Double-layer dynamic path planning method applied to ice appearance scanning survey under polar region ice

Abstract

A double-layer dynamic path planning method applied to polar region under-ice ice appearance scanning survey comprises the following steps: a shore-based system processes an image obtained by a subscription satellite to obtain initial boundary longitude and latitude information of a detection global task area, and rasterizes a global task area map; the shore-based system transmits the optimal global ATSP path to the underwater robot and transmits a corresponding coverage path to a path tracking module of the underwater robot; the underwater robot executes a local initial global coverage path, and obtains environment information in real time through a carried sensor; the underwater robot adopts a carried multi-beam sonar to obtain an under-ice ice appearance image of a scanning area in real time, and transmits the under-ice ice appearance scanning image to the shore-based system through the communication module; and comparing the ice bottom ice appearance image of the first-layer scanning measurement with the under-ice ice appearance image of the current-layer scanning measurement.

Description

Technical field:

[0001] The invention relates to a double-layer dynamic path planning method applied to ice surface scanning under polar ice. Background technology:

[0002] As global warming intensifies, polar regions have gradually become the focus of attention. Monitoring the polar marine environment is of great significance to the study of global warming. Compared with other monitoring methods, underwater robots can adapt to the harsh environment under the ice and realize three-dimensional observation of the ice under floating ice.

[0003] Most of the existing underwater robot path planning is carried out by verifying relevant information. However, faced with the uncertainty of large-scale ice surface scanning tasks under floating ice and the unknown environment under polar ice, planning paths by verifying information is not applicable. Specifically, the traditional preset path does not take the shape of the floating ice into consideration for ATSP path points, and mostly uses the center position of the floating ice as the global ATSP path point, which is not suitable for large-scale floating ice scanning tasks. On the other hand, traditional paths all set the underwater robot to scan a fixed mission area at different depths to achieve three-dimensional scanning of the floating ice, resulting in low efficiency of the scanning task. Summary of the invention:

[0004] The embodiment of the present invention provides a double-layer dynamic path planning method for scanning ice features under polar ice. The method is reasonably designed, and a grid map is established to use the ISSA algorithm of the global path planner to calculate and optimize the global path of traditional path points. A global path with the shortest path can be efficiently planned, and an optimal global scanning path can be dynamically planned according to the sensor data carried by the underwater robot itself, thereby effectively improving the search efficiency and detection intelligence of the underwater robot, improving the traditional layered scanning method, and proposing a layered scanning strategy for a layered dynamically reduced task area, which can effectively reduce the task workload of the underwater robot, improve the task completion efficiency, and solve the problems existing in the prior art.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A two-layer dynamic path planning method for polar subglacial ice scanning, the path planning method comprising the following steps:

[0007] S1, the shore-based system processes the images obtained by the subscribed satellite to obtain the initial boundary longitude and latitude information of the global mission area, and rasterizes the global mission area map, and uses the ISSA algorithm of the global planner to plan the optimal global ATSP path including the local starting position and the end position;

[0008] S2, the shore-based system transmits the optimal global ATSP path to the underwater robot, and the double-layer dynamic path planning module of the underwater robot uses the improved CCPP algorithm to calculate the initial global coverage path of the local area, and transmits the corresponding coverage path to the path tracking module of the underwater robot;

[0009] S3, the underwater robot executes the local initial global coverage path, obtains environmental information in real time through the sensors it carries, dynamically updates the local grid and global grid state information, and calculates the local obstacle avoidance scanning path through the grid state calculator;

[0010] S4, the underwater robot uses the multi-beam sonar it carries to obtain the ice image under the ice in the scanned area in real time, and transmits the ice scanned image under the ice to the shore-based system through the communication module;

[0011] S5, comparing the ice bottom ice appearance image of the first layer scanned with the ice under the ice appearance image of the current layer scanned, to determine whether the underwater robot has completed the ice under the ice appearance scanning task in the local task area; when the local task area is completed, the shore-based system will display the complete ice under the ice appearance image corresponding to the local task area;

[0012] S6, when the underwater robot completes the full coverage scan of the local task area, it moves to the end position of the local task area, and moves to the next global path point with reference to the optimal global ATSP path, fully performing the above steps S2-S5 until the scan of the global task area is completed.

