CN-122018548-A - Method for planning trapping path based on improved artificial potential field method

CN122018548ACN 122018548 ACN122018548 ACN 122018548ACN-122018548-A

Abstract

The invention provides a trapping path planning method based on an improved artificial potential field method, which comprises the steps of generating trapping reference points according to real-time motion data of a target boat, constructing artificial potential field resultant force comprising trapping reference point attractive force, inter-boat collision prevention repulsive force and target safety zone repulsive force, introducing an adaptive gain and weight adjustment mechanism, mapping the artificial potential field resultant force into unmanned boat control quantity, mapping resultant force direction into heading, mapping resultant force amplitude into speed, combining unmanned boat speed and steering constraint to generate a control instruction, dynamically adjusting safety zone repulsive force weight according to the distance between a trapping boat and a target safety zone boundary, enabling the trapping boat to keep approaching capability in a long-distance stage, enhancing safety constraint in a short-distance stage, updating trapping reference points, potential field resultant force and control output in real time, and judging trapping termination according to whether the trapping boat meets zone arrival conditions. The invention effectively suppresses the unreachable problem caused by local minimum values, gives consideration to the collision prevention of multiple boats, and reduces the path oscillation.

Inventors

ZHENG KAI
CHEN LIN
GAO QIQIANG
LIANG XIAO
JIANG YI

Assignees

大连海事大学

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (9)

1. The method for planning the trapping path based on the improved artificial potential field method is characterized by comprising the following steps of: s1, calculating N evenly-distributed trapping reference points on a circumference taking a target boat as a center according to real-time motion data of the target boat; S2, constructing an artificial potential field force comprising the attraction force of the trapping reference points, the collision prevention repulsive force between boats and the repulsive force of a target safety zone according to the trapping reference points, and introducing a self-adaptive gain and weight adjustment mechanism; S3, mapping the artificial potential field resultant force into unmanned ship control quantity, mapping the resultant force direction into heading, mapping the resultant force amplitude into speed, and generating a control instruction by combining unmanned ship speed and steering constraint; s4, dynamically adjusting the repulsive force weight of the safety zone according to the distance between the trapping boat and the boundary of the target safety zone, so that the trapping boat keeps approaching capability in a long-distance stage, and safety constraint is enhanced in a short-distance stage; s5, circularly executing the steps S1 to S4 according to a preset control period, updating the trapping reference point, potential field force and control output in real time, and judging the trapping termination according to whether the trapping boat meets the region arrival condition.
2. The method for enclosure path planning based on the improved artificial potential field method of claim 1, wherein step S1 comprises: S11, acquiring real-time motion data of a target boat, including position, course and speed; s12, at the target boat position The surrounding construction radius is Is defined by a reference circumference of (2); S13, generating N evenly distributed reference points on the reference circumference Calculate the first The coordinates of the surrounding reference points are defined as follows: Wherein, the For the reference radius, N is the number of reference points.
3. The method for enclosure path planning based on the improved artificial potential field method of claim 1, wherein step S2 comprises: s21, uniformly adopting a two-dimensional plane coordinate system, wherein the position, the speed and the force are two-dimensional vectors respectively expressed as Distance, distance Is scalar, is calculated by Euclidean norm, and has any two points And (3) with The distance between them is defined as: s22, constructing a trapping boat The artificial potential field forces are as follows: Wherein, the As the weight of the gravitational force, Is a trapping boat The attraction vector to which the reference point is assigned, In order for the repulsive force to be weighted, Is the first First and second The repulsive force between the boats is caught, For the repulsive force weight of the safe zone, Is a trapping boat Is a safe zone repulsive force.
4. A method of claim 3, wherein the method comprises the steps of Gravitational vectors pointing to their assigned reference points The definition is as follows: Wherein, the As the coefficient of the gain of the attraction force, Is the first The current position coordinates of the boat are captured, Representing displacement vector pointing to trapping reference point from current position of trapping vessel to avoid trapping vessel When approaching the reference point, frequent fine adjustment or overshoot is generated due to overlarge attraction force Cut off the upper limit, or appropriately decrease in the short distance stage 。
5. A method of enclosure path planning based on an improved artificial potential field method according to claim 3, wherein the first step is First and second Repulsive force between ship and ship The construction process of (1) comprises: Setting a minimum distance threshold The method is used for avoiding numerical divergence caused by excessively small denominator zero; Set the first First and second The distance between the surrounding boats is ; When (when) Time of day When (when) At the time, the first First and second Repulsive force between ship and ship The definition is as follows: Wherein, the In order for the repulsive force to act over a distance, The repulsive force gain is increased, the repulsive force in the speed direction is used for avoiding the serial following of a plurality of boats, and the repulsive force gain is increased when the speed direction is similar and the distance is relatively close to the speed direction in order to avoid the serial trailing phenomenon of the plurality of boats in the process of trapping Or adjust the repulsive force direction to enhance the lateral separation ability.
6. A method of claim 3, wherein the method comprises the steps of Is a repulsive force of a safety zone of (2) The construction process of (1) comprises: Setting the target position The radius of the safety zone is Order-making ; When (when) In the time-course of which the first and second contact surfaces, When (when) When in use, the ship is caught Is a repulsive force of a safety zone of (2) The definition is as follows: Wherein, the In order to be the range of action of the safety zone, The repulsive force is increased for the safety zone, and the repulsive force item prevents the trapping boat from approaching the target excessively in the terminal stage, so that the safety and stability of the trapping process are ensured.
7. The method for enclosure path planning based on the improved artificial potential field method of claim 1, wherein step S3 comprises: s31, setting a trapping boat The artificial potential field force is ; S32, enclosing the boat The artificial potential field force is converted into course angle The following are provided: s33, enclosing the boat The magnitude of the applied artificial potential field force is mapped to speed The following are provided: Wherein, the As a function of the base speed of the vehicle, For the speed to be mapped to the gain factor, Is the maximum speed upper limit, and the cut-off function is defined as 。
8. The method for enclosure path planning based on the improved artificial potential field method of claim 1, wherein step S4 comprises: S41, when Entering the area of influence of the safe zone When the repulsive force weight of the safety zone is increased ; S42, adjusting the repulsive force weight of the safety area by adopting linear or cut-off based on distance : Wherein, the As an initial weight of the potential field of the safe area, Gain factors are adjusted for safe zone weights.
9. The method for enclosure path planning based on the improved artificial potential field method of claim 1, wherein step S5 comprises: s51, controlling period Step S1 to step S4 are circularly executed, the states of the target boat and the capturing boat are updated in each period, the resultant force of the reference point and the potential field is updated, and a control instruction is output ; S52, in order to reduce frequent fine adjustment caused by accurate point reaching of the terminal, converting point reaching into area reaching, and defining a trapping target to be centered on a reference point and radius Is a circular area of the ship, and the trapping boat enters the area, namely is regarded as reaching the target; s53, set area determination conditions are as follows: Wherein, the Is the first The ship is used for capturing the current position of the boat, Assigning a reference point center thereto; S54, ending the trapping process when all trapping boats meet the set region reaching judgment conditions and keep stable formation or meet the preset termination conditions.

