Robust control of hybrid plants in the presence of quantization errors

In this paper, the hybrid system consisting of the interconnection of an uncertain continuous-time plant and of a digital controller is considered. The plant is supposed to be affected by matched uncertainties belonging to a wide class. It is also assumed the presence of an A/D converter with bounded quantization errors. A robust controller based on quasi-sliding modes is designed using quantized state information. The behavior of the solutions of the system is investigated, with reference also to the bounds on the quantization size.