Sequence optimization for high speed robotic assembly using simulated annealing

Optimal task sequence planning using a simulated annealing technique is developed for a high throughput chip placement machine. To minimize tact time, chips are mounted by multiple robots on moving PC boards being transferred by a precision conveyer. To avoid both geometric and dynamic interferences among multiple robots, while minimizing the tact time, the sequence of operations as well as the allocation of the multiple robots are optimized by using simulated annealing. The optimization problem is a type of traveling salesman problem, but is highly complicated because the target destinations for placing individual chips keep moving together with the PC board. First, the configuration of the new chip placement system is described. The task sequence optimization problem is then formulated, followed by the application of simulated annealing to solving the problem. An efficient algorithm for perturbing a task sequence is developed and applied to practical chip placement tasks