From CAD-based kinematic modeling to automated robot programming

The objective of this work is twofold: firstly, to present the potential of CAD-based techniques with respect to implementing a user-friendly tool for systematic and efficient kinematic modeling and analysis of general assembly products, and secondly, to detail the significance of this approach for the development of a Robotic Assembly Language Planning Hierarchy (RALPH), a task-level automatic robot programming system. With the Product Assembly Modeler (PAM) as the environment for kinematic modeling, the geometric and topological information in the system's database is utilized to derive and solve the kinematic equations that characterize a mechanism. Spatial relationships play a central role in this process as they represent the kinematic constraints implied by the joints. The advantages of embedding kinematic analysis in PAM comprise the flexibility of modeling open and closed loop mechanisms, the visual study of motion of a mechanism, and the evaluation of the integrity of the design. PAM also provides the geometric and topological data for RALPH to generate a process plan for robotic assembly. CAD-based kinematic modeling and analysis plays a key role with respect to automated programming of industrial robots due to the importance of the inverse kinematic problem.