Abstract: Aiming at the randomness of pel storage in the interactive graphics file used in the numerical control (NC) automatic programming, a new optimization method of contour machining path based on the greedy algorithm and genetic algorithm is proposed. The genetic algorithm is used to optimize the scheduling and processing sequence for each contour trajectory, and the greedy algorithm is also fused to select the control point of the empty run path between the two interfacing trajectories in the confirmed sequence. Then the total distance of empty run paths and the individual fitness are calculated according to the selected control points. The genetic manipulation is made to evaluate individual, which consists of selection, crossover and mutation. The method not only simplifies the coding, but also eliminates the invalid solution. The results of simulation and test prove that the method shortens the empty run distances, decreases the number of cutter landing gear, and improves the NC machining efficiency.

Key words: CNC engraving, Drawing interchange format, Genetic algorithm, Greedy algorithm, Path optimization