H∞ filtering design for straightening bending system of elevator guide rail with time-delay and disturbance

In this paper, H_∞ filtering design for straightening bending system of elevator guide rail with time-delay and disturbance is considered. In the straightening bending machine, straightness detection is essential for the bending process. However, time-delay in signal transmission and external disturbance can affect the detection result. By the use of Lyapunov functional and robust stability theory, sufficient conditions are proposed to guarantee the existence of the filter that satisfying H_∞ performance constraint, and in terms of linear matrix inequalities, the gain of filter is also acquired. Finally, a numerical example is given to demonstrate the effectiveness of proposed method.