A New Shape Adaptive Motion Control System

Abstract

In recent years there is a growing trend on integrating Computer Aid Design (CAD), Computer Aid Manufacturing (CAM) and Computer Aided Inspection (CAI). This thesis presents a new shape adaptive motion control system that integrates part measurement with motion control. The proposed system consists of five blocks: surface measurement; surface reconstruction; tool trajectory planning; axis motion control and part alignment In this thesis, the key technology used in surface measurement and surface reconstruction is spatial spectral analysis. In the surface measurement block, a new special spectrum comparison method is proposed to find out an optimal digitizing frequency. In the surface reconstruction block, different interpolation methods are compared in the spatial spectral domain. A spatial spectral B-Spline method is presented. In the tool trajectory planning block, a method is developed to select the motion profile first and then determine the tool locations according to the reconstructed surface in order to improve the accuracy of the planned path. In the part alignment, a three-point alignment method is presented to align the part coordinates with the machine coordinates. Based on the proposed methods, a software package is developed and implemented on the polishing robot constructed at Ryerson University. The effectiveness of the proposed system has been demonstrated by the experiment on edge polishing. In this experiment, the shape of the part edges is measured first, and then constructed as a wire-frame CAD model, based on which tool trajectory is planned to control the tool to polish the edges.