Adaptive tracking constrained control for nonlinear systems with parameter estimator triggering: A composite error/state-dependent method

This paper discusses the problem of adaptive event-triggered control for uncertain nonlinear systems with composite boundary functions. The function transformations are constructed for the tracking error and state variables, respectively. While the state constraints are not violated, the tracking error can achieve prescribed time convergence where the settling time and steady-state accuracy can adjust according to the demand. The state-dependent mapping function is used to practicalize the asymmetric state constraint without the prerequisite of the feasibility condition for the virtual controllers. In addition, the event-triggered mechanism is introduced based on both controller and parameter estimator, and the challenge of parameter estimator triggering strategy is addressed by adding compensation items. The theoretical results show that the proposed scheme can effectively reduce the number of triggers. The efficacy of the proposed control method is confirmed through simulation examples.