Method for optimizing tunnel positioning precision

Abstract

The invention discloses a method for optimizing tunnel positioning precision, and belongs to the technical field of vehicle navigation and positioning, and the method comprises the steps: building a specific path of a tunnel based on a map, and building key latitude and longitude coordinates; generating longitude and latitude coordinate points based on the key longitude and latitude coordinates; acquiring a vehicle driving distance based on an encoder of the vehicle; and matching the driving distance with the longitude and latitude coordinate points to obtain an accurate positioning result of the vehicle. The method does not need to depend on satellite signals in the tunnel, and a high-precision vehicle positioning result can be obtained only through calculation of the pre-calibrated longitude and latitude points and the driving distance of the vehicle.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle navigation and positioning, and in particular relates to a method for optimizing tunnel positioning accuracy. Background Art

[0002] Existing vehicle positioning systems typically rely on navigation modules such as the Global Positioning System (GPS) or BeiDou. In open areas, vehicles can use satellite signals from these systems to obtain highly accurate positioning data.

[0003] However, in enclosed environments like tunnels, where satellite signals cannot be received, vehicle positioning accuracy drops dramatically, and positioning drift is common. This drift can lead to navigation errors, impacting vehicle safety and the driving experience. Current technologies often estimate vehicle position by inferring driving trajectories or utilizing the vehicle's inertial measurement unit (IMU), but these still suffer from insufficient accuracy and accumulated errors. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention proposes a method for optimizing tunnel positioning accuracy to solve the problems existing in the above prior art.

[0005] To achieve the above object, the present invention provides a method for optimizing tunnel positioning accuracy, comprising:

[0006] Construct key longitude and latitude coordinates based on the specific path of the tunnel constructed on the map;

[0007] Generate longitude and latitude coordinate points based on the key longitude and latitude coordinates;

[0008] Obtaining the vehicle's travel distance based on the vehicle's encoder;

[0009] The driving distance is matched with the latitude and longitude coordinate points to obtain an accurate positioning result of the vehicle.

[0010] Preferably, the process of constructing key longitude and latitude coordinates of the specific path of the tunnel based on the map includes: drawing the specific path of the tunnel based on the Internet map, generating key longitude and latitude coordinate points in the tunnel, and constructing a path model for the vehicle traveling in the tunnel based on the key longitude and latitude coordinate points in the tunnel.

[0011] Preferably, the process of generating longitude and latitude coordinate points based on the key longitude and latitude coordinates includes: processing the key longitude and latitude coordinates based on a linear interpolation method to generate longitude and latitude coordinate points every 1 meter in the entire tunnel.

[0012] Preferably, the process of obtaining the vehicle's travel distance based on the vehicle's encoder includes:

[0013] Installing a high-precision encoder on the vehicle and recording the distance traveled by the vehicle in the tunnel based on the high-precision encoder;

[0014] The distance traveled by the vehicle in the tunnel is calculated based on the time axis to generate a total distance traveled by the vehicle at any moment.

[0015] Preferably, the process of obtaining an accurate positioning result of the vehicle includes:

[0016] When a vehicle travels in a tunnel, obtaining a travel distance based on an encoder of the vehicle;

[0017] The driving distance is matched with the latitude and longitude coordinate points every 1 meter in the entire tunnel to obtain an accurate positioning result of the vehicle.

[0018] Preferably, the process of obtaining the accurate positioning result of the vehicle further includes: if the vehicle speed is higher than a speed threshold, updating the accurate positioning result of the vehicle by the ratio between the longitude and latitude coordinate points every 1 meter of the entire tunnel.

[0019] On the other hand, the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements a method for optimizing tunnel positioning accuracy when executing the computer program.

[0020] On the other hand, the present invention further provides a computer-readable storage medium storing a computer program, which implements a method for optimizing tunnel positioning accuracy when executed by a processor.