[0013] The underwater robot includes a main control center, a perception subsystem, a data transmission subsystem and a navigation control subsystem;

[0014] The main control center includes a main controller, to which a data management unit, a control calculation unit, an emergency diagnosis unit and a planning and decision-making unit are connected; the perception subsystem includes an obstacle avoidance system and a scanning system, the obstacle avoidance system includes a forward-looking sonar and an underwater light, and the scanning system includes a multi-beam sonar and an underwater light camera; the data transmission subsystem includes a data transmission module, and the data transmission module includes a data transmission radio, a picture transmission radio, an underwater acoustic communicator and a wireless network; the navigation control subsystem includes a motion control module and an inertial navigation module, the motion control module includes a main thruster, a side thruster and a servo, and the inertial navigation module includes an IMU, a DVL, a USBL, a GPS and a depth meter.

[0015] The sweep width calculation method of the forward-looking sonar is related to the installation angle, water quality, beam opening angle and transmission frequency, and varies with the height H from the ice surface; the forward-looking sonar has different detection widths in the horizontal and vertical directions; the longitudinal sweep width W of the forward-looking sonar is L And the lateral sweep width W T The calculation formula is:

[0016]

[0017] Among them, the longitudinal beam opening angle of the forward-looking sonar is β, and the lateral beam opening angle is γ.

[0018] The single scan width of the multi-beam sonar will vary with the installation angle, water quality, transmission frequency, beam opening angle, and height H from the ice surface. The calculation formula for the scan width W of the multi-beam sonar is:

[0019]

[0020] Where α is the beam opening angle of the multibeam sonar.

[0021] The double-layer dynamic path planning module includes a global planner, a local planner and a grid state calculator; the double-layer dynamic path planning module is used to transmit a feasible path to the main control center of the underwater robot, and the main control center of the underwater robot is used to transmit the initial position, depth, local environmental information and mission area of ​​the underwater robot to the double-layer dynamic path planning module; the main control center of the underwater robot exchanges data with the shore-based system through the communication module.

[0022] The scanning width of the initial global coverage path is determined by the altimeter measurement depth, the sonar inclination angle and the manually set accurate threshold.

[0023] The present invention adopts the above structure, and by establishing a grid map, it can use the ISSA algorithm of the global path planner to calculate and optimize the global ATSP path of the traditional TSP path points, and can efficiently plan a global path with the shortest path; through the improved CCPP algorithm and the dynamic Glas ius bionic neural network path planning algorithm driven by real-time data, it can dynamically plan an optimal global scanning path according to the sensor data carried by the underwater robot itself and effectively improve the search efficiency and detection intelligence of the underwater robot; by proposing a hierarchical scanning strategy of the task area with hierarchical dynamic reduction, the task workload of the underwater robot is effectively reduced, which has the advantages of intelligence, practicality, energy saving and high efficiency. Description of the drawings:

[0024] Figure 1 It is a schematic diagram of the process of the present invention.

[0025] Figure 2 It is a schematic structural diagram of the underwater robot of the present invention.

[0026] Figure 3 The figure is a flowchart of the operation of the underwater robot of the present invention.

[0027] Figure 4 It is a flow chart of the double-layer dynamic path planning module of the present invention. Specific implementation method:

[0028] In order to clearly illustrate the technical features of the present solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0029] like Figure 1-4 As shown in , a two-layer dynamic path planning method for polar subglacial ice scanning is provided, and the path planning method comprises the following steps:

[0030] S1, the shore-based system processes the images obtained by the subscribed satellite to obtain the initial boundary longitude and latitude information of the global mission area, and rasterizes the global mission area map, and uses the ISSA algorithm of the global planner to plan the optimal global ATSP path including the local starting position and the end position;

[0031] S2, the shore-based system transmits the optimal global ATSP path to the underwater robot, and the double-layer dynamic path planning module of the underwater robot uses the improved CCPP algorithm to calculate the initial global coverage path of the local area, and transmits the corresponding coverage path to the path tracking module of the underwater robot;

[0032] S3, the underwater robot executes the local initial global coverage path, obtains environmental information in real time through the sensors it carries, dynamically updates the local grid and global grid state information, and calculates the local obstacle avoidance scanning path through the grid state calculator;

