Automatic Active Control of Structures

Some of the benefits gained from using closed-loop control in controlling flexible structures are illustrated. It is shown that a closed-loop active control provides the active damping and stiffness needed by any kind of current response of the structure. That leads to the idea of designing a closed-loop control system for a simplified structural model, neglecting those factors which complicate the design. The efficiency of the designed control system is then checked afterwards by considering those factors which have been neglected previously. The design may be revised if the controlled response, considering the neglected factors, is not acceptable. A revision proves to be rarely needed. The procedure outlined in the paper enables one to find easily a closed-loop control for nonlinear or high-order structural systems. An automatic controlled bridge is presented as an example.