A simplified approach to admittance-type haptic device impedance evaluation

Abstract

Evaluating the transparency, or output impedance more generally, of admittance-type haptic devices is challenging due to their inherently non-back-drivable mechanical characteristics. To address this, we describe a new, simplified evaluation approach that eliminates the need for external test fixtures. The simplified approach relies on the easily obtainable closed-loop position control response of the device in combination with a device/system dynamic model. In addition to evaluating output impedance, the approach can be used of evaluate the overall stable rendering range of the device. Finally, the limitations of the approach are discussed.

The Effects of Admittance Term on Back-Drivability

“…In the literature, admittance type devices are rarely seen as haptic systems, however it is mandatorily used as haptic system when there are mechanical limitations such as high inertia, high friction and as a consequence of these, non-backdrivability. The admittance type haptic systems are mostly preferred in surgical operations [4,5], rehabilitation systems [6,7], industrial operations [8,9] and haptic researches [10,11].…”

Realizing low-impedance rendering in admittance-type haptic interfaces using the input-to-state stable approach

“…Peer [3] also concluded that the firm operator grasp aghil.jafari@uwe.ac.uk makes the admittance haptic interfaces unstable. Parthiban [4] proposed a method to evaluate the stable rendering range of the admittance-type haptic displays. Nambi [5] analyzed the effect of velocity, admittance gain, and force on human force control ability.…”