The handling of one AGV is simple, but how to arrange a number of AGVs reasonably to achieve the highest efficiency, which requires the use of AGV scheduling system. Once the AGV dispatching system specifies the path for the vehicles, the vehicle controller on the AGV will complete specific motion control tasks according to the instructions, such as speed to maintain, how to rotate wheels when turning at intersections, and so on. Therefore, in a complete system, AGV dispatching system is located in the middle of the upper control system and the lower control system, and its role as a housekeeper. For multiple AGVs, the scheduling problem becomes very difficult, and the more AGVs there are, the more difficult it is. Therefore,AGV dispatching system has become a key technology in AGV industry.
Quantity of AGVs that can be scheduled also becomes an important index to judge whether a scheduling system is strong or not. For this, Mircolomay said: at present, there are not many AGV enterprises that have independent R&D AGV scheduling system, and the number of AGV enterprises that can really optimize the scheduling system and make the most efficient use of AGV system is few. The software of AGV dispatching system developed by Mircolomay has many functions, such as task management, vehicle status monitoring, path planning, map editing, database query, etc.
The scheduling of multiple AGVs requires planning different AGV paths, so we first understand the existing path planning methods. AGV is a obedient robot. If the dispatching system wants AGV to move from point A to point B, it can not simply give the information of sites A and B to AGV, but tell AGV the complete path between A and B. At present, "graph" is widely used to model the driving space of AGV, and "graph" consists of nodes and edges. So the AGV's traveling path can be expressed as a series of adjacent nodes.
Mircolomay believes that AGV scheduling problem can be regarded as a special case of multi-Robot Coordination. Multiple robots share an environment, how to coordinate their movements so that all robots can achieve their goals. The multi-robot coordination problem is discussed in order to have a better understanding of the scheduling problem. One of the earliest and simplest methods is to set different priorities for different robots. The robot with higher priority first plans its own path, and the robot with lower priority regards the path of the robot with higher priority as an obstacle, and then plans it. Of course, this method has one obvious disadvantage: the high priority robot is too aggressive, it blocked all the roads, so that the low priority robot can not find the way. Then we have to adjust our priorities.
