| 摘要 |
1276136 Programmed control of machine tools LICENTIA PATENT-VERWALTUNGSG m b H 30 May 1969 [4 June 1968] 27618/69 Heading G3N In a programmed numerical control system for positioning a machine tool of the type wherein a digital interpolator 2, controlled by a constant frequency timing-pulse generator 15, supplies conventional X and Y axis closed loop position and speed control circuits 3---9 and 3<SP>1</SP> ---9<SP>1</SP>, the output of the generator 15 is passed through an AND gate 16 controlled by a threshold network 14 which delivers a blocking output signal when the difference between the actual and desired machining speeds exceeds a predetermined value, so that the gate 16 only transmits the timing pulses to the interpolator 2 when the actual speed is within a predetermined range below the desired speed. A signal V ist representative of the actual speed is obtained from a calculating circuit 10 which receives position error signals V x,ist and V y,ist from the D/A converters 4, 4<SP>1</SP> of the position control loops and derives the square root of the sum of their squares. A signal V soll is derived from a store 13 via a D/A converter 12 and is applied, as the desired speed signal, to a comparison network 11 whose output signal V soll -V ist is applied to the threshold network 14. |
