Adaptive vibration isolation for flexible structures

Vibration isolation control for flexible structures restricts the response resulting from external disturbances to ureas not requiring high precision positioning and/or pointing. This paper introduces adaptive feedback isolat ion controllers, based on Lyapunov theory that regulate and allow tracking of the undisturbed (controlled) coordinates in a flexible structure. Under assumptions of inertially: decoupled controlled and uncontrolled coordinate s, symmetric and positive definite mass matrix for the controlled subsystem , asymptotically stable eigenvalues for the uncontrolled subsystem, and bou nded disturbances, an adaptive regulator asymptotically drives the controll ed coordinates to zero. Under similar assumptions, an adaptive tracking alg orithm drives the controlled coordinates to desired time trajectories. Expe rimental results on a three mass system compare the response of the adaptiv e isolation controllers with standard PID control. The adaptive regulator p rovides faster transient decay than PID control using the same control effo rt. The adaptive tracking controller has the same tracking error as PID usi ng 30 percent less control effort.