Abstract:

In order to improve the stability of shaft speed of ultrasonic levitation bearing systems, the ADRC(Active Disturbance Rejection Control) controller is designed insuring the piezoelectric transducer that is the core of the system devices to work under the state of resonance, and to make the ultrasonic bearing system to be stable, through the control of amplitude. According to the equivalent model and experimental parameters of piezoelectric transducer, the simulation system of piezoelectric transducer was built, using Matlab 7.0 software simulation environment. The step response of system and the performance of anti-disturbance is simulated. The simulation results show that the proposed ADRC controller with the comparation of the PID(Proportion Integration Differentiation) controller provides good speed of response. With the working conditions changing, it can control the attenuation of amplitude. Moreover, it has good ability of anti-disturbance.

Key words: ultrasonic levitation bearing, active disturbance rejection control, piezoelectric transducer, amplitude, attenuation