Active damping of dynamical structures using piezo self sensing

Piezo actuators are widely used in high-precision equipment where accurate nanometer positioning is required. Piezo material, like PZT, show significant hysteretic behaviour, typically needing position feedback control or solutions like charge amplification to minimize hysteresis effects. Other materials like LiNbO3 show linear behaviour themselves. Both, however, have an inherent high stiffness and lightly damped mechanical resonances leading to unwanted vibration. This paper investigates the use of self sensing in piezo's, using current and voltage in the electrical domain, for active damping purposes. In particular, the combination with charge control is shown, and a hysteresis cancellation technique is proposed.