Event-triggered output feedback sliding mode control of mechanical systems

This paper is concerned with event-triggered sliding mode control (SMC) for uncertain mechanical systems subject to limited communication capacity. We consider the scenario where samplings of the system output and of the control input are generated by two different event-triggered strategies. An event-triggered mechanism is incorporated in the sensor to decide when the position information is transmitted from the sensor to observer. The super-twisting algorithm (STA)-based observer is developed to recover the unmeasured velocities by using event-triggered sampling of the position information. Besides, an SMC law is proposed and an input event-triggered mechanism is introduced to decide when the control signal is transmitted over the network to the actuator side. The stability for the overall closed-loop system is analyzed. It is proved that under the proposed output and input event-triggered strategies, there is no Zeno behavior exhibited. Examples are finally presented to illustrate the effectiveness of the proposed event-triggered STA-based observer and the event-triggered SMC scheme.