Abstract
In this paper, the problem of robust stabilization is considered for sampled-data control systems, where the conitinuous-time plant with additive perturbation is robustly stabilized by a digital controller. First, sufficient conditions for the robust stability are derived using the small gain theorem. The conditions are given in terms of the L2-induced norm of a certain sampled-data system and its state-space form. Next, we develope a state-space condition for the robust stabilizability. The maximum uncertainty bound with respect to the sampling period can be computed by solving only two discrete-time Riccati equations. Finally, we investigate the properties of the maximum uncertainty bound, and it is shown that the maximum uncertainty bound tends to that for the continuous controller case as the sampling period goes to zero. The possibility for the improvement of the bound by changing the hold function is illustrated by simple examples.
