Research on a geometric model based 3D inspection machine

Currently only contact systems - where a probe touches the part on its surfaces - have the resolution required for inspecting in the manufacturing industry. In this paper, the development of a noncontact Structured Light Machine Vision (SLMV) inspecting system using structured light imaged by a machine vision camera gives fast inspection at high resolution. The key technology of this system is inspecting simulation software using a geometric model of the inspected part. The geometric model eliminates spurious range data from multiple reflections that has plagued previous SLMV systems. In addition, the new system eliminates 99% of the data to be studied in detail, reducing both the pixels acquired and the pixels analyzed to just those which contribute to determining the part's dimensions. Resolution is improved by averaging many points over a part's surface. Experimentally, a single-axis machine measured several dimensions of a part in less than a second to micron resolution.