S. Rakheja et al., DEVELOPMENT OF LINEAR AND NONLINEAR HAND-ARM VIBRATION MODELS USING OPTIMIZATION AND LINEARIZATION TECHNIQUES, Journal of biomechanics, 26(10), 1993, pp. 1253-1260
Hand-arm vibration (HAV) models serve as an effective tool to assess t
he vibration characteristics of the hand-tool system and to evaluate t
he attenuation performance of vibration isolation mechanisms. This pap
er describes a methodology to identify the parameters of HAV models, w
hether linear or nonlinear, using mechanical impedance data and a nonl
inear programming based optimization technique. Three- and four-degree
s-of-freedom (DOF) linear, piecewise linear and nonlinear HAV models a
re formulated and analyzed to yield impedance characteristics in the 5
-1000 Hz frequency range. A local equivalent linearization algorithm,
based upon the principle of energy similarity, is implemented to simul
ate the nonlinear HAV models. Optimization methods are employed to ide
ntify the model parameters, such that the magnitude and phase errors b
etween the computed and measured impedance characteristics are minimum
in the entire frequency range. The effectiveness of the proposed meth
od is demonstrated through derivations of models that correlate with t
he measured X-axis impedance characteristics of the hand-arm system, p
roposed by ISO. The results of the study show that a linear model cann
ot predict the impedance characteristics in the entire frequency range
, while a piecewise linear model yields an accurate estimation.