Analysis on rigidity of hydraulic hoses for electro-hydrostatic actuators

Abstract

Electro-hydrostatic actuators (EHAs) are said to have potential as actuators for robotic systems because they have high power-to-weight ratio, compact, and energy saving systems compared to general hydraulic systems. However, modeling approaches and analyses on dynamic characteristics have not been quite concrete yet. In order to expand EHAs' potential to be used for robots, further studies of their characteristics are necessary. The previous research has shown two-inertia resonance would occur in EHAs and EHAs can be modeled as two-inertia systems. Nevertheless, how the rigidity of hydraulic hoses relates to resonance frequency and efficiency of EHAs has not been discussed. The rigidity of hydraulic hoses has been said to have an impact on resonance characteristics of general hydraulic systems. However, dynamic characteristics of EHAs and analyses on the rigidity of hydraulic hoses have not been clearly examined. Thus, this study investigates the effect of the rigidity of hydraulic hoses by applying different type of hoses in an EHA.