[0021] Compared with the prior art, the present invention has the following advantages and technical effects:

[0022] This method eliminates the need for satellite signals within tunnels and achieves highly accurate vehicle positioning by calculating the distance between the vehicle and pre-calibrated latitude and longitude points. This method is not only applicable to common tunnel scenarios but can also be expanded to other locations where satellite signals are insufficient, such as underground parking lots and the interiors of large, enclosed buildings. This method requires only a small hardware investment, such as an encoder on the vehicle, and can be implemented in conjunction with existing high-precision map services. It eliminates the need for additional expensive sensors and is highly cost-effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0024] Figure 1This is a flow chart of a method for optimizing tunnel positioning accuracy according to an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the operation of the method for optimizing tunnel positioning accuracy according to an embodiment of the present invention. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0028] Example 1

[0029] like Figure 1 As shown, this embodiment provides a method for optimizing tunnel positioning accuracy, including:

[0030] Construct key longitude and latitude coordinates based on the specific path of the tunnel constructed on the map;

[0031] Generate longitude and latitude coordinate points based on the key longitude and latitude coordinates;

[0032] Obtaining the vehicle's travel distance based on the vehicle's encoder;

[0033] The driving distance is matched with the latitude and longitude coordinate points to obtain an accurate positioning result of the vehicle.

[0034] To further optimize the solution, the process of constructing the key longitude and latitude coordinates of the specific path of the tunnel based on the map includes:

[0035] 1. Draw the specific path of the tunnel based on Amap;

[0036] 2. Generate key longitude and latitude coordinates within the tunnel;

[0037] 3. Construct a path model for vehicles traveling in the tunnel based on the key latitude and longitude coordinate points in the tunnel.

[0038] To further optimize the solution, we used the AutoNavi path planning API to obtain a sequence of key longitude and latitude points in the tunnel. These key points include intersection locations and auxiliary points at curves, which are connected by straight lines to form a complete tunnel path. To improve the accuracy of subsequent location attribution, we interpolated line segments where the distance between adjacent key points exceeded 1 meter. The specific method is as follows:

[0039] 1. For any two adjacent key longitude and latitude points A(λ1,φ1) and B(λ2,φ2), first calculate the distance D (meters) between them;

[0040] 2. If D is greater than 1 meter, you need to insert between the two points points (n is D rounded down), so that the distance between adjacent points does not exceed 1 meter. Calculate the interpolation point P i The latitude and longitude coordinates of:

[0041] λ i =λ1+i / (n+1);

[0042] φ i =φ1+i / (n+1);

[0043] Where i is the index of the interpolation point, i=1,2,...,n, λ i is the longitude of the interpolation point, φ i Latitude of the interpolation point;

[0044] , that is, round down operation, which means taking the integer part of the value of D. Assuming the value of D is 2.7 meters, then , that is, insert 2 points between A and B. The purpose here is to control the distance between adjacent points to be no more than 1 meter.

[0045] In this way, it is ensured that the distance between all adjacent points does not exceed 1 meter, thus providing a reference point with meter-level accuracy for subsequent location attribution.

[0046] Further optimizing the solution, the process of obtaining the vehicle's travel distance based on the vehicle encoder includes:

[0047] Installing a high-precision encoder on the vehicle and recording the distance traveled by the vehicle in the tunnel based on the high-precision encoder;

[0048] The distance traveled by the vehicle in the tunnel is calculated based on the time axis to generate a total distance traveled by the vehicle at any moment.

[0049] A high-precision wheel encoder is installed on the vehicle. This encoder detects the number of wheel rotations and angle changes using sensors mounted on the wheel. Each time the wheel rotates, the encoder generates a fixed number of pulse signals. By counting these pulses and combining them with the wheel's circumference, the vehicle's distance traveled can be accurately calculated. Based on this distance data, the system can accurately calculate the vehicle's cumulative distance traveled at any given moment in time.

[0050] Note: Considering that lane changes are generally prohibited in tunnels and vehicles tend to travel in a straight line, the distance measured by the encoder can effectively reflect the vehicle's actual displacement in the tunnel. Even slight lateral movement will have an acceptable impact on overall positioning accuracy.

[0051] Further optimizing the solution, the process of obtaining accurate vehicle positioning results includes:

[0052] When a vehicle travels in a tunnel, obtaining a travel distance based on an encoder of the vehicle;

[0053] The driving distance is matched with the latitude and longitude coordinate points every 1 meter in the entire tunnel to obtain an accurate positioning result of the vehicle.

