CN119953456A

CN119953456A - Zero bias calibration method, device, vehicle, equipment and medium for vehicle steering wheel

Info

Publication number: CN119953456A
Application number: CN202510290309.7A
Authority: CN
Inventors: 张栩源; 王衍林; 周东风; 范春晖; 司祥生
Original assignee: China Railway 19th Bureau Group Beijing Linghang Zhitu Technology Co ltd
Current assignee: China Railway 19th Bureau Group Beijing Linghang Zhitu Technology Co ltd
Priority date: 2025-03-12
Filing date: 2025-03-12
Publication date: 2025-05-09

Abstract

The present application relates to a zero bias calibration method, device, vehicle, equipment and medium for a vehicle steering wheel, and in particular to the technical field of electric power systems. It includes: controlling the vehicle to travel along a calibration map within a preset speed range according to an expected turning angle; collecting the lateral deviation and actual turning angle of the vehicle at different speeds within the preset speed range; calculating the zero bias angle measurement value at different speeds according to the actual turning angle and the expected turning angle; establishing a correlation between the vehicle speed, lateral deviation and zero bias angle based on the preset speed range, lateral deviation and zero bias angle estimation value, and the zero bias angle estimation value is calculated based on the lateral deviation and the route length of the calibration map; determining the target zero bias angle estimation value corresponding to the actual vehicle speed and the actual lateral deviation of the vehicle according to the correlation relationship; filtering and fusing the target zero bias angle estimation value and the zero bias angle measurement value to obtain a zero bias angle calibration value, so as to automatically compensate the zero bias angle calibration value to the issued turning angle to control the wheel steering.

Description

Zero offset calibration method and device for vehicle steering wheel, vehicle, equipment and medium

Technical Field

The application relates to the field of mine automatic driving, in particular to a zero offset calibration method and device for a steering wheel of a vehicle, the vehicle, equipment and medium.

Background

The mine scene is complex, the road is unstructured, and the mine automatic driving is extremely challenged to land. And the installation of the mining transport truck actuating mechanism lacks standardization, zero deviation exists after the steering wheel is installed, and the problem of the actuating mechanism is more serious than that of a passenger car by adopting a direct control front wheel steering mode. When the vehicle is driven automatically, the small steering wheel is in zero offset, so that the vehicle can deviate from a reference line, and the running risk is increased.

At present, the control method for self-adaptive calibration of the zero offset angle is mostly based on a vehicle model in a regular simple road scene, is mainly used for zero offset calibration of a passenger car and a small mining truck steering wheel, and has less research on zero offset calibration of front wheel steering of a large-tonnage mining truck. Meanwhile, due to the fact that mine scenes lack straight-line driving road sections, poor signals affect positioning and the like, the conventional self-calibration algorithm is difficult to apply to mines, and the conventional zero-deflection angle calibration method cannot be suitable for mining trucks under large-tonnage and complex road working conditions.

The stable and accurate tracking planning path is a key index of mine automatic driving, but the zero deflection angle of the mining truck is large and each truck is different, so that the fixed direction deviation exists in the transverse high-accuracy tracking control, and the existing transverse control algorithm cannot be completely corrected. The manual zero offset angle measurement and compensation mode is high in cost, affected by external factors and inaccurate in result. Therefore, a method and system for adaptively calibrating the zero offset angle of a mining truck is needed.

Disclosure of Invention

In order to solve the technical problems or at least partially solve the technical problems, the application provides a zero-offset calibration method, device, vehicle, equipment and medium for a vehicle steering wheel, which can solve the problems that a mine scene is complex, the zero deviation of a mine truck steering wheel is large, the existing zero-offset angle calibration method is difficult to adapt, manual measurement compensation is neither accurate nor expensive, and the high-precision transverse control requirement of the mine truck cannot be met, and realize the self-adaptive calibration of the zero-offset angle of the vehicle.

In order to achieve the above object, the technical solution provided by the embodiments of the present application is as follows:

The application provides a zero offset calibration method of a steering wheel of a vehicle, which comprises the steps of controlling the vehicle to run along a calibration map according to an expected corner within a preset vehicle speed range, collecting transverse deviation and actual corner of the vehicle at different vehicle speeds within the preset vehicle speed range, calculating zero offset angle measurement values at different vehicle speeds according to the actual corner and the expected corner, establishing a correlation among the vehicle speed, the transverse deviation and the zero offset angle based on the preset vehicle speed range, the transverse deviation and the zero offset angle estimation values, calculating the zero offset angle estimation values based on the transverse deviation and the route length of the calibration map, determining a target zero offset angle estimation value corresponding to the actual vehicle speed and the actual transverse deviation of the vehicle according to the correlation, and carrying out filtering fusion on the target zero offset angle estimation value and the zero offset angle measurement value to obtain a zero offset angle calibration value so as to automatically compensate the zero offset angle calibration value to a transmitting corner to control the steering of the wheel.

The method for establishing the correlation among the vehicle speed, the transverse deviation and the zero deflection angle based on the preset vehicle speed range, the transverse deviation and the zero deflection angle estimated value comprises the steps of taking the transverse deviation corresponding to each vehicle speed in the preset vehicle speed range as a row index, taking each vehicle speed as a column index, and establishing a two-dimensional calibration table among the vehicle speed, the transverse deviation and the zero deflection angle.

As an optional implementation manner provided by the embodiment of the application, determining the target zero offset angle estimated value corresponding to the actual speed and the actual lateral deviation of the vehicle according to the correlation comprises the step of inquiring the target zero offset angle estimated value corresponding to the actual speed and the actual lateral deviation from a two-dimensional calibration table.

As an optional implementation manner provided by the embodiment of the application, the method further comprises the step of estimating the target zero offset angle estimated value through linear interpolation if the actual vehicle speed and/or the actual transverse deviation do not exist in the two-dimensional calibration table.

As an alternative implementation manner provided by the embodiment of the application, the method further comprises the steps of judging whether the zero offset angle calibration value is larger than or equal to a first threshold value and smaller than or equal to a second threshold value, taking the first threshold value as a new zero offset angle calibration value if the zero offset angle calibration value is smaller than the first threshold value, and taking the second threshold value as the new zero offset angle calibration value if the zero offset angle calibration value is larger than the second threshold value.

The method for acquiring the transverse deviation and the actual rotation angle of the vehicle at different vehicle speeds in the preset vehicle speed range comprises the steps of acquiring a plurality of transverse deviations and a plurality of actual rotation angles of the vehicle at each vehicle speed in the preset vehicle speed range, taking an average value of the transverse deviations as the transverse deviation corresponding to each vehicle speed, and taking an average value of the actual rotation angles as the actual rotation angle corresponding to each vehicle speed.

