Research And Application Of Multiple AGVs Path Planning Using A Time-Space Network Model

With the development of flexible manufacturing system(FMS)and stereoscopic warehouse(SW),the requirements for the automatic mode of material transportation are increasing gradually.Therefore,the automatic guided vehicle(AGV)has been used widely in the world and the research on AGV related technology has become the current research hotspot.In this paper,path planning of AGV,one of the key technologies of AGV system,is studied in order to optimize the path of multi-AGV system without conflicting.This paper proposed a new approach for collision-free path planning of AGVs using flexible time-space network(FTSN)models.Existing time-space network(TSN)models for path planning of AGVs consider fixed transportation time between two adjacent nodes.The AGVs stop and wait or choose to bypass other paths to avoid conflict in the system.In the proposed FTSN model,transportation time are regarded as decision variables and the waiting time can be transformed into longer transportation time.It can effectively avoid the repeated start and stop actions during the operation of AGV and search the optimal path of AGV transportation.Based on the topological structure method,this paper builds the electronic map of the running environment of AGVs.Aiming at the TSN model and the FTSN model,extensive case studies involving different numbers of vehicles and network scales are carried out.In the experiment,the shorests transportation time is taken as the optimization goal.And it mainly analyzes the path planning results,the transportation time,the traveling distance,the energy consumption of AGVs and the computing time.Simulation results show that the proposed model can achieve slightly shorter transportation time and traveling distance to finish the given tasks compared to the existing TSN model.So the results prove the efficiency of the FTSN model.Taking the above research as the theoretical basis,this paper takes the mesh routing as the transportation environment and uses the two wheels differential drive robot car with fixed guidance path to carry out the application experiments.The experimental results show that the path planning approach proposed in this paper is reliable and feasible in the collision-free path planning of multiple AGVs system.It can improve the transportation efficiency of FMS.Therefore,it plays the role of theoretical reference and guiding significance for the production and application of multi-AGV system.At last,the research work of this paper is summarized briefly and the prospect and planning research for the next step of the research are put forward.