A dead reckoning trajectory accuracy estimation method and system

Abstract

The present invention provides a dead reckoning trajectory accuracy estimation method and system, which calibrates a target vehicle; obtains dead reckoning data from the target vehicle during cruising, along with global navigation satellite system data from that process; converts the acquired global navigation satellite system data to a station-centered coordinate system to obtain a vehicle trajectory distribution map with the vehicle starting point as the origin; annotates the acquired dead reckoning data on the map to obtain two sets of trajectory distribution lines; and calculates the dead reckoning trajectory accuracy based on the difference between the two sets of trajectory distribution lines. This invention can effectively verify the reliability of dead reckoning.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent driving technology and relates to a dead reckoning trajectory accuracy estimation method and system. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] An inertial navigation system (INS) is an autonomous navigation system that uses inertial sensors (IMUs) to measure the vehicle's specific force and angular velocity. This information, combined with given initial conditions and information from systems like the Global Navigation Satellite System (GNSS), allows for real-time estimation of velocity, position, attitude, and other parameters. GNSS systems, using carrier phase observations for real-time kinematic positioning (RTK), can achieve centimeter-level positioning accuracy. A vehicle's dead-reckoning (DR) module is affected by factors such as electric power steering (EPS) system delay, EPS backlash, wheel speed pulse signal errors, IMU zero drift, and temperature drift, leading to a range of errors in the DR trajectory. Summary of the Invention

[0004] To address the above-mentioned issues, the present invention proposes a dead reckoning trajectory accuracy estimation method and system. The present invention utilizes a combination of a global navigation satellite system and real-time dynamic relative positioning technology services to test the accuracy of vehicle dead reckoning to verify its reliability.

[0005] According to some embodiments, the present invention adopts the following technical solutions:

[0006] A dead reckoning trajectory accuracy estimation method comprises the following steps:

[0007] Calibrate the target vehicle;

[0008] Obtaining dead reckoning data of the target vehicle during its cruising process, as well as global navigation satellite system data during the process;

[0009] The acquired global navigation satellite system data is converted into a station center coordinate system to obtain a movement trajectory distribution map of the vehicle with the vehicle starting point as the origin;

[0010] The acquired dead reckoning data is marked in the figure to obtain two sets of trajectory distribution lines. The dead reckoning trajectory accuracy is calculated based on the difference between the two sets of trajectory distribution lines.

[0011] As an optional implementation, the specific process of calibrating the target vehicle includes calibrating based on the center of the rear axle of the vehicle as the origin.

[0012] As a further step, the calibration is carried out on a flat terrain.

[0013] As an optional embodiment, the target vehicle performs cruising less than a set value during the cruising process, and performs parking actions in horizontal and vertical parking spaces.

[0014] As an optional implementation, the data conversion process includes creating a path to the files related to the global navigation satellite system data to be processed, defining three empty lists for receiving the longitude, latitude, and altitude data to be processed, traversing and filtering from the original files and adding them to the corresponding lists, then converting the lists into matrices and passing them as parameters to the called coordinate conversion function, and setting up a canvas to draw the returned x, y matrix.

[0015] As an optional implementation, when calculating the estimated trajectory accuracy, the difference between the two groups of trajectory distribution lines is determined by using the trajectory fitting degree and the average difference method.

[0016] A dead reckoning trajectory accuracy estimation system, comprising:

[0017] a calibration module, configured to perform calibration of a target vehicle;

[0018] a data acquisition module configured to acquire dead reckoning data of the target vehicle during cruising and data from a global navigation satellite system during the cruising process;

[0019] A coordinate conversion module is configured to convert the acquired global navigation satellite system data into a station center coordinate system to obtain a movement trajectory distribution map of the vehicle with the vehicle starting point as the origin;

[0020] The estimation calculation module is configured to mark the acquired dead reckoning data in the graph, obtain two sets of trajectory distribution lines, and calculate the dead reckoning trajectory accuracy based on the difference between the two sets of trajectory distribution lines.

[0021] A computer-readable storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor of a terminal device and executing the steps in the method.

[0022] A terminal device includes a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded by the processor and executing the steps in the described method.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention has high positioning accuracy, which can be accurate to the centimeter level, and can effectively verify the reliability of the DR module during the development of related functions such as automatic parking. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 It is a schematic flow diagram of the present invention;

[0027] Figure 2 It is a movement trajectory distribution map. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] Example 1

[0032] A dead reckoning trajectory accuracy estimation method comprises the following steps:

[0033] 1. Calibrate the target vehicle

[0034] Calibration is performed based on the center of the vehicle's rear axle as the origin. When calibrating, it is necessary to choose a site with flat terrain as much as possible.

[0035] ① Park the vehicle on a flat ground with open space around to ensure a good GPS signal.

[0036] ② Mark the vertical position of the rear axle center on the roof, place the antenna on the roof, and secure it to prevent it from moving while the vehicle is driving.

[0037] ③ Use a tape measure to measure the distance from the antenna to the rear axle center mark in the X and Y directions, and measure the vehicle body dimensions.

[0038] ④ Input the test parameters into the inertial navigation software, set automatic calibration, drive the vehicle along an S-shaped route, and wait for the prompt "Automatic calibration successful". Restart the device to complete the calibration.

[0039] 2. Scene Data Collection

[0040] In an unobstructed and relatively open area, the vehicle is driven at a low speed cruise, parking is performed in horizontal and vertical parking spaces, and DR and GNSS data collection is completed.

[0041] 3. Convert GNSS data into coordinates

[0042] The conversion relationship between the Earth-centered Earth-fixed coordinate system, the station-centered coordinate system, and the geographic coordinate system is existing technology and will not be described in detail here.

