Event-triggered control for adaptive bilateral teleoperators with communication delays

Bilateral teleoperation systems have been widely applied for human operators to manipulate slave robots in accomplishing various tasks within remote environments. However, most teleoperation systems developed previously have heavily relied on continuous communication or a network with higher sampling rates. In this study, the authors propose novel control schemes to guarantee stability and tracking performance of bilateral teleoperation by considering an event-based transmission. Based on local output signals and the proposed triggering mechanisms, the master and slave robots transmit signals over a communication network only when the triggering conditions are satisfied. An event-triggered coordinating controller is presented to guarantee stability and position tracking for non-linear teleoperators. Input-to-state stability of the proposed teleoperation system with bounded external forces is studied with guaranteed static force reflection. Subsequently, a transformation-based framework is addressed with the event-triggered coordinating control to cope with bilateral teleoperation systems under time delays. The Zeno behaviour is demonstrated to be excluded in the proposed event-triggered teleoperation systems. Numerical examples and experiments are presented to discuss the efficacy of the proposed event-triggered teleoperation systems.