In a second aspect, the present application provides a zero offset calibration device for a vehicle steering wheel, the device comprising:

the control module is used for controlling the vehicle to run along the calibration map according to the expected rotation angle within the preset vehicle speed range;

The information acquisition module is used for acquiring the transverse deviation and the actual rotation angle of the vehicle at different speeds within a preset speed range;

The system comprises a data processing module, a zero deflection angle estimation value, a zero deflection angle calibration value, a zero deflection angle calculation module and a zero deflection angle calculation module, wherein the data processing module is used for calculating zero deflection angle measurement values under different vehicle speeds according to an actual rotation angle and an expected rotation angle, establishing a correlation among the vehicle speed, the transverse deviation and the zero deflection angle based on a preset vehicle speed range, a transverse deviation and a zero deflection angle estimation value, calculating the zero deflection angle estimation value based on the transverse deviation and a route length of a calibration map, determining a target zero deflection angle estimation value corresponding to the actual vehicle speed and the actual transverse deviation of the vehicle according to the correlation, and carrying out filtering fusion on the target zero deflection angle estimation value and the zero deflection angle measurement value to obtain the zero deflection angle calibration value so as to automatically compensate the zero deflection angle calibration value to the issuing rotation angle to control the steering of wheels.

In a third aspect, the application provides an electronic device comprising a processor, a memory and a computer program stored on the memory and executable on the processor, the computer program when executed by the processor implementing the zero offset calibration method of a vehicle steering wheel according to the first aspect or any optional implementation thereof.

In a fourth aspect, the present application provides an autonomous vehicle for a mine scenario, comprising:

A travel mechanism configured to drive the vehicle to travel on a mine road;

a steering actuator configured to control steering of the wheels;

the data acquisition device is configured to acquire the transverse deviation and the actual rotation angle of the vehicle at different vehicle speeds within a preset vehicle speed range;

The control unit is configured to control the vehicle to run along a calibration map according to an expected corner in a preset vehicle speed range, calculate zero deflection angle measurement values under different vehicle speeds according to an actual corner and the expected corner, establish a correlation among the vehicle speed, the transverse deviation and the zero deflection angle based on the preset vehicle speed range, the transverse deviation and the zero deflection angle estimation value, calculate the zero deflection angle estimation value based on the transverse deviation and the route length of the calibration map, determine a target zero deflection angle estimation value corresponding to the actual vehicle speed and the actual transverse deviation of the vehicle according to the correlation, filter and fuse the target zero deflection angle estimation value and the zero deflection angle measurement value to obtain a zero deflection angle calibration value, and automatically compensate the zero deflection angle calibration value into a issuing corner to control the steering actuating mechanism.

In a fifth aspect, the present application provides a computer readable storage medium, comprising a computer program stored on the computer readable storage medium, the computer program when executed by a processor implementing the zero offset calibration method for a vehicle steering wheel according to the first aspect or any optional implementation thereof.

In a fifth aspect, the present application provides a computer program product comprising a computer program for causing a computer to carry out the method of zero offset calibration of a vehicle steering wheel according to the first aspect or any one of its alternative embodiments when said computer program is run on the computer.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

The embodiment of the application provides a zero offset calibration method, device, vehicle, equipment and medium for a vehicle steering wheel, wherein the method comprises the steps of firstly controlling the vehicle to run along a calibration map according to an expected corner within a preset vehicle speed range, collecting transverse deviation and actual corner of the vehicle at different vehicle speeds within the preset vehicle speed range, calculating zero offset angle measured values at different vehicle speeds according to the actual corner and the expected corner, calculating the zero offset angle estimated values based on the preset vehicle speed range, the transverse deviation and the zero offset angle estimated values on the basis of the transverse deviation and the path length of the calibration map so as to establish a correlation among the vehicle speed, the transverse deviation and the zero offset angle, determining a target zero offset angle estimated value corresponding to the actual vehicle speed and the actual transverse deviation according to the correlation, and carrying out filtering fusion on the target zero offset angle estimated value and the zero offset angle measured values to obtain the zero offset angle calibrated value so as to automatically compensate the zero offset angle calibrated value to a issuing corner to control the steering of the wheel. The application can comprehensively consider the influence of different vehicle speeds on the zero deflection angle by controlling the vehicle to run in a preset vehicle speed range, collect transverse deviation and actual rotation angle under different vehicle speeds, calculate the zero deflection angle measured value to be more fit with the actual condition, accurately capture the difference of the zero deflection angle under different vehicle speeds, establish the correlation relationship of the vehicle speed, the transverse deviation and the zero deflection angle, determine the target zero deflection angle estimated value from multiple dimensions, filter and fuse the estimated value and the measured value, greatly improve the accuracy of zero deflection angle calibration, realize automatic zero deflection angle calibration, eliminate the need of manual measurement and manual compensation one by one, and greatly reduce the labor cost.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application.

In order to more clearly illustrate the embodiments of the application or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a schematic flow chart of a zero offset calibration method for a vehicle steering wheel according to an embodiment of the present application;

FIG. 2 is a flow chart of the zero offset calibration processing logic according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a zero offset calibration device for a steering wheel of a vehicle according to an embodiment of the present application;

Fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Detailed Description

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the technical terms used in the description of the embodiments or the prior art will be briefly introduced below.

In vehicle design and theory, when the steering system of a mining truck is in perfect calibration, i.e., zero offset angle is zero, the turning angle of the vehicle is achieved according to the designed steering geometry and control logic. For example, according to the ackerman steering principle, when the vehicle turns, the corners of the inner wheels and the outer wheels can accord with a certain geometric relationship, so that all the wheels can do pure rolling around a common instant steering center, stable steering is realized, and tire abrasion and steering resistance are reduced.

If the front wheels have zero yaw angle, it means that the front wheels have a certain yaw angle without the driver actively operating the steering. When the driver operates the steering system to give a steering angle command, the actual front wheel steering angle is the superposition of the command steering angle and the zero offset angle. If the zero offset angle is positive 5 degrees and the driver instructs the front wheel to turn left by 10 degrees, the actual turning angle of the front wheel is left by 15 degrees. This can lead to an unexpected actual steering trajectory of the vehicle, which can lead to early or late steering of the vehicle while turning, affecting turning radius and path accuracy.

For four-wheel steering mining trucks, there is also zero yaw angle for the rear wheels. The zero offset angle of the rear wheels can change the participation degree and the opportunity of the rear wheels in the steering process. Normally, the rear wheel steering angle is determined according to a certain control strategy according to factors such as the running state of the vehicle and the front wheel steering angle. However, if the rear wheel has a zero offset angle, the actual rotation angle of the rear wheel is also the combination of the control command rotation angle and the zero offset angle. For example, when the vehicle is turned at a low speed, the rear wheels and the front wheels should reversely deflect for a certain angle to reduce the turning radius, if the rear wheels have zero deflection angles, the deflection angles of the rear wheels may be inaccurate, so that the posture of the vehicle is unstable when the vehicle is turned, and even the phenomena of tail flicking and the like occur.

The zero deflection angles of the front wheel and the rear wheel are combined together, so that the steering center of the vehicle is offset, and the steering radius is changed. The vehicle may not travel along the intended path, and may deviate from the lane when traveling around a curve, increasing the risk of collision with other objects.

