A Method for Selecting Velocity Filter Cutoff Frequency for Maximizing Impedance Width Performance in Haptic Interfaces

This paper analyzes the effect of velocity filtering cut-off frequency on the Z-width performance in haptic interfaces. Finite Difference Method (FDM) cascaded with a lowpass filter is the most commonly used technique for estimating velocity from position data in haptic interfaces. So far, there is no prescribed method for obtaining the FDM+filter cut-off frequency that will maximize the Z-width performance. We present a simulation based method to demonstrate that there exists such an ideal FDM+filter cut-off frequency, and that it can be predicted by numerical simulation. Experiments are conducted on a single degree-of-freedom linear haptic interface to validate the simulation results.