KR20240052099A - Error detection system of GPS coordinates using HD map - Google Patents

Abstract

The present invention relates to an error detection system for GPS coordinates using a precision map. According to the present invention, even without adding a separate environmental sensor such as a camera, the presence of an error in the GPS coordinates obtained from the GPS module is determined using precision map data. Follow-up actions can be taken.

Description

Error detection system of GPS coordinates using HD map}

The present invention relates to an error detection system for GPS coordinates using a precision map, and more specifically, to a technology that detects errors in GPS coordinates and enables follow-up action without adding a separate environmental sensor.

In the field of smart cars and self-driving cars, technology to accurately determine (position) the vehicle's location is essential.

GNSS is the most widely used positioning system. GNSS (Global Navigation Satellite System) is a general term for a system that uses satellites to provide information about the location, altitude, and speed of objects on the ground. A representative example is the US GPS (Global Positioning System).

In the case of widely distributed low-cost GPS, it is sufficient to determine the direction or location of the vehicle and which road it is currently located on. However, in the case of low-cost GPS, an error of around 2 meters occurs, and when the signal reception environment is poor, such as in urban areas with many high-rise buildings or mountainous areas, errors as large as 7 meters or more may occur. Therefore, it is difficult to use low-cost GPS in an autonomous driving environment where driving lanes must be distinguished.

For this purpose, self-driving cars are often equipped with an RTK (Real-Time Kinematic) GPS system that improves location accuracy by receiving information from a reference station and calculating corrections for GPS coordinates received from satellites. However, RTK GPS may also experience errors if it does not receive correction information from the reference station.

Meanwhile, related technologies for determining the location of a vehicle include Republic of Korea Patent No. 10-1752342 (June 23, 2017, ‘Vehicle Location Location Method’).

The present invention was developed to solve the problems of the prior art as described above. Even without adding a separate environmental sensor such as a camera, the present invention enables follow-up measures by accurately detecting errors in GPS coordinates using a precision map. The purpose is to provide technology.

To achieve the above object, the error detection system for GPS coordinates using a precision map according to the present invention extracts center line coordinates from precision map data stored in a precision map DB, generates center line curve information, and uses the vehicle as the origin. A center line extraction unit that converts to display in a relative coordinate system; a reference range setting unit that sets a reference range for an allowable error based on a center line curve in a relative coordinate system with the vehicle as the origin; and an error determination unit that determines whether the GPS coordinates are in error by checking whether the GPS coordinates obtained from the GPS module are within the reference range set by the reference range setting unit.

Here, the reference range setting unit may set the area between the curve connecting points separated by a certain distance with positive and negative values in the lateral direction of the vehicle from the center line curve as the reference range.

In addition, if there is no lane information within the intersection in the precision map data stored in the precision map DB, the center line extraction unit generates virtual lane information corresponding to the driving path using the end points of each lane before entering the intersection, and You can create centerline coordinates that pass through the center.

The GPS coordinate error detection system using a precision map according to the present invention can determine whether there is an error in the GPS coordinates obtained from the GPS module using precision map data even without adding a separate environmental sensor such as a camera.

In other words, the center line coordinates included in the precision map data are not used only to refer to the driving route, but are used as the correct coordinates. If it is confirmed that the center line curve deviates from a certain standard range, it is determined that the GPS module is operating abnormally. This allows coordinate information to be secured using a different method.

Figure 1 is a block diagram illustrating an error detection system for GPS coordinates using a precision map according to an embodiment of the present invention.
Figure 2 is a flowchart illustrating a method for correcting errors in GPS coordinates using a precision map according to an embodiment of the present invention.
Figure 3 is a diagram for explaining the process of generating a center line curve using center line coordinates extracted from precision map data.
Figure 4 is a diagram for explaining the process of setting a reference range using a center line curve.
Figure 5 is a diagram for explaining the process of detecting errors in GPS coordinates using the reference range of the center line curve.

Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, some components that are unrelated to the gist of the invention will be omitted or compressed, but the omitted components are not necessarily components that are unnecessary in the present invention, and may be used in combination by those skilled in the art to which the present invention pertains. You can.

Figure 1 is a block diagram for explaining an error detection system for GPS coordinates using a precision map according to an embodiment of the present invention. As shown in Figure 1, the error detection system for GPS coordinates according to an embodiment of the present invention (hereinafter referred to as the 'error detection system 30') includes a center line extraction unit 31, a reference range setting unit 32, and an error detection system. It includes a judgment unit 33.

Self-driving vehicles are equipped with a system that performs various functions necessary for autonomous driving, such as determining the exact location of the vehicle 100, predicting the driving path, or tracking the movements of surrounding vehicles, as shown in Figure 1. Each functional configuration of the error detection system 30 may be a part of an existing autonomous driving system or a system linked thereto. Additionally, each configuration may be integrated into a hardware configuration, may be composed of individual hardware and interoperable with each other, and some configurations may be designed in software.

