A SPICE based fuzzy logic speed controller for PMDC motor drives

This paper presents a novel fuzzy logic rule based speed regulator and its SPICE model for permanent magnet variable speed (PMDC) motor drives. The motor speed is regulated using the speed error excursion vector R~_ω and a proportional plus integral control law. The controller gain is adjusted online using the fuzzy assignment table based on the error excursion vector and its rate of change at any given time, so the control action is scaled online by the error level for the control correction needed. The scaling is based on the excursion error vector R~_ω=√(e_ω²+e˙_ω²) and its rate of change dR~_ω in the [e_ω-e˙_ω] equivalent phase portrait plane.