A New Adaptive Controller for Nonlinear Systems with Uncertain Virtual Control Gains

This paper addresses the adaptive asymptotic tracking control problem for nonlinear systems whose virtual gains are unknown functions of system states. Only in first step, Nussbaum gain technique is utilized to handle uncertain gain. In remaining steps, dealt with by constructing novel laws without approximation and external disturbances neural networks or fuzzy logic. New defined compensate gains, parameters, disturbances. Finally, an controller designed applied a 3-order robot system, which guarantees boundedness all signals closed-loop stability error.