Wave filter bank for high fidelity passive multirate haptic interaction with slowly updated virtual environments

This paper proposes a filter bank-like structure with a local model of interaction for improving the performance of passive multirate wave variable control of haptic interaction with a slowly updated virtual environment. In the proposed structure, the low frequency component of the outgoing wave at the user´s side is sent to the slow virtual environment, and the high frequency component is sent to a local model of interaction. Low-pass and high-pass filters separate the outgoing wave into the two components. Frequency domain analysis tools and lifting are used to investigate the effect of utilizing a local model of interaction in conjunction with the slow virtual environment. The analysis shows that: (1) the proposed control structure significantly improves the admittance transmitted to the user at both low and high frequencies; and (2) the parameters of the local model have little impact on the stability of the haptic system, unlike the parameters of local models developed in the power domain. Experiments with a Phantom Omni haptic device probing a slowly updated virtual wall validate the analytical results.