Friction Stir Welding (FSW) is a relatively new welding technique where metals are joined through mechanical stirring. Due to its numerous advantages over older welding methods, it has been implemented in an increasing number of industries. However, there are remaining challenges to be overcome in FSW. One of the most serious is its reliance on accurate weld parameters. Additionally, faults or poor quality welds can develop from problems not easily detectible by an operator or robotic welder. In our work, we pursue automatic means of detecting fault occurrences and other quality problems. Force signals are collected from control welds run in aluminum as well as welds containing gap faults. Signal processing techniques, specifically Support Vector Machines (SVMs), are then used to correctly detect fault occurrences. Results demonstrate the ability for in-process fault detection of FSW.

No abstract

No abstract

No abstract

In this paper we present some final results from a resr;lrch project focused on introducing automatic control to the operation of cupola iron furnaas. The main aim of lhis research is to irnprovc tlie operational ef€icienq and performance of the cupola furnace, an important foundry process used to melt iron P m o u s papers have described the development, of appropriate conml system axhileaures for the cupola In this paper experimental data is used to calibrate the model, which is taken as a firstadex multivariable system with time delay. l i e n relative gain analysis is used to select loop pairings to be used in a multiloop conmller. The resulting controller pairs meltrate with blast volume, iron temperature with oxygen addition, and &n composition with metal-rocoke ratio. Special (nonlinear) filters are used to compute meltrate from actual scale readings of I~I C arnounl of iron produced and to smooth the temperam rneasureinent The temperature and meltrate loops use singleloop PI control. The composition loop uses a Smith predictor to discount die deadtime associated with m a s transport through the furnace. Experiments conducted at the Department of Energy Albany Research Center's experimental research cupola validarc die conceptual controller design and provide proof-ofconcept of the idea of controlling a foundry cupola.