact on the dynamic and static performance of the vehicle.

[0045] Currently, the estimation of the slope is mainly completed through the relationship between the sensor signal and the vehicle acceleration. For example, Figure 1 in the ideal uphill state (the vehicle is stationary, moving at a constant speed or moving with a constant acceleration) as shown, the vehicle conforms to the following kinematic model:

[0046]

[0047] In the kinematic model, a M is the sensed acceleration of the acceleration sensor in the traveling direction, V is the vehicle speed of the whole vehicle, which is the reference vehicle speed extracted based on the vehicle message information, g is the acceleration due to gravity, is the slope value.

[0048] Based on the kinematic model, the slope value can be calculated.

[0049]

[0050] However, under actual road conditions, the sensed acceleration a M , and the vehicle acceleration V' may both change due to the influence of road conditions, and the change rule is often irregular, resulting in inaccurate estimation of the slope.

[0051] For example Figure 2In the uphill situation shown, the vehicle starts from Figure 2 the horizontal section shown in A and accelerates, and when it converts to Figure 2 the uphill section shown in B, the acceleration sensor can maintain the same performance under the action of the gravity component. The vehicle speed of the whole vehicle should decrease under the influence of the slope, but in actual situations, the vehicle is likely to be affected by factors such as the change of slip ratio, and the decrease amplitude of the vehicle speed of the whole vehicle does not match the ideal state. Therefore, the estimation of the slope is inaccurate.

[0052] The road slope calculation method provided by this application, as Figure 3 shown, includes the following steps:

[0053] Step 101, obtain vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction.

[0054] In the actual implementation process, the vehicle controller monitors information such as the vehicle speed of the whole vehicle, the acceleration measured by the acceleration sensor, and the wheel speeds of each wheel in real time. And it can be understood that both the vehicle speed and the sensed acceleration are positive in the traveling direction of the vehicle.

[0055] Step 102, obtain the maximum wheel acceleration and the minimum wheel acceleration according to the wheel speeds of each wheel, and obtain the vehicle acceleration of the whole vehicle according to the vehicle speed.

[0056] For the four wheels of the vehicle, the acceleration a wl of each wheel can be obtained by taking the derivative of the wheel speed v Wl :

[0057] a wl_i =(v Wl_i )'

[0058] where i represents FL / FR / RL / RR, which are the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel respectively.

[0059] Among them, the maximum wheel acceleration a wl_max is:

[0060]

[0061] The minimum wheel acceleration a wl_min is:

[0062]

[0063] It can be understood that in general, the four-wheel accelerations of the vehicle may be different, but mostly maintain the same acceleration and deceleration.

[0064] Step 103, judge the sensed limited state of the vehicle according to the sensed acceleration and the maximum wheel acceleration.

[0065] The sensed limited state can be understood as Figure 2 the state where it is difficult to accurately estimate the slope based on the output value of the acceleration sensor as shown, specifically including the uphill limited state and the downhill limited state.

[0066] In this embodiment, the uphill limited state can also be called the Min limit state, and the state judgment condition is: the sensed acceleration is greater than zero, and the maximum value of the wheel acceleration is less than or equal to zero.

[0067] When the above Min limit state is satisfied, the wheels are in a decelerating state, but the acceleration measured by the vehicle body due to the slope is still positive, so it can be judged that the vehicle is in a special uphill state.

[0068] In this embodiment, the downhill limited state can also be called the Max limit state, and the state judgment condition is: the sensed acceleration is less than or equal to zero, and the maximum value of the wheel acceleration is greater than or equal to zero.

[0069] Similar to the Min limit state, when the above Max limit state condition is satisfied, the wheels are in an accelerating state, but the acceleration measured by the vehicle body due to the slope is still negative, so it can be judged that the vehicle is in a special downhill state.

[0070] Step 104, determine the original slope value when the vehicle is in the sensed limited state.

[0071] When the vehicle controller monitors that the sensed acceleration is positive and the wheel accelerations are negative or zero for multiple consecutive cycles, it can be judged that the vehicle is going uphill, and then the Min limit state is activated. Specifically, in this embodiment, the maximum value of the wheel acceleration is selected as the characteristic value of the four wheels for calculation to reduce the complexity of judgment.

