Modeling and Validation of a Passive Truss-Link Mechanism for Deployable Structures Considering Friction Compensation with Response Surface Methods

Han-Sol Choi,Dong-Yeon Kim,Tae Seong Jang,Jeong-Hoon Park,Jae Hyuk Lim

doi:10.3390/app12010451

Abstract

In this study, a passive truss-link mechanism applicable to large-scale deployable structures was designed to achieve successful deployment in space. First, we simplified the selected truss-link mechanisms to the two-dimensional geometry and calculated the degrees of freedom (DOF) to determine whether a kinematic over-constraint occurs. The dimensions of the truss-link structure were determined through a deployment kinematic analysis. Second, a deployment simulation with the truss-link was conducted using multibody dynamics (MBD) software. Finally, a deployment test was performed considering gravity compensation, and the results were compared with those of MBD simulation. The results of the deployment simulations were confirmed to be slightly faster than those of the deployment test due to friction effects existing in the joints and gravity compensation devices. To address this issue, inverse identification of the equivalent frictional torque (EFT) at the revolute joints in the deployment test was conducted through response surface methods (RSM) combined with the central composite design technique. As a result, we confirmed that the deployment angle history of the deployment simulation was similar to that of the deployment test.

Highlights

Received: 13 November 2021Synthetic aperture radar (SAR), which can provide high-resolution earth images regardless of weather conditions or time of day has recently been used in various fields of domestic and international observation satellites [1,2]
An inverse identification technique for equivalent friction torque (EFT) was proposed based on the results of the response surface method combined with the central composite design technique
There remains a slight gap between the analysis and the test after friction compensation, this is explained by all the sources of friction occurring in the test which cannot be considered

Summary

Introduction

Received: 13 November 2021Synthetic aperture radar (SAR), which can provide high-resolution earth images regardless of weather conditions or time of day has recently been used in various fields of domestic and international observation satellites [1,2]. In the case of SAR antennas, to maximize resolution and power gain in acquiring high-resolution images, a large deployable panel is accommodated. To deploy such a large space deployment structure in orbit, it is essential to use specific mechanisms that allow the structure to be appropriately folded and stored inside the launch-vehicle fairing and fully deployed in orbit [1,2,3,4,5,6]. The stiffness of the rotational spring hinges of deployable panels is often increased in order to obtain high deployment stability This mechanism shortens the deployment time but leads to a high impact load when fully deployed and latched. By contrast, decreased stiffness of the rotational spring hinges reduces the deployment impact load by increasing the deployment time, but cannot guarantee successful full deployment due to harness resistance and mechanical friction of deployment devices at low temperatures [7]

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