| The human hand is very sensitive to the high frequency accelerations produced by tool contact with a hard object, yet most time delayed telerobots neglect this feedback band entirely in order to achieve stability. This document presents a control architecture that both incorporates this important information and provides the ability to scale and shape it independently of the low frequency force feedback. Leveraging the clean power flows afforded by wave variables, this augmented controller preserves the passivity of any environment that it renders to the user but is not subject to the limitations of being passive itself. This architecture guarantees stability in the presence of communication delay while achieving a level of feedback not possible with a passive controller. Experiments show that this feedback augmentation and shaping can present a high frequency acceleration profile to the user's hand that is similar to that experienced by the slave end effector. Several human subject tests confirm that this increased feedback enables improved perception of the remote environment. |
