CN113436467A - Collision avoidance decision method for unmanned surface vehicle in river course navigation - Google Patents
Collision avoidance decision method for unmanned surface vehicle in river course navigation Download PDFInfo
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- CN113436467A CN113436467A CN202110698636.8A CN202110698636A CN113436467A CN 113436467 A CN113436467 A CN 113436467A CN 202110698636 A CN202110698636 A CN 202110698636A CN 113436467 A CN113436467 A CN 113436467A
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Abstract
The invention relates to a collision avoidance decision method for an unmanned surface vehicle during navigation in a river channel, which comprises the following steps: 1. acquiring river channel boundary information; 2. when in navigation, the unmanned ship sensing system is used for detecting in real time to acquire information of obstacles or ships meeting; 3. analyzing the meeting situation and judging whether collision danger exists or not; 4. respectively calculating feasible collision prevention measures for the targets with collision risks; 5. determining a preliminary preferred scheme and a preliminary selected scheme by using a principle that a steering angle is small as a preferred principle; 6. calculating the distance between the avoidance points of the preliminary preferred scheme and the preliminary selected scheme and the river channel boundary; 7. and determining a final avoidance scheme by using the large distance as a preferred principle. The invention provides a collision avoidance decision method aiming at the collision avoidance problem of the unmanned ship in the river channel, namely in a narrower polygonal area, provides a collision avoidance scheme for the unmanned ship, outputs a calculation result in real time, has good practical application value, and can be applied to the collision avoidance of the river channel or the collision avoidance of a designated polygonal water area.
Description
Technical Field
The invention belongs to the technical field of navigation, and relates to a collision avoidance decision method for river channel navigation, in particular to a collision avoidance decision method for an unmanned surface vehicle in river channel navigation.
Background
The unmanned surface vehicle has the advantages of small volume, high speed, high autonomy, no casualties, wide activity area and the like, can flexibly fight in the military aspect, is mobile to deploy, is convenient to use, can follow a fighting ship to sail to execute a task, can independently execute the task in a dangerous area or an area which is not suitable for dispatching the manned ship, expands the maritime fighting range, has good cost performance, and is more and more emphasized by the naval of various countries.
An important premise for safe navigation of the unmanned surface vehicle is that the unmanned surface vehicle can realize an autonomous collision avoidance function. As one of core technologies for research on the unmanned surface vehicle, the autonomous collision avoidance of the unmanned surface vehicle reflects the intelligent level of the unmanned surface vehicle to a certain extent, and is also one of key technologies for realizing autonomous safe and reliable navigation of the unmanned surface vehicle.
When navigating in a curved river channel with limited width, the unmanned ship autonomously avoids collision and has higher decision generation difficulty than when navigating in an open sea area. How to ensure that the unmanned ship safely avoids dangerous obstacles when navigating in the river is a technical problem to be solved urgently by technical personnel in the field.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a collision avoidance decision method for the unmanned surface vehicle during navigation in the river channel, which has the advantages of reasonable design, strong practicability and easy realization.
The invention solves the practical problem by adopting the following technical scheme:
a collision avoidance decision method for an unmanned surface vehicle during navigation in a river channel comprises the following steps:
step 1, acquiring boundary information of a river channel or a specified polygonal water area;
step 3, analyzing meeting situation and judging whether collision danger exists or not;
step 4, respectively calculating feasible collision prevention measures for the targets (obstacles or ships) with collision risks;
and 7, determining a final avoidance scheme by taking the distance as a preferred principle.
And in addition, the boundary information of the river channel or the specified polygonal water area in the step 1 is the longitude and latitude information of the vertex of the clockwise polygon of the feasible river channel section or the specified navigation area.
And the obstacle or vessel meeting information in the step 2 comprises information of the position, distance, navigational speed and heading of the static obstacle or the dynamic vessel meeting.
