Research On Motion Planning For Autonomous Underwater Vehicle

Along with the depletion of resources on the land and the development of humansocieties, people’s demand for natural resources is gradually shifted from land to the richmarine resources. In the past half century, the underwater robot technology has gained acomprehensive development and was widely used in the exploitation of marine resourcesand ocean space.AUV works in unknown and structured ocean environment to complete complex tasks.The research of motion planning for AUV is an important direction of current research. Themotion planning for AUV mainly includes two aspects of path planning and motion control.This paper studies the path planning and motion control of AUV respectively, and the mainwork of this paper is as follows:Firstly, the present research of path planning method and motion control technology isdiscussed in detail, and the environment model and planning method of the path planning isintroduced.Secondly, this paper expounds the mathematical foundation of the simple geneticalgorithm, and the genetic operators of genetic algorithm are analyzed in detail. By makingimprovement on the basis of the simple genetic algorithm, the global path planning methodfor AUV based on genetic algorithm is researched. The environment model of AUV isdescribed by grid map, and the path is encoded into serial number notation encoding.Selection operator, crossover operator, mutation operator and delete operator are designedso that GA can be lead to an optimized result rapidly. And the effectiveness of the proposedmethod is verified by simulation experiment.Thirdly, this paper analyzes the motion and force of AUV, and the six-degree offreedom space motion model of AUV is established. For the need of project research, propersimplification to the model is conducted, so the four-degree of freedom motion model ofAUV is attained.Lastly, this paper adopts sliding mode variable structure control algorithm to realize themotion trajectory tracking of AUV. The sliding mode controllers are designed based onindex reaching law and quasi-sliding mode, and the simulation experiment of motiontrajectory tracking for AUV is conducted. The simulation results show that, the sliding modecontroller based on quasi-sliding mode well weakens the chattering and get goodperformance in trajectory tracking.