A study on torch path planning in laser cutting processes - Part 2: Cutting path optimization using simulated annealing

In Part 1 of this paper [beginning on page 54], the heat flow in contour laser beam cutting was calculated by using the finite difference model, and a modified analytic model was developed based on the numerical experiments. Part 2 addresses the problem of optimal torch path planning for the 2D laser cutting of a stock plate nested with irregular parts. Under the constraint of the relative positions of parts enforced by nesting, the optimization algorithm generates a feasible cutting path. The simulated annealing technique is adopted for solving the torch path optimization problem to minimize a specified cost function. The objective is to traverse the cutting contours with a minimum path length and, at the same time, to minimize the effect of heat on the cutting path sequence. To minimize the heat effect and avoid overheating, the critical temperature that should be avoided during the whole cutting sequence is considered. In this way, a global solution can be obtained in a reasonable time. Several examples are presented to illustrate the effectiveness of the proposed method.