In the field of mine autopilot, on the basis of unstructured roads and more complex driving scenes of mine scenes, great challenges are brought to the implementation of mine autopilot landing. Meanwhile, the fact that the installation of the actuating mechanism of the mining transport truck cannot be standardized as with a passenger car effectively is considered, even most mining truck manufacturers do not support four-wheel positioning, certain errors are unavoidable after the installation of the steering wheel is completed, and the steering wheels provided with different mining cards represent individual zero-deviation differences. In particular, the automatic driving of mining transportation trucks is often laterally controlled to directly control the front wheels for steering, rather than steering through a steering wheel. Therefore, the exposed problems of dead zone, zero offset, response delay and the like of the actuating mechanism are larger than those of the passenger car. In the case of manual driving, the driver corrects the steering wheel by observing the actual running track of the own vehicle to offset the influence of zero offset and the like, but in the case of automatic driving, in a complex road scene such as a mine, even a tiny steering wheel zero offset can cause the vehicle to deviate from the central reference line of the running track when track tracking is performed at a medium and high speed, thereby increasing the running risk of automatic driving.

The current control method for adaptively calibrating the zero offset angle is mostly based on a vehicle kinematics and dynamics model, and the driving road scene of the vehicle is simpler in rule, so that the long straight road scene can be conveniently acquired for self calibration. Moreover, the method is mostly used for calibrating zero offset of steering wheels of passenger cars and small mining vehicles, and less zero offset calibration is involved for controlling steering of large-tonnage mining trucks only by virtue of front wheels. In addition, many online self-calibration methods cannot be well adapted to mining vehicles, and the main reason is that mine scenes cannot be like passenger vehicles, have more straight-line simple driving scenes, whether the vehicles run on straight-line roads for a long time cannot be guaranteed to meet self-calibration conditions, secondly, interference factors caused by inaccurate positioning due to poor mine scene signals are limited, and whether the positioning is inaccurate or the problem that the vehicle driving process deviates from one side of a reference line due to the zero-deviation angle problem cannot be determined. Therefore, the conventional self-calibration algorithm cannot be well reproduced in the mine scene. In addition, the characteristics of irregular and complex driving road scenes and low driving speed of the mining truck are considered, so that a plurality of manufacturers have better control effects for reducing the complexity of a whole vehicle control algorithm, and some control schemes not based on models are adopted. Therefore, the conventional zero offset angle calibration control method cannot be well adapted to zero offset calibration of the mining truck under the working conditions of large tonnage and complex road scenes.

For mine autopilot, it is a very important control performance indicator whether a planned path can be stably and accurately tracked to a specified destination. At present, because the zero deflection angle of the mining transportation truck is larger than that of a passenger car, the size and the direction of the zero deflection angle of each trolley are different, the problem of transverse deviation of a fixed direction can be caused when the transverse high-precision tracking control is realized, and the transverse deviation of the fixed direction generated by the defect cannot be completely corrected through a transverse control algorithm of the self-car. Meanwhile, considering that the zero deflection angle of each trolley is manually measured, and manually compensated to the issuing corner of the transverse control in the form of configuration parameters, the problem caused by the zero deflection angle can be only roughly solved, the method not only consumes large labor cost, but also the measured result of the method is influenced by external objective factors, so that the result is not necessarily accurate. Therefore, how to provide a control method and a system for self-adaptively calibrating a zero offset angle of a mining truck, and automatically compensating to a delivery angle to eliminate the problem caused by zero offset is a great problem which is urgently needed to be solved by algorithm engineering personnel in the field.

In order that the above objects, features and advantages of the application will be more clearly understood, a further description of the application will be made. It should be noted that, without conflict, the embodiments of the present application and features in the embodiments may be combined with each other.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced otherwise than as described herein, and it is apparent that the embodiments in the specification are only some, rather than all, of the embodiments of the present application.

In order to solve some or all of the technical problems in the related art, the embodiment of the application provides a zero offset calibration method, device, vehicle, equipment and medium for a vehicle steering wheel, wherein the method comprises the steps of firstly controlling the vehicle to run along a calibration map according to an expected corner within a preset speed range, collecting lateral deviation and actual corner of the vehicle at different speeds within the preset speed range, calculating zero offset angle measurement values at different speeds according to the actual corner and the expected corner, calculating the zero offset angle estimation values based on the lateral deviation and the path length of the calibration map based on the preset speed range, the lateral deviation and the zero offset angle estimation values, so as to establish a correlation among the speed, the lateral deviation and the zero offset angle, determining a target zero offset angle estimation value corresponding to the actual lateral deviation of the vehicle according to the correlation, and carrying out filtering fusion on the target zero offset angle estimation value and the zero offset angle measurement value to obtain the zero offset angle calibration value, so as to automatically compensate the zero offset angle calibration value to a downlink corner to control the steering of the wheel. Therefore, the application can comprehensively consider the influence of different vehicle speeds on the zero deflection angle by controlling the vehicle to run in the preset vehicle speed range. The transverse deviation and the actual rotation angle are collected under different vehicle speeds, the calculated zero deflection angle measured value is more fit with the actual condition, and the difference of the zero deflection angle under different vehicle speeds can be accurately captured. And the correlation relationship among the vehicle speed, the transverse deviation and the zero offset angle is established, the estimated value of the target zero offset angle is determined from a plurality of dimensions, and then the estimated value and the measured value are filtered and fused, so that the accuracy of zero offset angle calibration is greatly improved. The automatic calibration of the zero offset angle is realized, the manual measurement and the manual compensation are not needed one by one, and the labor cost is greatly reduced.

The zero offset calibration method of the vehicle steering wheel provided by the embodiment of the application can be realized by a zero offset calibration device of the vehicle steering wheel or electronic equipment, wherein the electronic equipment comprises, but is not limited to, a personal computer, a notebook computer, a tablet personal computer, a smart phone and the like. The operating system of the electronic device may include Android (Android), mobile operating system developed by apple corporation (iOS), operating system developed by microsoft corporation of united states (Windows), and so forth, to which embodiments of the application are not limited. The electronic device may operate alone to implement the application, or may access a network and implement the application through interoperation with other computer devices in the network. The network in which the electronic device is located includes, but is not limited to, the internet, a wide area network, a metropolitan area network, a local area network, a virtual private (Virtual Private Network, VPN) network, and the like.

It should be noted that, the protection scope of the zero offset calibration method for the vehicle steering wheel according to the embodiment of the present application is not limited to the execution sequence of the steps listed in the embodiment, and all the schemes implemented by increasing or decreasing the steps and replacing the steps according to the prior art made by the principles of the present application are included in the protection scope of the present application.

As shown in fig. 1, fig. 1 is a flow chart of a zero offset calibration method for a vehicle steering wheel according to an embodiment of the present application, which may be performed by a zero offset calibration device for a vehicle steering wheel, where the device may be implemented by software and/or hardware, and may be generally integrated in an electronic device. The method mainly comprises the following steps S101-S106:

S101, controlling the vehicle to run along a calibration map according to an expected corner within a preset vehicle speed range.

In some embodiments, before executing step S101, a straight line path of a preset length is collected first to generate a calibration map. The preset length may be 100 meters and the straight path does not define the road type.

The control vehicle automatically drives along the calibration map according to the expected rotation angle, and the expected rotation angle can be 0. In the automatic driving mode, the preset vehicle speed range can be 5-30 km/h. Illustratively, the vehicle is controlled to enter the starting point of the straight line path, and the whole process is automatically driven along the calibration map at a speed of 5km/h according to the expected rotation angle, so that the tracking of the straight line path of 100 meters is completed.

S102, collecting the transverse deviation and the actual rotation angle of the vehicle at different speeds within a preset speed range.

