An Elastodynamic Analysis and Control of Flexible Linkages Using Piezoceramic Sensors and Actuators

This paper presents an analytical and experimental study on the elastodynamic analysis and control of flexible linkages mechanisms using piezoceramic sensors and actuators. A mixed variational principle is developed to provide the basis for deriving the finite element equations which govern the dynamic responses of the flexible links, behavior of the piezoelectric materials and their coupling relationships, while being subjected to both mechanical and electric boundary conditions. The piezoceramic devices featuring the characteristics of smart materials capable of sensing and controlling elastodynamic responses of the flexible links are employed in an LQG/LTR (Linear Quadratic Gaussian with Loop Transfer Recovery) control scheme to ensure a stable performance. Finally, a four-bar linkage mechanism with one flexible link is utilized as an illustrative example. The results show that the midspan vibration of the flexible link has been greatly suppressed and the control/observer spillover-induced instability has been avoided.