Adaptive output feedback event-triggered tracking control for nonlinear systems with unknown control coefficient

Highlights：

• A new pair of high-gain observer and output feedback controller with an improved dynamic gain are presented for a class of nonlinear systems having severe parameter uncertainty and unknown time-varying control coefficient without the precise information of their bounds.

• Two kinds of adaptive output feedback event-triggered control schemes are proposed respectively based on the improved fixed threshold (time-varying) and the improved relative threshold (dynamic) strategies. The non-identification adaptive gain is used to compensate the sampling error, which simplifies the control design especially in the case of the dynamic threshold.

• The global boundedness of the closed-loop system is guaranteed, while a large class of bounded time-varying reference signals can be well tracked under arbitrary preset precision.