The specific method of step 3 is: calculating a safe meeting distance SDA according to the rotation characteristic, the control precision and the environmental parameters of the unmanned ship; according to the unmanned navigation state and the target information, calculating the nearest meeting distance DCPA and the nearest meeting time TCPA; comparing the sizes of the DCPA and the SDA, if the DCPA is smaller than the SDA, the danger of collision avoidance exists, and entering the step 4; otherwise, returning to the step 2 if no collision danger exists.
Moreover, the step 4 specifically includes: and under the condition of constant speed change, a steering avoidance scheme for safely driving from the left side or the right side of the target is given.
The specific method of 5 is as follows: compared with the steering angle of safely driving from the left side or the right side of the target, the determination that the steering angle is relatively small is a preliminary preferred scheme, and the determination that the steering angle is relatively large is a preliminary alternative scheme.
Moreover, the specific step of calculating the distance between the avoidance point of the preliminary preferred scheme and the avoidance point of the preliminary selected scheme and the river channel boundary in the step 6 comprises the following steps:
(1) respectively calculating the collision avoidance point positions of the two schemes, namely safely avoiding dangerous obstacles when the ship navigates towards the collision avoidance point positions, and directly re-navigating after driving through the collision avoidance point;
(2) river channels on two sides are intersected, and intersection points are extracted to determine boundary line segments on two sides of the current river channel;
(3) respectively avoiding the distances from the collision points to boundary line segments on two sides of the current river channel;
(4) and obtaining the distance from the collision avoidance point of the preliminary alternative scheme to the boundary at two sides of the river channel in the same way.
The specific method of step 7 is: and comparing the distance between the avoidance points of the preliminary preferred scheme and the preliminary selected scheme and determining the final avoidance scheme when the distance is relatively large.
The invention has the advantages and beneficial effects that:
1. the invention provides a collision avoidance decision method based on river channel boundary information, aiming at the collision avoidance problem of an unmanned ship in a river channel, namely a narrow polygonal area, and the collision avoidance decision method is used for calculating in real time and outputting a calculation result in real time, so that a safe collision avoidance scheme is provided for the unmanned ship, and the navigation safety of the unmanned ship is guaranteed. The method is simple, easy to implement and high in practical application value, can be applied to river channel collision avoidance or collision avoidance of specified polygonal water areas, and provides a river channel navigation unmanned ship obstacle avoidance method with high practicability for engineering application.
2. Aiming at the navigation condition of a river channel or an appointed polygonal water area, the invention firstly fully extracts the information of the boundary of the river channel or the boundary of the appointed polygonal water area, determines the feasible water area and avoids the risk of bank contact stranding caused by boundary departure; secondly, providing an avoidance scheme for left steering or right steering of the target through avoidance analysis, calculating the shortest distance from the boundary when each scheme is avoided by combining boundary information, and taking the scheme with the larger distance as a final output decision so as to improve navigation safety and solve the problem of avoiding dynamic and static obstacles when the river is navigated.
Drawings
FIG. 1 is a flow chart of collision avoidance decision making of the present invention;
fig. 2 is a schematic diagram of an example collision avoidance decision of the present invention.
Detailed Description
The embodiments of the invention will be described in further detail below with reference to the accompanying drawings:
a collision avoidance decision method for an unmanned surface vehicle during navigation in a river channel is shown in figures 1 and 2 and comprises the following steps:
step 1, acquiring boundary information of a river channel or a specified polygonal water area;
and the boundary information of the river channel or the appointed polygonal water area in the step 1 is the longitude and latitude information of the vertex of the clockwise polygon of the feasible river channel section or the appointed navigation area.
In this embodiment, the longitude and latitude information of the river channel boundary points is sequentially acquired in a clockwise order.
The boundary information is longitude and latitude information from a point 1 to a point 8 in sequence, and the minimum width of the river channel is 40 m.
the obstacle or meeting ship information in the step 2 comprises information of the position, distance, navigational speed and heading of a static obstacle or a dynamic meeting ship.
In this embodiment, the unmanned ship sensing system includes a navigation radar, a laser radar, and an AIS, and performs real-time detection, target recognition, target tracking, and target fusion to obtain information of a target (here, a static obstacle or a dynamically met ship) such as a position, a distance, a speed, and a heading.