The center line extraction unit 31 is provided to extract specific data through precision map data stored in the precision map DB 20 and generate a center line curve using the extracted data. A detailed description of generating the center line curve in the center line extraction unit 31 will be discussed again below.

The reference range setting unit 32 is provided to set a reference range using the center line curve generated by the center line extraction unit 31. The standard range refers to the standard for how much error in GPS coordinates can be tolerated.

The error determination unit 33 is provided to determine whether there is an error in the GPS coordinates by comparing the GPS coordinates obtained from the GPS module 10 with the reference range set by the reference range setting unit 32.

The specific process of detecting errors in GPS coordinates and determining correction coordinates using the error detection system 30 according to the embodiment of the present invention described above will be discussed in more detail through FIGS. 2 to 5.

Figure 2 is a flowchart illustrating a method for correcting errors in GPS coordinates using a precision map according to an embodiment of the present invention. That is, it relates to a process of detecting errors in GPS coordinates obtained from the GPS module 10 using the error detection system 30 shown in FIG. 1 and outputting the results.

Before explaining, the GPS module 10 used in the error detection system 30 according to an embodiment of the present invention receives information from a reference station and calculates correction for the coordinate information received from the satellite, thereby improving location accuracy. -Time Kinematic) Assume that a GPS system is used. That is, it is assumed that very accurate GPS coordinates can always be obtained through the GPS module 10 during most of the time during normal operation.

In addition, the precision map data stored in the precision map DB 20 will first be described as follows. The precision map DB 20 stores detailed coordinate information (absolute coordinates) of lanes, traffic lights, signs, road marks, road facilities, and buildings, and also includes information related to the center line between lanes.

Referring to Figure 3, the center line refers to the line that passes through the centers of the left lane (LL) and the right lane (RL) when a vehicle is driving in a specific lane, and the precision map DB 20 contains center lines at regular intervals along these center lines. Coordinates (GPS coordinate values) (C1, C2) are displayed. Of course, when the precision map DB (20) was first introduced, center line information (center line coordinates) may not have been included in the precision map data. In this case, the center line extraction unit 31 can use the lane data to generate center line data for the centers of both lanes and then use it in real time or update it in the precision map DB 20.

Also, in the case of intersections, there are cases where there are lane guidance lines, but in many cases, there are no lane guidance lines. In this case as well, the center line extraction unit 31 can create virtual lane information corresponding to the driving path using the end points of each lane before entering the intersection and generate center line coordinates centered on these lanes. That is, it is assumed that all driving routes and center line information (coordinate information between lanes) within intersections are stored in the precision map DB 20 used in the present invention.

In order to detect errors in the GPS coordinates obtained from the GPS module 10, the center line extraction unit 31 first extracts the center line coordinates from the precision map DB 20 and generates a center line curve <S205>. As described above, the precision map DB 20 contains information about center line coordinates (C1, C2) at regular intervals along the center line between each lane (LL, RL), and the center line extractor 31 is currently The center line coordinates (C1) closest to the GPS coordinates obtained from the GPS module 10 can be extracted. Afterwards, if a certain number of nearby center line coordinates (C2) are extracted from the lane where the extracted center line coordinates (C1) are located and connected, a center line curve (CL) is created. The process of extracting the center line coordinates (C1, C2) and generating the center line curve (CL) using each center line coordinate (C1, C2) is repeated at regular time intervals.

The center line curve CL can be generated in the form of an equation, and the center line extraction unit 31 converts the center line curve into a relative coordinate system with the vehicle 100 as the origin <S210>. Referring to Figure 4, it can be seen that a relative coordinate system with the current GPS coordinates (G2) of the vehicle 100 as the origin can be confirmed, and the extracted center line curve (CL) has been drawn in this relative coordinate system. The point where the center line curve (CL) passes the origin becomes the point closest to the current GPS coordinates (G2) among the center line coordinates (C1, C2) forming the center line curve (CL).

In autonomous driving mode, the subject vehicle 100 drives along the centers of both lanes LL and RL. Therefore, the center line curve (CL) represents the exact driving path (or expected path) along which the vehicle moves normally, and if normal driving occurs, the GPS coordinates acquired from the GPS module 10 are also on the center line curve (CL). It should be located in

Of course, even if the precision of the GPS module 10 is high, the GPS coordinates obtained from the GPS module 10 and the center line coordinates extracted from the precision map DB 20 do not exactly match. However, since the vehicle is already using the coordinates obtained from the GPS module 10 believing that they are correct, a slight deviation from the center line curve should not always be judged as an error. To this end, the reference range setting unit 32 sets the standard based on the center line curve. Set the range <S215>.

