A track laying method and a magnetic nail navigation method for unmanned vehicle

Abstract

The application discloses a magnetic track laying method and a magnetic nail navigation method of an unmanned vehicle, and the magnetic track laying method comprises the following steps: when a straight section is laid, N or S pole upward magnetic nails are laid along the center of a road as a magnetic track center line, and S or N pole upward magnetic nails are laid along the two sides of the road as a magnetic track guardrail; when a turning section is laid, N or S pole upward magnetic nails are laid along the center of the road as a magnetic track center line, S or N pole upward magnetic nails are laid along the two sides of the road as a magnetic track guardrail, and N or S pole upward magnetic nails are laid on the inner side of the magnetic track center line as turning guide magnetic nails. The application effectively protects the unmanned vehicle from deviating from the expected track by the guardrail magnetic nails, and improves the driving safety factor of the unmanned vehicle. The turning guide magnetic nails are used to efficiently guide the unmanned vehicle to complete the turning driving task, and improve the turning efficiency and the turning speed. The early warning magnetic nails are used to effectively reduce the driving risk factor of the unmanned vehicle at the road intersection, and avoid the dangerous event of vehicle-vehicle or vehicle-person collision.

Description

Technical Field

[0001] This invention relates to unmanned vehicle navigation technology, and in particular to a magnetic track laying method and an unmanned vehicle magnetic nail navigation method. Background Technology

[0002] Autonomous vehicles are intelligent vehicles that utilize navigation devices and are controlled by computers to achieve driverless operation, and they are currently showing a trend towards practical application. The main navigation methods for autonomous vehicles include GPS navigation, optical navigation, laser navigation, and magnetic navigation, each with the following characteristics:

[0003] (1) GPS navigation requires receiving signals from more than four satellites. The more satellites received, the more accurate the positioning. However, this method has the advantages of global all-weather and relatively short positioning time. GPS navigation has high requirements for satellite signal quality, and the received signal cannot be blocked by surrounding environments such as tall buildings.

[0004] (2) Optical navigation uses a camera as a sensor to perform real-time positioning in unknown environments and build a map of the surrounding environment. However, to improve navigation accuracy, it is necessary to install lighting equipment or use more expensive high-precision cameras to ensure navigation accuracy at night.

[0005] (3) Laser navigation obtains parameters such as the distance, azimuth, altitude, and even shape of a target by transmitting and receiving the returned laser light from a lidar. Lidar can obtain extremely high accuracy in angle, distance, and velocity, but it is easily affected by weather, especially in heavy rain, dense smoke, and dense fog, where laser attenuation is severe and the propagation distance is greatly reduced.

[0006] (4) Magnetic strip navigation obtains the unmanned vehicle's positional deviation relative to the target path by measuring the magnetic field signal on the path, thereby achieving positioning. Magnetic strip navigation has high measurement accuracy and is not affected by weather conditions. However, magnetic strips are easily crushed and damaged, and laying magnetic strips is also a potential problem. In addition, most of the magnetic nail navigation methods currently used adopt a single row of magnetic nails and a single magnetic setting. This laying method does not make full use of the bipolar characteristics of magnetic nails, nor does it take protective measures against serious deviations of the vehicle from the driving route. Summary of the Invention

[0007] Purpose of the invention: In view of the above problems, the purpose of this invention is to provide a method for laying magnetic tracks and a method for magnetic nail navigation for unmanned vehicles.

[0008] Technical solution: One aspect of the present invention provides a method for laying magnetic tracks, comprising:

[0009] When laying straight sections, lay N or S pole facing up magnetic nails along the center of the road as the center line of the magnetic track, and lay S or N pole facing up magnetic nails along both sides of the road as magnetic track guardrails.

[0010] When laying the turning section, lay N or S pole facing up magnetic nails along the center of the road as the center line of the magnetic track, lay S or N pole facing up magnetic nails along both sides of the road as magnetic track guardrails, and lay N or S pole facing up magnetic nails inside the center line of the magnetic track as turning guide magnetic nails.

