With autonomous driving of robotic vehicles, path planning is one of the key challenges we face with. For coordinated operation of a group of automated guided vehicles (AGV) in the transport of material in modern warehouses and production facilities, part of path planning is also avoidance of potential conflicts. In this paper, we propose a new path planning approach with an algorithm which is based on the well-known algorithm A* and upgraded for path planning of multiple AGVs in such a way that it finds a solution without collisions and unnecessary congestions. The approach considers the priorities of transport orders, the map in the form of a weighted oriented graph, and the predicted time windows of the occupancy of the map segments. The algorithm first finds a path for AGVs with higher priorities. At the end of path planning for every AGV, the algorithm marks predicted time windows of occupancy of roads and nodes according to found path. These occupancies are then considered when planning a path for an AGV with a lower priority so that it does not obstruct the driving of AGVs with a higher priority and so that it avoids conflict. Two important options that the algorithm considers and suggests are waiting in front of the node or on the way to the node in order to clear the passage, and the possibility of r moving out of the way to a side road in case the waiting is disabled. The algorithm also takes into account the possibility of several vehicles driving on the same road at the same time and the option of restarting planning at any time. The approach is evaluated on simulation cases.
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