Deployment Module Research Articles

Design, kinematics and dynamic analysis of a novel double – scissors link deployable mechanism for space antenna truss

A novel truss deployable mechanism composed of scissors links is proposed in this paper. First, the geometry analysis of the general single modular unit of truss deployable antenna and the construction of the planar double scissors link mechanism module is conducted. The entire antenna is prepared by connecting the single module in a circular configuration. Using the Gruebler's method, the mobility of the double scissors link truss deployable module is proved equals to 1. Furthermore, based on the Newtonian approach, kinematic characteristics of the double scissors link truss deployable mechanism are examined. The velocities and accelerations of the antenna components obtained analytically are validated through simulations in MATLAB, SolidWorks and ADAMS. In addition to this, the forces, torques and bearing stresses involved in various struts and joints are calculated to ensure that the operation is within the yield limits. The dynamic characteristics of the antenna i.e., acceptable natural frequency is calculated by developing a 10 DoF vibration model. The analytical equations are solved using MATLAB, and the results are validated through simulations in ANSYS Workbench. The novel antenna assembly gives the natural frequency response of 0.0652 Hz with a 1.6 % error. The proposed double scissors link truss deployable mechanism shows storage ratio of 1 and 10.2 along vertical and radial directions respectively. The dynamic response and storage ratio of novel assembly is validated with results in literature. The research lays the foundation for the kinematics and dynamics analysis of other space deployable mechanisms.

Kinematics and Performance Analysis of a Deployable 7R Overconstrained Single-Loop Mechanism for Aerospace Platform

Abstract This paper studies a special deployable 7R single-loop mechanism (SLM), which is characterized by its overconstraints, 1-DOF, and single-loop structure. Based on these characteristics, a series of performance evaluation indices, including the overconstraint performance, input and output motion/force transmission performance, and deploying/folding ratio, are proposed to evaluate its performance. To analyze these performances, the kinematics of the 7R SLM is analyzed. Then, these performance indices are used to evaluate the 7R SLM. The performance analysis result shows that the mechanism exhibits excellent performance. A 3D-printed prototype of the 7R overconstrained SLM is presented and used to assemble a deployable module. Their deploying motion verifies the assembly capability and deployability of the mechanism and its potential as a basic unit to construct more complex, overconstrained deployable mechanisms for aerospace platforms. This study plays a significant role in the analysis, design, and optimization of overconstrained SLMs while also providing theoretical support for applications in aerospace platforms and other related fields.

Ultra-large Sn3O4 nanosheets with Sn2+ defect for highly efficient hydrogen sensing

Hydrogen (H2) is the cleanest energy but also dangerous, thus the real-time detection of H2 leakage is crucially important. Herein, we develop ultra-large micro-sized Sn3O4 nanosheet hierarchies via a facile hydrothermal method using polyvinyl pyrrolidone as a regulating agent. Structural analyses reveal the as-prepared Sn3O4 nanosheets are single-crystalline with {010}-facet exposure and Sn2+-deficiency. When examined as gas sensing materials, the {010}-faceted Sn2+-deficient Sn3O4 nanosheets demonstrate highly efficient H2 sensing with excellent selectivity/response (two times higher than those for NO2, SO2, H2S, and H2O) and stability upon long-term testing (over 37 days). The sensor displays fast response /recovery times of 9.4/24 s to 10 ppm H2 at a low working temperature of 150 °C, and even well responds to 50 ppb H2 with a theoretical limit of detection (LOD) of 0.54 ppb. The excellent H2 sensing performance of the Sn3O4 nanosheets has been verified by the first-principle calculation based on density functional theory (DFT), suggesting that the Sn2+-deficient {010} surface of Sn3O4 provides abundant adsorption sites for hydrogen molecules. Moreover, we demonstrate the practical application of Sn3O4 sensor embedded into a miniaturized deployable module, which realizes the real-time on-line H2 monitoring with excellent repeatability and selectivity for long-term operation.

Structural Designs of Novel Deployable Polyhedral Grippers for Noncontact Capturing Missions

Abstract Deployable polyhedral grippers have attracted increasing attention for their priority in noncontact capturing missions. Enrichment of these grippers may benefit the conduction of various capturing tasks. In this paper, novel deployable polyhedral grippers are presented. A design flow is proposed for the structural designs of diverse grippers. The core problem during the construction is reducible to the structural designs and combination of multiple synchronously deployable modules. Each module, containing three faces connected by two revolute joints, can realize one-degree-of-freedom deployment. Type synthesis of synchronously deployable modules adopting different layouts of revolute joints is conducted. The mobility and kinematics of these modules are analyzed to verify the achieved motion. As examples, four deployable polyhedral grippers based on different polyhedrons and deployment diagrams are presented. The deployment performance of the prototype proves the validity of the proposed design method and exhibits the potential of these deployable polyhedral grippers for diverse capturing missions.

