On design conservativeness in networked control over a quantized lossy channel

In this paper, the conservativeness issue is addressed for networked control of discrete time systems through a quantized lossy channel. The quantized lossy channel is first characterized as an uncertainty disturbance in signal-to-noise-ratio forms with both the input and output signals of the channel. Then it is shown that appropriate uncertainty characterization should be applied to conduct robust stability control and robust performance control, in order to achieve less conservative design. Single-input-single-output quantized lossy channels with both relative-error and multiplicative-error quantization as well as a multiplicative random noise are presented to illustrate the main ideas.