[0054] When a vehicle is traveling in a tunnel, the distance traveled as reported by the encoder is matched to pre-generated tunnel path data with a 1-meter accuracy to determine the longitude and latitude coordinates corresponding to the vehicle's current position. These coordinates are the vehicle's accurate positioning results.

[0055] When collecting data in a tunnel, the real-time latitude and longitude of any point can be obtained on the device side. After exiting the tunnel and network information is restored, the data can also be transmitted to the cloud.

[0056] According to a further optimization scheme, the process of obtaining the accurate positioning result of the vehicle further includes: if the vehicle speed is higher than the speed threshold, the accurate positioning result of the vehicle is updated by the ratio between the longitude and latitude coordinate points every 1 meter in the entire tunnel.

[0057] like Figure 2 As shown, Figure 2 The functional module composition of the entire system is shown, which mainly includes the following key parts:

[0058] Host system: As the core control unit of the entire system, it is responsible for coordinating the data of the positioning module and encoder, including executing core algorithms such as path calibration, linear interpolation, distance calculation and position estimation;

[0059] The positioning module is used to provide the vehicle's initial positioning information before the tunnel entrance, obtain the tunnel's key latitude and longitude coordinates based on internet map data, and assist in building a tunnel driving path model;

[0060] The encoder is a high-precision encoder installed on the vehicle. It detects wheel rotation and calculates the actual distance the vehicle has traveled in the tunnel, providing basic data input for position calculation.

[0061] The core algorithm module contains four key functions:

[0062] Path calibration: Obtain the key latitude and longitude point sequence of the tunnel based on the Amap API

[0063] Linear interpolation: Process key longitude and latitude points to generate longitude and latitude coordinates every 1 meter

[0064] Distance calculation: Calculate the actual distance traveled by the vehicle based on encoder data

[0065] Position estimation: Match the driving distance with the longitude and latitude coordinates to get the real-time location

[0066] The high-precision positioning of the vehicle is the final output of the system. Through distance matching and linear interpolation algorithms, the high-precision positioning of the vehicle in the tunnel is achieved. When the vehicle speed is high, the time axis is also combined for accuracy optimization.

[0067] The collaborative workflow between these modules is:

[0068] 1. The host system receives the tunnel path data provided by the positioning module and the distance data from the encoder;

[0069] 2. Perform data processing and calculation through algorithm modules;

[0070] 3. Finally output the high-precision positioning results of the vehicle;

[0071] Through the above steps, the present invention realizes the accurate calculation of the real-time position of the vehicle through linear interpolation calculation and driving distance feedback when there is no satellite signal in the tunnel, thereby avoiding positioning drift and improving the positioning accuracy in the tunnel to 1 meter.

[0072] Example 2

[0073] This embodiment provides a method for optimizing tunnel positioning accuracy, including:

[0074] First, using an internet map, a detailed map of the tunnel section is mapped to obtain the key longitude and latitude coordinates of this section. Assume that the acquired points are Point A (starting point), Point B (tunnel bend), and Point C (end point). A linear interpolation algorithm is used to subdivide the path between Points A, B, and C, generating longitude and latitude coordinates every 1 meter. Assuming the total tunnel length is 1000 meters, 1000 longitude and latitude calibration points with a 1-meter accuracy are ultimately obtained. In principle, the higher the interpolation accuracy, the higher the final positioning accuracy.

[0075] An encoder is installed on the vehicle to record the distance traveled from the tunnel entrance. Once the vehicle enters the tunnel, the satellite signal disappears, but the encoder still records the distance traveled. Assume the vehicle has traveled 325 meters. By matching the pre-generated 1-meter-accurate longitude and latitude points, the vehicle's latitude and longitude coordinates corresponding to the 325th point can be determined, thereby determining the vehicle's current position within the tunnel.

