Automation of 3D view acquisition for geometric tolerances verification

Geometrical tolerances control of mechanical components requires methods and tools in order to improve the efficiency of process in terms of time. Dedicated software systems in order to plan and simulate the control and hardware tools in order to rapidly acquire the needed 3D information can support the process improvement. In this context it is important to use the 3D CAD (Computer Aided Design) model, as base to plan and pilot the whole process. The aim of present work is to describe an automatic geometrical tolerances measurement system usable during the design stage. It is based on three main tools: a CAD-based modular software tool, in order to plan, simulate, and pilot the whole verification process, a 3D optical digitizer, as shape acquisition system, and a multi-axis Degree of Freedom (DoF) robot arm in order to move the digitizer. This paper is focused on the developed algorithms to optimize the 3D views acquisition planning. Surface Normal Method and Visibility Map concepts have been reworked for range scanner positions determination and the optimal path is computed by a graph of alignable simulated scans. Experimental test cases are reported in order to show the system performance.