Active noise control of one-dimensional duct via sampled-data H∞ control

This paper deals with a synthesis problem for active noise control systems for one-dimensional duct. Since it is important to reduce the cost of the active noise control systems for practical use, the sampled-data H_∞ control synthesis is applied to design a digital controller with long sampling period. As a conventional synthesis method, continuous-time H_∞ control based synthesis is also applied, where the Tustin transformation is used to discretize continuous-time H_∞ controllers. The experimental results show that the conventional method work well for short sampling period, however, when the sampling period is not short enough, the system loose stability. In contrast, the sampled-data H_∞ control synthesis does not cause such problems, and longer sampling period is achieved without performance degradation compared to the conventional method.