Robot-based computer-integrated manufacturing as applied in manufacturing automation

Abstract

In this paper, a study of robot-based computer-integrated manufacturing (CIM) automation is presented. In the study, we investigated issues regarding robotic workspace utilization, accuracy, repeatability and statistical considerations of fixture design that are relevant to the CIM system integration. Taguchi Methods are used to conduct parameter design to improve the accuracy of the Cartesian positions of the end-effector within the robot workspace, subject to spatial considerations of 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 of the robot which gives rise to better accuracy using the S/N ratios of the Taguchi Methods. The results are compared with theoretical development and show very good agreement. In addition, the design of fixture is investigated with both analytical and statistical approaches. Reliability is defined to facilitate the fixture design. The robot-based CIM system encompasses equipment including a SCARA robot, a spatial robot, a CNC milling machine, a conveyor belt and programmable logic controllers (PLC). The system follows a typical factory floor set-up to demonstrate the ability of robotic applications in manufacturing automation. The CIM system utilizes a graphics user interface (GUI) within a message-based, object-oriented programming environment and is also packaged with interactive multimedia to facilitate the dissemination of research results.