[0072] In the conventional method, the estimated slope signal value is usually directly obtained based on the vehicle acceleration and the sensed acceleration:

[0073]

[0074] In this embodiment, the slope signal value calculated based on the vehicle acceleration is used as the first slope value. In the Min limit state, the true slope signal value should not be less than the second slope value

[0075]

[0076] Therefore, taking the second slope value as the limiting condition in the Min limit state, that is:

[0077]

[0078] When the vehicle controller monitors that the sensed acceleration is zero or negative, but the acceleration on each wheel remains zero or positive for multiple cycles, it is determined that the vehicle is moving downhill, and the Max limit state is activated. In particular, the maximum value of the wheel acceleration is selected as the characteristic value of the four wheels.

[0079] In the Max limit state, the true slope signal value shall not be greater than the third slope value

[0080]

[0081] Therefore, the third slope value is used as the limit condition in the Max limit state, that is:

[0082]

[0083] Under different limit states, different calculation strategies for the original slope value are adopted.

[0084] In an implementation manner of this embodiment, the above true slope signal value can be uniformly calculated in the following manner:

[0085] Define an intermediate variable

[0086]

[0087] Define the original slope value

[0088]

[0089] The original slope value is the estimated value of the true slope under any limit state. Because it combines the judgment of specific scenarios and limits the estimated limit value of the slope signal based on the limit state, the slope value is approximated to the true slope, improving the accuracy of the estimation.

[0090] In this embodiment, when neither the Min limit state nor the Max limit state is activated, the first slope value can be taken as the original slope value according to the normal state as the original slope value.

[0091] Step 105, update the output value according to the original slope value. Specifically, based on the original slope value and the first slope output value at the previous moment, the second slope output value at the current moment is obtained by weighting, so as to control the vehicle based on the second slope output value.

[0092] It is understandable that the original slope value obtained by the above calculation is the instantaneous value at the current moment. There is a large-scale jump phenomenon, which will make other strategies that need to use the slope signal invalid and produce unexpected results. It is usually necessary to control the output of the slope signal through a filter coefficient. In general, the following weighted calculation is performed based on the credibility of the signal:

[0093]

[0094] in, is the output value at the current moment, is the original slope value at the current moment, is the slope output value at the previous moment, U f It is a weighting coefficient or filtering coefficient, also known as the forgetting factor.

[0095] In some embodiments, the forgetting factor U f It can be predefined according to different scenarios. At present, in order to prevent the slope signal from fluctuating too much, the filter coefficient is often increased to control the large changes in the slope signal output, which also reduces the accuracy of the estimated slope.

[0096] In one embodiment, the output value is updated by first-order mean filtering. Specifically, the original slope values at multiple historical moments are obtained and the original slope mean is obtained by mean filtering. The second slope output value is obtained by weighting the original slope mean and the first slope output value. The mathematical expression is as follows:

[0097]

[0098] in, is the average value of the original slope value in the last n moments.

[0099] By adding the mean filtering method, the fluctuation of the original slope is reduced, and the impact of short-term estimation error on slope estimation is reduced. Compared with directly increasing the forgetting factor U f The estimation is more real-time and the result is more accurate.

[0100] In some embodiments, the weighting coefficient U f Update based on different scenario update strategies.

[0101] For example, according to the scene update strategy, the vehicle driving state is divided into four states: static, static-to-rotating, dynamic, and dynamic-to-static. The slope is dynamically updated based on different vehicle driving states. According to the comparison between the vehicle parameters and the corresponding preset thresholds, it is determined which driving scene the vehicle is in. The four state determination conditions are exemplified as follows:

[0102] (1) Static: The absolute value of the maximum wheel speed is less than the first wheel speed threshold, and the absolute value of the maximum wheel acceleration is less than the wheel acceleration threshold, and the absolute value of the vehicle acceleration is less than the vehicle acceleration threshold.

[0103] (2) From static to rotational: The current vehicle speed is greater than the first vehicle speed threshold, or the maximum wheel speed of the vehicle is greater than the second wheel speed threshold, or the absolute value of the vehicle acceleration change rate is greater than the change rate threshold, or the sum of the motor drive torques is greater than the torque threshold, or the absolute value of the maximum wheel speed change rate of the vehicle is greater than the wheel speed change rate threshold.

