Butterfly-shaped linear ultrasonic motor robust control based on Takagi-Sugeno fuzzy systems

For one-dimensional platform driven by butterfly-shaped linear ultrasonic motor, the Takagi-Sugeno (T-S) models are approached through sector nonlinearity. Based on the T-S models the system augmented method is used for design of servo positioning control algorithm without steady-state error. By considering the robust H∞, a disturbance rejection controller design for the T-S fuzzy models is presented. The designed control algorithm is realized on an embedded micro-controller. Experiments with different values of the stepper servo positioning were carried out. The experimental results show that the overshoot of the system in a different step value are less than 4%. The experimental comparison of servo positioning control between the no-load and load conditions show that the system maximum overshoot is less than 5%. This indicates that the system is robust.