Research Of AGV Automatic Material Handling System

With the "Made in China 2025" put forward,traditional manufacturing plants need to be transformed to intelligent factories.The primary task is to achieve unmanned workshop.As a workshop transportation tool,Automatic Guided Vehicle(AGV)will be an important part of achieving unmanned workshop.AGV scheduling and conflict-free path planning are key technologies to effectively implement these AGV handling systems.Therefore,they are studied from the perspective of deadlock and conflict.Firstly,a single AGV path planning technique and the operating environment modeling are investigated.The electronic map file structure is designed to transform the environment map into the information that the source program can recognize.Based on the above electronic map information,some common single AGV path planning algorithms are realized.Secondly,a multi-AGV collision free path planning algorithm based on improved A* is proposed.It sloves the problem of deadlock and conflict by combining time window and A* algorithm.Furthermore,it introduces the turning factor in the evaluation function of A* algorithm to make the AGV motion path smoother.The strategy of dynamically adjusting expected driving distance of AGV according to the performance solves the error problem between the time window and the actual operation of AGV.Thirdly,urgent tasks can't reach the optimal path according to the priority using the improved A* algorithm.And the AGV path needs to be replanned during emergency.Therefore,a multi-AGV coordination based on the improved A* algorithm and embedded priority is presented.With the goal of minimizing the AGV delay time,the scheduling takes priority into account,so that urgent tasks can be completed through a shorter path.In addition,the control architecture of multi-AGV scheduling system is proposed based on coordination graph.It is divided into three layers: task layer,scheduling layer and execution layer.Finally,the AGV scheduling software is developed to realize the system function of material handling.The control strategy based on improved A* algorithm is verified by simulation.