Machining time estimation of sculptured surfaces using NC block distributions

NC 블록 분포를 이용한 자유곡면의 가공시간 예측

The estimation of NC machining time is of significance since it provides shop floor engineers with information for the determination of the productivity of the floor as well as process schedules. The NC machining time commonly depends on NC programs since they have various important information such as tool positions, feed rates, and other miscellaneous functions. Thus, nominal NC machining time can be easily acquired based on the programs. Actual machining time, however, cannot be simply obtained because of the dynamic characteristics of a NC machine controller such as acceleration and deceleration. Hence, this study presents a NC machine time estimation model for sculptured surfaces, considering the dynamic characteristics. The estimation model uses the distribution of NC blocks according to a factor influencing the machining time. Finally, machining time is estimated by a statistical machining time estimation model representing the relationship between the block distribution and the machining time. The parameters in the model are searched out by a genetic algorithm.