A comparison of H_2 optimized design and cross-over point design for acceleration feedback control

摘要

In classical approaches to control of flexible structures, system equations are usually rewritten in a state space domain, but these state space transformations often lose insight into the physics of the problem from the point of view of a structural dynamicist. On the other hand, second order compensators enable the designers to keep the system equations of motion in their second order form. In particular, acceleration feedback control, which uses second order equations, shows unconditional stability for single degree of freedom systems and collocated pairs of sensor and actuator. AFC can also be effectively used with non-collocated actuators and sensors, even thought it is not unconditionally stable. The objective of the paper is to compare two different designs of acceleration feedback control compensators. First, the technique, based on the crossover point design of the controller, is reviewed. Then, a new acceleration feedback control method based on minimizing the H_2 norm of the closed loop transfer function is developed. Both these techniques are validated by numerical simulation studies. Then, than experimental program is designed to control more than one mode with a single piezoceramic actuator for a tapered cantilevered plate.