[0033] S4, the underwater robot uses the multi-beam sonar it carries to obtain the ice image under the ice in the scanned area in real time, and transmits the ice scanned image under the ice to the shore-based system through the communication module;

[0034] S5, comparing the ice bottom ice appearance image of the first layer scanned with the ice under the ice appearance image of the current layer scanned, to determine whether the underwater robot has completed the ice under the ice appearance scanning task in the local task area; when the local task area is completed, the shore-based system will display the complete ice under the ice appearance image corresponding to the local task area;

[0035] S6, when the underwater robot completes the full coverage scan of the local task area, it moves to the end position of the local task area, and moves to the next global path point with reference to the optimal global ATSP path, fully performing the above steps S2-S5 until the scan of the global task area is completed.

[0036] The underwater robot includes a main control center, a perception subsystem, a data transmission subsystem and a navigation control subsystem;

[0037] The main control center includes a main controller, to which a data management unit, a control calculation unit, an emergency diagnosis unit and a planning and decision-making unit are connected; the perception subsystem includes an obstacle avoidance system and a scanning system, the obstacle avoidance system includes a forward-looking sonar and an underwater light, and the scanning system includes a multi-beam sonar and an underwater light camera; the data transmission subsystem includes a data transmission module, and the data transmission module includes a data transmission radio, a picture transmission radio, an underwater acoustic communicator and a wireless network; the navigation control subsystem includes a motion control module and an inertial navigation module, the motion control module includes a main thruster, a side thruster and a servo, and the inertial navigation module includes an IMU, a DVL, a USBL, a GPS and a depth meter.

[0038] The sweep width calculation method of the forward-looking sonar is related to the installation angle, water quality, beam opening angle and transmission frequency, and varies with the height H from the ice surface; the forward-looking sonar has different detection widths in the horizontal and vertical directions; the longitudinal sweep width W of the forward-looking sonar is L And the lateral sweep width W T The calculation formula is:

[0039]

[0040] Among them, the longitudinal beam opening angle of the forward-looking sonar is β, and the lateral beam opening angle is γ.

[0041] The single scan width of the multi-beam sonar will vary with the installation angle, water quality, transmission frequency, beam opening angle, and height H from the ice surface. The calculation formula for the scan width W of the multi-beam sonar is:

[0042]

[0043] Where α is the beam opening angle of the multibeam sonar.

[0044] The double-layer dynamic path planning module includes a global planner, a local planner and a grid state calculator; the double-layer dynamic path planning module is used to transmit a feasible path to the main control center of the underwater robot, and the main control center of the underwater robot is used to transmit the initial position, depth, local environmental information and mission area of ​​the underwater robot to the double-layer dynamic path planning module; the main control center of the underwater robot exchanges data with the shore-based system through the communication module.

[0045] The scanning width of the initial global coverage path is determined by the altimeter measurement depth, the sonar inclination angle and the manually set accurate threshold.

[0046] The working principle of a double-layer dynamic path planning method applied to polar subglacial ice scanning in an embodiment of the present invention is: establishing a grid map and using the ISSA algorithm of the global path planner to calculate and optimize the global path of traditional path points, which can efficiently plan a global path with the shortest path, and at the same time dynamically plan an optimal global scanning path based on the sensor data carried by the underwater robot itself, effectively improving the search efficiency and detection intelligence of the underwater robot, improving the traditional layered scanning method, and proposing a layered scanning strategy with a layered dynamically reduced task area, which can effectively reduce the task workload of the underwater robot and improve the efficiency of task completion.

[0047] Due to the irregular shape of floating ice, the traditional method of using the center of the local mission area as the ATSP path point is not applicable. It is necessary to determine the starting and ending positions of the full coverage scan for the irregular mission area. At the same time, traditional floating ice scanning schemes are completed through simple three-dimensional uniform stratification, but this stratification method will lead to an increase in the total path cost. Therefore, it is necessary to propose a new dynamic stratified scanning scheme to reduce energy consumption.

