Realization of self-sensing electrostatic suspension using a variable capacitor

In order to achieve electrostatic suspension, it is necessary to control the voltage. The authors have proposed a control system using a variable capacitor. This paper describes a self-sensing control method for this system. In the previous control system, the variable capacitor was connected with an electrostatic actuator and a constant power supply. The voltage applied to the actuator can be adjusted by varying the capacitance of the variable capacitor. To this the authors now add a self-sensing control method as follows. The position can be estimated by measuring the capacitance of the variable capacitor and voltage applied to the electrostatic actuator or the variable capacitor. Based on an analysis of the static and dynamic characteristics of the estimated signal, the feasibility of self-sensing control was shown. The estimated signal was used for suspension as the feedback signal and self-sensing electrostatic suspension was achieved.