[0011] When laying magnetic nails at intersections, for east-to-north and west-to-south routes, N or S poles facing upwards are laid along the center of the road as the magnetic track centerline. N or S poles facing upwards are laid inside the magnetic track centerline as turning guide nails, and S or N poles facing upwards are laid outside the magnetic track centerline as reference guide nails. For north-to-west and south-to-east routes, S or N poles facing upwards are laid along the center of the road as the magnetic track centerline. S or N poles facing upwards are laid inside the magnetic track centerline as turning guide nails, and N or S poles facing upwards are laid outside the magnetic track centerline as reference guide nails.

[0012] Furthermore, when laying straight sections, before the road intersection, magnetic nails with opposite magnetic poles to the center line are laid on both sides as warning magnetic nails.

[0013] Furthermore, when laying straight sections, the distance between adjacent magnetic nails on the center line of the magnetic track is equal, and the distance between the magnetic track guardrails on both sides of the road and the center line of the magnetic track is equal and greater than half of the detection range of the autonomous vehicle's magnetic navigation sensor.

[0014] Furthermore, when laying the turning sections, the distance between adjacent magnetic nails on the center line of the magnetic track is equal.

[0015] Another aspect of the present invention provides a magnetic nail navigation method for unmanned vehicles, comprising: during normal driving, the unmanned vehicle uses an onboard magnetic navigation sensor to detect magnetic nails on the center line of the magnetic track, and uses the line connecting the center magnetic nails as a reference trajectory for the unmanned vehicle's driving; when the unmanned vehicle deviates from the center line of the magnetic track, the magnetic navigation sensor will detect the guardrail magnetic nails on both sides of the road, and at this time the unmanned vehicle will make emergency corrections to its course based on the relative positions of the center magnetic nail at the previous moment and the guardrail magnetic nails at the current moment.

[0016] Furthermore, when driving on a straight section, if the magnetic navigation sensor detects two magnetic nails with their S or N poles facing upwards and one magnetic nail with its N or S poles facing upwards for the first time, the autonomous vehicle will automatically reduce its speed and increase the detection frequency of the magnetic navigation sensor to cope with high-risk road intersections. When the magnetic navigation sensor detects two magnetic nails with their S or N poles facing upwards and one magnetic nail with its N or S poles facing upwards again, it means that the autonomous vehicle has left the road intersection area, and at this time the autonomous vehicle will return to normal driving mode.

[0017] Furthermore, when driving on a curve, when the magnetic navigation sensor detects two magnetic nails with N or S poles facing upwards and one magnetic nail with S or N poles facing upwards for the first time, the autonomous vehicle begins to turn. At the same time, the direction of the autonomous vehicle's turn and the turning radius to reach the next central magnetic nail are determined based on the magnitude and sign of d; where d represents the distance between the turning guide magnetic nail on the inside of the curve and the central magnetic nail.

[0018] Furthermore, when the autonomous vehicle deviates from the center line of the magnetic track, and magnetic nail A is detected by the magnetic navigation sensor, the distance L from the center of the magnetic navigation sensor to the center axis of the dual rear wheel axles is calculated. w Unmanned vehicle heading ψ n and the coordinates (x) of magnetic nail A A ,y A The current position of the autonomous vehicle is corrected, and the actual position coordinates (x, y) of the autonomous vehicle are obtained. n ,y n The calculation expression is:

[0019] x n =x A -L w cosψ n +Lsinψ n

[0020] y n =y A -L w sinψ n +Lcosψ n

[0021] Where L represents the lateral offset between the unmanned vehicle and the centerline of the magnetic track, and its calculation expression is:

[0022]

[0023] The magnetic navigation sensor is installed at the front centerline of the unmanned vehicle, perpendicular to the vehicle's axis. It has p Hall effect detection points, numbered from left to right as 1 to p, where p>2. Δ represents the spacing between each Hall effect detection point, m represents the number of consecutive detection points with output, and h represents the number of the leftmost detection point.

