ABSTRACT
In this paper, by combining a newly developed constant-voltage-driver (CVD) based electrotactile rendering system with an on-line identification method, parameters of the resistor-capacitor (R-C) load bioimpedance model of fingertip skin are dynamically characterized and analyzed. The CVD rendering system is capable of producing varying stimulation voltage/current waveforms to fingertip. The proposed on-line identification method is a discrete-time extended least squares (ELS) iterative approach with forgetting factor (FF), which serves as an adaptive law to estimate parameters of the bioimpedance model of fingertip skin during performing the stimulation current tracking control in z-domain. Experimental results demonstrate dynamic characteristics of the identified fingertip skin bioimpedance for the sampled population.
