Inventors:
Kenneth A. Ilseman - Brookfield WI
Richard W. Caddell - Brookfield WI
Assignee:
Kearney & Trecker Corporation - West Allis WI
International Classification:
G05B 1919
G06F 1546
Abstract:
An electronic control system for a machine tool employs a monitoring system for monitoring the absolute position of a reversibly (and linearly or rotationally) movable moving member in the machine tool. The monitoring system includes a clock, a digital feedback position counter having a predetermined count range, an exciter, a feedback device responsive to movement of the movable member, a digital position storage device, a zero crossing detector, and a zero position counter. The feedback position counter, which operates at a clock frequency, controls the exciter which provides a pulsed exciter signal to the feedback device. The feedback position counter also provides a position count Nc to the position storage device and to the zero position counter. The feedback device provides, through a zero crossing detector, a pulsed feedback signal to the position storage device (and to the zero position counter) and the phase shift between the exciter signal and feedback signal is linearly related to the displacement of the moving member. The position storage device provides a continuously updated position number Np which is also linearly related to member displacement, i. e.