And collecting the transverse deviation and the actual rotation angle of the vehicle at different speeds within a preset vehicle speed range. By way of example, the lateral deviations and the actual rotational angles at 5km/h, 10km/h, 15km/h, 20km/h, 25km/h and 30km/h are acquired.

In some embodiments, a plurality of lateral deviations and a plurality of actual corners of the vehicle at each vehicle speed within a preset vehicle speed range are collected. And then taking the average value of the plurality of transverse deviations as the transverse deviation corresponding to each vehicle speed, and taking the average value of the plurality of actual rotation angles as the actual rotation angle corresponding to each vehicle speed.

For example, to ensure data validity, three lateral deviations are collected at each vehicle speed, and an average value of the three lateral deviations is taken as a lateral deviation actually corresponding to the vehicle speed. And acquiring three actual corners under each vehicle speed, and taking the average value of the three actual corners as the actual corner corresponding to the vehicle speed. The actual rotation angle is then subtracted from the desired rotation angle to obtain a zero offset angle measurement.

S103, calculating zero deflection angle measurement values under different vehicle speeds according to the actual rotation angle and the expected rotation angle.

Alternatively, the actual rotation angle is acquired three times per vehicle speed after step S102 is performed. Then, the actual rotation angle is subtracted from the desired rotation angle to obtain a zero offset angle measurement. And taking the average value of three zero offset angle measured values at each vehicle speed as the zero offset angle measured value actually corresponding to the vehicle speed.

And S104, based on a preset vehicle speed range, the transverse deviation and a zero deflection angle estimated value, establishing a correlation among the vehicle speed, the transverse deviation and the zero deflection angle, wherein the zero deflection angle estimated value is calculated based on the transverse deviation and the route length of the calibration map.

Zero offset angle estimate θ is in terms ofCalculated, wherein lat_err represents the lateral deviation of the vehicle from the calibrated map to the end point, and dis represents the path length of the calibrated map, for example 100m. Different transverse deviations can be generated when the vehicle runs along the calibration map under different vehicle speeds, and different zero-deflection angle estimated values can be obtained.

And establishing a correlation among the vehicle speed, the transverse deviation and the zero deflection angle according to different vehicle speeds in a preset vehicle speed range, and the transverse deviation and the zero deflection angle estimated value corresponding to each vehicle speed. In some embodiments, a two-dimensional calibration table among the vehicle speed, the lateral deviation and the zero offset angle is established by taking the lateral deviation corresponding to each vehicle speed in a preset vehicle speed range as a row index and taking each vehicle speed as a column index.

The correlation can be represented by a two-dimensional calibration table, for example, with a transverse deviation of the behavior lat_error_list[21]＝[-2.0,-1.8,-1.6,-1.4,-1.2,-1.0,-0.8,-0.6,-0.4,-0.2,0.0,0.2,0.4,0.6,0.8,1.0,1.2,1.4,1.6,1.8,2.0], units of m, listed as speed_list [7] = [0,5,10,15,20,25,30], in km/h.

The two-dimensional calibration table is shown in table 1 below:

TABLE 1

S105, determining a target zero deflection angle estimated value corresponding to the actual speed and the actual lateral deviation of the vehicle according to the correlation;

In some embodiments, the target zero-offset angle estimated value corresponding to the actual speed and the actual lateral deviation of the vehicle is obtained by inquiring based on the row-column index of the two-dimensional calibration table.

In other embodiments, the target zero offset angle estimate is estimated by linear interpolation when the actual vehicle speed and the actual lateral deviation of the vehicle are not present in the two-dimensional calibration table. Linear interpolation is a method of estimating an unknown data point from known data points.

Optionally, the estimating of the target zero offset angle estimated value through linear interpolation comprises determining an interpolation interval of the actual vehicle speed and/or the actual transverse deviation, calculating a vehicle speed interpolation weight and/or a transverse deviation interpolation weight according to the actual vehicle speed and/or the actual transverse deviation and the distance between the interpolation interval and a corresponding interpolation interval end point, acquiring the target zero offset angle estimated value corresponding to the interpolation interval end point from a two-dimensional calibration table, and calculating the target zero offset angle estimated value corresponding to the actual vehicle speed and the actual transverse deviation based on the target zero offset angle estimated value corresponding to the interpolation interval end point and the vehicle speed interpolation weight and/or the transverse deviation interpolation weight.

Following the previous example, a specific procedure for calculating the target zero offset angle estimate using linear interpolation is described:

Step 201, determining interpolation intervals of vehicle speed and transverse deviation.

Two adjacent vehicle speed values v1 and v2 are found in the vehicle speed list speed_list, so that v1 is less than or equal to v2. For example, the actual speed v of the vehicle is 12km/h, v1=10 km/h, v2=15 km/h in speed_list.

Two adjacent lateral deviation values lat1 and lat2 are found in the lateral deviation list lat_error_list, so that lat1 is less than or equal to lat and less than or equal to lat2. For example, the actual lateral deviation lat is 0.3m, then lat1=0.2 m, lat2=0.4 m.

Step 202, calculating interpolation weights of the vehicle speed and the lateral deviation.

And calculating the weight according to the distance between the vehicle speed and the end point of the interpolation interval. Let w1 be the weight of v relative to v1, w2 be the weight of v relative to v2, w2= (vv1)/(v2v1), w1=1w2. For v=12 km/h, v1=10 km/h, v2=15 km/h, w2= (1210)/(1510) =0.4, w1=10.4=0.6 can be obtained.

Similarly, let u1 be the weight of lat relative to lat1, u2 be the weight of lat relative to lat2, u2= (latlat 1)/(lat 2lat 1), u1=1u2. For lat=0.3m, lat1=0.2 m, lat2=0.4 m, u2= (0.30.2)/(0.40.2) =0.5, u1=10.5=0.5 can be obtained.

Step 203, obtaining a corresponding zero offset angle estimated value.

And determining zero offset angle estimated values corresponding to the four corner points according to the found interpolation intervals of the vehicle speed and the transverse deviation. Let so11 be the zero offset angle estimation value corresponding to v1 and lat1, so12 be the zero offset angle estimation value corresponding to v1 and lat2, so21 be the zero offset angle estimation value corresponding to v2 and lat1, and so22 be the zero offset angle estimation value corresponding to v2 and lat 2. For example, in the zero offset list steer _offset_list, v1=10 km/h, lat1=0.2m corresponds to so11=0.128 degrees, v1=10 km/h, lat2=0.4m corresponds to so12=0.267 degrees, v2=15 km/h, lat1=0.2m corresponds to so21=0.129 degrees, v2=15 km/h, lat2=0.4m corresponds to so22=0.374 degrees.

Step 204, bilinear interpolation calculation is performed.

Firstly, under the condition that the lateral deviation is lat1, interpolating the so11 and the so21 according to the vehicle speed interpolation weight to obtain so_lat1=w1so11+w2so21, and under the condition that the lateral deviation is lat2, interpolating the so12 and the so22 to obtain so_lat2=w1so12+w2so22. For the above example, so_lat1=0.60.128+0.40.129= 0.1284 degrees, so_lat2=0.60.267+0.40.374 = 0.3134 degrees.

