Sectional type unmanned ship global path planning method in whole process of departure, navigation and arrival

Abstract

The unmanned ship global path planning method provided by the invention covers the whole process from departure to sailing to an open sea area and then to entering the port, firstly sets detailed sailing routes and parameters, distinguishes three routes of departure, open sea area and entering the port, configures or dynamically calculates the resolution and safety distance of each segment of A star planning grid, and finally calculates the global path of the unmanned ship according to the resolution and safety distance of each segment of A star planning grid. Dividing a planning area according to navigation routing points, obtaining sea chart obstacle data in the planning area, performing data point interpolation processing, planning a path by applying an A star algorithm of a corresponding grid resolution under the condition of considering the safe distance of the unmanned ship aiming at each section of area, and performing path point simplification smoothing to ensure that all obstacles are avoided; and finally, seamlessly splicing the three paths of departure, open sea area and arrival to form a complete and safe global navigation path. According to the method, specific requirements of different sea areas are considered, a more refined path planning strategy is provided, an efficient and safe navigation scheme is provided for the unmanned ship, and the accuracy and efficiency of path planning are improved.

Description

Technical Field

[0001] The present invention relates to the field of global path planning for unmanned ships at sea, and specifically to a global path planning method for unmanned ships in the whole process of segmented departure, navigation and arrival at a port. Background Art

[0002] With the rapid development of intelligent and unmanned ship technology, unmanned ships are increasingly used in ocean sampling, environmental monitoring, hydrological measurement, maritime search and rescue and other fields; however, in a complex marine environment, how to plan a safe and efficient navigation path has become a key technical problem for the autonomous navigation of unmanned ships. Traditional global path planning methods often find it difficult to take into account the specific needs of different sea areas, especially in key stages such as leaving the port, sailing in open seas and entering the port, which require more refined path planning strategies; therefore, we improve the existing global path planning method for unmanned ships. Summary of the invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies of the existing technology, provide a global path planning for an unmanned ship that aims at a complete realistic navigation demand from a port of departure to another port of destination, and propose a segmented global path planning for an unmanned ship that realizes the entire process of leaving the port, navigating in open sea, and entering the port. The entire path planning is subdivided into a port departure section, an open sea section, and a port entry section, and path planning is performed separately according to the characteristics of each section to ensure that the unmanned ship can navigate safely and efficiently in different sea areas, thereby realizing a segmented global path planning method for an unmanned ship that realizes the entire process of leaving the port, navigating, and entering the port.

[0004] The technical problem to be solved by the present invention is achieved through the following technical solutions: a global path planning method for an unmanned ship in the whole process of segmented departure, navigation and arrival at a port, comprising the following steps: Step S1: Set the sailing route and parameters. Set the sailing route from the current port to the destination port, including three routes and the corresponding longitude and latitude information and route types. The route types include Type_ChuGang for departure, Type_KaiKuo for open sea, and Type_JinGang for arrival. Set the A-star planning grid resolution RESO_1, RESO_2, RESO_3 for each route type, and the corresponding safety distance SafeDis respectively. Step S2: Determine the planning area: According to the four routing points A, B, C, and D of the navigation route, respectively determine the square areas R1, R2, and R3 with the midpoints of the lines connecting A and B, B and C, and C and D as the center points of the rectangles and the length of the lines as the lengths and expanded by 2 times; Step S3: Outbound route planning: In the square area R1, all navigation obstacles data are obtained using the electronic chart data interface, and the outbound route P is planned using the A-star algorithm based on the grid resolution RESO_1. AB ; Step S4: Path planning in the open sea area: In the square area R2, all navigation obstacles data are obtained using the electronic chart data interface, and the open sea path P is planned using the A-star algorithm based on the grid resolution RESO_2. BC ; Step S5: Port entry path planning: In the square area R3, all chart obstacles data are obtained using the electronic chart data interface, and the port entry path P is planned using the A-star algorithm based on the grid resolution RESO_3. CD ; Step S6: P AB , P BC , P CD The complete longitude and latitude coordinates P of the global path planning are obtained by splicing.

[0005] Preferably, in steps S3-S5, linear interpolation is performed on the linear and planar obstacle data according to the grid resolution to ensure that the interval between the data points after interpolation is smaller than the corresponding grid resolution.

[0006] Preferably, for each square area R1, R2, R3, its corresponding grid resolution RESO_1, RESO_2, RESO_3 can be assigned a specific value according to the corresponding route type, or dynamically calculated according to the square area R1, R2, R3.

[0007] Preferably, the grid resolutions RESO_1, RESO_2, and RESO_3 are set based on: The range of RESO_1 and RESO_3 is limited to between 50 and 500 meters. The specific value is determined by the number of grids divided into the corresponding rectangular areas R1 and R3 at the resolution of RESO_1 and RESO_3, and the number of horizontal or vertical grids does not exceed 200; The range of RESO_2 is limited to between 500 and 10,000 meters. The specific value is determined by the number of grids divided into the corresponding rectangular area R2 at the RESO_2 resolution, and the number of horizontal or vertical grids does not exceed 300.

