Research On Fast Route Planning For Underwater Unmanned Vehicles

As a main component of autonomous navigation system, path planning plays an important role in Underwater Unmanned Vehicle(UUV). For an UUV to perform a scheduled task, in the presence of obstacles and other constraints, finding a safe and efficient path is a very important and complex work. In this paper, the problems of finding an optimal path for an UUV under ocean environment is discussed. First Establish the marine environment modeling for path palnning, then study route planning methods based on this model.In this paper, the research background of the path planning field is introduced, and a brief description of several typical planning algorithms is given.This paper discusses problem of the route planning under complex ocean environment, and then the problem on how to build a reasonable model of ocean environment is studied. Firstly the vector electronic charts,which is the data source of the environment model, is introduced. Then the process modeling ocean environment is described in detail. The entire planning area is divided into small grid in accordance with the principle that all grid scale is same,and then environment area information is added to each grid.Based on the model of ocean environment, this paper proposes a fast route plan method based inter-visibility analysis. This method uses "walking to see" strategy which checks inter-visibility between the current point of aircraft and the target point and then decides the way to move forward. After several inter-visibility analysis, aircraft can reach the target avoiding constraint regions. The method can get planning result in a short time,however it is difficult to guarantee optimal since "walking to see" strategy is actually a greedy algorithm. On the basis of the inter-visibility check, we proposed heuristic route planning method based the inter-visibility cost. The method uses the inter-visibility cost as the global heuristic information to ensure optimal result. In this paper, multiple sets of comparative experiments are made, and experimental results are analyzed in detail. The results show that fast route planning method based visibility analysis is faster, however the optimality of the results discounted. heuristic route planning method based the inter-visibility cost, slower rate than the former, can obviously a better path.Finally, the UUV route planning system is introduced,and the overall design of the system, including system module design, the overall flow of the system and system interface, is described. Last the two and three dimensional simulation results is showed.