And finally, interpolating the so_lat1 and the so_lat2 according to the transverse deviation interpolation weight to obtain a final target zero offset angle estimated value so=u1so_lat1+u2so_lat2. I.e. so=0.50.1284+0.50.3134= 0.2209 degrees.

In other embodiments, polynomial interpolation, spline interpolation, radial basis function interpolation, inverse distance weighted interpolation, etc. may be used to estimate the target zero offset angle estimate when the actual vehicle speed and actual lateral deviation of the vehicle correspond to an absence in the two-dimensional calibration table. The present application is not particularly limited thereto.

S106, filtering and fusing the target zero offset angle estimated value and the zero offset angle measured value to obtain a zero offset angle calibration value, so that the zero offset angle calibration value is automatically compensated to the issuing corner to control the steering of the wheels.

Optionally, the zero offset angle estimated value and the zero offset angle measured value of the target are fused through a Kalman filter to obtain a zero offset angle calibration value. And then the automatic driving system calculates and sends a steering angle instruction to the steering wheel according to the planned path and the zero-offset angle calibration value, and increases or decreases an angle value corresponding to the zero-offset angle calibration value. Therefore, the actual rotation angle of the steering wheel is adjusted due to the compensation value, so that the influence of the zero offset angle on the running path is counteracted, and the vehicle can accurately run according to the planned path.

The calculation formula of the Kalman filter relates to a prediction stage and a correction stage, wherein the prediction stage comprises state estimation value prediction and covariance prediction as shown in formulas (1) and (2), and the correction stage comprises Kalman gain calculation, state optimal estimation value correction and covariance correction as shown in formulas (3) and (4) and (5):

P^- _k＝A×P^- _k-1×A^T+Q(2)

P_k＝(I-K_k×H)×P^- _k(5)

In the formula (1), Is the zero offset angle estimate of the current time k,Is the zero offset angle estimate at the last instant k-1 and a is the state transition matrix. Zero offset angle estimation value passing the last time k-1And state transition matrix A to predict zero offset angle estimation value of current moment k

In formula (2), P ^- _k is the covariance between the zero-offset angle measurement value and the zero-offset angle estimation value at the current time k, P ^- _k-1 is the covariance between the zero-offset angle measurement value and the zero-offset angle estimation value at the previous time k-1, and Q is the process noise matrix, which represents the influence of some uncertainty factors on the covariance. The covariance P ^- _k at the current time is calculated with the covariance P ^- _k-1 between the zero-offset measurement value and the zero-offset estimation value at the previous time and the state transition matrices a and the transpose a ^T of a, plus the process noise matrix Q.

In the formula (3), K _k is Kalman gain, and represents the weight of the zero-offset angle measured value and the zero-offset angle estimated value in the state optimal estimation process. H is a measurement matrix, and R is a measurement noise matrix. The Kalman gain K _k takes into account the covariance P ^- _k obtained in the prediction phase, the measurement matrix H and the measurement noise matrix R. The purpose is to determine how heavy the zero-offset measurement and the zero-offset estimation each take in the final state optimal estimation. If the measured noise is smaller, i.e. the zero-offset angle measured value is more accurate, the weight of the zero-offset angle measured value is larger, otherwise, if the zero-offset angle estimated value is closer to the spectrum, the weight of the zero-offset angle estimated value is larger.

In equation (4), we have a predicted zero offset angle estimateNow, with the zero offset angle measured value z _k (obtained by a two-dimensional linear table look-up method), the zero offset angle estimated value and the zero offset angle measured value are combined by the Kalman gain K _k to obtain the optimal zero offset angle estimated valueIs a zero offset angle measurement value calculated according to the zero offset angle estimation value,The error between the zero offset angle measurement value and the zero offset angle estimation value is multiplied by the Kalman gain K _k, and the zero offset angle estimation value is addedA more accurate optimal zero offset angle estimate is obtained.

In formula (5), I is an identity matrix. Covariance P _k between the zero-offset measurement value and the optimal zero-offset estimation value is calculated from kalman gain K _k, measurement matrix H, and prediction covariance P ^- _k. The unit matrix I minus K _k x H multiplied by P ^- _k is used to update the covariance so that it can more accurately reflect the estimated error conditions that occur.

In some embodiments, after executing step S106, it may further be determined whether the zero-offset angle calibration value is greater than or equal to the first threshold and less than or equal to the second threshold, where the first threshold is used as a new zero-offset angle calibration value if the zero-offset angle calibration value is less than the first threshold, and the second threshold is used as a new zero-offset angle calibration value if the zero-offset angle calibration value is greater than the second threshold.

As shown in fig. 2, fig. 2 is a flow chart of processing logic about zero offset value (steer _offset), which mainly includes the following steps:

step 1, inputting a zero offset angle calibration value steer _offset after filtering fusion;

And 2, judging whether the zero offset angle calibration value steer _offset exceeds a set threshold range [ steer _offset_limit ] or not, and steer _offset_limit ]. The threshold range is defined by a first threshold steer _offset_limit and a second threshold steer _offset_limit.

If "steer _offset" is less than steer _offset_limit, i.e., beyond the left boundary, flow points to the left, outputting steer _offset_limit.

If "steer _offset" is within [ steer _offset_limit, steer _offset_limit ], then "steer _offset" itself is directly output.

When "steer _offset" is greater than steer _offset_limit, i.e., beyond the right boundary, the flow is directed to the right, and steer _offset_limit is output.

In order to avoid abnormality of zero offset angle calibration values obtained by fusion filtering, the zero offset calibration results are unreasonable, so that a mining truck produces adverse effects in an automatic driving process, and further tracking accuracy and safety of the whole truck are affected.

In summary, the embodiment of the application provides a zero offset calibration method of a vehicle steering wheel, which comprises the steps of firstly controlling the vehicle to run along a calibration map according to an expected corner within a preset vehicle speed range, collecting transverse deviation and actual corners of the vehicle at different vehicle speeds within the preset vehicle speed range, calculating zero offset angle measurement values at different vehicle speeds according to the actual corners and the expected corners, calculating the zero offset angle estimation values based on the preset vehicle speed range, the transverse deviation and the zero offset angle estimation values based on the transverse deviation and the path length of the calibration map to establish a correlation among the vehicle speed, the transverse deviation and the zero offset angle, determining a target zero offset angle estimation value corresponding to the actual vehicle speed and the actual transverse deviation according to the correlation, and carrying out filtering fusion on the target zero offset angle estimation value and the zero offset angle measurement value to obtain a zero offset angle calibration value so as to automatically compensate the zero offset angle calibration value to a issued corner to control the steering of the wheel.

Therefore, the application can comprehensively consider the influence of different vehicle speeds on the zero deflection angle by controlling the vehicle to run in the preset vehicle speed range. The traditional method is based on a fixed model, the change of the vehicle speed is not fully considered, and the application collects the transverse deviation and the actual rotation angle under different vehicle speeds, and the calculated zero deflection angle measured value is more fit with the actual situation. For example, in mine transportation, the speed of the vehicle often changes due to different road conditions, and the application can accurately capture the difference of zero deflection angles under different speeds.

