Decomposing the performance of admittance and series elastic haptic rendering architectures

In this paper, we explore certain tradeoffs in haptic rendering performance with different device architectures, specifically examining admittance and series elastic actuator (SEA) architectures. We apply performance analysis techniques that decompose the driving point impedance frequency response into effective stiffness, inertia, and damping and discuss device behaviors as rendering reverts to hardware dynamics with increasing frequency. SEA has previously been discussed in terms of stiffness limitations due to stability; here we discuss a frequency limit for haptic rendering with both architectures, and discuss differing high-frequency behaviors to consider when selecting a device architecture. Theoretical conclusions are accompanied by experimental frequency response data and a perceptual experiment using a reconfigurable haptic device.