Structure derivative design, network, and kinematic analysis of a class of two-dimensional deployable mechanisms for aerospace platforms

A systematic method is presented to deal with the structure design of two-dimensional truss-shaped deployable aerospace platforms. Firstly, the DOF, constraints, and singularities of a symmetrical 7R single-loop mechanism (SLM) are analyzed using screw theory. Based on these characteristics, a symmetric double-layer deployable module with one degree of freedom (DOF) is designed by connecting eight 7R SLMs. Taking this deployable module as the parent mechanism, seven homologous deployable modules are derived using the derivative design method. These modules are single DOF and have good symmetry and deployment performance. Then, the networking methods are proposed for planar deployable modules and spatial deployable modules. Using these networking methods, a class of 1-DOF large-scale truss-shaped deployable aerospace platforms with good symmetry and deployment performance are proposed, which verifies the rationality and feasibility of the networking method and design method. Finally, the kinematics and deployment performance of the deployable modules are analyzed. The research fills the gap in the design of deployable aerospace platforms and provides a reference for the derivative design and networking of the deployable mechanisms.

Built On-orbit Robotically assembled Gigatruss (BORG): A mixed assembly architecture trade study.

This paper explores a mixed assembly architecture trade study for a Built On-orbit Robotically assembled Gigatruss (BORG). Robotic in-space assembly (ISA) and servicing is a crucial field to expand endeavors in space. Currently, large structures in space are commonly only deployable and must be efficiently folded and packed into a launch vehicle (LV) and then deployed perfectly for operational status to be achieved. To actualize being able to build increasingly large structures in space, this scheme becomes less feasible, being constrained by LV volume and mass requirements. ISA allows the use of multiple launches to create even larger structures. The common ISA proposals consist of either strut-by-strut or multiple deployable module construction methodologies. In this paper, a mixed assembly scheme is explored and a trade study is conducted on its possible advantages with respect to many phases of a mission: 1) manufacturing, 2) stowage and transport, 3) ISA, and 4) servicing. Finally, a weighted decision matrix was created to help compare the various advantages and disadvantages of different architectural schemes.

COST-EFFECTIVENESS ANALYSIS OF IN SILICO CLINICAL TRIALS OF VASCULAR STENTS

Today, it takes ten to twelve years on average to complete a clinical trial before a new drug is approved and brought to marktet. Moreover, the evaluation of the efficacy and safety of drugs or devices has been performed in the linear and sequential manner with limited change over the past decade. The InSilc project is an EU funded project (www.insilc.eu) within which the InSilc platform was developed for designing, developing and assessing coronary stents. The InSilc platform contains the following modules: Mechanical Modelling Module, 3D Reconstruction and Plaque Characterization Tool, Deployment Module, Fluid Dynamics Module, Drug Delivery Module, Degradation Module, Myocardial Perfusion Module, Virtual Population Physiology and Virtual Population Database. We analyze the cost of three different in silico scenarios for clinical study. In Scenario 1, two different stent designs are compared according to the ISO standard for in silico mechanical tests. Scenario 2 predicts the stenting outcome for a virtual anatomy where design/material could be changed. Scenario 3 compares two stents using the same virtual anatomies from the Virtual vessel database. Cost-effectiveness analysis was performed for real clinical trials with metallic and BVS stent and in silico clinical trials. It was observed that in silico clinical trials are almost 90 times cheaper than real clinical trials for 1000 patients. In Silico clinical trials will not completely replace real clinical studies but the evidence shows that they can significantly reduce the cost of a real clinical study which will open a new avenue for future hybrid real and in silico clinical trials.

Modal analysis of a bistable deployable module with a refined joint model

Bistable deployable scissor structures (BDS) are interesting solutions for temporary civil engineering structures having the requirement of rapid erection and use. The transformation and design of BDS have been studied in various works in the literature using numerical simulations based on a quasi-static loading assumption. In contrast, their dynamic behavior and factors influencing it have not yet been extensively investigated. This contribution presents a computational study in which the natural frequencies and vibration modes of a single square BDS module are evaluated, incorporating the effects of the variation of particular design parameters specific to BDS, i.e. the materials used for inner and outer scissors, finite joint stiffness and manufacturing imperfections on the member lengths (in a stochastic approach) and two geometrical parameters of the module. The most dominant parameters are identified, and their effect is quantified, yielding results of practical interest for design and manufacturing that can be used to reach a target dynamic behavior of BDS.