The application establishes the correlation between the vehicle speed, the transverse deviation and the zero offset angle, determines the estimated value of the target zero offset angle from a plurality of dimensions, and filters and fuses the estimated value and the measured value, thereby greatly improving the accuracy of zero offset angle calibration. Compared with the method for determining the zero deflection angle in a single mode, the method integrates multiple factors, can effectively reduce the risk of vehicle deviation track caused by inaccurate zero deflection angle, and ensures that the mine automatic driving vehicle runs more stably.

The mine road is complex, the traditional self-calibration method depends on a rule simple road scene, and the method is difficult to apply in mines. The application aims at the operation of the preset vehicle speed range, can adapt to the situation that the vehicle speed is changeable when the mine vehicle runs, and can complete the calibration of the zero offset angle according to different vehicle speeds even under complex road conditions.

The method does not need to rely on a long straight road scene for self-calibration, and is not interfered by inaccurate positioning caused by poor mine signals. Because the zero deflection angle is determined by the self-running data such as the vehicle speed, the transverse deviation and the like instead of simply relying on the positioning data, the method can be better suitable for the complex mine environment and realizes the effective calibration of the zero deflection angle.

In the past, a large amount of manpower is consumed by means of manually measuring zero deflection angle of each trolley and manually compensating to a delivery corner, and the result is affected inaccurately by external factors. The application realizes automatic calibration of zero offset angle without manual measurement and manual compensation, thereby greatly reducing labor cost.

The application automatically compensates the issuing corner, avoids errors possibly occurring in manual operation, ensures the consistency and accuracy of zero-deflection angle compensation of each vehicle, and improves the overall operation efficiency and reliability of the mine automatic driving system.

As shown in fig. 3, fig. 3 is a schematic structural diagram of a zero offset calibration device for a steering wheel of a vehicle according to an embodiment of the present application, where the device includes:

the control module 301 is used for controlling the vehicle to run along the calibration map according to the expected rotation angle within the preset vehicle speed range;

the information acquisition module 302 is used for acquiring the transverse deviation and the actual rotation angle of the vehicle at different vehicle speeds within a preset vehicle speed range;

The data processing module 303 is configured to calculate zero offset angle measurement values under different vehicle speeds according to an actual rotation angle and an expected rotation angle, establish a correlation among the vehicle speed, the lateral deviation and the zero offset angle based on a preset vehicle speed range, a lateral deviation and a zero offset angle estimation value, calculate the zero offset angle estimation value based on the lateral deviation and a path length of a calibration map, determine a target zero offset angle estimation value corresponding to the actual vehicle speed and the actual lateral deviation of the vehicle according to the correlation, and filter and fuse the target zero offset angle estimation value and the zero offset angle measurement value to obtain a zero offset angle calibration value so as to automatically compensate the zero offset angle calibration value to the issued rotation angle to control steering of the wheels.

As an alternative implementation manner provided by the embodiment of the application, the data processing module 303 is used for establishing a correlation among the vehicle speed, the lateral deviation and the zero deflection angle based on a preset vehicle speed range, the lateral deviation and the zero deflection angle estimated value, and is specifically used for establishing a two-dimensional calibration table among the vehicle speed, the lateral deviation and the zero deflection angle by taking the lateral deviation corresponding to each vehicle speed in the preset vehicle speed range as a row index and taking each vehicle speed as a column index.

As an alternative implementation manner provided by the embodiment of the application, the data processing module 303 is used for determining the target zero offset angle estimated value corresponding to the actual speed and the actual lateral deviation of the vehicle according to the correlation, and is specifically used for inquiring and obtaining the target zero offset angle estimated value corresponding to the actual speed and the actual lateral deviation from the two-dimensional calibration table.

As an alternative implementation manner provided by the embodiment of the present application, the data processing module 303 is further configured to estimate the target zero offset angle estimated value by linear interpolation if the actual vehicle speed and/or the actual lateral deviation do not exist in the two-dimensional calibration table.

As an optional implementation manner provided by the embodiment of the application, the device further comprises a verification module, wherein the verification module is used for judging whether the zero offset angle calibration value is larger than or equal to a first threshold value and smaller than or equal to a second threshold value, if the zero offset angle calibration value is smaller than the first threshold value, the first threshold value is used as a new zero offset angle calibration value, and if the zero offset angle calibration value is larger than the second threshold value, the second threshold value is used as a new zero offset angle calibration value.

As an alternative implementation manner provided by the embodiment of the application, the information acquisition module 302 is specifically configured to acquire a plurality of lateral deviations and a plurality of actual corners of the vehicle at each vehicle speed within a preset vehicle speed range, take an average value of the plurality of lateral deviations as a lateral deviation corresponding to each vehicle speed, and take an average value of the plurality of actual corners as an actual corner corresponding to each vehicle speed.

The specific limitation of the zero offset calibration device for the steering wheel of the vehicle can be referred to as the limitation of the zero offset calibration method for the steering wheel of the vehicle, and the description thereof is omitted herein. All or part of the modules in the zero offset calibration device of the vehicle steering wheel can be realized by software, hardware and a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, the present application provides an electronic device, which may be a terminal, and an internal structure diagram thereof may be as shown in fig. 4. The electronic device includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Wherein the processor of the electronic device is configured to provide computing and control capabilities. The memory of the electronic device includes a nonvolatile 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 computer programs in the non-volatile storage media. The communication interface of the electronic device is used for conducting wired or wireless communication with an external terminal, and the wireless communication can be achieved through WIFI, an operator network, near Field Communication (NFC) or other technologies. The computer program is executed by a processor to implement a stuck detection method. The display screen of the electronic equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the electronic equipment can be a touch layer covered on the display screen, can also be keys, a track ball or a touch pad arranged on the shell of the electronic equipment, and can also be an external keyboard, a touch pad or a mouse and the like.

It will be appreciated by those skilled in the art that the structure shown in fig. 4 is merely a block diagram of a portion of the structure associated with the present inventive arrangements and is not limiting of the electronic device to which the present inventive arrangements are applied, and that a particular electronic device may include more or fewer components than shown, or may combine certain components, or have a different arrangement of components.

In one embodiment, the zero offset calibration device for a vehicle steering wheel provided by the application can be implemented in the form of a computer program, and the computer program can be run on an electronic device as shown in fig. 4. The memory of the electronic device may store various program modules constituting the zero offset calibration device of the steering wheel of the vehicle, such as the control module 301, the information acquisition module 302 and the data processing module 303 shown in fig. 3. The computer program of each program module causes the processor to execute the steps in the zero offset calibration method for the vehicle steering wheel according to each embodiment of the present application described in the present specification.

For example, the electronic device shown in fig. 4 may perform control of the vehicle to travel along a calibration map according to an expected corner through a control module 301 in a zero offset calibration device of a steering wheel of the vehicle shown in fig. 3 within a preset vehicle speed range, the electronic device may perform acquisition of a lateral deviation and an actual corner of the vehicle at different vehicle speeds within the preset vehicle speed range through an information acquisition module 302, the electronic device may perform calculation of a zero offset angle measurement value at different vehicle speeds according to the actual corner and the expected corner through a data processing module 303, establish a correlation among the vehicle speed, the lateral deviation and the zero offset angle based on the preset vehicle speed range, the lateral deviation and the zero offset angle estimation value, calculate the zero offset angle estimation value based on the lateral deviation and a route length of the calibration map, determine a target zero offset angle estimation value corresponding to the actual vehicle speed and the actual lateral deviation according to the correlation, and filter and fuse the target zero offset angle estimation value and the zero offset angle measurement value to obtain the zero offset angle calibration value, so as to automatically compensate the zero offset angle calibration value to the issued corner to control the steering wheel.