[0104] (3) Dynamic: The current vehicle speed is greater than the second vehicle speed threshold.

[0105] (4) From dynamic to static: The current vehicle speed is less than the third vehicle speed threshold.

[0106] It should be noted that the above threshold judgment conditions can be more or less according to the calibration situation, and the values of each threshold can be calibrated according to the actual situation.

[0107] After determining the driving scenario of the vehicle, determine the weighting coefficient of the first slope output value from the preset first correspondence according to the driving scenario.

[0108] Exemplarily illustrate the first correspondence. For the static scenario of the vehicle, that is, when the vehicle is stationary, the credibility of the original slope value is relatively high. Therefore, the weight of the previous moment output value can be appropriately reduced and the weight of the current value can be increased. The weighting coefficient is taken as 0.95, and the output value can be updated quickly.

[0109] For the vehicle in the state transition scenario, that is, in the stage from static to rotational or from dynamic to static, the credibility of the original slope value is very low at this time, and the forgetting factor is taken as 1, that is, the output slope signal is not updated.

[0110] For the dynamic scenario, the value can be taken according to the value between 0.95 and 1.

[0111] Combining the above value-taking methods, when defining the first correspondence, the weighting coefficient in the static scenario is taken to be less than the weighting coefficient corresponding to the dynamic scenario, and the weighting coefficient corresponding to the dynamic scenario is taken to be less than the weighting coefficient in the state transition scenario.

[0112] In an implementation manner of the above embodiment, the dynamic scenario can be divided into more sub-states. For example, determine the sub-states in the dynamic scenario according to the maximum value of the slip rate in the wheels and / or the vehicle acceleration change rate.

[0113] The slip rate and the acceleration change rate are used as two judgment dimensions for the sub-states in the dynamic scenario. The specific judgment methods are as follows:

[0114] (1) Judgment based on the slip rate

[0115] In the actual implementation process, according to the vehicle speed of the whole vehicle and the wheel speeds of each vehicle, the slip ratio S of each wheel is obtained according to the following mathematical expression i :

[0116]

[0117] Select the maximum value of the slip ratio as the judgment characteristic parameter. When the maximum value of the slip ratio is greater than the slip ratio threshold (calibration), it is defined that the vehicle is in a slip state, otherwise it is in a non-slip state.

[0118] (2) Judgment based on the acceleration change rate

[0119] Exemplarily, it is described with the acceleration change rate being positive. The first threshold, the second threshold, and the third threshold of the preset acceleration change rate are set to divide the small acceleration change rate interval, the medium acceleration change rate interval, and the large acceleration change rate interval.

[0120] The judgment conditions of the sub-states in the dynamic scenario can be determined based on the foregoing judgment dimensions or combinations of dimensions. Exemplary description:

[0121] The first sub-state: ① Dynamic small acceleration change rate & ② Non-slip state;

[0122] The second sub-state: ① Dynamic medium acceleration change rate & ② Non-slip state;

[0123] The third sub-state: ① Dynamic high acceleration change rate & ② Non-slip state;

[0124] …….

[0125] After determining that the vehicle is in the dynamic scenario, the current sub-state can be determined according to the maximum value of the slip ratio and / or the acceleration change rate.

[0126] A second corresponding relationship can be predefined in advance. In the second corresponding relationship, each sub-state corresponds to a preset weighting coefficient U f , it can be understood that in the second corresponding relationship, the greater the maximum value of the slip ratio and the acceleration change rate, the lower the credibility of the original slope value. Therefore, the weighting coefficient has a positive correlation with both the maximum value of the slip ratio and the acceleration change rate.

[0127] For some specific situations, such as the slip state, it can be considered that the sensing credibility of the vehicle in this state is extremely low, and a relatively high weighting coefficient can be directly defined, and the output value is updated according to an extremely low speed.

[0128] In another embodiment, it is considered that in the sensing limited state, the credibility of the slope signal is very high. A third corresponding relationship can be directly predefined, and the weighting coefficient in the sensing limited state is determined according to a lower preset value, and the slope signal is updated quickly.

