Force-reflecting event-triggered predefined-time cooperative control for teleoperation of NMMs via data-driven based observer

Abstract

This paper investigates the cooperative control problem for the teleoperation system of networked mobile manipulators (NMMs), in which each mobile manipulator is subject to nonholonomic constraints, model uncertainty and external disturbances. The control objective of such a teleoperation system is to synchronize the task-space position between the human-controlled master manipulator and the slave mobile manipulators, and meanwhile enable the slave mobile manipulators to achieve a formation. For this purpose, a hierarchical predefined-time cooperative control (HPTCC) framework involving predefined-time distributed event-triggered (PTDET) estimator, predefined-time stability (PTS) controller and data-driven based (DDB) observer, is proposed. The PTDET estimator is used to generate the information that the slave mobile manipulators need to track and enable multiple slave mobile manipulators to interact through an event-triggered communication network. The PTS controller is presented to ensure the predefined-time stability of the master manipulator and the slave ones. Moreover, for improving the telepresence of the considered teleoperation system, the DDB observer is proposed to reestablish the interaction force between the slave mobile manipulators and the complex operating environment (i.e., the environmental force) on the human operator side. Based on the hierarchical control analysis as well as Lyapunov theory, several sufficient conditions are derived to guarantee the predefined-time stability for the teleoperation system of NMMs. Finally, several simulations are conducted to demonstrate the effectiveness of the proposed control scheme.