The Use of Petri Nets for the Performance Evaluation of Robotic Welding Cells

The paper presents how T-timed Petri nets can be used to model and simulate a robotic manufacturing cell. The cell is designed to make a welded subassembly composed of three types of parts. Two welding robots and one handling robot work within the cell. The development of Petri net models was gradual. The first model assumed the accumulation of welding times from robots 1 and 2. The results obtained by simulation were not satisfactory. The second version of the model assumed the division of the operations performed by the components of the cell into elementary sequences. The third version of the model with Petri nets also includes the supply sequences of the stocks with the components to be welded.