A new algorithm for CAD-directed CMM dimensional inspection

Abstract

In this investigation, a framework for integrating the CMM into the CAD/CAM environment is developed to automate the process of design, manufacturing and inspection. An algorithm to generate an optimum collision free CMM probe path is proposed. This algorithm uses the ray tracing technique to locate the collision of the possible paths, between the initial probe point and the target point, with the workpiece to be inspected. If there is a collision, the algorithm walks through the topological structure of the part and selects the midpoint of the edge, shared by the face with which the path collides and the adjacent face nearest to the target point, as the next probe point. This procedure is followed till the target point is reached. The first half of the proposed algorithm is implemented using Mechanical Desktop and its Runtime Extension (ARX) as the API, running on an Windows NT 4.0 platform. The effectiveness of the proposed algorithm is verified by the results of the implementation demonstrating optimum collision-free dimensional inspection path generation for three prismatic parts.