Research On The Method Of Formation Path Planning For Wave Gliders

Wave Glider is a wave-driven surface vehicle capable of long-term operation.With the deepening of the research on multi-regional coordinated observation of oceans,topographic and geomorphological mapping,the formation of multi-wave glider network formation is the development trend in future.During the travelling of wave glider,how to realize the cooperation of wave glider formations,and how to ensure the optimal travel route and avoid obstacles safely under the conditions of obstacles such as islands and buoys in the ocean,and how to proceed according to the principle of energy optimization under the interference of ocean currents are the difficult points that need to be overcome.In view of the above problems,the path planning algorithms of wave glider formation was researched in this thesis,and the following research work has been finished.Firstly,a four-degree-of-freedom kinematic model of the wave glider was established.When studying the path planning problem,the global path was used as a reference path for the purpose of guidance,while the aim of local path planning is to navigate and pass the steering angle to the next execution controller.The kinematic constraints were introduced into the global and local path planning algorithm to make it more realistic,and this method had a significant effect on improving the continuity and smoothness of the path.Secondly,taking into account the kinematic constraints of the wave glider,the existing A * global path planning algorithm was improved to enhance the safety of the planned path.The distance constraint was added to reduce the amount of calculation and calculation time.The steering cost was introduced in the heuristic function,which avoided frequent turns when the wave glider was traveling.The redundant point elimination method was used to eliminate redundant points of the planned path,shorten the planned path length,and pave the way for subsequent local path planning algorithms.Thirdly,instead of the traditional vector force,the potential field strength was used to establish a potential field strength model and improve the local path planning algorithm of the artificial potential field.Combining with the improved global path planning algorithm,a local multi-sub-target artificial potential field algorithm was proposed to overcome the shortcomings that easily fell into the local minimum domain of the existing artificial potential field algorithm.A formation control strategy under random state was proposed for formation forming and formation maintenance.Fourthly,to solve the problem of excessive energy consumption of the full power drive of the wave glider under the disturbance of the ocean current,a progressive optimal path planning using the energy optimization as an index was proposed,and a current model was established by a numerical method.A progressive optimal path was obtained by the algorithm,which improved the travelling efficiency of the wave glider,reduced energy consumption and shortened the time to reach the target point.Finally,the experimental platform was constructed and sea trial experiments were performed to verify the effectiveness of the wave glider formation path planning algorithm and formation strategy.