Dynamic Characteristics And Electrostatic Levitation Analysis For Electromechanical Integrated Electrostatic Harmonic Micro Drive

Electromechanical integrated electrostatic harmonic drive is a novel generalizedcomposite drive, which integrates control, drive and transmission. The stator consists of aseries of electrodes insulated between each other. The rotor consists of a thin-film which isconductive and easily deformed. The stator is excited by sequential electric field, by whichthe sequential deformation of the rotor is produced. When the electric field rotates by onecycle, the rotor generates a small angle displacement opposite to the direction of therotating electric field. Because of smooth operation, larger speed ratio, higher efficiency, the drivesystem will find its broad application.In this dissertation, a static model of the electromechanical coupled continuous bodyconsidering non-uniform load is presented. The equations of the radial displacements ofthe flexible ring and its output torque for the drive are given. Analyzed the radialdisplacements of the flexible ring and the output torque. The results show that the effectsof non-uniform load on the radial displacements of the flexible ring and the output torquecan not be ignored.Using the electromechanical coupled dynamic equations of the flexible ring, effectsof non-uniform load on the natural frequencies and the vibrating modes of the flexible ringare investigated. Based on the mode superposition method, the forced response equationsof the flexible ring for the drive to the electric excitation are deduced. Using the equations,investigate the responses of the systerm. Results show that in some cases, effects of thenon-uniform load on the vibrating modes and the forced responses of the system areimportant.Friction in the drive affects dynamics and working performance of the micro systemdirectly. Depth-keeping of the flexible ring by PID control system can reduce the friction,guaranteeing the coaxality of the flexible ring and electrode. Therefore, this can reduce thestarting torque of the electric machine.Mathematic model of the eccentric center regulating system is given. PID controlparameters are determined. Control capability of open and closed loop control system isinvestigated and compared. Simulink simulation model of eccentric center control system of flexible ring is presented. Eccentric center control under step voltage is simulated.Results show that eccentric center control by PID controller can give expectant effect.