Universal Output Feedback Control of Nonlinear Systems with Unknown Growth Rate

This paper investigates the problem of global stabilization by output feedback for afamily of uncertain nonlinear systems dominated by a triangular system satisfying linear growthcondition. In contrast to the previous work in the literature, the growth rate here is a positiveconstant but not known a priori, and therefore the problem cannot be addressed by the existingoutput feedback control schemes. Using the idea of universal control integrated with the recentoutput feedback design method that is not based on the separation principle, we construct auniversal-type output feedback controller which globally regulates all the states of the uncertainsystems without knowing the growth rate. We also discuss briefly how this result can be extendedto a larger class of nonlinear systems with unknown parameters.