[0024] Beneficial effects: Compared with the prior art, the significant advantages of this invention are:

[0025] When facing large driving areas and complex routes, this invention enables unmanned vehicle navigation by laying magnetic nails in the middle and on both sides of the road. Magnetic nails are easier to lay and have lower installation costs. Using guardrail magnetic nails effectively protects the unmanned vehicle from deviating from its intended trajectory, improving driving safety. Using turning guidance magnetic nails efficiently guides the unmanned vehicle to complete turning tasks, improving turning efficiency and speed. Using warning magnetic nails effectively reduces the driving risk at road intersections, preventing vehicle-to-vehicle / pedestrian collisions. Furthermore, based on the continuous navigation information provided by the magnetic nails, a magnetic navigation sensor is used for navigation throughout the entire driving path. This method is simple to use, highly safe, stable, and reliable. The magnetic navigation sensor is not easily affected by temperature, light, weather, or the surrounding environment, adapting to various road conditions and offering high positioning accuracy. The navigation method of this invention can effectively correct the cumulative error of the encoder over long periods of operation, ensuring the unmanned vehicle can operate stably in the factory area for extended periods. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the straight section of the magnetic track in Example 1;

[0027] Figure 2 This is a schematic diagram of the track laying in the turning section of Example 1;

[0028] Figure 3 This is a schematic diagram of the magnetic track laying at the intersection in Example 1;

[0029] Figure 4 This is a schematic diagram of the magnetic track laying at the intersection in Example 1;

[0030] Figure 5 This is a schematic diagram of the side offset measurement for magnetic nail navigation in Example 2. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0032] Example 1

[0033] The magnetic track laying method described in this embodiment includes:

[0034] When laying straight sections, N-pole-up magnetic nails are laid along the center of the road as the center line of the magnetic track, and S-pole-up magnetic nails are laid along both sides of the road as magnetic track guardrails.

[0035] When laying the turning section, lay N-pole-up magnetic nails along the center of the road as the center line of the magnetic track, lay S-pole-up magnetic nails along both sides of the road as magnetic track guardrails, and lay N-pole-up magnetic nails inside the center line of the magnetic track as turning guide magnetic nails.

[0036] When laying magnetic nails at intersections, for east-to-north and west-to-south routes, a magnetic nail with the N pole facing upwards is laid along the center of the road as the centerline. Inside this centerline, another magnetic nail with the N pole facing upwards is laid as a turning guide nail, and outside the centerline, a magnetic nail with the S pole facing upwards is laid as a reference guide nail. For north-to-west and south-to-east routes, a magnetic nail with the S pole facing upwards is laid along the center of the road as the centerline. Inside this centerline, another magnetic nail with the S pole facing upwards is laid as a turning guide nail, and outside the centerline, a magnetic nail with the N pole facing upwards is laid as a reference guide nail. Figure 4 As stated above.

[0037] In one embodiment, when laying straight sections, the center magnetic nail of the track centerline can also have its S pole facing upwards, while the corresponding guardrail magnetic nail, which serves as a track barrier, has its N pole facing upwards. Similarly, when laying turning sections, the center magnetic nail of the track centerline can also have its S pole facing upwards, the guardrail magnetic nail, which serves as a track barrier, has its N pole facing upwards, and the turning guide magnetic nail has its S pole facing upwards. When laying sections at intersections, for east-to-north and west-to-south routes, the center magnetic nail of the track centerline has its S pole facing upwards, the turning guide magnetic nail has its S pole facing upwards, and the reference guide magnetic nail has its N pole facing upwards; for north-to-west and south-to-east routes, the center magnetic nail of the track centerline has its N pole facing upwards, the turning guide magnetic nail has its N pole facing upwards, and the reference guide magnetic nail has its S pole facing upwards.

[0038] In one example, such as Figure 1 As shown, when laying straight sections, magnetic nails with the N pole facing upwards are laid along the center of the road as the center line of the magnetic track, and magnetic nails with the S pole facing upwards are laid along both sides of the road as magnetic track guardrails. The distance between adjacent magnetic nails on the center line of the magnetic track is equal, and the distance between the magnetic track guardrails on both sides of the road and the center line of the magnetic track is equal and greater than half of the detection range of the Hall sensor of the unmanned vehicle.

[0039] In one example, such as Figure 2 As shown, when laying the turning section, N-pole-up magnetic nails are laid along the center of the road as the center line of the magnetic track, and S-pole-up magnetic nails are laid along both sides of the road as magnetic track guardrails. N-pole-up magnetic nails are laid inside the center line of the magnetic track as turning guide magnetic nails; the distance between adjacent magnetic nails on the center line of the magnetic track is equal.

