Digital interpolator for numerically controlled machines - with logic block providing drive control based upon binary adder and accumulator control loop

摘要

A two dimensional linear interpolar for numerically controlled machine tool or drafting machine applications provides direct function computation. Two interpolator registers are used to hold the functions for the x and y axes, and the outputs coupled to a logic block generating outputs for the machine control. An interpolation step is performed each time a clock is applied and outputs may be generated singly or together to two adders operating in closed loop around an accumulator register. A flig-flop based stage within the logic block performs comparison of the input register contents and a 'y' axis drive signal is generated if the path inclination is greater or equal to 45 degrees. If less than 45 degrees, an 'x' axis drive signal is generated.