Online estimation method, system and medium for installation angle error of low-cost embedded integrated navigation system on vehicles

Abstract

The present invention relates to the field of algorithms for estimating the installation angle error of integrated navigation systems, and more specifically, to a method, system, and medium for online estimation of the installation angle error of low-cost embedded integrated navigation systems for vehicles. The method comprises receiving current vehicle navigation data in real time and performing dynamic alignment judgment, and executing either a continued dynamic alignment judgment or integrated navigation attitude convergence based on the judgment result; executing integrated navigation attitude convergence and determining whether the current vehicle is traveling straight, and executing a continued dynamic alignment judgment or saving the integrated navigation data based on the judgment result; and saving the integrated navigation data and utilizing the current vehicle's velocity relationship under the V and B frames to obtain the final estimated pitch and heading angle data of the installation angle error. The method has the advantages of low computational complexity, real-time processing capability, no need for external assistance, embedded application, and low cost, making it suitable for popular in-vehicle navigation and positioning applications.

Description

Technical Field

[0001] The present invention relates to the field of combined navigation installation angle error estimation algorithms, and in particular to a method, system and medium for online estimation of vehicle-mounted low-cost embedded combined navigation installation angle error. Background Art

[0002] With the increasing popularity of vehicles and the development of autonomous driving technology, the demand for accurate vehicle navigation and positioning is increasing. The GNSS / INS / ODO integrated navigation algorithm is currently the most widely used technology in the integrated navigation field. Since there is always a certain degree of directional deviation between the INS and ODO when they are installed, the INS / ODO combination inevitably encounters the problem of installation angle error. Therefore, how to estimate this installation angle error with high precision has become a pressing issue.

[0003] Currently, mainstream installation angle estimation algorithms use post-processing to calculate the installation angle error before running this value in the system. While this method offers high accuracy, it is not suitable for mass adoption. For mass-market in-vehicle navigation and positioning, the installation angle error must be estimated online. Furthermore, these methods often suffer from high computational complexity and the inability to execute in embedded systems. Summary of the Invention

[0004] This paper proposes a practical online installation angle error estimation algorithm. This algorithm boasts low computational effort, real-time processing capability, no external assistance, embedded application, and low cost, making it suitable for popular in-vehicle navigation and positioning applications. While achieving high-precision estimation of the installation angle error, it also performs real-time calculations and processing, eliminating the need for tedious user operations such as calculation and subsequent entry, thus resolving the challenges of difficult and costly operation.

[0005] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0006] A low-cost vehicle-mounted embedded integrated navigation installation angle error online estimation method is characterized by including

[0007] Receive the current vehicle navigation data in real time and perform dynamic alignment judgment, and execute the dynamic alignment judgment or the integrated navigation attitude convergence according to the judgment result;

[0008] Execute the integrated navigation attitude convergence and determine whether the current vehicle is going straight, and execute the continued dynamic alignment or save the integrated navigation data according to the determination result;

[0009] The combined navigation data is saved, and the pitch angle data and heading angle data of the final estimated installation angle error are obtained by using the speed relationship of the current vehicle under the V system and the B system.

[0010] Preferably, including

[0011] Receive GNSS and sensor data;

[0012] Make judgment based on the dynamic alignment judgment conditions;

[0013] If the dynamic alignment judgment condition is met, the dynamic alignment judgment is passed, otherwise the dynamic alignment judgment continues.

[0014] Preferably, the dynamic alignment judgment conditions include:

[0015] Judgment condition 1: whether the current GNSS RTK is a fixed solution;

[0016] Judgment condition two: whether the current inertial navigation has completed initial alignment.

[0017] The condition for passing the dynamic alignment judgment is that both judgment condition 1 and judgment condition 2 are met at the same time.

[0018] Preferably, the integrated navigation data includes a GNSS RTK / INS integrated navigation speed value and an odometer output speed value.

[0019] As a preference, the scale factor k of the odometer in the straight-ahead state is calculated based on the speed of the carrier in the b frame and the speed output by the odometer, and the speed of the odometer in the v frame is obtained based on k. .

[0020] As a preference, according to the speed relationship between the v system and the b system Then, according to the small angle principle, the pitch angle data and heading angle data of the installation angle error are obtained.

[0021] Preferably, including

[0022] Save heading angle data and pitch angle data;

[0023] Delete the maximum and minimum values ​​in the heading angle data and average the remaining heading angle data;

[0024] Delete the maximum and minimum values ​​in the pitch angle data and average the remaining heading angle data;

[0025] The final estimated installation angle error pitch angle data and heading angle data are obtained.

