Stiffness Perception Analysis in Haptic Teleoperation with Imperfect Communication Network

Incomplete communication networks (e.g., time delay and packet loss/switching) in haptic interaction and remote teleoperation systems can degrade both user performance and system stability. In this study, we hypothesized that human operator performance would decrease monotonically as network imperfections worsened. To test this hypothesis, we conducted two psychophysical experiments measuring the just-noticeable difference (JND), point of subjective equality (PSE), and perception time under varying conditions of packet separation time and packet loss. Our findings show that increasing packet separation time significantly elevated both JND and PSE, indicating a poorer discrimination ability and a systematic bias toward perceiving the environment as stiffer. By contrast, packet loss rates of up to 75% had no significant impact on perceptual performance, suggesting that, at sufficiently high sampling rates, human operators can compensate for substantial data loss. Overall, the results underscore that packet separation time, rather than packet loss, is the dominant factor affecting perceptual performance in haptic teleoperation.