An integrated vision touch-probe system for dimensional inspection tasks

This paper discusses the integration of vision and touch sensors in a coordinate measuring machine (CMM) controller used for dimensional inspection tasks. A real-time hierarchical control system is presented in which a vision system extracts positions of features on a part to be inspected, and then guides a touch probe to efficiently measure these features. The probe is tracked by the vision system as it scans surfaces so that it's motion can be visually servoed. Minimalist sensor- derived representations, involving only task-specific information, are used in this process. Although the camera itself remains uncalibrated, a real-time calibration of very limited scope is performed each processing cycle to transform the task-specific image information into 3-D information used as feedback to guide the probe.