[0040] In one example, such as Figure 3 As shown, when laying straight sections, before the road intersection, when the N-pole-up magnetic nail serves as the center line of the track, S-pole-up magnetic nails are laid on both sides of the center line as warning magnetic nails. Alternatively, when the S-pole-up magnetic nail serves as the center line of the track, N-pole-up magnetic nails are laid on both sides of the center line as warning magnetic nails.

[0041] Example 2

[0042] A magnetic nail navigation method for unmanned vehicles is disclosed. This method is used for navigation on roads paved using the magnetic track laying method described in Embodiment 1. The method includes: during normal driving, the unmanned vehicle uses an onboard Hall sensor to detect magnetic nails on the center line of the magnetic track, and uses the line connecting the center magnetic nails as a reference trajectory for the unmanned vehicle's driving; when the unmanned vehicle deviates from the center line of the magnetic track, the Hall sensor will detect the guardrail magnetic nails on both sides of the road, and at this time, the unmanned vehicle will make emergency corrections to its course based on the relative positions of the center magnetic nails at the previous moment and the guardrail magnetic nails at the current moment.

[0043] In one example, when driving on a straight section, if the Hall sensor detects two magnetic nails with their S or N poles facing up and one magnetic nail with its N or S poles facing up for the first time, the autonomous vehicle will automatically reduce its speed and increase the detection frequency of the Hall sensor to deal with the high-risk road intersection area. When the Hall sensor detects two magnetic nails with their S or N poles facing up and one magnetic nail with its N or S poles facing up again, it means that the autonomous vehicle has left the road intersection area, and at this time the autonomous vehicle will return to normal driving mode.

[0044] In one example, when driving on a curve, the autonomous vehicle begins to turn when the Hall sensor first simultaneously detects two N or S poles facing upwards and one S or N pole facing upwards. At the same time, the direction of the autonomous vehicle's turn and the turning radius to reach the next central magnetic nail are determined based on the magnitude and sign of d; where d represents the distance between the turning guide magnetic nail on the inside of the curve and the central magnetic nail.

[0045] Specifically, when the autonomous vehicle deviates from the center line of the magnetic track, and the Hall sensor detects magnetic nail A, the distance L from the center of the Hall sensor to the center axis of the dual rear wheel axles is used to determine the location of the magnetic nail. w Unmanned vehicle heading ψ n and the coordinates (x) of magnetic nail A A ,y A The current position of the autonomous vehicle is corrected, and the actual position coordinates (x, y) of the autonomous vehicle are obtained. n ,y n The calculation expression is:

[0046] x n =x A -L w cosψ n +Lsinψ n

[0047] y n =y A -L w sinψ n +Lcosψ n

[0048] Among them, heading ψ nThe coordinates are obtained by inertial navigation on the unmanned vehicle, and L represents the lateral offset between the unmanned vehicle and the centerline of the magnetic track. The calculation expression is:

[0049]

[0050] The Hall sensor is installed at the front centerline of the unmanned vehicle, perpendicular to the vehicle's axis, and has p Hall detection points. The Hall detection points are numbered from 1 to p from left to right, Δ is the spacing between each Hall detection point, m represents the number of consecutive detection points with output, and h represents the number of the leftmost detection point.

[0051] In one example, the vehicle-mounted Hall sensor is installed at the front centerline of the autonomous vehicle, perpendicular to the vehicle's axis. Taking a magnetic Hall sensor with 16 Hall detection points as an example... Figure 5 As shown, the spacing between each Hall sensor detection point is Δ, and the detection points are numbered 1 to 16 from left to right. When there are m consecutive detection points with output, and the leftmost detection point is numbered h, then the lateral offset L between the unmanned vehicle and the center line of the magnetic track is:

[0052]

