Self-Sensing Compounding Control of Piezoceramic Micro-Motion Worktable Based on Integrator

The displacement of micro-motion worktable driven by piezoceramic actuator can be measured by self-sensing method in the absence of independent sensor. And a displacement self-sensing control system is made. The free charges on the wafers of piezoceramic actuator contain displacement information. So a displacement self-sensing method of piezoceramic actuator based on integrator is presented. Integrator circuit is designed for gathering free charges on the wafers of actuator. It is convenient to adjust the circuit and easy to acquire sensitive signal using this method. And the impedance mismatching problem met in bridge method is overcome. In order to improve the static and dynamical performance of the piezoceramic micro-motion worktable, the compounding control method by combining feedforward control and feedback control is designed. The self-sensing displacement is the feedback signal of control system of piezoceramic micro-motion worktable. The availability of the self-sensing compounding control is validated by experiment. Comparison experiments among such kind of control, feedforward control, general PID feedback control with independent sensor and compound control with independent sensor are took. The experimental results show that self-sensing compounding control has the same good performance of compounding control with independent sensor