[0048] In the overall scheme, the path planning method includes the following steps: the shore-based system processes the images obtained by the subscribed satellite to obtain the initial boundary longitude and latitude information of the global mission area, and rasterizes the global mission area map, and uses the ISSA algorithm of the global planner to plan the optimal global ATSP path including the local starting position and the end position; the shore-based system transmits the optimal global ATSP path to the underwater robot, and the double-layer dynamic path planning module of the underwater robot uses the improved CCPP algorithm to calculate the initial global coverage path of the local area, and transmits the corresponding coverage path to the path tracking module of the underwater robot; the underwater robot executes the local initial global coverage path, obtains environmental information in real time through the sensors it carries, dynamically updates the local grid and global grid state information, and calculates the local obstacle avoidance scanning path through the grid state calculator; the underwater robot uses the multi-beam sonar it carries Acquire the sub-ice ice appearance images in the scanned area in real time, and transmit the sub-ice ice appearance scanning images to the shore-based system through the communication module; compare the ice bottom ice appearance images of the first layer scanned with the sub-ice ice appearance images of the current layer scanned to determine whether the underwater robot has completed the sub-ice ice appearance scanning task in the local mission area; when the local mission area is completed, the shore-based system will display the complete sub-ice ice appearance images corresponding to the local mission area; when the underwater robot completes the full coverage scanning of the local mission area, it moves to the end position of the local mission area, and moves to the next global path point with reference to the optimal global ATSP path, completing the above steps S2-S5 until the scanning of the global mission area is completed.

[0049] The underwater robot in the present application includes a main control center, a perception subsystem, a data transmission subsystem and a navigation control subsystem; the main control center includes a main controller, to which a data management unit, a control calculation unit, an emergency diagnosis unit and a planning and decision-making unit are connected; the perception subsystem includes an obstacle avoidance system and a scanning system, the obstacle avoidance system includes a forward-looking sonar and an underwater light, and the scanning system includes a multi-beam sonar and an underwater light camera; the data transmission subsystem includes a data transmission module, and the data transmission module includes a data transmission radio, a picture transmission radio, an underwater acoustic communicator and a wireless network; the navigation control subsystem includes a motion control module and an inertial navigation module, the motion control module includes a main thruster, a side thruster and a servo, and the inertial navigation module includes an IMU, a DVL, a USBL, a GPS and a depth meter.

[0050] The double-layer dynamic path planning module mainly includes a global planner, a local planner and a grid state calculator; the double-layer dynamic path planning module is used to transmit feasible paths to the main control center of the underwater robot, and the main control center of the underwater robot is used to transmit the initial position, depth, local environmental information and mission area of ​​the underwater robot to the double-layer dynamic path planning module; the main control center of the underwater robot exchanges data with the shore-based system through the communication module.

[0051] The local planner plans the local obstacle avoidance scanning path through the grid state, and obtains the corresponding path according to the different scanning widths of the two sensors carried by the underwater robot.

[0052] Specifically, the scan width calculation method mainly includes forward-looking sonar scan width calculation and multi-beam sonar scan width calculation; the forward-looking sonar scan width calculation method is related to the installation angle, water quality, beam opening angle and transmission frequency, and varies with the height from the ice surface; the single scan width of the multi-beam sonar will vary with the installation angle, water quality, transmission frequency and beam opening angle as well as the height from the ice surface.

[0053] In order to ensure the imaging effect of ice scanning under floating ice, polar underwater robots are required to navigate at a constant depth. Due to the randomness of ice bottom obstacles, in order to give the underwater robot enough obstacle avoidance reaction time, the ratio of the multi-beam sonar scanning width to the forward-looking sonar scanning width is set to 1:3.

[0054] It is particularly noted that this application uses the ISSA algorithm to plan the globally optimized ATSP path points and uses the real-time data of the sensor to obtain an adaptive dynamic full coverage path. According to this path, the detection efficiency and intelligence of the underwater robot can be effectively improved, thereby realizing the accurate scanning of the ice bottom and ice appearance information in the mission area.

[0055] In summary, a double-layer dynamic path planning method for scanning polar subglacial ice features in an embodiment of the present invention establishes a grid map and uses the ISSA algorithm of the global path planner to calculate and optimize the global path of traditional path points. It can efficiently plan a global path with the shortest path, and dynamically plan an optimal global scanning path based on the sensor data carried by the underwater robot itself, effectively improving the search efficiency and detection intelligence of the underwater robot, improving the traditional layered scanning method, and proposing a layered scanning strategy with a layered dynamically reduced task area, which can effectively reduce the task workload of the underwater robot and improve the efficiency of task completion.