The static target is 62m away from the boat and has the azimuth of 14 degrees; the boat initially sails at 6kn towards 15 deg..
Step 3, analyzing meeting situation and judging whether collision danger exists or not;
the specific method of the step 3 comprises the following steps: calculating a safe meeting distance SDA according to the rotation characteristic, the control precision and the environmental parameters of the unmanned ship; according to the unmanned navigation state and the target information, calculating the nearest meeting distance DCPA and the nearest meeting time TCPA; comparing the sizes of the DCPA and the SDA, if the DCPA is smaller than the SDA, the danger of collision avoidance exists, and entering the step 4; otherwise, returning to the step 2 if no collision danger exists.
In this embodiment, the safety encounter distance SDA is 10 meters, in this embodiment, the DCPA of the static target is 2m, and the TCPA is 20s, so that there is a collision risk.
Step 4, respectively calculating feasible collision prevention measures for the targets (obstacles or ships) with collision risks;
the step 4 is specifically as follows: and under the condition of constant speed change, a steering avoidance scheme for safely driving from the left side or the right side of the target is given.
In this embodiment, the vehicle is steered to pass from the left side of the target or steered to pass from the right side of the target without changing the speed. In the embodiment, two feasible measures of driving from the left side of the target by rotating 7 degrees left or driving from the right side of the target by rotating 6 degrees right exist.
the specific method of the step 5 comprises the following steps: compared with the steering angle of safely driving from the left side or the right side of the target, the determination that the steering angle is relatively small is a preliminary preferred scheme, and the determination that the steering angle is relatively large is a preliminary alternative scheme.
In this embodiment, comparing the two possible measures, the right-turn measure with a relatively small steering angle is determined as a preliminary preferred solution, and the left-turn measure with a relatively large steering angle is determined as a preliminary alternative solution.
the specific method for calculating the distance between the avoidance point of the preliminary preferred scheme and the avoidance point of the preliminary selected scheme and the river channel boundary in the step 6 comprises the following steps:
firstly, respectively calculating the collision avoidance point positions of the two schemes, namely the ship can safely avoid dangerous obstacles when sailing towards the collision avoidance point position and can directly go back to the ground after driving through the collision avoidance point;
secondly, taking the collision prevention point of the primary preferred scheme as the center, making a rectangular area to enable the rectangular area to be respectively intersected with the river channels on the left side and the right side, and extracting intersection points to determine boundary line segments on the two sides of the current river channel;
then respectively avoiding the distances from the collision points to boundary line segments on two sides of the current river channel;
and finally, obtaining the distance from the collision avoidance point of the preliminary alternative scheme to the boundary at the two sides of the river channel in the same way.
In the present embodiment, the avoidance point position B1 of the left-turn measure and the avoidance point position B2 of the right-turn measure are calculated first; then, taking the position of the obstacle target as the center, making a square area with the side length of 60m, and respectively solving boundary line segments, namely 1-8 segments and 3-4 segments, of the obstacle frame, which are intersected with the two sides of the river channel, as a blue frame of the image; finally, the distances from the B1 point to the segments 1-8 and the distances from the B2 point to the segments 3-4 are respectively calculated.
And 7, determining a final avoidance scheme by taking the distance as a preferred principle.
The specific method of the step 7 comprises the following steps: and comparing the distance between the avoidance points of the preliminary preferred scheme and the preliminary selected scheme and determining the final avoidance scheme when the distance is relatively large.
In the present embodiment, a collision avoidance plan with a large distance is selected and output according to the distance value calculated in step 6. In this embodiment, the distance from B1 to the boundary is 8m, and the distance from B2 to the boundary is 19m, so that the output right turn is 6 ° as an avoidance scheme. The invention carries out real-time calculation according to the target information acquired in real time so as to ensure that the optimal collision avoidance scheme is output in real time.
It should be emphasized that the examples described herein are illustrative and not restrictive, and thus the present invention includes, but is not limited to, those examples described in this detailed description, as well as other embodiments that can be derived from the teachings of the present invention by those skilled in the art and that are within the scope of the present invention.
