Research On Target Tracking Strategy For Unmanned Surface Vehicle

Unmanned surface vehicle is a kind of intelligent marine motion platform,it is a small,good mobility and autonomous decision-making ship.It replace of human beings to carry plenty of complex dangerous tasks by installed all kinds of modular sensor or combat equipment.It will play an important role in future military combat.This paper specifically research on the target tracking strategy.It put forward two different tracking strategies depending on different scenarios.Aiming at the ideal tracking environment,we constantly adjust the course and speed in a restricted area to track the target.Aiming at the cluttered environment,we put forward the tracking strategy of real-time path planning to search a less consumption and covert path.Firstly,the paper classifies the target tracking problem.It introduce the arithmetics about tracking in visual field of image and the arithmetics that a real robot track the target.It may be continue to classify about this problem.The USV is underactuated and hysteresis.And the tracking maybe happen on the cluttered environment or ideal environment.It show that how to solve this problem and what I need to achieve.Secondly,This paper focuses on the tracking strategy in complex environment.I take A* search algorithm as the first choice because of the time constrain,JPS algorithm is improved and compared with A* in the run time and memory consumption.Then considering the dynamic characteristic of the USV,I use the Dynamic Windows Approach Sample to get the arc trajectory.In the path planning process,I choose the method of layer generation path.So two parameters are used to trade off the computation time and optimality of the path.There are many constraints when it run in the real ocean channel,so we try to give the solutions.Finally,I design two experiments to verify the tracking effect.In the simple environment,I use the fuzzy method to calculate surge speed,and use geometric method to calculate heading.Target tracking happen in the restricted area.I use three tracking headings to verify tracking effect,and change the frequency of algorithm to observe the different results.This simulation explain that off-line fuzzy method is unsuitable the all target movement situations.In complex environment,I test the behavior set parameters how to influence the length of the trajectory and the computation time.To verify the effect of velocity adjusting to avoid moving obstacle in three kinds of active collision avoidance situations.When using dynamic path planning as the tracking strategy,the USV can effectively avoid static obstacles and shorten the tracking distance and achieve hidden tracking.