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for laying magnetic tracks, characterized in that, include: When laying straight sections, lay N or S pole facing up magnetic nails along the center of the road as the center line of the magnetic track, and lay S or N pole facing up magnetic nails along both sides of the road as magnetic track guardrails. When laying the turning section, lay N or S pole facing up magnetic nails along the center of the road as the center line of the magnetic track, lay S or N pole facing up magnetic nails along both sides of the road as magnetic track guardrails, and lay N or S pole facing up magnetic nails inside the center line of the magnetic track as turning guide magnetic nails. When laying magnetic nails at intersections, for east-to-north and west-to-south routes, N or S poles facing upwards are laid along the center of the road as the magnetic track centerline. N or S poles facing upwards are laid inside the magnetic track centerline as turning guide nails, and S or N poles facing upwards are laid outside the magnetic track centerline as reference guide nails. For north-to-west and south-to-east routes, S or N poles facing upwards are laid along the center of the road as the magnetic track centerline. S or N poles facing upwards are laid inside the magnetic track centerline as turning guide nails, and N or S poles facing upwards are laid outside the magnetic track centerline as reference guide nails. The N and S poles are set accordingly.

2. The method for laying magnetic tracks according to claim 1, characterized in that, When laying straight sections, before the road intersection, lay magnetic nails on both sides of the magnetic track centerline with opposite magnetic poles to the centerline magnetic nails as warning magnetic nails.

3. The method for laying magnetic tracks according to claim 2, characterized in that, When laying straight sections, the distance between adjacent magnetic nails on the center line of the magnetic track is equal, and the distance between the magnetic track guardrails on both sides of the road and the center line of the magnetic track is equal and greater than half of the detection range of the autonomous vehicle's magnetic navigation sensor.

4. The method for laying magnetic tracks according to claim 1, characterized in that, When laying the turning section, the distance between adjacent magnetic nails on the center line of the magnetic track is equal.

5. A magnetic nail navigation method for unmanned vehicles, the method being used for navigation on roads paved using the magnetic track laying method described in any one of claims 1-4, characterized in that, include: During normal driving, the autonomous vehicle uses its onboard magnetic navigation sensors to detect magnetic nails on the center line of the magnetic track, and uses the line connecting the central magnetic nails as a reference trajectory for the autonomous vehicle's driving. When the autonomous vehicle deviates from the center line of the magnetic track, the magnetic navigation sensors will detect the magnetic nails on the guardrails on both sides of the road. At this time, the autonomous vehicle will make emergency corrections to its course based on the relative positions of the central magnetic nails at the previous moment and the guardrail magnetic nails at the current moment.

6. The unmanned vehicle magnetic nail navigation method according to claim 5, characterized in that, When driving on a straight section, if the magnetic navigation sensor detects two magnetic nails with their S or N poles facing up and one magnetic nail with its N or S poles facing up simultaneously for the first time, the autonomous vehicle will automatically reduce its speed and increase the detection frequency of the magnetic navigation sensor to deal with high-risk road intersections. When the magnetic navigation sensor detects two magnetic nails with their S or N poles facing up and one magnetic nail with its N or S poles facing up simultaneously again, it means that the autonomous vehicle has left the road intersection area, and at this time the autonomous vehicle will return to normal driving mode.

7. The unmanned vehicle magnetic nail navigation method according to claim 5, characterized in that, When driving on a curve, the autonomous vehicle begins to turn when the magnetic navigation sensor detects two magnetic nails with N or S poles facing upwards and one magnetic nail with S or N poles facing upwards for the first time. At the same time, the turning direction and the turning radius to reach the next central magnetic nail are determined based on the magnitude and sign of d; where d represents the distance between the turning guide magnetic nail on the inside of the curve and the central magnetic nail.

8. The unmanned vehicle magnetic nail navigation method according to claim 5, characterized in that, When the autonomous vehicle deviates from the center line of the magnetic track, and magnetic nail A is detected by the magnetic navigation sensor, the distance from the center of the magnetic navigation sensor to the center axis of the dual rear wheel axles is used to determine the location of the vehicle. Unmanned vehicle heading Coordinates of magnetic nail A The current position of the autonomous vehicle is corrected, and the actual coordinates of the current position of the autonomous vehicle are obtained. The calculation expression is: ； ； Where L represents the lateral offset between the unmanned vehicle and the centerline of the magnetic track, and its calculation expression is: ； The magnetic navigation sensor is installed at the front centerline of the autonomous vehicle, perpendicular to the vehicle's axis, and has p Hall effect detection points. The Hall effect detection points are numbered sequentially from left to right as follows: , The spacing between each Hall effect detection point, m represents the number of consecutive detection points with output, and h represents the number of the leftmost detection point.

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