Virtual Sculpting and Polyhedral Machining Planning System with Haptic Interface

Abstract

This research proposes the methodology of a novel haptic sculpting and machining planning system for virtual prototyping and manufacturing. A lab-built 6-DOF (degree of freedom) input and 5-DOF output haptic interface system is utilized in the proposed haptic sculpting and machining planning system. A dexel-based haptic virtual prototyping CAD system and a triangulated surface-based machining planning (manufacturing) system are developed. A dexel-based collision detection method and a force-torque feedback analysis are proposed for virtual prototyping module. The output of the virtual prototyping module can be either STL polyhedral surface model, or the tool motion, which is recorded as NC (numerically-controlled) commands. Haptic interface is also used in the machining planning to help determine the feasible tool orientation for 5-axis NC tool path generation. A new machining strategy of 5-axis pencil-cut machining is proposed with the haptic interface. An OBB (object bounding box)-tree and point-cloud-based Two-phase collision detection and force-torque feedback algorithm are proposed for virtual manufacturing module. Dexel-based method is developed for global tool interference avoidance with other components in a complex machining environment. To bridge the virtual prototyping module and machining planning module, a conversion marching algorithm is proposed to construct STL surface models from Dexel volume models. The algorithm can be used in both virtual prototyping system and NC simulation and verification. In the virtual sculpting module, a user can virtually sculpt a stock volume material intuitively by the haptic interface system. Hardware and software implementations of the haptic sculpting and machining planning system are also presented in this paper. The proposed methodology and developed haptic sculpting and machining planning system can be used in CAD/CAM systems and virtual prototyping.