Theoretical investigation on wireless vibration control of thin beams using photostrictive actuators

This paper presents an investigation into wireless remote vibration control of flexible beams using photostrictive materials and laser Doppler vibrometers. To increase the response speed of photostrictive actuator to light irradiation, a thin lead lanthanum zirconate titanate (PLZT) film with transparent electrodes is bonded onto the host beam as the actuator. A mathematical model is presented to describe the interaction between the motion of the host beam and light-induced strain of the photostrictive actuator. To perform remote wireless control, a laser Doppler vibrometer is used as the sensor to measure the vibrating velocity and the sensing equation that relates output of the vibrometer and velocity of the vibrating beam is presented. A modal velocity filter (MVF) is presented to observe the desired modal velocities, which is fed back to form light intensity of the photostrictive actuator to perform the closed-loop wireless vibration control. A characteristic equation is presented from which the frequencies and active damping ratios for all modes can be evaluated. Finally, a simulation example is given to show the effectiveness of the present model and control scheme.