Research And Implementation Of Unmanned Vehicle Path Planning In Park

Unmanned vehicle is one of the important research directions in the field of robot technology application,and advanced technologies in various fields are widely used.Autonomous navigation is the basic function of unmanned vehicle,among which path planning is one of the core technologies of autonomous decision-making of unmanned vehicles.At present,the path planning technology is more and more mature in the park unmanned vehicle application,but there are still some problems:(1)without GPS,the park area is large,the search path speed on map model is slow,and it is difficult to meet the requirements of real-time planning;(2)the complex environment of the park,many dynamic obstacles,the speed and safety of unmanned vehicles can not be considered;(3)the road searched out There are many problems in the path,such as redundant path,many nodes in the path,and the difficulty of unmanned vehicle control.In this paper,the method of mixed map layer is used to carry out path planning,in which the topological map layer is used for global path planning,and the grid map layer uses the improvement and fusion of dynamic window approach and A*algorithm to carry out local path planning.Local area selects the optimal path according to the evaluation function at every moment,and obtains the optimal path of the whole park.The main research contents are as follows:Firstly,the environment of the park is analyzed,and the park is abstracted as a topological map model for global path planning.The A* algorithm is adopted,and the European distance is taken as the substitute value to obtain the global optimal path,which solves the problem of slow searching path of the large area map in the park;secondly,under the grid map,the limitations of A* algorithm and dynamic window approach are analyzed.Dynamic window approach is easy to fall into local trap,can not consider speed and security,and A* algorithm has problems such as the failure of dynamic obstacle avoidance,path irregularity,redundant points and redundant turning points.The two algorithms are verified separately,and it is found that the single algorithm can not meet the path planning between the local topological points.Therefore,a global dynamic path planning method combining the improved A*algorithm and the adaptive dynamic window approach is proposed.The method can solve the problems of local obstacle avoidance and the consideration of the speed and safety of unmanned vehicles.Finally,according to the situation of road blockage due to the complex obstacles and many obstacles in the park In case,local and global paths need to be re planned.Re-planning is to re plan the path on the connectivity road or safety area of the map.In conclusion,this paper adopts the Hybrid Map hierarchical path planning method of the global path planning and the grid map local planning.The simulation results show that the method can search global paths quickly and meet the real-time requirements in the park.The local paths can take into account the speed and safety of unmanned vehicles,and the planned path nodes are few,the path is smooth,and it meets the constraints of dynamics,and an optimal path can be obtained as a whole.