Event-Triggered Adaptive Control for a Class of Nonlinear Systems With Mismatched Uncertainties via Intermittent and Faulty Output Feedback

Due to the difficulty in handling the issue of nondifferentiable virtual control signals, there is still no available result considering output triggering and sensor faults simultaneously for nonlinear systems subject to mismatched parameteric uncertainties via backstepping design, even though the underlying problem is practically important and frequently encountered. In this article, to deal with this challenging problem, several crucial design ideas are proposed in developing the control scheme. First, to generate the continuous substitutes for the states, which are necessary in differentiating the virtual control signals in the backstepping design, we construct a state observer driven by intermittent and faulty output arising from output triggering and sensor faults. Second, to ensure the existence of the first derivative of the virtual control signal, we use the estimated output signal to design the virtual control signals. Third, to avoid the repeated differentiations of virtual control signals in backstepping design, we employ the idea of dynamic filtering technique. It is shown that all signals in the resulting closed-loop system are semiglobally uniformly ultimately bounded. Simulation examples are given to demonstrate the effectiveness of the proposed control strategy.