Interpolation and initialization technique for computer control of machine tools

Claim 1

In a direct numerical control system, a system for setting up a sequence of ordinally designated command words for each axis, for subsequently providing command pulses to each axis servo of a machine tool to effect movement of the slides of said machine tool, in response to input signals indicative of the length and velocity that each slide is to move during the cutting of increments forming a segment, said system comprising: processing means in said computer for calculating a control number J for each axis for said segment in response to said input signals, said control number comprising the ratio of the number of predetermined time periods required to cut said segment to the length of said segment along said axis; a core storage unit in said computer including output buffer tables therein for storing said sequence of command words, each of said command words having bit positions for containing command bits for each slide in accordance with whether the command word is to effect incremental movement of each slide and whether said movement is in a positive or negative direction; and means for entering command bits in said storage unit in the Jth designated command word for each axis, the 2Jth command word for each axis, the 3Jth command word for each axis and each subsequent Jth command word for each axis until the number of command bits required for each axis for the cutting of said segment have been entered, said means operating in response to said control number and said length input signal for each said axis.