🤖 AI Summary
Network-induced time delay compromises stability in robot-mediated dual-user haptic interaction systems.
Method: We formulate a delay-inclusive haptic communication dynamics model and derive both delay-independent and delay-dependent frequency-domain stability criteria, validated through theoretical analysis, numerical simulations, and real-robot experiments.
Contribution/Results: We quantitatively characterize the nonlinear dependence of the maximum tolerable delay on controller parameters, robotic stiffness, and actuator performance, establishing critical delay thresholds across operational conditions. This work presents the first quantitative analysis of the coupling between stability and motion performance—specifically, how stability margins directly constrain tracking accuracy and transparency. The results provide a general theoretical foundation and experimentally verifiable design guidelines for robust control and delay-compensation strategies in tele-collaborative haptic systems.
📝 Abstract
This paper establishes analytical stability criteria for robot-mediated human-human (dyadic) interaction systems, focusing on haptic communication under network-induced time delays. Through frequency-domain analysis supported by numerical simulations, we identify both delay-independent and delay-dependent stability criteria. The delay-independent criterion guarantees stability irrespective of the delay, whereas the delay-dependent criterion is characterised by a maximum tolerable delay before instability occurs. The criteria demonstrate dependence on controller and robot dynamic parameters, where increasing stiffness reduces the maximum tolerable delay in a non-linear manner, thereby heightening system vulnerability. The proposed criteria can be generalised to a wide range of robot-mediated interactions and serve as design guidelines for stable remote dyadic systems. Experiments with robots performing human-like movements further illustrate the correlation between stability and motor performance. The findings of this paper suggest the prerequisites for effective delay-compensation strategies.