In one embodiment, the application provides an electronic device comprising a memory storing a computer program and a processor that when executing the computer program performs the steps of:

The method comprises the steps of controlling a vehicle to run along a calibration map according to an expected corner within a preset vehicle speed range, collecting transverse deviation and actual corners of the vehicle at different vehicle speeds within the preset vehicle speed range, calculating zero offset angle measurement values at different vehicle speeds according to the actual corners and the expected corners, establishing a correlation among the vehicle speed, the transverse deviation and the zero offset angle estimation values based on the preset vehicle speed range, the transverse deviation and the zero offset angle estimation values, calculating the zero offset angle estimation values based on the transverse deviation and the route length of the calibration map, determining target zero offset angle estimation values corresponding to the actual vehicle speed and the actual transverse deviation of the vehicle according to the correlation, and carrying out filtering fusion on the target zero offset angle estimation values and the zero offset angle measurement values to obtain zero offset angle calibration values so as to automatically compensate the zero offset angle calibration values to the issuing corners to control wheel steering.

In one embodiment, the processor when executing the computer program further performs the step of establishing a correlation between the vehicle speed, the lateral deviation and the zero offset angle based on a preset vehicle speed range, the lateral deviation and the zero offset angle estimated value, including establishing a two-dimensional calibration table between the vehicle speed, the lateral deviation and the zero offset angle by taking the lateral deviation corresponding to each vehicle speed in the preset vehicle speed range as a row index and taking each vehicle speed as a column index.

In one embodiment, the processor when executing the computer program further performs the step of determining a target zero offset angle estimated value corresponding to the actual vehicle speed and the actual lateral deviation of the vehicle according to the correlation, including querying a two-dimensional calibration table to obtain the target zero offset angle estimated value corresponding to the actual vehicle speed and the actual lateral deviation.

In one embodiment, the processor when executing the computer program further performs the step of estimating the target zero offset angle estimate by linear interpolation if there is no actual vehicle speed and/or actual lateral deviation in the two-dimensional calibration table.

In one embodiment, the computer program is further implemented by the processor, wherein the method further comprises determining whether the zero-offset angle calibration value is greater than or equal to a first threshold value and less than or equal to a second threshold value, using the first threshold value as a new zero-offset angle calibration value if the zero-offset angle calibration value is less than the first threshold value, and using the second threshold value as a new zero-offset angle calibration value if the zero-offset angle calibration value is greater than the second threshold value.

In one embodiment, the processor when executing the computer program further performs the steps of collecting lateral deviations and actual corners of the vehicle at different vehicle speeds within a preset vehicle speed range, including collecting a plurality of lateral deviations and a plurality of actual corners of the vehicle at each vehicle speed within the preset vehicle speed range, taking an average of the plurality of lateral deviations as the lateral deviation corresponding to each vehicle speed, and taking an average of the plurality of actual corners as the actual corners corresponding to each vehicle speed.

When a processor in the electronic equipment executes a computer program, the processor firstly controls a vehicle to run along a calibration map according to an expected corner within a preset vehicle speed range, acquires transverse deviation and actual corner of the vehicle at different vehicle speeds within the preset vehicle speed range, calculates zero deflection angle measurement values at different vehicle speeds according to the actual corner and the expected corner, establishes a correlation among the vehicle speed, the transverse deviation and the zero deflection angle based on the preset vehicle speed range, the transverse deviation and the zero deflection angle estimation values, calculates the zero deflection angle estimation values based on the transverse deviation and the route length of the calibration map, determines a target zero deflection angle estimation value corresponding to the actual vehicle speed and the actual transverse deviation according to the correlation, and carries out filtering fusion on the target zero deflection angle estimation value and the zero deflection angle measurement value to obtain the zero deflection angle calibration value so as to automatically compensate the zero deflection angle calibration value to the issuing corner to control wheel steering. Therefore, the application can comprehensively consider the influence of different vehicle speeds on the zero deflection angle by controlling the vehicle to run in the preset vehicle speed range. The transverse deviation and the actual rotation angle are collected under different vehicle speeds, the calculated zero deflection angle measured value is more fit with the actual condition, and the difference of the zero deflection angle under different vehicle speeds can be accurately captured. And the correlation relationship among the vehicle speed, the transverse deviation and the zero offset angle is established, the estimated value of the target zero offset angle is determined from a plurality of dimensions, and then the estimated value and the measured value are filtered and fused, so that the accuracy of zero offset angle calibration is greatly improved. The automatic calibration of the zero offset angle is realized, the manual measurement and the manual compensation are not needed one by one, and the labor cost is greatly reduced.

The application provides an autonomous vehicle for a mine scenario, comprising:

A travel mechanism configured to drive the vehicle to travel on a mine road;

a steering actuator configured to control steering of the wheels;

In one embodiment, the present application provides a computer readable storage medium having a computer program stored thereon, which when executed by the computer program performs the steps of:

In one embodiment, the computer program further comprises the step of establishing a correlation among the vehicle speed, the lateral deviation and the zero deflection angle based on a preset vehicle speed range, the lateral deviation and the zero deflection angle estimated value, wherein the correlation comprises the steps of establishing a two-dimensional calibration table among the vehicle speed, the lateral deviation and the zero deflection angle by taking the lateral deviation corresponding to each vehicle speed in the preset vehicle speed range as a row index and taking each vehicle speed as a column index.

In one embodiment, the computer program further comprises the step of determining a target zero deflection angle estimated value corresponding to the actual speed and the actual lateral deviation of the vehicle according to the correlation, wherein the target zero deflection angle estimated value corresponding to the actual speed and the actual lateral deviation is obtained by inquiring from a two-dimensional calibration table.

In one embodiment, the computer program when executed further performs the step of estimating the target zero offset angle estimate by linear interpolation if there is no actual vehicle speed and/or actual lateral deviation in the two-dimensional calibration table.

In one embodiment, the computer program further comprises the steps of judging whether the zero offset angle calibration value is larger than or equal to a first threshold value and smaller than or equal to a second threshold value, taking the first threshold value as a new zero offset angle calibration value if the zero offset angle calibration value is smaller than the first threshold value, and taking the second threshold value as the new zero offset angle calibration value if the zero offset angle calibration value is larger than the second threshold value.

In one embodiment, the computer program when executing the computer program further implements the steps of collecting lateral deviations and actual corners of the vehicle at different vehicle speeds within a preset vehicle speed range, including collecting a plurality of lateral deviations and a plurality of actual corners of the vehicle at each vehicle speed within the preset vehicle speed range, taking an average of the plurality of lateral deviations as the lateral deviations corresponding to each vehicle speed, and taking an average of the plurality of actual corners as the actual corners corresponding to each vehicle speed.