[0008] Preferably, the safety distance SafeDis of the unmanned ship is set according to different navigation areas. The safety distance in the port departure and arrival areas can be set to 3 times the ship length, and the safety distance in the open sea area can be set to 10 times the ship length.

[0009] Preferably, the method further includes the step of optimizing the result of the A-star algorithm, using the ray method or the Bresenham straight line algorithm to perform collision detection between the path point connection line and obstacles, so as to achieve simplification and smoothing of the path turning points.

[0010] Preferably, when performing the A-star algorithm, the longitude and latitude coordinates are first converted to the corresponding XY plane coordinates, and then the obstacles are projected onto the corresponding grid according to the resolution RESO and deduplication is performed. After the obstacles are projected, the obstacle grid is expanded considering the safety distance SafeDis to ensure the safety of the planned path PR. After simplifying and smoothing PR, it is reconverted to the longitude and latitude coordinate system, and the final path P is obtained. AB , P BC , P CD , and splice them together to get the complete path P for leaving the port, open sea, and entering the port.

[0011] Preferably, the grid expansion is calculated according to the safety distance SafeDis / resolution RESO to obtain ExpandSize, and when the Euclidean distance between the surrounding grid coordinates and the current obstacle coordinates is less than ExpandSize, the current grid is set as the obstacle grid.

[0012] Compared with the prior art, the beneficial technical effects of the present invention are: (1) The segmented path planning strategy of the present invention can customize corresponding navigation plans according to the characteristics of different sea areas, thereby effectively avoiding collision risks and significantly improving the navigation safety of unmanned ships in complex sea areas; (2) This method proposes a global path planning method for unmanned ships that comprehensively covers the entire process from leaving the port, sailing in open sea to entering the port. The entire path planning is finely divided into three major links: leaving the port, sailing in open sea, and entering the port. According to the unique environment and requirements of each link, customized path planning strategies are implemented respectively. In this way, no matter what kind of sea environment the unmanned ship is in, it can ensure that its navigation is safe, efficient, and practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a system flow chart of the present invention; Figure 2 This is a schematic diagram of the ABCD three-stage port departure, open sea area and port arrival of the present invention; Figure 3 The rectangular area R is calculated by the present invention according to the starting point A and the target point B; Figure 4 It is a schematic diagram of grid expansion of the present invention; Figure 5 The schematic diagram of the splicing effect of the ABCD three-stage planning path for leaving the port, open sea area and entering the port in the present invention Figure 1 ; Figure 6 The schematic diagram of the splicing effect of the ABCD three-stage planning path for leaving the port, open sea area and entering the port in the present invention Figure 2 ; Figure 7The schematic diagram of the splicing effect of the ABCD three-stage planning path for leaving the port, open sea area and entering the port in the present invention Figure 3 ; Figure 8 This is a simplified schematic diagram of the grid of the present invention. DETAILED DESCRIPTION

[0014] The specific technical solutions of the present invention are further described below with reference to the accompanying drawings, so as to facilitate further understanding of the present invention by those skilled in the art, and do not constitute a limitation on the rights thereof.

[0015] Example 1, reference Figure 1-8 The global path planning method for the whole process of unmanned ship leaving the port, sailing and entering the port in a segmented manner includes the following steps: Step S1: Set the sailing route and parameters. Set the sailing route from the current port to the destination port, including three routes and the corresponding longitude and latitude information and route types. The route types include Type_ChuGang for departure, Type_KaiKuo for open sea, and Type_JinGang for arrival. Set the A-star planning grid resolution RESO_1, RESO_2, RESO_3 for each route type, and the corresponding safety distance SafeDis. The resolution and safety distance can be set specifically or calculated dynamically. You can choose according to your needs. Step S2: Determine the planning area: According to the four routing points A, B, C, and D of the navigation route, respectively determine the square areas R1, R2, and R3 with the midpoints of the lines connecting A and B, B and C, and C and D as the center points of the rectangles and the length of the lines as the lengths and expanded by 2 times; Step S3: Outbound route planning: In the square area R1, all navigation obstacles data are obtained using the electronic chart data interface, and the outbound route P is planned using the A-star algorithm based on the grid resolution RESO_1. AB ; Step S4: Path planning in the open sea area: In the square area R2, all navigation obstacles data are obtained using the electronic chart data interface, and the open sea path P is planned using the A-star algorithm based on the grid resolution RESO_2. BC ; Step S5: Port entry path planning: In the square area R3, all chart obstacles data are obtained using the electronic chart data interface, and the port entry path P is planned using the A-star algorithm based on the grid resolution RESO_3. CD ; Step S6: P AB , P BC , P CD The complete longitude and latitude coordinates P of the global path planning are obtained by splicing.

