ROBOT-BASED COMPUTER-INTEGRATED MANUFACTURING AS APPLIED IN MANUFACTURING AUTOMATION

In this paper, a study of robot-based computer-integrated manufacturin g (CIM) automation is presented. In the study, we investigated issues regarding robotic workspace utilization, accuracy, repeatability and s tatistical considerations of fixture design that are relevant to the C IM system integration. Taguchi Methods are used to conduct parameter d esign to improve the accuracy of the Cartesian positions of the end-ef fector within the robot workspace, subject to spatial considerations o f the manufacturing process and required boundary conditions. A SCARA robot with known tolerances of link length and joint angles is used to illustrate the methodology. We find the region within the workspace o f the robot which gives rise to better accuracy using the SIN ratios o f the Taguchi Methods. The results are compared with theoretical devel opment and show very good agreement. In addition, the design of fixtur e Is investigated with both analytical and statistical approaches. Rel iability is defined to facilitate the fixture design. The robot-based CIM system encompasses equipment including a SCARA robot, a spatial ro bot, a CNC milling machine, a conveyor belt and programmable logic con trollers (PLC). The system follows a typical factory floor set-up to d emonstrate the ability of robotic applications in manufacturing automa tion. The CIM system utilizes a graphics user interface (GUI) within a message-based, object-oriented programming environment and is also pa ckaged with interactive multimedia to facilitate the dissemination of research results. (C) 1997 Elsevier Science Ltd.