On the Uncertainty Analysis via Low Frequency Inputs for Hydraulic Cylinder Dynamics

This paper discusses a new uncertainty analysis via low frequency inputs for hydraulic cylinder dynamics. First, we review the nonlinear nominal modeling and the existence of the nonlinearity phenomenon despite the absence of nonlinear friction. Second, we propose a new uncertainty analysis by both physical parameter identification and measurement of the input-output behavior by the identification input within low frequency domain. Finally, we experimentally apply the new uncertainty analysis without ignoring the low frequency region. Unexpectedly, there is the non-negligible uncertainty within low frequency domain which can be important for model-based control of hydraulic robots.