Enhancing the Transparency by Onomatopoeia for Passivity-Based Time-Delayed Teleoperation

Robotic teleoperation with force feedback has been studied extensively since it was first developed in the 1940 s. Time delay is a common problem of bilateral teleoperation systems. Although many efforts on optimizing the control architectures have been made, there is always a trade-off between transparency and stability for bilateral systems, and the perfect transparency and stability can only be achieved simultaneously in ideal situations. In this letter, we propose a novel approach to compensate for the degraded transparency while using the conventional passivity-based approach to maintain system stability under time-delay. The proposed approach is based on visual feedback and enhances the transparency by displaying different kinds of onomatopoeia according to contact force detected on the slave side. The basic performance is evaluated by conducting a stiffness classification task under constant round trip time delays (0 ms, 500 ms and 1000 ms). The preliminary results indicate that the subjects have higher accuracy for classifying the stiffness of a remote object by using onomatopoeia enhanced force feedback compared with the conventional passivity-based position-force feedback.