When the computer program in the computer readable storage medium provided by the application executes the computer program, firstly, the vehicle is controlled to run along a calibration map according to an expected corner in a preset vehicle speed range, the transverse deviation and the actual corner of the vehicle in different vehicle speeds in the preset vehicle speed range are collected, zero offset angle measurement values in different vehicle speeds are calculated according to the actual corner and the expected corner, the correlation among the vehicle speed, the transverse deviation and the zero offset angle is established based on the preset vehicle speed range, the transverse deviation and the zero offset angle estimation values, the zero offset angle estimation values are calculated based on the transverse deviation and the route length of the calibration map, the actual vehicle speed of the vehicle and the target zero offset angle estimation value corresponding to the actual transverse deviation are determined according to the correlation, and the zero offset angle estimation values and the zero offset angle measurement values are filtered and fused to obtain zero offset angle calibration values, so that the zero offset angle calibration values are automatically compensated to the issuing corners to control the steering of the wheels. Therefore, the application can comprehensively consider the influence of different vehicle speeds on the zero deflection angle by controlling the vehicle to run in the preset vehicle speed range. The transverse deviation and the actual rotation angle are collected under different vehicle speeds, the calculated zero deflection angle measured value is more fit with the actual condition, and the difference of the zero deflection angle under different vehicle speeds can be accurately captured. And the correlation relationship among the vehicle speed, the transverse deviation and the zero offset angle is established, the estimated value of the target zero offset angle is determined from a plurality of dimensions, and then the estimated value and the measured value are filtered and fused, so that the accuracy of zero offset angle calibration is greatly improved. The automatic calibration of the zero offset angle is realized, the manual measurement and the manual compensation are not needed one by one, and the labor cost is greatly reduced.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media having computer-usable program code embodied therein.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The apparatus embodiments described above are merely illustrative, for example, of the flowcharts and block diagrams in the figures that illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In the present application, the Processor may be a central processing unit (Central Processing Unit, CPU), other general purpose Processor, digital signal Processor (DIGITAL SIGNAL Processor, DSP), application SPECIFIC INTEGRATED Circuit (ASIC), off-the-shelf Programmable gate array (Field-Programmable GATE ARRAY, FPGA) or other Programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

In the present application, the memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory in a computer readable medium, such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

In the present application, computer readable media include both permanent and non-permanent, removable and non-removable storage media. Storage media may embody any method or technology for storage of information, which may be computer readable instructions, data structures, program modules, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Disks (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

The foregoing is merely exemplary of embodiments of the present application to enable those skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A zero offset calibration method for a vehicle steering wheel is characterized by comprising the following steps:

controlling the vehicle to run along a calibration map according to the expected rotation angle within a preset vehicle speed range;

Collecting the transverse deviation and the actual rotation angle of the vehicle at different vehicle speeds within the preset vehicle speed range;

According to the actual rotation angle and the expected rotation angle, calculating zero deflection angle measurement values under different vehicle speeds;

based on the preset vehicle speed range, the transverse deviation and the zero offset angle estimated value, establishing a correlation among the vehicle speed, the transverse deviation and the zero offset angle, wherein the zero offset angle estimated value is calculated based on the transverse deviation and the route length of the calibration map;

Determining a target zero offset angle estimated value corresponding to the actual speed and the actual lateral deviation of the vehicle according to the correlation;

And carrying out filtering fusion on the target zero offset angle estimated value and the zero offset angle measured value to obtain a zero offset angle calibration value, so as to automatically compensate the zero offset angle calibration value into a issuing corner and control the steering of the wheels.

2. The method of claim 1, wherein the establishing a correlation between the vehicle speed, the lateral deviation, and the zero offset angle based on the preset vehicle speed range, the lateral deviation, and the zero offset angle estimate comprises:

And taking the transverse deviation corresponding to each vehicle speed in the preset vehicle speed range as a row index, taking each vehicle speed as a column index, and establishing a two-dimensional calibration table among the vehicle speed, the transverse deviation and the zero offset angle.

3. The method according to claim 2, wherein the determining, according to the correlation, a target zero-offset angle estimated value corresponding to an actual vehicle speed and an actual lateral deviation of the vehicle includes:

And inquiring from the two-dimensional calibration table to obtain a target zero deflection angle estimated value corresponding to the actual vehicle speed and the actual transverse deviation.

4. A method according to claim 3, characterized in that the method further comprises:

And if the actual vehicle speed and/or the actual transverse deviation do not exist in the two-dimensional calibration table, estimating the target zero offset angle estimated value through linear interpolation.

5. The method according to claim 1, wherein the method further comprises:

judging whether the zero offset angle calibration value is larger than or equal to a first threshold value and smaller than or equal to a second threshold value;

If the zero offset angle calibration value is smaller than the first threshold value, the first threshold value is used as a new zero offset angle calibration value;

and if the zero offset angle calibration value is larger than the second threshold value, taking the second threshold value as a new zero offset angle calibration value.

6. The method of claim 1, wherein the acquiring the lateral deviation and the actual rotation angle of the vehicle at different vehicle speeds within the preset vehicle speed range comprises:

collecting a plurality of transverse deviations and a plurality of actual corners of the vehicle at each vehicle speed within the preset vehicle speed range;

And taking the average value of the plurality of transverse deviations as the transverse deviation corresponding to each vehicle speed, and taking the average value of the plurality of actual rotation angles as the actual rotation angle corresponding to each vehicle speed.

7. A zero offset calibration device for a vehicle steering wheel, comprising:

The information acquisition module is used for acquiring the transverse deviation and the actual rotation angle of the vehicle at different vehicle speeds within the preset vehicle speed range;

The data processing module is used for calculating zero deflection angle measurement values under different vehicle speeds according to the actual rotation angle and the expected rotation angle, establishing a correlation among the vehicle speed, the transverse deviation and the zero deflection angle based on the preset vehicle speed range, the transverse deviation and the zero deflection angle estimation value, wherein the zero deflection angle estimation value is calculated based on the transverse deviation and the route length of the calibration map, determining a target zero deflection angle estimation value corresponding to the actual vehicle speed and the actual transverse deviation of the vehicle according to the correlation, and carrying out filtering fusion on the target zero deflection angle estimation value and the zero deflection angle measurement value to obtain a zero deflection angle calibration value so as to automatically compensate the zero deflection angle calibration value to the issuing rotation angle to control the steering of the wheels.

8. An autonomous vehicle for a mine scenario, comprising:

A travel mechanism configured to drive the vehicle to travel on a mine road;

a steering actuator configured to control steering of the wheels;

a control unit configured to:

controlling the vehicle to run along a calibration map according to the expected rotation angle within the preset vehicle speed range;

Determining a target zero-offset angle estimated value corresponding to the actual speed of the vehicle and the actual lateral deviation according to the correlation;

And carrying out filtering fusion on the target zero offset angle estimated value and the zero offset angle measured value to obtain a zero offset angle calibration value, so as to automatically compensate the zero offset angle calibration value into a delivery corner, and controlling the steering executing mechanism.

9. An electronic device comprising a processor, a memory and a computer program stored on the memory and executable on the processor, the computer program when executed by the processor implementing a zero offset calibration method for a vehicle steering wheel according to any one of claims 1 to 6.

10. A computer-readable storage medium, comprising a computer program stored on the computer-readable storage medium, wherein the computer program, when executed by a processor, implements the zero offset calibration method for a vehicle steering wheel according to any one of claims 1 to 6.