[0076] To further improve real-time performance and accuracy, the following methods are used to process encoder data while the vehicle is moving:

[0077] Distance matching calibration:

[0078] The accumulated driving distance obtained by the encoder is matched with the pre-generated calibration points per meter;

[0079] When the driving distance D falls between two calibration points P1(D1) and P2(D2), the latitude and longitude coordinates of the current position are calculated based on the distance ratio:

[0080] λ=λ1+(D-D1) / (D2-D1);

[0081] φ=φ1+(D-D1) / (D2-D1);

[0082] Timeline precision optimization:

[0083] For high-speed driving conditions (e.g., when the vehicle speed exceeds 60 km / h), the vehicle travels within a distance of 1 meter in a very short time (less than 0.06 seconds);

[0084] At this point, the exact position between the two calibration points can be calculated based on the vehicle speed V and time t:

[0085] D(t)=D1+V×t;

[0086] Then use the same proportional formula above to calculate the exact latitude and longitude coordinates at the corresponding moment;

[0087] Through this dual calibration method based on distance matching and time compensation, the positioning accuracy can be controlled at the sub-meter level.

[0088] On the other hand, this embodiment also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements a method for optimizing tunnel positioning accuracy when executing the computer program.

[0089] On the other hand, this embodiment further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for optimizing tunnel positioning accuracy is implemented.

[0090] The technical effects of this embodiment are as follows:

[0091] 1. High-precision tunnel positioning: By using linear interpolation to generate latitude and longitude coordinates within the tunnel with an accuracy of 1 meter, combined with real-time calculation of vehicle travel distance, positioning accuracy can reach 1 meter, significantly superior to existing inference or inertial measurement methods.

[0092] 2. No reliance on satellite signals: This method does not rely on satellite signals in tunnels. It can obtain high-precision vehicle positioning results by simply calculating the distance between pre-calibrated longitude and latitude points and the vehicle.

[0093] 3. Wide scope of application: The method of the present invention is not only applicable to common tunnel scenarios, but can also be expanded to other scenarios where satellite signals are insufficient, such as underground parking lots, inside large enclosed buildings, etc.

[0094] 4. Low-cost implementation: This method only requires a small amount of hardware investment, such as adding an encoder on the vehicle, and can be implemented in combination with existing high-precision map services. It does not require additional expensive sensors and is highly economical.

[0095] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for optimizing tunnel positioning accuracy, characterized in that: The following steps are involved: Construct the specific path of the tunnel based on the map to construct key longitude and latitude coordinates; Generate longitude and latitude coordinate points based on the key longitude and latitude coordinates; Obtaining the vehicle's travel distance based on the vehicle's encoder; Matching the travel distance with the latitude and longitude coordinate points to obtain an accurate positioning result of the vehicle; The process of constructing the key longitude and latitude coordinates of the specific path of the tunnel based on the map includes: drawing the specific path of the tunnel based on the Internet map, generating key longitude and latitude coordinate points in the tunnel, and constructing a path model for the vehicle traveling in the tunnel based on the key longitude and latitude coordinate points in the tunnel.

2. The method for optimizing tunnel positioning accuracy according to claim 1, characterized in that: The process of generating longitude and latitude coordinate points based on the key longitude and latitude coordinates includes: processing the key longitude and latitude coordinates based on a linear interpolation method to generate longitude and latitude coordinate points every 1 meter in the entire tunnel.

3. The method for optimizing tunnel positioning accuracy according to claim 1, characterized in that: The process of obtaining the vehicle travel distance based on the vehicle encoder includes: A high-precision encoder is installed on the vehicle, and a travel distance of the vehicle in the tunnel is recorded based on the high-precision encoder; The travel distance of the vehicle in the tunnel is calculated based on the time axis to generate a total distance that the vehicle has traveled at any time.

4. The method for optimizing tunnel positioning accuracy according to claim 2, characterized in that: The process of obtaining the accurate positioning result of the vehicle includes: When the vehicle travels in the tunnel, obtaining a travel distance based on an encoder of the vehicle; The driving distance is matched with the longitude and latitude coordinate points of every 1 meter in the entire tunnel to obtain an accurate positioning result of the vehicle.

5. The method for optimizing tunnel positioning accuracy according to claim 2, characterized in that: The process of obtaining the accurate positioning result of the vehicle also includes: if the vehicle speed is higher than the speed threshold, the accurate positioning result of the vehicle is updated by the ratio between the longitude and latitude coordinate points every 1 meter of the entire tunnel.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method described in any one of claims 1 to 5 is implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method described in any one of claims 1 to 5 is implemented.

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