Real-time closed-loop computer numerical control system of machine tool

Abstract

The computer numerical control(CNC) system that has a direct numerical control metal processing facility is implemented by using a minicomputer(Nova 1200) and peripheral equipement. As the control scheme, two types of closed loop contouring controls are considered. One is a closed loop scheme which after each step checks the machine status to determine if the path is correct. The error occured is compensated so as to minimize the future errors. The other closed loop scheme is to allow the entire table movement to be complete before the check routine determines if the table is at its final location. This is used a point-to-point operation where the path is immaterial. The conversational computer language BASIC has been expanded to include various machine tool performance commands which are applied to manufacturing equipment from a standard input terminal. Also there are commands that force a machine tool to move to a desired position, that specify a delay or dwell of time or that generate a display of the programed part. In order to show the possibility of the adaptive control system, a simple case of the adaptive control system is simulated. As actuators, a stepping motor and hydrauric servo system are used. Analysis of the actuators is given in the thesis.