Application of the dynamic high-gain scaling methodology to servocompensator design

The error-feedback servomechanism problem is addressed for a general class of strict-feedback-like systems. We provide two error-feedback control designs based on our recent results on adaptive outputfeedback based on dynamic high-gain scaling. One control design is of a dual high-gain observer/controller structure, whereas the other control design utilizes a backstepping-based controller in conjunction with a dynamic high-gain scaling-based observer. Owing to the particular robustness properties offered by a dynamic high-gain scaling-based controller and a backstepping-based controller, the two designs require slightly different sets of assumptions on the system. Both design techniques allow the system to contain both unknown functions and uncertain appended input-to-state stable dynamics. Copyright 2008 John Wiley and Sons, Ltd.