Control of bistable structures using a modified hybrid position feedback controller

Abstract

Bistable structures show promise for morphing applications as they have the capability of obtaining two stable shapes which do not require energy to be maintained. The vibration of a bistable structure has been modelled previously as a Duffing-Holmes oscillator. To control the motion of a bistable structure from one equilibrium point to the other, a hybrid unstable-then-stable position feedback controller has been successfully employed. The hybrid controller destabilizes the structure around the initial equilibrium position then stabilizes it around the second equilibrium point. Previously, the decision to switch from destabilization mode to stabilization mode is made based upon the position of the structure. In the present research, new methods for determining when to activate and deactivate the stabilizing and destabilizing control schemes are presented. The proposed methods employ optimization techniques, model predictive control, and energy methods to determine when to activate or deactivate each scheme. Results of numerical simulations for the proposed switching methods are presented in this work.