The Parameter Oscillation Problem in Adaptive Vibration Isolation

A fundamental problem in the design of adaptive control systems for vibration isolation is discussed. This application is often characterized by lightly damped dynamics in the adaptive loop. It is shown that these dynamics can adversely affect the stability and performance of the adaptive algorithm. The result is typically an oscillation in parameter estimates, which is not predicted by general analysis approaches, such as averaging theory. Compensation for these dynamics is suggested, based on a control design viewpoint, and simulation evidence for its efficacy is provided.