[0129] Based on the above different scenarios, the corresponding relationship of the weighting coefficients as shown in Table 1 can be preset.

[0130] Table 1:

[0131]

[0132] By adopting the above scenario-based dynamic update strategy, the efficiency, real-time performance, and accuracy of road slope estimation can be effectively improved.

[0133] It should be understood that although Figure 3 each step in the flowchart of Figure 3 is displayed in sequence according to the indication of the arrow, these steps do not necessarily need to be executed in sequence according to the order indicated by the arrow. Unless otherwise clearly stated in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover,

[0134] In one embodiment, as Figure 4 shown, a road slope calculation device is provided, including: an acquisition module 201, a first calculation module 202, a judgment module 203, a second calculation module 204, and an output module 205, where:

[0135] The acquisition module 201 is configured to acquire vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction;

[0136] The first calculation module 202 is configured to obtain the maximum wheel acceleration and the minimum wheel acceleration according to the wheel speeds of each wheel, and obtain the vehicle acceleration of the whole vehicle according to the vehicle speed of the whole vehicle;

[0137] The judgment module 203 is configured to judge the sensed restricted state of the vehicle according to the sensed acceleration and the maximum wheel acceleration, including: when the sensed acceleration is greater than zero and the maximum wheel acceleration is less than or equal to zero, it is determined as an uphill restricted state; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, it is determined as a downhill restricted state;

[0138] A second calculation module 204 is configured to determine an original slope value when the vehicle is in a sensing-limited state, including: when in an uphill-limited state, determining the larger value of a first slope value and a second slope value as the original slope value; when in a downhill-limited state, determining the smaller value of the first slope value and a third slope value as the original slope value; wherein, based on a vehicle kinematic model, the first slope value is obtained according to the vehicle acceleration and the sensed acceleration, the second slope value is obtained according to the maximum wheel acceleration and the sensed acceleration, and the third slope value is obtained according to the minimum wheel acceleration and the sensed acceleration;

[0139] An output module 205 is configured to obtain a second slope output value at the current moment by weighting based on the original slope value and the first slope output value at the previous moment, so as to control the vehicle based on the second slope output value.

[0140] The above-mentioned road slope calculation device determines the sensing-limited state of the vehicle according to the sensed acceleration and the maximum wheel acceleration. When the sensed acceleration of the sensor is positive but the maximum wheel acceleration is equal to or even negative, it is determined that the vehicle is in a special uphill state. At this time, the estimated slope signal value should not be less than the angle value calculated according to the maximum wheel acceleration and the sensed acceleration according to the kinematic model. Therefore, a minimum value limit is imposed on the original slope value; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, it is determined that the vehicle is in a special downhill state. At this time, the estimated slope signal value should not be greater than the angle value calculated according to the minimum wheel acceleration and the sensed acceleration according to the kinematic model. Therefore, a maximum value limit is imposed on the original slope value. By adopting the above-mentioned limit output method, the influence of road conditions on the vehicle is excluded, the slope value is approximated to the true slope, and the accuracy of slope estimation is improved.

[0141] In one embodiment, when the acceleration sensor is in a normal state, the second calculation module 204 can determine the first slope value as the original slope value.

[0142] In some embodiments, the output module 205 calculates the output value by means of mean filtering. Specifically, the output module 205 collects the original slope values at multiple historical moments, and obtains the original slope mean value through mean filtering; and obtains the second slope output value by weighting based on the original slope mean value and the first slope output value.

[0143] In one embodiment, the output module 205 is connected to a scene recognition module. The scene recognition module determines the driving scene of the vehicle according to the comparison between the vehicle parameters and the corresponding preset thresholds, and determines the weighting coefficient of the first slope output value from a preset first correspondence according to the current driving scene.

[0144] When the driving scenario is a dynamic scenario, the scenario recognition module is further configured to determine the sub-state in the current dynamic scenario. Specifically, the current sub-state is determined according to the maximum slip ratio and / or the acceleration change rate.

[0145] After determining the current sub-state, the scenario recognition module determines the weighting coefficient of the first slope output value from a preset second correspondence.