[0056] The above specific implementation manner cannot be used as a limitation on the protection scope of the present invention. For those skilled in the art, any substitution, improvement or change made to the implementation manner of the present invention falls within the protection scope of the present invention.

[0057] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A two-layer dynamic path planning method for polar subglacial ice scanning. It is characterized in that The path planning method comprises the following steps: S1, the shore-based system processes the images obtained by the subscribed satellite to obtain the initial boundary longitude and latitude information of the global mission area, and rasterizes the global mission area map, and uses the ISSA algorithm of the global planner to plan the optimal global ATSP path including the local starting position and the end position; S2, the shore-based system transmits the optimal global ATSP path to the underwater robot, and the double-layer dynamic path planning module of the underwater robot uses the improved CCPP algorithm to calculate the initial global coverage path of the local area, and transmits the corresponding coverage path to the path tracking module of the underwater robot; S3, the underwater robot executes the local initial global coverage path, obtains environmental information in real time through the sensors it carries, dynamically updates the local grid and global grid state information, and calculates the local obstacle avoidance scanning path through the grid state calculator; S4, the underwater robot uses the multi-beam sonar it carries to obtain the ice image under the ice in the scanned area in real time, and transmits the ice scanned image under the ice to the shore-based system through the communication module; S5, comparing the ice bottom ice appearance image of the first layer scanned with the ice under the ice appearance image of the current layer scanned, to determine whether the underwater robot has completed the ice under the ice appearance scanning task in the local task area; when the local task area is completed, the shore-based system will display the complete ice under the ice appearance image corresponding to the local task area; S6, when the underwater robot completes the full coverage scan of the local task area, it moves to the end position of the local task area, and moves to the next global path point with reference to the optimal global ATSP path, fully performing the above steps S2-S5 until the scan of the global task area is completed.

2. According to claim 1, a double-layer dynamic path planning method for scanning ice features under polar ice, Features: The underwater robot includes a main control center, a perception subsystem, a data transmission subsystem and a navigation control subsystem; The main control center includes a main controller, to which a data management unit, a control calculation unit, an emergency diagnosis unit and a planning and decision-making unit are connected; the perception subsystem includes an obstacle avoidance system and a scanning system, the obstacle avoidance system includes a forward-looking sonar and an underwater light, and the scanning system includes a multi-beam sonar and an underwater light camera; the data transmission subsystem includes a data transmission module, and the data transmission module includes a data transmission radio, a picture transmission radio, an underwater acoustic communicator and a wireless network; the navigation control subsystem includes a motion control module and an inertial navigation module, the motion control module includes a main thruster, a side thruster and a servo, and the inertial navigation module includes an IMU, a DVL, a USBL, a GPS and a depth meter.

3. According to claim 2, a double-layer dynamic path planning method for scanning ice features under polar ice, Features: The sweep width calculation method of the forward-looking sonar is related to the installation angle, water quality, beam opening angle and transmission frequency, and varies with the height H from the ice surface; the forward-looking sonar has different detection widths in the horizontal and vertical directions; the longitudinal sweep width W of the forward-looking sonar is L And the lateral sweep width W T The calculation formula is: Among them, the longitudinal beam opening angle of the forward-looking sonar is β, and the lateral beam opening angle is γ.

4. According to claim 5, a double-layer dynamic path planning method for scanning ice features under polar ice, Features: The single scan width of the multi-beam sonar will vary with the installation angle, water quality, transmission frequency, beam opening angle, and height H from the ice surface. The calculation formula for the scan width W of the multi-beam sonar is: Where α is the beam angle of the multibeam sonar.

5. A double-layer dynamic path planning method for scanning ice features under polar ice according to claim 2, Features: The double-layer dynamic path planning module includes a global planner, a local planner and a grid state calculator; the double-layer dynamic path planning module is used to transmit a feasible path to the main control center of the underwater robot, and the main control center of the underwater robot is used to transmit the initial position, depth, local environmental information and mission area of ​​the underwater robot to the double-layer dynamic path planning module; the main control center of the underwater robot exchanges data with the shore-based system through the communication module.

6. A double-layer dynamic path planning method for scanning ice features under polar ice according to claim 1, Features: The scanning width of the initial global coverage path is determined by the altimeter measurement depth, the sonar inclination angle and the manually set accurate threshold.

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