Abstract: An approach to robotic assembly task scheduling is presented, which yields an optimal solution. Times Petri nets are used to model the assembly activities of a flexible assembly cell (FAC) including two assembly robots, a screw robot and a manufacturing center. The execution times of assembly activities are determined during the generation of reach ability graph and an algorithm to determine the minimum-time paths is proposed, the simulation and experiments show that the task scheduling approach can calculate the time more accurately and it can generate the assembly plan better.

Key words: Assembly planning, Robotic assembly, Timed Petri nets