Post-processing methodologies for off-line robot programming within computer integrated manufacture

Abstract

A robot simulation system has been used not only as a design and simulation tool, but it also serves as an off-line programming system for industrial robots and other machines with a computer integrated manufacture (CIM) system. A robot simulation system is one of the essential elements for virtual manufacturing and agile manufacturing. A post-processor is an important element of an off-line robot programming system, as it allows the commercially available robot simulation systems to be used as off-line robot programming tools. The post-processor translates output statements from a robot simulator to a target robot language. Typically, the sequence of motion and data required to drive the robot can be transmitted through the use of a serial or parallel data link, between an off-line computer and a robot controller. The design of a general post-processor capable of translating the output of multiple robot simulators to multiple robot programming languages is an extremely complex problem. There are two basic ways of describing robot movements in robot control systems; one describes the manipulator movements in terms of the manipulator end-effector location (in compound transformation or absolute); whilst the other describes the movements in terms of manipulator joint angles. The former approach is suitable for future and present generation robots with a language processor installed in their controllers, whilst the latter is only specifically linked to earlier generation robot languages. Discrepancies between a specific robot simulation system and a real robot system which should be resolved as part of the post-processing, are analysed. The feasibility of generalising the post-processor was studied. In this paper different approaches of post-processing for off-line programs and methods of downloading off-line programs to robot controller are discussed also.