A hybrid control approach to ${H_{\infty}}$ problem of nonlinear descriptor systems with actuator saturation

In this note, the ${H_{\infty}}$ problem of nonlinear descriptor systems (NDSs) is investigated. For regular or non-descriptor systems, this problem can be solved via the event-triggered control law. But this control law may be ineffective for the same problem of descriptor systems. The reason is that the discontinuity of the event-triggered controller will cause sudden failure of the algebraic part of descriptor systems at each triggering instant. From the perspective of mathematics, the algebraic equation will have no solution at each triggering instant. To address this problem, a novel hybrid control scheme is introduced. The main characteristic of this control scheme is that it consists of an event-triggered controller and an impulsive controller. It is shown that the impulsive controller plays an extremely important role in adjusting system states to satisfy the algebraic equation. Based on this hybrid control scheme, some improved results are proposed compared with the existing ones. Finally, an example about circuit systems is given to illustrate the effectiveness of the results.