Automated Optical Rouginess Inspection

Abstract

This paper describes the theory and implementation of automated optical roughness inspection. This work is being conducted at the Inspection Workstation (IWS) in the Automated Manufacturing Research Facility (AMRF) at the National Bureau of Standards. The Surface Roughness Instrument Controller (SRIC) supervises the automated optical roughness inspection of parts. This controller is an integrated, data-driven, hierarchical control software system. The SRIC controls two pieces of equipment-the surface roughness instrument (SRI) and the automatic dial indicator (ADI). The SRI is a photo-optical surface roughness inspection device which monitors surface roughness by measuring the angular distribution of light scattered from the surface of a part. Its tasks are coordinated with those of the IWS inspection robot. Using the SRI optical signals as sensory input, the robot properly aligns the part in front of the SRI so that a valid optical scattering reading is obtained. The ADI is used to help the robot position the part in front of the SRI for its initial reading. The SRIC uses the optical data obtained to estimate values of root mean square roughness (R_q) for parts machined in the AMRF.