Global Dynamic Double Side Event-Triggered Adaptive Control for Interconnected Nonlinear Systems via Intermittent Output Feedback

The global asymptotic stabilization control algorithm is proposed for interconnected nonlinear systems utilizing intermittent output feedback. A dynamic double side event-triggered mechanism (ETM) is designed to make the available output intermittent, reducing the frequency of signal updates. In this case, we relax some restrictive conditions from related studies. The considered system features unknown time-varying parameters, mismatched uncertainties, and uncertain functions that satisfy nonlinear growth conditions. These complexities render the standard backstepping recursive design scheme inapplicable, as the derivative of the virtual controller does not exist. To address the intermittent output feedback problem, we introduce a novel dynamic backstepping control method. First, we establish a dynamic gain observer using the triggered output signals to reconstruct the unmeasurable state variables. Next, the concept of dynamic gain is introduced through a coordinate transformation, with its derivative employed to offset discontinuous terms, which solves the challenges in recursive backstepping design caused by intermittent output and regulates that the state variable converges asymptotically to the origin in the global sense. Final, the simulation example is proposed to show the validity of the developed algorithm.