Petri Nets and Dual-Handed Assembly Robots

A method to detect and manage collision situations of the concurrent operations made by two robot arms in a shared work space is presented. Two different strategies, collision avoidance and in-turns operation are considered. The operation of a dual-armed assembly robot is modeled using Petri nets. The model is then tested by the means of an animated virtual assembly system. By observing the operation of the virtual robot, the observer can verify that the robot arms work correctly and that the possible deadlock situations are avoided successfully. Finally, the performance of the collision avoidance method and that of the in-turn operation mode are compared.