Mode localization induced by a nonlinear control loop

We present the analysis of a nonlinear control system that is used to excit e and maintain a specified amplitude of oscillation in the Jet Propulsion L aboratory vibratory gyroscope. This experimental application shows that non linear localization through active means can be implemented in a practical system when it is desirable to confine the response to a favorable mode. Th e closed-loop system response predicted by the model shows very close agree ment with the experimental results for a significant range of controller pa rameters. We also experimentally demonstrate that the actively localized mo tion is eliminated through bifurcation, similar to what was observed in pre vious passive localization studies applied to extended flexible oscillators .