Fuzzy logic control of automated screw fastening

In this paper, we present an intelligent control strategy for automated screw fastening. In automated assembly processes, there are often found dedicated stations for various types/sizes of screw fastening. Problems found in current processes include cross-threading, screw jamming, slippage and the need to apply precise torque. The intelligent controller developed here supervises the integrated process of an electric driver mounted on a robotic positioning system to fasten screws. The new scheme controls continuously the motion and driving stages to avoid process-caused failures, to achieve a desired precise torque and to detect bad parts at early stages of the assembly. Initial simulation results are encouraging. Copyright (C) 1996 Elsevier Science Ltd.