A note on fuzzy PI-type controllers with resetting action

In this note we analyze the effect of the resetting operation in the fuzzy PI controller proposed by Lee (IEEE Trans. Fuzzy Systems 1(4) (1993) 298-30 1). We justify that the resetting operation can result in a steady-state er ror for different systems thereby destroying one of the important character istics of PI-type controllers. We also exhibited through simulations with s everal second-order linear as well as non-linear systems with and without i ntegration that the resetting operation makes the fuzzy PI controller behav e more like a fuzzy PD controller, although for some systems the resetting operation can improve the transient response significantly. (C) 2001 Elsevi er Science B.V. All rights reserved.