Accessibility analysis for CMM inspection planning by means of haptic device and STL representation

Inspection planning plays one of important roles in examining a manufactured part in 3D sizes, positions and forms using coordinate measuring machine (CMM). Accessibility analysis must be done during CMM inspection planning. Usually, accessibility analysis is based on the computation of a part's computer-aided design (CAD) model and the model of a probe. In this paper, a new accessibility analysis method for CMM inspection planning is proposed based on a haptic device and STL representation. Different collision modes are analyzed. A quick collision detection algorithm is given, which is based on the STL representation. Force response is analyzed to distinguish between an occurred collision and a normal contacting of the tip to an inspection point. Using STL representation, the virtual CMM probe unit model is more precise, which results in the accessibility analysis implemented precisely. With the force feedback generated by a phantom desktop haptic device, the accessibility analysis is performed much easier.