[0016] Example 2, the global path planning method for the whole process of unmanned ship with segmented departure, navigation and arrival described in Example 1, in steps S3-S5, linear interpolation is performed on the linear and surface obstacle data according to the grid resolution to ensure that the interval between data points after interpolation is less than the corresponding grid resolution.

[0017] Example 3, the global path planning method for the whole process of unmanned ship with segmented departure, navigation and arrival in the port as described in Example 1, for each square area R1, R2, R3, its corresponding grid resolution RESO_1, RESO_2, RESO_3 can be specified according to the corresponding route type, or dynamically calculated according to the square areas R1, R2, R3.

[0018] Example 4, the global path planning method for the whole process of unmanned ship in the segmented departure, navigation and arrival in the port described in Examples 1-3, the grid resolutions RESO_1, RESO_2, and RESO_3 are set based on: The range limit of RESO_1 and RESO_3 is between 50 meters and 500 meters. The specific value is determined by the number of grids divided by the corresponding rectangular areas R1 and R3 at the resolution of RESO_1 and RESO_3, and the number of horizontal or vertical grids does not exceed 200. The specific number can also be 100, and the range limit can also be between 100 meters and 1000 meters. It can be set or selected according to needs. The calculation process is as follows: (1) Determine the side length: Since R1 is a square, its side length is denoted by a (here a=L=W); (2) Calculate the initial resolution: Use the side length of the square and the limit on the number of grids (no more than 200 grids) to calculate the initial resolution. Because the square is the same length in the horizontal and vertical directions, we only need to consider the number of grids in one direction; initial resolution = a / 200, but please note that this initial resolution may need to be adjusted according to the range of RESO_1 (50 meters to 500 meters); (3) Adjust the resolution to fit the range: Compare the initial resolution with the range of RESO_1 (50 m to 500 m). If the initial resolution is less than 50 m, set RESO_1 to 50 m. If it is within 50-500 m, consider rounding to a multiple of 50 m. If the initial resolution is greater than 500 m, set RESO_1 to 500 m.

[0019] The range of RESO_2 is limited to between 500 meters and 10,000 meters. The specific value is determined by the number of grids divided into the corresponding rectangular area R2 at the RESO_2 resolution, and the number of horizontal or vertical grids does not exceed 300. The specific number and range limit can be set or selected according to actual needs.

[0020] It should be noted that when sending routes, if the grid resolution is specified, then RESO_1, RESO_2, and RESO_3 do not need to be calculated, and the set values ​​can be used directly. For example, RESO_1 is specified as 200, RESO_2 is 2000, and RESO_3 is 100. In this case, the grid resolution is not limited by the number of grids.

[0021] In Embodiment 4, the network resolution may use a set value or be dynamically calculated, depending on whether a default value is specified.

[0022] Example 5, the global path planning method for the whole process of segmented departure, navigation and arrival of an unmanned ship as described in Example 4, the safety distance SafeDis of the unmanned ship is set according to different navigation areas, the safety distance in the departure and arrival areas can be set to 3 times the ship length, and the safety distance in the open sea can be set to 10 times the ship length.

[0023] Example 6, the global path planning method for the entire process of segmented departure, navigation and arrival of an unmanned ship described in Example 5, also includes the step of optimizing the results of the A-star algorithm, using the ray method or the Bresenham straight line algorithm to perform collision detection between path point connections and obstacles, and achieving simplification and smoothing of path turning points.

[0024] Example 7: The global path planning method for the whole process of unmanned ship with segmented departure, navigation and arrival described in Example 6, when performing the A-star algorithm, the longitude and latitude coordinates are first converted into the corresponding XY plane coordinates, and then the obstacles are projected onto the corresponding grids according to the resolution RESO and de-duplication is performed. After the obstacles are projected, the obstacle grid is expanded considering the safety distance SafeDis to ensure the safety of the planned path PR. After simplifying and smoothing PR, it is reconverted to the longitude and latitude coordinate system, and the final path P is obtained. AB , P BC , P CD , and splice them together to get the complete path P for leaving the port, open sea, and entering the port.

[0025] Example 8, the global path planning method for the whole process of segmented departure, navigation and arrival of an unmanned ship as described in Example 7, specifically: the grid expansion is calculated according to the safety distance SafeDis / resolution RESO to obtain ExpandSize, and when the Euclidean distance between the surrounding grid coordinates and the current obstacle coordinates is less than ExpandSize, the current grid is set as an obstacle grid.

[0026] In addition, it should be noted that the above-mentioned path planning can be three segments, or it can be expanded to more than three segments according to actual needs. It can be selected according to usage needs and is not limited to this.