Claims (8)
1. A collision avoidance decision method for an unmanned surface vehicle during navigation in a river channel is characterized by comprising the following steps: the method comprises the following steps:
step 1, acquiring boundary information of a river channel or a specified polygonal water area;
step 2, detecting in real time by using an unmanned ship sensing system during navigation to acquire information of obstacles or ships meeting;
step 3, analyzing meeting situation and judging whether collision danger exists or not;
step 4, respectively calculating feasible collision prevention measures for the targets (obstacles or ships) with collision risks;
step 5, determining a preliminary preferred scheme and a preliminary selected scheme by taking a small steering angle as a preferred principle;
step 6, calculating the distance between the avoidance points of the preliminary preferred scheme and the preliminary selected scheme and the river channel boundary;
and 7, determining a final avoidance scheme by taking the distance as a preferred principle.
2. The collision avoidance decision method of the unmanned surface vehicle in the river course navigation according to claim 1, characterized in that: and the boundary information of the river channel or the appointed polygonal water area in the step 1 is the longitude and latitude information of the vertex of the clockwise polygon of the feasible river channel section or the appointed navigation area.
3. The collision avoidance decision method of the unmanned surface vehicle in the river course navigation according to claim 1, characterized in that: the obstacle or meeting ship information in the step 2 comprises information of the position, distance, navigational speed and heading of a static obstacle or a dynamic meeting ship.
4. The collision avoidance decision method of the unmanned surface vehicle in the river course navigation according to claim 1, characterized in that: the specific method of the step 3 comprises the following steps: calculating a safe meeting distance SDA according to the rotation characteristic, the control precision and the environmental parameters of the unmanned ship; according to the unmanned navigation state and the target information, calculating the nearest meeting distance DCPA and the nearest meeting time TCPA; comparing the sizes of the DCPA and the SDA, if the DCPA is smaller than the SDA, the danger of collision avoidance exists, and entering the step 4; otherwise, returning to the step 2 if no collision danger exists.
5. The collision avoidance decision method of the unmanned surface vehicle in the river course navigation according to claim 1, characterized in that: moreover, the step 4 specifically includes: and under the condition of constant speed change, a steering avoidance scheme for safely driving from the left side or the right side of the target is given.
6. The collision avoidance decision method of the unmanned surface vehicle in the river course navigation according to claim 1, characterized in that: the specific method of the step 5 comprises the following steps: compared with the steering angle of safely driving from the left side or the right side of the target, the determination that the steering angle is relatively small is a preliminary preferred scheme, and the determination that the steering angle is relatively large is a preliminary alternative scheme.
7. The collision avoidance decision method of the unmanned surface vehicle in the river course navigation according to claim 1, characterized in that: the specific step of calculating the distance between the avoidance point of the preliminary preferred scheme and the avoidance point of the preliminary selected scheme and the river channel boundary in the step 6 comprises the following steps:
(1) respectively calculating the collision avoidance point positions of the two schemes, namely safely avoiding dangerous obstacles when the ship navigates towards the collision avoidance point positions, and directly re-navigating after driving through the collision avoidance point;
(2) river channels on two sides are intersected, and intersection points are extracted to determine boundary line segments on two sides of the current river channel;
(3) respectively avoiding the distances from the collision points to boundary line segments on two sides of the current river channel;
(4) and obtaining the distance from the collision avoidance point of the preliminary alternative scheme to the boundary at two sides of the river channel in the same way.
8. The collision avoidance decision method of the unmanned surface vehicle in the river course navigation according to claim 1, characterized in that: the specific method of the step 7 comprises the following steps: and comparing the distance between the avoidance points of the preliminary preferred scheme and the preliminary selected scheme and determining the final avoidance scheme when the distance is relatively large.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116312063A (en) * | 2023-05-23 | 2023-06-23 | 中国船舶集团有限公司第七〇七研究所 | Ship avoidance decision method, device, equipment and medium |
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