STEP-compliant process planning system for compound sheet metal machining

Compound punch-cutting machines are referred as machines that perform both punching and laser-cutting operations. Such machines can greatly increase the efficiency and flexibility of sheet metal manufacturing. Though there are computer-aided design (CAD) systems developed to take care of product design, and computer-aided process planning (CAPP) systems to generate optimal tool paths and plans and computer-aided manufacturing (CAM) systems for various manufacturing requirements, according to our literature search, there is no platform or system dedicated to compound sheet metal machining, which lead to problems such as low efficiency and high cost due to lack of optimal scheduling methods for the compound machining methods. This research attempts to develop a prototype STEP-compliant process planning system for supporting the compound punch-cutting machines. The system has interfaces to input CAD product data and output machine control codes. It integrates software modules for nesting optimization, cutting/punch path optimization and planning, simulation, and machining parameters set up. The focus of the paper is placed on investigating the problems and solutions of compound machining, the structure of the STEP-compliant system, and the definition of STEP-compliant product data models and interfaces for creating a STEP-compliant programming environment, where the above mentioned software modules are integrated.