Description

Method for planning trapping path based on improved artificial potential field method Technical Field The invention relates to the technical field of unmanned ships and unmanned ships cooperative control and motion planning, in particular to a method for planning a trapping path based on an improved artificial potential field method, which is used for real-time path planning, obstacle avoidance and cooperative convergence control of a plurality of unmanned ships on water under the interaction of dynamic targets and ship groups. Background With the rapid development of ocean technology, unmanned boats on the water surface are widely applied to the fields of ocean monitoring, maritime search and rescue, sea patrol and the like. The trapping task is used as a typical scene of the collaborative operation of a plurality of unmanned boats, the target is in a water area, continuous approximation and space constraint are implemented on a moving target, the moving space of the target is continuously reduced, and finally the limitation or the capture of the target is realized. In the trapping process, the path planning needs to meet the requirements of real-time performance, stability and safety, so that the rapid convergence of multiple boats is ensured, the collision between the boats is avoided, the trapping formation is invalid, and the requirements of safety distance and the like are met. The artificial potential field method is widely applied because of small calculated amount, easy realization and natural fusion of target guidance and obstacle avoidance. In the trapping scene, a target or a trapping reference point is generally regarded as an attractive force source, an obstacle and other trapping vessels are regarded as repulsive force sources, and the movement direction and the movement speed are generated through the resultant force direction, so that the cooperative approximation of multiple vessels to the target is realized. However, the traditional artificial potential field method still has certain defects in the multi-unmanned-ship trapping scene, local minima are easy to occur, so that the unmanned ship is easy to stagnate, detour or wander when not reaching a reference point, heading swing, speed shake and occupation conflict are easy to occur due to mutual interference in the multi-ship simultaneous convergence process, formation closing is influenced, overshoot and short-distance oscillation are easy to occur in the terminal stage, and trapping stability is reduced. In addition, because the parameters of the traditional artificial potential field method are usually fixed, the method is difficult to adapt to the requirements of different stages in the trapping process. Therefore, a path planning method of an improved artificial potential field method for a multi-unmanned-ship trapping scene needs to be designed, the unreachable problem caused by local minima can be effectively restrained while the real-time performance is maintained, the multi-ship collision prevention is considered, the path oscillation is reduced, and the safe and stable collaborative trapping convergence is realized, so that the success rate and the efficiency of trapping tasks are improved. Disclosure of Invention According to the technical problems that local minima easily occur under a multi-unmanned-ship trapping scene by the traditional artificial potential field method to cause unmanned-ship stagnation, detouring or loitering, course swing, speed shake and occupation conflict are generated due to mutual interference in the multi-ship simultaneous convergence process, overshoot and close-range oscillation easily occur in a terminal stage, and fixed parameters are difficult to adapt to requirements of different stages of the trapping process, the trapping path planning method based on the improved artificial potential field method is provided. According to the invention, by constructing the multi-source composite potential field and introducing the self-adaptive gain and weight adjustment mechanism, real-time path planning, cooperative convergence and safe obstacle avoidance in the multi-unmanned ship trapping task are realized, and the trapping efficiency and success rate are improved. . The invention adopts the following technical means: an enclosure path planning method based on an improved artificial potential field method comprises the following steps: s1, calculating N evenly-distributed trapping reference points on a circumference taking a target boat as a center according to real-time motion data of the target boat; S2, constructing an artificial potential field force comprising the attraction force of the trapping reference points, the collision prevention repulsive force between boats and the repulsive force of a target safety zone according to the trapping reference points, and introducing a self-adaptive gain and weight adjustment mechanism; S3, mapping the artificial potential field resultant force into unmanned