[0026] A low-cost vehicle-mounted embedded integrated navigation installation angle error online estimation system, including

[0027] The first module is configured to receive the current vehicle navigation data in real time and perform dynamic alignment judgment, and to continue the dynamic alignment judgment or perform combined navigation attitude convergence according to the judgment result;

[0028] The second module is configured to execute the integrated navigation posture convergence and determine whether the current vehicle is moving straight, and to execute the continued determination of dynamic alignment or save the integrated navigation data according to the determination result;

[0029] The third module is configured to store the combined navigation data and obtain the pitch angle data and heading angle data of the final estimated installation angle error by using the speed relationship of the current vehicle under the V system and the B system.

[0030] An electronic device, a computer-readable storage medium storing computer-executable instructions; and one or more processors, the one or more processors being coupled to the computer-readable storage medium and configured to execute the computer-executable instructions so that the device performs any of the methods described.

[0031] A readable storage medium stores computer-executable instructions, which, when executed by a processor, configure the processor to perform any one of the methods described above.

[0032] Therefore, the present invention offers the following advantages: low computational complexity, real-time processing, no external assistance, embedded application, and low cost, making it suitable for popular in-vehicle navigation and positioning applications. While achieving high-precision estimation of installation angle error, it also performs real-time calculation and processing, eliminating the need for tedious user operations such as calculation and subsequent entry, thus resolving the issues of difficult and costly operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Attachment Figure 1 It is a schematic flow chart of a method of the present invention. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0035] Example 1:

[0036] According to the first aspect of the present invention, a mathematical model for online estimation of the installation angle error is designed with low computational effort. For vehicle navigation, the installation angle error can be derived using the velocity relationship between the B-axis and the V-axis. Considering the lever arm between the IMU center and the vehicle's right rear wheel contact point, the velocity of the IMU center and the vehicle's non-steering right rear wheel have the following relationship:

[0037]

[0038] According to matrix transformation, the above formula can be rewritten as follows:

[0039]

[0040] From the above formula, we can see that the second term on the right side of the equal sign is the speed generated when the vehicle turns under the b system. In order to reduce and The effect of this item on the estimation of the installation angle error should be ignored. That is,

[0041]

[0042] This means that the vehicle should be moving in a straight line when calculating the installation error. Assuming that the installation angle errors of the IMU are α, β, and γ, which represent the roll angle, pitch angle, and heading angle respectively, the transformation matrix from the b system to the v system is It can be expressed as,

[0043]

[0044] Since the installation angle error is a small angle, the above formula can be equivalent to,

[0045]

[0046] Where I is the identity matrix, Represents an antisymmetric matrix. Transpose the above formula, we have

[0047]

[0048] Odometer speed It is the quantity corrected by the odometer scale factor, which can be expressed in the v system as

[0049]

[0050] Substituting (6) and (7) into (3), we can obtain:

[0051]

[0052] Arranging the above formula, we can get:

[0053]

[0054] Therefore, the pitch and heading angles of the installation angle error are:

[0055]

[0056] Where V(2) and V(3) represent vectors The second and third elements of the pose matrix and the velocity v in the n system n , it can be represented by the convergence result of the previous GNSS RTK / INS integrated navigation.

[0057] According to the first aspect of the present invention, an embedded process of an algorithm for online estimation of installation angle error is designed. The algorithm has the advantages of small computational complexity and no need for external assistance, and is suitable for popular vehicle navigation and positioning applications. Online estimation of installation angle error uses the speed information and attitude information output by the GNSS RTK / INS combined navigation to replace the high-precision external reference used in post-processing estimation of installation angle error. Then, based on the relationship between the odometer speed information and the speed information output by the GNSS / INS combined navigation, the IMU installation angle error is calculated. It is mainly divided into four steps (see the flowchart in the attached Figure 1 ):

[0058] S1. First, receive GNSS and sensor data, determine whether the current GNSS RTK solution is fixed and whether the inertial navigation system has completed initial alignment. If the judgment condition is false, continue with dynamic alignment. If true, it indicates that the inertial navigation system initial alignment is successful, and then execute GNSS RTK / INS integrated navigation for attitude convergence. At the same time, determine the vehicle's straight-ahead status. If it is straight-ahead, save the current GNSS RTK / INS integrated navigation speed value and odometer output speed value. If it is not straight-ahead, return to the next data reception and execute integrated navigation operation.

[0059] S2. Calculate the scale factor k of the odometer in the straight-ahead state based on the carrier's speed in the b frame and the speed output by the odometer, and then use k to obtain the speed of the odometer in the v frame.