[0146] In one embodiment, the scenario recognition module determines whether the current vehicle is in a spinning state or a non-spinning state according to the comparison between the maximum slip ratio and the slip ratio threshold; when in the non-spinning state, the weighting coefficient is determined from the second correspondence according to the range of the acceleration change rate; when in the spinning state, the weighting coefficient in the spinning state is determined from the second correspondence.

[0147] Generally, when the scenario recognition module recognizes that the current state is a sensing-limited state, the weighting coefficient of the first slope output value is determined according to a preset third correspondence.

[0148] For the specific limitation of the road slope calculation device, reference can be made to the limitation of the road slope calculation method in the above text, which will not be elaborated here. Each module in the above road slope calculation device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0149] In one embodiment, a computer device is provided. The computer device can be a terminal, and its internal structure diagram can be as Figure 5 shown. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. The computer program, when executed by the processor, implements a road slope calculation method. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covered on the display screen, or a button, a trackball, or a touchpad set on the housing of the computer device, or an external keyboard, a touchpad, or a mouse, etc.

[0150] Those skilled in the art can understand, Figure 5The structure shown is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0151] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented:

[0152] Obtain vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction;

[0153] According to the wheel speeds of each wheel, obtain the maximum wheel acceleration and the minimum wheel acceleration, and obtain the vehicle acceleration of the whole vehicle according to the vehicle speed of the whole vehicle;

[0154] Judge the sensed restricted state of the vehicle according to the sensed acceleration and the maximum wheel acceleration, including: when the sensed acceleration is greater than zero and the maximum wheel acceleration is less than or equal to zero, it is determined as an uphill restricted state; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, it is determined as a downhill restricted state;

[0155] Determine the original slope value when the vehicle is in the sensed restricted state, including: when in the uphill restricted state, determine the larger value of the first slope value and the second slope value as the original slope value; when in the downhill restricted state, determine the smaller value of the first slope value and the third slope value as the original slope value; where, based on the vehicle kinematic model, the first slope value is obtained according to the vehicle acceleration and the sensed acceleration, the second slope value is obtained according to the maximum wheel acceleration and the sensed acceleration, and the third slope value is obtained according to the minimum wheel acceleration and the sensed acceleration;

[0156] Weight the original slope value and the first slope output value at the previous moment to obtain the second slope output value at the current moment, so as to control the vehicle based on the second slope output value.

[0157] In one embodiment, when the processor executes the computer program, the following steps are also implemented:

[0158] Obtain the original slope values at multiple historical moments, and obtain the original slope mean through mean filtering;

[0159] Weight the original slope mean and the first slope output value to obtain the second slope output value.

[0160] In one embodiment, when the processor executes the computer program, the following steps are further implemented:

[0161] Based on the comparison between the vehicle parameters and the corresponding preset thresholds, determine the driving scenario of the vehicle, where the driving scenario includes a static scenario, a dynamic scenario, and a state transition scenario;

[0162] Determine the weighting coefficient of the first slope output value from a preset first correspondence, where the weighting coefficient in the static scenario is less than the weighting coefficient corresponding to the dynamic scenario, and the weighting coefficient corresponding to the dynamic scenario is less than the weighting coefficient in the state transition scenario.

[0163] In one embodiment, when the processor executes the computer program, the following steps are further implemented:

[0164] When the driving scenario is a dynamic scenario, determine the sub - state in the dynamic scenario, including: obtaining the slip ratio of each wheel based on the vehicle speed of the whole vehicle and the wheel speeds of each vehicle, and determining the maximum slip ratio; obtaining the acceleration change rate of the vehicle based on the vehicle speed of the whole vehicle;

[0165] Determine the current sub - state based on the maximum slip ratio and / or the acceleration change rate;

[0166] Determine the weighting coefficient of the first slope output value from a preset second correspondence, where in the second correspondence, the weighting coefficient has a positive correlation with both the maximum slip ratio and the acceleration change rate.

