Progress report of the quality in automation project for FY88

Abstract

This document describes a quality control architecture that uses real-time sensing, deterministic metrology methods, machine tool characterization, process-intermittent gauging, and process certification to control automated machining processes. The architecture was developed for the quality in automation (QIA) project which has the twofold objective of reducing the reliance on traditional post-process inspection methods and moving toward greater reliance on in-process verification. The QIA project is developing a computer-based system that includes realtime sensors, a quality database, quality monitors, quality controllers, an inspection station, and a communication network, which allows data to flow among components of the quality system. The quality architecture includes control loops such as post-processing characterization, preprocessing characterization, process-intermittent gauging and real-time '^'7

PIECS - a software program for machine tool Process-Intermittent Error Compensation

“…segmentjio\ The next segment of the NC program that 'will be executed. There is a machining segment (1), probing segment (2) and scanning segment (3) for each session.…”

“…The variable "total_points" counts only the points actually gauged, skipping those missed by the probe. digit [1] ; part_no [0] ; part_no [1] ; part_no [2] ; if ( (in_file = fopen (attrib_f ile, "r")) == NULL ) { sprintf (dummy, "\nNo attributes file exists for Part %s.\n", part_no) The values read in from each attributes file are: The number of gauge points on a cut, the cut direction in x, the cut direction in z, the next intersecting cut number, the end point spec coord (usually X) , the end point coord number (odd number) , end point spec coord (usually Z) , the endpoint coord number (usually even) , degree of x curve, degree of z curve, number of prior cut, angle (counterclockwise) it makes with current cut, number of next cut, angle it makes with current cut.…”

“…The first session (1) is the semi-finished session that includes machining and then gauging. The second session(2) is the finished cut session that includes machining and gauging. Piecs is executed between the semifinished probe, called segment 2, and the finished machining segment, called segment 3.…”