Vibration control of flexible structures using self-sensing actuators

In this paper, the design and implementation of smart actuators for active vibration control of mechanical systems are considered. The proposed smart actuator is composed of one or several layers of piezoelectric materials that works: both as a sensor and an actuator, in vibration control applications. An adaptive technique is developed for estimating the unknown equivalent capacitance of the piezoelectric material, which would be used for separating the effect of actuation from the measured (sensed) signal due to the strain in the material. This algorithm can be implemented in real time on a digital signal processor (DSP), allowing for the development of a DSP-based adaptive self-sensing actuator. This self-sensing actuator is then used in the vibration control of flexible structures. The vibration control system includes a power electronic amplifier, a data acquisition system, and a digital signal processor (DSP) for digital control implementation. A simple PID control strategy is employed for vibration reduction and motion control of cantilever beams using the proposed self-sensing actuators. Simulations and preliminary experiments show good results.