[0043] In this embodiment, the three coordinate system conversions can be implemented using a program. It is necessary to write corresponding functions for the three coordinate systems according to the conversion operation relationship and call them. The specific implementation method is divided into the following steps:

[0044] (1) Write the main program structure: Create the path of the GNSS data CSV file to be processed, define three empty lists, prepare to receive the data of longitude, latitude, and altitude to be processed, traverse and filter from the original CSV file and add it to the list, then convert the list into a matrix and pass it as a parameter to the called coordinate conversion function, finally set the canvas and draw the returned x, y matrix.

[0045] (2) Define functions that encapsulate coordinate system transformation operations;

[0046] (3) Visual two-dimensional coordinate display. Run the main program and, based on the loaded collected GNSS data, obtain the movement trajectory distribution map based on the station center enu coordinate system, that is, the vehicle starting point as the origin, as shown in the figure below. Figure 2 shown.

[0047] 4. Comparison and Calculation

[0048] By synchronously displaying the collected DR data in the above coordinate system, two sets of GNSS and DR trajectory distribution lines can be obtained. The DR trajectory accuracy can be calculated by trajectory fitting and taking the average difference method.

[0049] Example 2

[0050] A dead reckoning trajectory accuracy estimation system, comprising:

[0051] a calibration module, configured to perform calibration of a target vehicle;

[0052] a data acquisition module configured to acquire dead reckoning data of the target vehicle during cruising and data from a global navigation satellite system during the cruising process;

[0053] A coordinate conversion module is configured to convert the acquired global navigation satellite system data into a station center coordinate system to obtain a movement trajectory distribution map of the vehicle with the vehicle starting point as the origin;

[0054] The estimation calculation module is configured to mark the acquired dead reckoning data in the graph, obtain two sets of trajectory distribution lines, and calculate the dead reckoning trajectory accuracy based on the difference between the two sets of trajectory distribution lines.

[0055] Example 3

[0056] A computer-readable storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor of a terminal device and executing the steps of the method in embodiment 1.

[0057] Example 4

[0058] A terminal device includes a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; the computer-readable storage medium is used to store multiple instructions, and the instructions are suitable for being loaded by the processor and executing the steps in the method in embodiment one.

[0059] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0060] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0061] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0062] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0063] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

[0064] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without any creative work are still within the scope of protection of the present invention.

Claims

1. A dead reckoning trajectory accuracy estimation method, characterized in that: The following steps are involved: Calibrate the target vehicle; Obtaining dead reckoning data of the target vehicle during its cruising, as well as global navigation satellite system data during the same process; The acquired global navigation satellite system data is converted into a station center coordinate system to obtain a movement trajectory distribution map of the vehicle with the vehicle starting point as the origin; The acquired dead reckoning data is marked on the graph to obtain two sets of trajectory distribution lines. The dead reckoning trajectory accuracy is calculated based on the difference between the two sets of trajectory distribution lines. The target vehicle performs a cruising operation less than a set value during the cruising operation and performs parking actions in horizontal and vertical parking spaces; The trajectory accuracy of DR is calculated by trajectory fitting and taking the average difference method; The target vehicle calibration is specifically as follows: Calibration is performed based on the center of the vehicle's rear axle as the origin; Place an antenna on the roof; Measure the distance from the antenna to the rear axle center mark in the X and Y directions, and measure the vehicle body size information; Enter the test parameters into the inertial navigation software, set automatic calibration, drive the vehicle in an S-shaped route, and wait for the prompt "Auto-calibration successful" to appear. Restart the device to complete the calibration.

2. A dead reckoning trajectory accuracy estimation method according to claim 1, characterized in that: The specific process of calibrating the target vehicle includes calibrating based on the center of the vehicle's rear axle as the origin.

3. A dead reckoning trajectory accuracy estimation method as claimed in claim 2, characterized in that: Calibration is carried out on a flat site.

4. The dead reckoning trajectory accuracy estimation method according to claim 1, wherein: The data conversion process involves creating a path to the files related to the GNSS data that needs to be processed, defining three empty lists to receive the longitude, latitude, and altitude data that need to be processed, filtering them from the original files and adding them to the corresponding lists, then converting the lists into matrices and passing them as parameters to the coordinate conversion function called, and setting up a canvas to draw the returned x,y matrix.

5. The dead reckoning trajectory accuracy estimation method according to claim 1, wherein: When calculating the estimated trajectory accuracy, the difference between the two sets of trajectory distribution lines is determined by the trajectory fitting degree and the average difference method.

6. A dead reckoning trajectory accuracy estimation system, based on a dead reckoning trajectory accuracy estimation method according to any one of claims 1 to 5, characterized in that: include: a calibration module, configured to perform calibration of a target vehicle; a data acquisition module configured to acquire dead reckoning data of the target vehicle during cruising and data from a global navigation satellite system during the cruising process; A coordinate conversion module is configured to convert the acquired global navigation satellite system data into a station center coordinate system to obtain a movement trajectory distribution map of the vehicle with the vehicle starting point as the origin; The estimation calculation module is configured to mark the acquired dead reckoning data in the graph, obtain two sets of trajectory distribution lines, and calculate the dead reckoning trajectory accuracy based on the difference between the two sets of trajectory distribution lines.

7. A computer-readable storage medium, characterized in that: A plurality of instructions are stored therein, and the instructions are suitable for being loaded by a processor of a terminal device and executing the steps of the method according to any one of claims 1 to 5.

8. A terminal device, characterized in that: The method comprises a processor and a computer-readable storage medium, wherein the processor is used to implement various instructions; and the computer-readable storage medium is used to store multiple instructions, wherein the instructions are suitable for being loaded by the processor and executing the steps in the method according to any one of claims 1 to 5.

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