New approaches to automatic control are needed if Variable Polarity Plasma ARC (VPPA) welding is to realize its full potential as a reliable, repeatable, cost effective process. Present VPPA control systems are first generation, elementary computer-based systems that depend on programs which are experimentally derived, and do not compensate for anomolies injected by tooling, part, and other independent variables.This SBIR effort will investigate the feasibility of using real-time measures of joint quality to control all aspects of welder operation. The key determinants of joint quality will be established, the ability to sense each quality determinant using available technology will be investigated, and an estimate of control ability will be made for each determinant. In Phase II, a set of requirements for this next generation control system will be derived, and a prototype will be designed and implemented.If successful, this innovation will transform an expensive, sensitive, and human-error-prone process into a reliable and easy to use process that can produce significant productivity gains in the manufacture of aerospace structures.STATUS: Project Proceded to Phase II
