Abstract: Piezoelectric actuator controlled by electric field shows serious hysteresis and creep phenomena, which severely degrades the positioning accuracy. A piezoelectric ceramic driver based on current control is designed using the linear relationship between the displacement of the piezo actuator and the free charge on it. The displacement of the piezo actuator is controlled by controlling its velocity through controlling the current of the piezo actuator. Special circuits and pertinent control algorithm realize the combination of quickly driving and precising positioning. The experimental data show that piezo driver can perform linearly driving and quickly precising positioning of piezo actuator.

Key words: Creep, Current control, Hysteresis, Piezo actuator, Piezo driver, Elemental gait, Elemental terrain, Gait topology, Gait unit, Wheel-legged robot