Stabilization of feedforward nonlinear time-delay systems with vanishing actuator effectiveness by linear time-varying feedback

This paper considers the problem of global stabilization for a class of feedforward nonlinear systems in the presence of state delay, uncertain parameters, and vanishing actuator effectiveness. By assuming that the time-delay nonlinear function is unknown but satisfies a linear growth condition with unknown parameters, a state feedback controller incorporating two time-varying parameters is designed. One parameter focuses on compensating for the vanishing actuator effectiveness, while the other addresses uncertain nonlinear terms. The feature of the approach is that the designed controller is linear, and its implementation do not necessitate online computation, thereby significantly conserving computational resources. An example is included to verify the effectiveness of the proposed approaches.