Self organizing variable structure controllers

Abstract

In this thesis the problem of chattering in variable structure controllers is addressed. To reduce the chattering phenomenon in the control signal a new performance index for chattering in self organizing variable structure controllers is presented. Application of Fuzzy Logic to eliminate chattering and improve the system performance is studied. A hybrid Scheme employing both adaptive and fuzzy logic schemes to smooth out the chattering phenomenon and simultaneously increase the speed of the system response is proposed and simulations are carried out for single input single output, single input multioutput and multiinput multioutput systems. The simulation results show that the hybrid scheme employing fuzzy logic alongwith self organizing variable structure controller with new performance index is very effective in reducing both magnitude of the control and chattering phenomenon without compromising speed of response of the systems.