Abstract:
A variable phase signal generator for driving a phase analog loop in a numerical control system wherein a computer responds to program data to output position number sequences and digital means are provided for converting the numbers in the sequences to a variable phase pulse train.
Abstract:
A converter is disclosed for operating on the proportional control signal output of a contouring-type numerical control system to make it suitable for use with an on-off servo of the type employed with tracer-controlled machines. The converter accepts the square wave outputs of the command counter of the numerical control system, the output of the feedback resolver rotor (the stator being energized by the output of the reference counter) and a voltage proportional to the rate of motion of the controlled machine member. When the first zero crossing occurs of the command or feedback wave a time delay is initiated which is proportional to the speed of the output member by adding the voltage proportional to the member speed to a ramp voltage initiated at the crossover of the appropriate wave, and detecting the zero crossing point of the sum. If the crossover point of the second input square wave occurs during the delay period no control signal is provided to the output servo. Therefore, a dead zone proportioned in width to the speed of the output member is created. If the square wave signal crossing occurs after the time delay an output signal to the servo is provided of a sign dependent upon which of the input square waves crossed zero first.