Adaptive Robust Stabilization of Output Feedback Systems With Application to Chua´s Circuit

This brief studies the adaptive robust stabilization problem for nonlinear systems in output feedback form with the high-frequency gain sign unknown. The problem is solved by integrating the robust control method and the Nussbaum gain technique. Also, we show that the celebrated Chua´s circuit is a nonlinear system in output feedback form, and apply our approach to design a control law to achieve global stability of the closed-loop system in the presence of uncertain parameters and unknown high-frequency gain sign