[0167] 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, the following steps are implemented:

[0168] Obtain vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction;

[0169] Based on the wheel speeds of each wheel, obtain the maximum wheel acceleration and the minimum wheel acceleration, and obtain the vehicle's overall acceleration based on the vehicle speed of the whole vehicle;

[0170] Based on the sensed acceleration and the maximum wheel acceleration, judge the sensed limited state of the vehicle, including: when the sensed acceleration is greater than zero and the maximum wheel acceleration is less than or equal to zero, determine it as an uphill limited state; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, determine it as a downhill limited state;

[0171] Determine the original slope value when the vehicle is in a sensing-limited state, including: when in an uphill-limited state, determine the larger value of the first slope value and the second slope value as the original slope value; when in a downhill-limited state, determine the smaller value of the first slope value and the third slope value as the original slope value; wherein, based on the vehicle kinematic model, the first slope value is obtained according to the vehicle acceleration and the sensed acceleration, the second slope value is obtained according to the maximum wheel acceleration and the sensed acceleration, and the third slope value is obtained according to the minimum wheel acceleration and the sensed acceleration;

[0172] Based on the original slope value and the first slope output value at the previous moment, obtain the second slope output value at the current moment by weighting, so as to control the vehicle based on the second slope output value.

[0173] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0174] When the acceleration sensor is in a normal state, determine the first slope value as the original slope value, so as to obtain the second slope output value by weighting.

[0175] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0176] Obtain the original slope values at multiple historical moments, and obtain the original slope mean value through mean filtering;

[0177] Based on the original slope mean value and the first slope output value, obtain the second slope output value by weighting.

[0178] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0179] According to the comparison between the vehicle parameters and the corresponding preset thresholds, determine the driving scenario of the vehicle, and the driving scenario includes a static scenario, a dynamic scenario, and a state transition scenario;

[0180] Determine the weighting coefficient of the first slope output value from a preset first correspondence according to the driving scenario, wherein the weighting coefficient in the static scenario is less than the weighting coefficient corresponding to the dynamic scenario, and the weighting coefficient corresponding to the dynamic scenario is less than the weighting coefficient in the state transition scenario.

[0181] In one embodiment, when the computer program is executed by a processor, the following steps are further implemented:

[0182] When the driving scenario is a dynamic scenario, determining sub-states in the dynamic scenario, including: obtaining the slip ratio of each wheel according to the vehicle speed of the whole vehicle and the wheel speeds of each vehicle, and determining the maximum slip ratio; obtaining the acceleration change rate of the vehicle according to the vehicle speed of the whole vehicle;

[0183] Determining the current sub-state according to the maximum slip ratio and / or the acceleration change rate;

[0184] Determining the weighting coefficient of the first slope output value from a preset second correspondence relationship, wherein in the second correspondence relationship, the weighting coefficient has a positive correlation with both the maximum slip ratio and the acceleration change rate.

[0185] Those of ordinary skill in the art can understand that all or part of the processes of implementing the methods in the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0186] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0187] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A method for calculating road slope, characterized in that, Including: Obtain vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction; Based on the wheel speeds of each wheel, obtain the maximum wheel acceleration and the minimum wheel acceleration, and obtain the vehicle acceleration of the vehicle based on the vehicle speed of the whole vehicle; Based on the sensed acceleration and the maximum wheel acceleration, determine the sensed restricted state of the vehicle, including: when the sensed acceleration is greater than zero and the maximum wheel acceleration is less than or equal to zero, it is determined as the uphill restricted state; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, it is determined as the downhill restricted state; Determine the original slope value when the vehicle is in the sensed restricted state, including: when in the uphill restricted state, determine the larger value of the first slope value and the second slope value as the original slope value; when in the downhill restricted state, determine the smaller value of the first slope value and the third slope value as the original slope value; where, based on the vehicle kinematic model, the first slope value is obtained according to the vehicle acceleration and the sensed acceleration, the second slope value is obtained according to the maximum wheel acceleration and the sensed acceleration, and the third slope value is obtained according to the minimum wheel acceleration and the sensed acceleration; Based on the original slope value and the first slope output value at the previous moment, obtain the second slope output value at the current moment by weighting, so as to control the vehicle based on the second slope output value.

2. The road slope calculation method according to claim 1, wherein After determining the sensed restricted state of the vehicle, it further includes: When the acceleration sensor is in the normal state, determine the first slope value as the original slope value to obtain the second slope output value by weighting.

