Adaptive λ-tracking for nonlinear systems with higher relative degree

Previous results for adaptive λ-tracker have focused on nonlinear systems with relative degree one or on linear systems with higher relative degree. We extend the adaptive λ-tracker to λ-stabilize nonlinear system with higher relative degree. Only little structural information about the system to be controlled is needed. λ-stability and convergence of the adaptation is proven for tracking a large class of reference trajectories. The design of the controller is very simple and intuitive, only few parameters have to be tuned