Output Feedback Regulation of a Class of Lower Triangular Nonlinear Systems with Arbitrary Unknown Measurement Sensitivity

In this paper, a regulation problem for a class of lower triangular nonlinear systems under unknown measurement sensitivity by output feedback is considered. The distinguished feature is that the unknown measurement sensitivity is only required to be positive and bounded. The analysis is carried out to show the relation between the gain selection of an output feedback controller and the bound of the measurement sensitivity. Then, the adaptive gain-scalings of the controller are utilized to dominate the unknown growth rate of the nonlinearity.