ANALYSIS OF COLLISION AVOIDANCE IN MULTIROBOT CELLS USING PETRI NETS.

The analysis of cycle times in multirobot assembly cells involves the representation, specification and modelling of the cell activities. Since such activities are concurrent and asynchronous in nature, Petri nets may be used as an expedient analysis tool. The cell operations in actual cells are of a stochastic nature and involve real time control strategies. Thus analytical approaches cannot be used to analyse the resulting Petri nets. We use a generalised Petri net simulator called ROBSIM to simulate Petri net models of the multirobot cell. This paper outlines a generalised procedure for addressing the collision aspect in evaluating the cycle times using ROBSIM. We believe that the procedure can also be used for other aspects of synchronization in multirobot applications.