That is, referring to FIG. 4, the reference range setting unit 32 sets a positive value and With a negative value, a virtual reference range (A) line can be created connecting points that are a certain distance (for example, 10 cm) apart. The symbol G1, which is not explained here, indicates the GPS coordinates (G1) acquired immediately before from the GPS module 10, and it can be seen that during normal operation, the previous value (G1) is also located on the center line curve.

The center line extraction unit 31 generates a center line curve (CL) connecting the center line coordinates extracted from the precision map DB 20, displays it on a relative coordinate system with the own vehicle 100 as the origin, and then sets the reference range. If the unit 32 sets a reference range (A) spaced at a certain distance to the left and right of the center line curve (CL), the error determination unit 33 determines that the GPS coordinates (G2) acquired in real time from the GPS module 10 are within the reference range. Determine whether there is an error by checking whether it is located within (A)<S225>.

For example, as shown in Figure 4, if it is confirmed that the GPS coordinates (G2) obtained from the GPS module 10 are located within the reference range (A) on the left and right of the center line curve (CL), <S230>, the error judgment unit 33 outputs information that the GPS coordinates are normal, and accordingly, in other systems for autonomous driving, the GPS coordinates obtained from the GPS module 10 can be used as is <S235>.

However, as shown in Figure 5, if it is confirmed that the GPS coordinates (G2') obtained from the GPS module 10 are outside the reference range (A) on the left and right of the center line curve (CL), <S230>, the error judgment unit 33 outputs information that the GPS coordinates are error.

The process of detecting an error in the error determination unit 33 is described in more detail as follows. First, referring to Figure 4, GPS coordinates are acquired from the GPS module 10, and the center line extraction unit 31 extracts the center line coordinates (C1, C2) through the precision map DB 20 to create a center line curve (CL). The process of generating and then displaying on a relative coordinate system centered on the vehicle 100 is repeated every scanning cycle. In addition, if all operations are performed smoothly, the GPS coordinates (G1, G2) obtained from the GPS module 10 will always be on the center line curve (CL), or at least within the reference range (A).

Additionally, the center line curve CL also represents the expected driving path of the vehicle 100. Therefore, the error determination unit 33 determines whether the coordinates (G2) acquired at the current time are out of the reference range (A) by substituting the coordinates (G2) obtained at the current time into the center line curve (CL) drawn when the previous coordinates (G1) were acquired. The coordinates (G2') acquired at the current time were substituted into the center line curve (CL) drawn when the previous coordinates (G1) were acquired, but the coordinates (G2') were outside the reference range (A) as shown in Figure 5. If so, error information is output from the error determination unit 33.

If the error judgment unit 33 outputs information that the GPS coordinates are error, the GPS coordinates must be corrected and used in a separate external device or the corrected coordinates must be secured in another way. However, the technology for correcting or newly securing the coordinate information is very difficult. Because of the variety, the present invention only deals with the process for error detection.

As described in detail above, the error detection system 30 for GPS coordinates using a precision map according to the present invention uses the GPS acquired from the GPS module 10 using precision map data even without adding a separate environmental sensor such as a camera. It is possible to determine whether there is an error in the coordinates.

In other words, the center line coordinates included in the precision map data are not used only to refer to the driving route, but are used as the correct coordinates. If it is confirmed that the center line curve is outside a certain standard range, the GPS module 10 is operating abnormally. By determining this, it is possible to secure coordinate information using a different method.

The preferred embodiments of the present invention described above have been disclosed for illustrative purposes, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications and changes will be possible. and additions should be regarded as falling within the scope of the patent claims of the present invention.

10: GPS module
20: Precision map DB
30: Error detection system
31: Center line extraction unit
32: Standard range setting unit
33: Error judgment unit
100: own vehicle
LL, RL: suboptimal
C1, C2: Center line coordinates
CL: center line curve
A: Standard range
G1, G2, G2': Coordinate information

Claims (3)

A center line extraction unit that extracts center line coordinates from precision map data stored in a precision map DB, generates center line curve information, and converts it to be displayed in a relative coordinate system with the vehicle as the origin;
a reference range setting unit that sets a reference range for an allowable error based on a center line curve in a relative coordinate system with the vehicle as the origin; and
Error detection of GPS coordinates using a precision map, comprising: an error determination unit that checks whether the GPS coordinates obtained from the GPS module are within the reference range set by the reference range setting unit and determines whether there is an error in the GPS coordinates; system.
According to paragraph 1,
The reference range setting unit sets as a reference range the area between the curves connecting points separated by a certain distance with positive and negative values in the transverse direction of the vehicle from the center line curve. Error detection system.
According to paragraph 1,
If there is no lane information within the intersection in the precision map data stored in the precision map DB, the center line extraction unit generates virtual lane information corresponding to the driving path using the end points of each lane before entering the intersection, and determines the center between lanes. An error detection system for GPS coordinates using a precision map characterized by generating coordinates of a passing center line.