[0027] It should be noted that Figure 5-7 In the figure, the three connected lines composed of denser dots are the route planning paths for leaving the port, open sea and entering the port, while the lines with fewer dots are the complete global path of the unmanned ship after smooth splicing. Figure 8 In the figure, the dotted lines are the original grid path points, and the polyline is the simplified path.

Claims

1. Global path planning method for unmanned ships in the whole process of segmented departure, navigation and arrival at the port. Features: The following steps are involved: Step S1: Set the sailing route and parameters. Set the sailing route from the current port to the destination port, including three routes and the corresponding longitude and latitude information and route types. The route types include Type_ChuGang for departure, Type_KaiKuo for open sea, and Type_JinGang for arrival. Set the A-star planning grid resolution RESO_1, RESO_2, RESO_3 for each route type, and the corresponding safety distance SafeDis respectively. Step S2: Determine the planning area: According to the four routing points A, B, C, and D of the navigation route, respectively determine the square areas R1, R2, and R3 with the midpoints of the lines connecting A and B, B and C, and C and D as the center points of the rectangles and the length of the lines as the lengths and expanded by 2 times; Step S3: Outbound route planning: In the square area R1, all navigation obstacles data are obtained using the electronic chart data interface, and the outbound route P is planned using the A-star algorithm based on the grid resolution RESO_1. AB ; Step S4: Path planning in the open sea area: In the square area R2, all navigation obstacles data are obtained using the electronic chart data interface, and the open sea path P is planned using the A-star algorithm based on the grid resolution RESO_2. BC ; Step S5: Port entry path planning: In the square area R3, all chart obstacles data are obtained using the electronic chart data interface, and the port entry path P is planned using the A-star algorithm based on the grid resolution RESO_3. CD ; Step S6: P AB , P BC , P CD The complete longitude and latitude coordinates P of the global path planning are obtained by splicing.

2. According to the global path planning method for the whole process of unmanned ship with segmented departure, navigation and arrival at port as described in claim 1, Features: In steps S3-S5, linear interpolation is performed on the linear and planar obstruction data according to the grid resolution to ensure that the interval between the data points after interpolation is less than the corresponding grid resolution.

3. According to the global path planning method for the whole process of segmented departure, navigation and arrival of unmanned ships in claim 1, Features: For each square area R1, R2, R3, the corresponding grid resolution RESO_1, RESO_2, RESO_3 can be assigned a specific value according to the corresponding route type, or dynamically calculated according to the square area R1, R2, R3.

4. The global path planning method for the whole process of unmanned ship for segmented departure, navigation and arrival according to any one of claims 1 to 3, Features: The grid resolutions RESO_1, RESO_2, and RESO_3 are set based on: The range of RESO_1 and RESO_3 is limited to between 50 and 500 meters. The specific value is determined by the number of grids divided into the corresponding rectangular areas R1 and R3 at the resolution of RESO_1 and RESO_3, and the number of horizontal or vertical grids does not exceed 200; The range of RESO_2 is limited to between 500 and 10,000 meters. The specific value is determined by the number of grids divided into the corresponding rectangular area R2 at the RESO_2 resolution, and the number of horizontal or vertical grids does not exceed 300.

5. According to claim 4, the global path planning method for the whole process of unmanned ship in the segmented departure, navigation and arrival at the port, Features: The safety distance SafeDis of the unmanned ship is set according to the different navigation areas. The safety distance in the port departure and arrival areas can be set to 3 times the ship length, and the safety distance in the open sea can be set to 10 times the ship length.

6. The global path planning method for the whole process of unmanned ship with segmented departure, navigation and arrival according to claim 5, Features: The method also includes the step of optimizing the results of the A-star algorithm, using the ray method or the Bresenham straight line algorithm to detect collisions between path point lines and obstacles, and achieving simplification and smoothing of path turning points.

7. The global path planning method for the whole process of unmanned ship with segmented departure, navigation and arrival according to claim 6, Features: When performing the A-star algorithm, the longitude and latitude coordinates are first converted to the corresponding XY plane coordinates. Then, according to the resolution RESO, the obstacles are projected onto the corresponding grid and deduplication is performed. After the obstacles are projected, the obstacle grid is expanded considering the safety distance SafeDis to ensure the safety of the planned path PR. After simplifying and smoothing PR, it is reconverted to the longitude and latitude coordinate system. The final path P is AB , P BC , P CD , and splice them together to get the complete path P for leaving the port, open sea, and entering the port.

8. The global path planning method for the whole process of unmanned ship with segmented departure, navigation and arrival according to claim 7, Features: The grid expansion is calculated based on the safety distance SafeDis / resolution RESO to obtain the expanded obstacle grid value ExpandSize. When the Euclidean distance between the surrounding grid coordinates and the current obstacle coordinates is less than the grid value ExpandSize, the current grid is set as the obstacle grid.

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