Partial Modeling and Fuzzy Control of AC Induction Motor Actuators

This paper describes and compares performances of different fuzzy controllers in stabilizing the balance of an inverted pendulum on a short track after a high disturbance occurs. It compares Mamdani (and its variants, e.g. Passino) with Takagi-Sugeno types of fuzzy controllers and concludes that Takagi-Sugeno is more promising when the length of the track is limited. The work then focuses on the actuator that produces the torque required for the horizontal movements of the inverted pendulum. A control model for the AC motor is used which includes the motor´s time constant as the crucial parameter in producing rapid response to the disturbances. Current fuzzy controllers for the inverted pendulum, receive a torque as the input. A disadvantage in this modeling is that the electrical motor dynamics is not built-in in the control system independently. Here, a flux vector control AC electrical motor is incorporated to the system, which receives a voltage as input and produces torque. The new approach in modeling a fuzzy control system assists in 1) selecting sensitive parameters for an optimum high performance electrical motor capable to stabilize the inverted pendulum system and 2) designing a Takagi-Sugeno type fuzzy controller