[0060] S3. Use the speed relationship between v system and b system Then, the pitch angle and heading angle of the installation angle error are obtained according to the small angle theory.

[0061] S4. Save the heading angle and pitch angle, then remove the maximum and minimum values ​​of the two respectively, and then average the remaining data to obtain the final estimated pitch angle and heading angle of the installation angle error.

[0062] b system - the carrier coordinate system refers to the carrier's center of mass as the origin, OY along the longitudinal axis, that is, the carrier's forward direction, OX along the carrier's lateral axis, pointing to the right wing, OZ along the carrier's vertical axis, which is a right-handed coordinate system (that is, pointing to the sky).

[0063] V system - vehicle coordinate system, refers to the coordinate system formed with the vehicle after the IMU is installed on the vehicle, with the X-axis facing the right side of the vehicle, the Y-axis facing the front of the vehicle, and the Z-axis facing the sky.

[0064] Example 2

[0065] The present invention also provides a low-cost vehicle-mounted embedded integrated navigation installation angle error online estimation system, comprising

[0066] The first module is configured to receive the current vehicle navigation data in real time and perform dynamic alignment judgment, and to continue the dynamic alignment judgment or perform combined navigation attitude convergence according to the judgment result;

[0067] The second module is configured to execute the integrated navigation posture convergence and determine whether the current vehicle is moving straight, and to execute the continued determination of dynamic alignment or save the integrated navigation data according to the determination result;

[0068] The third module is configured to store the combined navigation data and obtain the pitch angle data and heading angle data of the final estimated installation angle error by using the speed relationship of the current vehicle under the V system and the B system.

[0069] Example 3

[0070] The present invention also provides an electronic device, a computer-readable storage medium storing computer-executable instructions; and one or more processors, the one or more processors being coupled to the computer-readable storage medium and configured to execute the computer-executable instructions so that the device performs the method described in Example 1.

[0071] Example 4

[0072] The present invention also provides a readable storage medium storing computer-executable instructions. When the computer-executable instructions are executed by a processor, the processor is configured to execute the method described in Example 1.

[0073] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A method for online estimation of installation angle error of low-cost embedded integrated navigation system on a vehicle, characterized in that: include Receive the current vehicle navigation data in real time and perform dynamic alignment judgment. According to the judgment result, continue the dynamic alignment judgment or perform integrated navigation attitude convergence, including: Receive GNSS and sensor data, determine whether the current GNSS RTK solution is fixed and whether the inertial navigation has completed initial alignment, if the judgment condition is false, continue dynamic alignment; if true, execute GNSS RTK / INS integrated navigation for attitude convergence; execute integrated navigation attitude convergence and determine whether the current vehicle is moving straight, and according to the judgment result, continue dynamic alignment or save integrated navigation data, including determining the vehicle's straight-ahead state. If the straight-ahead state is satisfied, save the current GNSS RTK / INS combined navigation speed value and odometer output speed value; if the straight-ahead state is not satisfied, return to continue receiving GNSS and sensor data next time and execute the integrated navigation dynamic alignment operation; Calculating a scale factor of the odometer in a straight-ahead state based on the speed of the carrier in the carrier coordinate system and the speed output by the odometer, and then using the scale factor to obtain the speed of the odometer in the vehicle coordinate system, wherein the origin of the carrier coordinate system is the center of mass of the carrier, the ordinate axis points in the forward direction of the carrier, the abscissa axis points in the lateral direction of the carrier, and the vertical axis points in the vertical direction of the carrier; saving the combined navigation data, and obtaining final estimated pitch angle data and heading angle data of the installation angle error using the relationship between the current vehicle speeds in the vehicle coordinate system and the carrier coordinate system; The heading angle data and the pitch angle data are saved, the maximum value and the minimum value in the heading angle data and the pitch angle data are removed respectively, and the remaining data in the heading angle data and the pitch angle data are averaged respectively to obtain the pitch angle and the heading angle of the final estimated installation angle error.

2. A low-cost vehicle-mounted embedded integrated navigation installation angle error online estimation system, characterized in that: For performing the method according to claim 1.

3. An electronic device, characterized in that: A computer-readable storage medium storing computer-executable instructions; and one or more processors coupled to the computer-readable storage medium and configured to execute the computer-executable instructions so that the device performs the method according to claim 1.

4. A readable storage medium, characterized in that: Computer executable instructions are stored which, when executed by a processor, configure the processor to perform the method according to claim 1 .

Images