Research On Automatic Obstacle Avoidance Path Planning Algorithm Based On Intelligent Bridge Crane

Since the 21 st century,following the rapid development of science and technology,intelligent equipment has stepped towards people’s life and work.Bridge crane,as a large material handling equipment,plays a very important role in the industrial development of our country and even the world.Bridge crane belongs to the traditional machinery industry,although it is developing towards intelligent industry,but it is still in its infancy.At present,the operation of bridge crane is completed by manual,but its working environment is complex,some specific sites are not suitable for manual operation,such as: nuclear waste sites,toxic gas workshop.Besides,Industrial accident can happen easily due to hand operation.This paper will address the above problems using A~* algorithm as the core algorithm of path planning to analyze its shortcomings and improve on the basis of two-dimensional A~* algorithm,and then extend the three-dimensional path planning method of bridge crane.The specific research contents are as follows:Firstly,the whole operation system of intelligent crane is analyzed,and the intelligent operation system is divided into man-machine interaction system,information acquisition system,central control system and motion control system.The functions and relevance of each system are explained,and the complete operation process is shown in the form of flow chart;Some key technologies of intelligent crane are described.Then,the shortcomings of two-dimensional A~* algorithm are analyzed and improved.The double layer security base grid method is used to build the map model to ensure the path security.The heuristic function of A~* algorithm is improved,and the improved estimated value is closer to the actual value,which improves the search efficiency and accuracy.The node optimization strategy is proposed to delete redundant nodes and reserve key nodes,which shortens the path and reduces the number of inflection points.A real-time obstacle avoidance method is proposed,which integrates the improved A~* algorithm with DWA algorithm to avoid the "lost phenomenon" caused by using DWA algorithm alone,so that the bridge crane has the ability to deal with sudden obstacles and dynamic obstacles,and enhances the adaptability of bridge crane in complex working environment.Finally,on the basis of improving two-dimensional A~* algorithm path planning,combining with the structural characteristics and movement rules of bridge crane,the three-dimensional path planning method of bridge crane is extended to solve the problems of unreachable targets and high path complexity in two-dimensional A~* algorithm path planning.According to the improvement of the node expansion rule,the path length is shortened,meanwhile,the quantity of inflection points is reduced,heuristic function and path optimization of three-dimensional A~* algorithm.This modified three-dimensional A~* algorithm can better meet the path planning of the bridge crane via improving the three-dimensional A~* algorithm with the DWA algorithm to make the bridge crane have the ability to deal with sudden obstacles and dynamic obstacle avoidance on the spatial translation surface.