Fuzzy Logic Based Fabrication Copensator for Rotary Mechanical Systems

Abstract

Very accurate posioning is required in mechanical devices such as surgical tools, computor desk drives assembly robots, micro-mechanisms etc.for many of these devices the performance ios limited by the friction , which may include undesirable tracking error,limit cycle and stick-slip motion. Thenegative effect of the friction is more significant at low velocity. Precise positioning , in particular, control of very small displacement is an specially difficult problem for the direct drive mechanism. These devices has non transmission between drive and the output motion.The absence of the transmission mechanism combined with the existence of non-linear friction often creates problem with precise positioning. friction parameter vary with load as well as many environmental factors, therfore it is always essential to detect the friction in moving parts at very low velocity. In this thesis a fuzzy logic approach is presented to predict the non linear(stick-slip) friction in the devices.