Observer-based quantized output feedback control of nonlinear systems

This paper addresses the problem of stabilizing a nonlinear system by means of quantized output feedback. A conceptual framework is presented in which the control input is generated by an observer-based feedback controller acting on quantized output measurements. A stabilization result is established under the assumption that this observer-based controller possesses robustness with respect to output measurement errors in an input-to-state stability (ISS) sense. Designing such observers and controllers is a largely open problem, some partial results on which are discussed. The main goal of the paper is to encourage further work on this important topic.