Interpolator for a numerically controlled machine with step size selected in response to feed rate

摘要

Input signals supplied for each block to an interpolator for a numerically controlled machine comprise displacement signals representative of conventional displacement data in terms of a conventional step size and a feed rate signal representative of a feed rate which, in turn, defines a conventional pulse distribution rate. The interpolator selects, in response to the feed rate signal, a working step size to be an integral multiple or an integral submultiple (exclusive of unity) of the conventional one, derives working displacement data and a working pulse distribution rate by dividing the conventional ones by the multiple or submultiple, and carries out pulse distribution in a conventional manner but by the use of the working displacement data and feed rate to produce those distribution signals at the working pulse distribution rate which make servos feed a machine tool relative to a workpiece with the working step size and at the feed rate. The input signal may include a signal indicative of the working step size.