Vision-aided Monitoring & Control of Thermal Spray, Spray

Vision is one of the most powerful forms of non-contact sensing for monitoring and control of manufactusang processes. However, processes involving an arc plasma or flame such as welding or thermal spraying pose particularly challenging problems to conventional vision sensing and processing techniques. The arc or plasma is not typically limited to a single spectral region and thus cannot be easily filtered out optically. This paper presents an innovative vision sensing system that uses intense stroboscopic illumination to overpower the arc light mad produce a video image that is free of arc light or glare and dedicated image processing and analysis schemes that can enhance the video images or extract features of interest and produce quantitative process measures which can be used for process monitoring and control. Results of two SBIR programs sponsored by NASA and DOE and fmushg an the application of this innovative vision sensing and processing technology to thermal spraying and welding process monitoring and control are discussed.