Research On AUV Obstacle Avoidance Strategy For Marine Cable Inspection Based On Fuzzy Artificial Potential Field Method

With the increasing emphasis on the development of marine resources,marine environmental protection and maintenance of marine rights,autonomous underwater robots(AUVs)have become a key research topic in many countries because of their low cost,wide range of activities and low environmental impact.Therefore,underwater obstacle avoidance algorithms have become one of the key research areas in the field of AUVs.Underwater obstacle avoidance algorithms are divided into two types: path planning obstacle avoidance in known environment and real-time obstacle avoidance in unknown environment,both of which are studied in this paper.Firstly,this paper selects the raster method to establish the working environment map of AUV for the path planning in known environment.Meanwhile,in order to better simulate the unknown complex ocean environment,this paper creates static obstacle model,dynamic obstacle model with uniform linear,uniform accelerated linear,uniform turning and random motion characteristics and ocean current model to lay a good foundation for the research of underwater obstacle avoidance algorithm in the later paper.Then,this paper selects the artificial potential field algorithm as the basic algorithm of path planning obstacle avoidance,and explains the basic principles,advantages and disadvantages of the traditional artificial potential field algorithm,as well as several classical improvement methods.In view of a series of problems arising from the traditional artificial potential field method in path planning obstacle avoidance,this paper proposes a fuzzy artificial potential field method that integrates fuzzy algorithm and artificial potential field method,adds the influence of ocean current force on AUV,modifies the potential field function,uses the fuzzy algorithm to obtain the navigation speed of AUV,takes it as the input of the improved artificial potential field method,calculates the AUV steering angle by improving the algorithm,and avoids obstacles by controlling the speed and steering angle of AUV,which makes up for the shortcomings of the traditional artificial potential field method.Verify the effectiveness and superiority of the improved algorithm.Secondly,two evaluation functions are designed according to different task requirements,namely the shortest path evaluation function and the lowest energy consumption evaluation function.In the scenarios of three different conditions,the simulation comparison experiment between the improved algorithm and the traditional algorithm is carried out and the evaluation function is obtained,and it can be seen that the path length of the improved algorithm is shorter and the energy consumption is lower in the known environment.Finally,under the condition that the local environment is unknown,the surrounding obstacle information is perceived by obstacle avoidance sonar P360,and a map update and replanning mechanism is proposed based on the rolling window method: polynomial fitting is used to dynamically predict unknown dynamic obstacle trajectories,and the real-time map and algorithm replanning are decided to update according to the prediction results.The performance of the algorithm in real-time path planning and obstacle avoidance of AUV is analyzed through simulation experiments,and the experimental results show that the proposed method meets the requirements of real-time obstacle avoidance of AUV in complex marine environment.