A Coupled Unilateral Teleoperation System Using an Omnidirectional Mobile Robot Haptic Interface

This paper proposes a novel coupled unilateral teleoperation system that enables position and force interaction between two operators located at different sites via omnidirectional mobile robot haptic interfaces. It supports simultaneous translational and rotational motion and can switch seamlessly between unilateral and bilateral operating modes, which offers capabilities that extend beyond those of traditional haptic devices. The proposed approach establishes two unilateral subsystems that are dynamically and kinematically identical. The kinematic and dynamic models, the velocity cone constraints, and a linear time invariant simplification are derived to analyze and provide the basis for controller design and stability proofs. Position control is implemented with a PID controller, and closed-loop stability in the presence of communication time delays is proven using the small gain theorem. To validate the approach, two practical experimental modes, position tracking and force interaction, were conducted between Japan and Thailand, thereby demonstrating system performance under high-latency conditions. The results show that the position tracking root mean square error remains within the millimeter range, whereas force interactions are achieved without oscillation. At the modeling level, the study demonstrates that a symmetrically coupled unilateral teleoperation system can realize stable, high-fidelity bilateral teleoperation.