Research On Path Planning And Co-ordination Algorithm Of Parking AGV

With the continuous increase of car ownership in China,the problem of urban parking is becoming increasingly prominent.As a new solution to alleviate the problem of parking,AGV intelligent parking has attracted more and more attention.In the AGV intelligent parking garage,vehicles are mainly transported by parking AGV,so the path planning and cooperative scheduling strategy of AGV is directly related to the stable and efficient operation of the parking garage.Taking AGV intelligent parking garage as the research background,this paper mainly studies the path planning algorithm of AGV and multi AGV cooperative scheduling strategy.At the same time,in order to improve the operation efficiency of the system,the AGV battery charging problem and parking resource scheduling problem are studied.According to the layout characteristics of the AGV intelligent parking garage,this paper uses the grid map method to construct the environment model,and researches the path planning algorithm on the established grid map: for the traditional A* algorithm,the operating efficiency is too low when the map is large.The problem is to preprocess the map based on the characteristics of the established environment model;to deal with the problem of too many inflection points of the path planned by the traditional A* algorithm,the estimated turning cost is introduced and multiple parent nodes are set for each extended node.In view of the collision and congestion that may occur when multiple AGVs are running at the same time,the corresponding scheduling strategy is formulated according to the collision type,and the optimization strategy based on the time window method is used to avoid the occurrence of traffic congestion.Aiming at the problem of AGV battery charging,offline charging is adopted as the main online charging method,and the corresponding charging scheduling strategy is formulated according to the characteristics of offline charging and online charging.Aiming at the scheduling problem of parking space resources in the parking garage,considering the parking time of vehicles,a scheduling strategy based on parking time allocation is proposed and compared with the random allocation strategy and the strategy of preferentially selecting the parking space closest to the pick-up point.Through the comparison of simulation results,after preprocessing the map in this paper,the path planning algorithm is up to 10 times longer than the traditional A* algorithm.To deal with the problem of the number of inflection points,the number of inflection points of the path planned by the improvement measures is similar.Compared with the traditional A* algorithm,it is more than doubled.The multi-AGV collaborative scheduling strategy can efficiently resolve the conflicts between AGVs.Compared with the traditional traffic rules method,the scheduling strategy used in this article can reduce the task completion time by about 35%.Offline charging is the main charging method supplemented by online charging.It makes full use of the idle time of the task for charging,and at the expense of charging frequency,it ensures that the number of AGVs available at any time period is not less than the actual number of AGVs required.In the parking space resource scheduling problem,the parking time allocation strategy proposed in this article is not as high as the task intensity and only a small part of the parking space is needed to meet the parking demand.The performance is not as good as the priority selection of the closest to the pick-up point.Parking space strategy;However,when the task intensity is high and most of the parking spaces in the parking garage are used until the time,the performance is significantly better than the other two scheduling strategies.Therefore,the research content of this paper is of certain significance to ensure the efficient and stable operation of the AGV intelligent parking garage and alleviate the difficulty of urban parking.