Optimal Task Sequence Planning for High Speed Robotic Assembly Using Simulated Annealing

Abstract

Optimal task sequence planning using a simulated annealing technique is developed for a high speed assembly station comprised of two robots. In order to minimize the tact time, parts are assembled by dual robots on moving workpieces which are transferred by a precision conveyer. The sequence of operations by the dual robots is optimized to minimize the tact time while avoiding the geometric and dynamic interferences between the dual robots. The optimization problem is a type of traveling salesman problem, but is highly complicated because the target destinations for placing individual parts keep moving on the conveyer. The speed of the conveyer which carries the workpieces should be also optimized in order to maximize the throughput of the assembly system. The task sequence optimization problem is formulated together with the problem of determining the conveyer speed. An efficient algorithm for the sequence optimization is developed and solved by the simulated annealing.