3. The road slope calculation method according to any one of claims 1-2, characterized in that The obtaining the second slope output value at the current moment by weighting includes: Obtain the original slope values at multiple historical moments, and obtain the original slope mean value through mean filtering; Based on the original slope mean value and the first slope output value, obtain the second slope output value by weighting.

4. The road slope calculation method according to any one of claims 1-2, characterized in that Before obtaining the second slope output value at the current moment by weighting, it further includes: Based on the comparison between the vehicle parameters and the corresponding preset thresholds, determine the driving scenario of the vehicle, and the driving scenario includes a static scenario, a dynamic scenario, and a state transition scenario; Determine the weighting coefficient of the first slope output value from a preset first correspondence according to the driving scenario, where the weighting coefficient in the static scenario is less than the weighting coefficient corresponding to the dynamic scenario, and the weighting coefficient corresponding to the dynamic scenario is less than the weighting coefficient in the state transition scenario.

5. The road slope calculation method according to claim 4, characterized in that After determining the driving scenario of the vehicle based on the comparison between the vehicle parameters and the corresponding preset thresholds, it further includes: When the driving scenario is a dynamic scenario, determine the sub-state in the dynamic scenario, including: obtain the slip rate of each wheel based on the vehicle speed of the whole vehicle and the wheel speeds of each vehicle, and determine the maximum slip rate; obtain the acceleration change rate of the vehicle based on the vehicle speed of the whole vehicle; Determine the current sub-state according to the maximum slip rate and / or the acceleration change rate; Determine a weighting coefficient of the first slope output value from a preset second correspondence according to the sub-state, wherein in the second correspondence, the weighting coefficient has a positive correlation with both the maximum slip ratio and the acceleration change rate.

6. The road slope calculation method according to claim 5, characterized in that, Determine the sub-state in the dynamic scenario according to the maximum slip ratio and / or the acceleration change rate, including: Determine whether the current vehicle is in a spinning state or a non-spinning state according to a comparison between the maximum slip ratio and a slip ratio threshold; When in the non-spinning state, determine the weighting coefficient from the second correspondence according to the range where the acceleration change rate is located; When in the spinning state, determine the weighting coefficient in the spinning state from the second correspondence.

7. The road slope calculation method according to claim 1, characterized in that Before weighting to obtain the second slope output value at the current moment, include: When in the sensing restricted state, determine the weighting coefficient of the first slope output value according to a preset third correspondence.

8. A road slope calculation device, characterized in that, The device includes: An acquisition module, configured to acquire vehicle parameters, where the vehicle parameters at least include the wheel speeds of each wheel, the vehicle speed of the whole vehicle, and the sensed acceleration of the acceleration sensor in the traveling direction; A first calculation module, configured to obtain the maximum wheel acceleration and the minimum wheel acceleration according to the wheel speeds of each wheel, and obtain the vehicle acceleration of the whole vehicle according to the vehicle speed of the whole vehicle; A judgment module, configured to judge the sensing restricted state of the vehicle according to the sensed acceleration and the maximum wheel acceleration, including: when the sensed acceleration is greater than zero and the maximum wheel acceleration is less than or equal to zero, determine it as an uphill restricted state; when the sensed acceleration is less than or equal to zero and the maximum wheel acceleration is greater than or equal to zero, determine it as a downhill restricted state; A second calculation module, configured to determine the original slope value when the vehicle is in the sensing restricted state, including: when in the uphill restricted state, determine the larger value between the first slope value and the second slope value as the original slope value; when in the downhill restricted state, determine the smaller value between the first slope value and the third slope value as the original slope value; wherein, based on the vehicle kinematic model, the first slope value is obtained according to the vehicle acceleration and the sensed acceleration, the second slope value is obtained according to the maximum wheel acceleration and the sensed acceleration, and the third slope value is obtained according to the minimum wheel acceleration and the sensed acceleration; An output module, configured to weight and obtain the second slope output value at the current moment according to the original slope value and the first slope output value at the previous moment, so as to control the vehicle based on the second slope output value.

9. A computer device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, 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 7.

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

Images