Nonstationary Robust Positioning Control of Flexible Structures

For positioning control of such vibrating system as flexible structures, it is important to reduce vibration. In the problem, influences of such uncertainties as variations of parameters of controllers possess nonstationary characteristics. This paper presents an integrated synthesis method of both motion and vibration controller maintaining the robustness of the control by using a time-varying criterion function. In this method, a smooth change from H2 positioning control to H vibration control is realized by solving time-varying Riccati equations in stead of time-invariant Riccati equations. This method is applied to a positioning problem of flexible tower-like structure. In comparison with the former methods proposed by the authors, the usefulness of the method is verified theoretically and experimentally.