Thermal Vacuum Test Campaign of the EIRSAT-1 Engineering Qualification Model

CubeSats facilitate rapid development and deployment of missions for educational, technology demonstration, and scientific purposes. However, they are subject to a high failure rate, with a leading cause being the lack of system-level verification. The Educational Irish Research Satellite (EIRSAT-1) is a CubeSat mission under development in the European Space Agency’s (ESA) Fly Your Satellite! Programme. EIRSAT-1 is a 2U CubeSat with three novel payloads and a bespoke antenna deployment module, which all contribute to the complexity of the project. To increase the likelihood of mission success, a prototype model philosophy is being employed, where both an engineering qualification model (EQM) and a flight model of EIRSAT-1 are being built. Following the assembly of the EQM, the spacecraft underwent a successful full functional test and month-long mission test. An environmental test campaign in ESA Education Office’s CubeSat Support Facility was then conducted with the EQM where both vibration and thermal verification test campaigns were performed. The focus of this paper is the thermal testing and verification of the EIRSAT-1 EQM. Over three weeks, the EQM was subjected to one non-operational cycle, three and a half operational cycles, and a thermal balance test in a thermal vacuum chamber. After dwelling at each temperature extreme, functional tests were performed to investigate the performance of the spacecraft in this space representative environment. The approach to planning and executing the thermal testing is described in detail including the documentation required, set up of the test equipment, and determination of the test levels. Overall, the campaign demonstrated that the mission can successfully operate in a space environment similar to that expected in orbit, despite encountering a number of issues. These issues included a payload displaying anomalous behaviour at cold temperatures and needing to redefine test levels due to an insufficient understanding of the internal dissipation in the spacecraft. A total of two major and three minor non-conformances were raised. Crucially, these issues could not have been found without thermal testing, despite the comprehensive ambient tests performed. The main results and lessons learned during this thermal test campaign are presented with the aim of guiding future missions on optimal approaches in organising and executing the thermal testing of their CubeSats.

Creating Interactive Three-Dimensional Applications to Visualise Novel Stent Grafts That Aid in the Treatment of Aortic Aneurysms.

Three-Dimensional (3D) medical animations incorporated into applications are highly beneficial for clinical outreach and medical communication purposes that work towards educating the clinician and patient. Aortic aneurysms are a clinically important area to communicate with multiple audiences about various treatment options; both abdominal and thoracic aortic aneurysms were selected to create 3D animations and applications to educate medical professionals and patients regarding treatment options. Fenestrated endovascular aortic repair (FEVAR) and thoracic endovascular aortic repair (TEVAR) are both tried and tested minimally invasive surgical methods for treating thoracic aortic aneurysms respectively. The Terumo Aortic Custom Relay Proximal Scalloped stent graft and Fenestrated Anaconda stent graft were both designed specifically for these procedures; however, it can be difficult to visually communicate to clinicians and patients in a straightforward way how these devices work. Therefore, we have developed two interactive applications that use 3D visualisation techniques to demonstrate how these aortic devices function and are implemented. The objective of these applications is to engage both clinicians and patients, therefore demonstrating that the addition of anatomically accurate 3D visualisations within an interactive interface would have a positive impact on public engagement while also ensuring that clinicians will have the best possible understanding of the potential uses of both devices, enabling them to exploit their key features to effectively broaden the treatable patient population.Detailed anatomical modelling and animation was used to generate realistic and accurate rendered videos showcasing both products. These videos were integrated into an interactive application within a modern, professional graphic interface that allowed the user to explore all aspects of the stent device. The resulting applications were broken down into three modules: deployment, clinical performance and features. Following application development, these applications were evaluated by professionals in the field. Overall, positive feedback was received regarding the user-friendly nature of the applications and highly effective animations to showcase the products. The clinical applications and feature modules were particularly successful, while the deployment modules had a neutral response. Biomedical applications such as these show great potential for communicating the key features of medical devices and promoting discussion between clinicians and patients; further testing would need to be conducted on a larger group of participants in order to validate the learning effectiveness of the applications.

Experimental Validation of a Highly Damped Deployable Solar Panel Module with a Pogo Pin-Based Burn Wire Triggering Release Mechanism

In this present work, a highly damped deployable solar panel module was developed for application in the 3 U CubeSat. The solar panel proposed herein is effective in guaranteeing the structural safety of solar cells under a launch environment owing to the superior damping characteristics achieved using multilayered stiffeners with viscoelastic acrylic tapes. A holding and release action of the solar panel was achieved by a new version of spring-loaded pogo pin-based burn wire triggering mechanism. A demonstration model of high-damping solar panel assembly was fabricated and tested to validate the effectiveness of the design. The holding and release mechanism achieved using a pogo pin was functionally tested through solar panel deployment tests under ambient room temperature and a thermal vacuum environment. The design effectiveness and structural safety of the solar panel module were validated through qualification-level launch and in-orbit environment tests.

Coupled Sizing, Shape and Topology Optimisation of Bistable Deployable Structures

Bistable scissor structures, consisting of beams connected by hinges, are transportable and can be transformed from a compact to a deployed configuration. Geometric incompatibilities can be introduced during transformation to obtain a bistable structural response which enforces some instantaneous structural stability in the deployed state. The design of bistable scissor structures requires assessing both the non-linear transformation behaviour, as well as the service state, since a proper structural design has to provide stiffness in the deployed state as well as flexibility during transformation. These contradicting requirements were formulated previously in Arnouts et al. [1] as a multi-objective shape and sizing optimisation (SSO). The originality of this contribution is the elaboration of a design methodology coupling a novel topology optimisation (TO) to SSO and demonstrating its performance for the design of a bistable deployable wall. In this novel step, the number of bistable deployable modules (BDM) of the structure is optimised at low computational cost by finding the location of BDM, yielding mixed structures composed of BDM and non-bistable modules (NBDM) of lower weight and complexity than structures entirely built from BDM. TO is incorporated and assessed in the design methodology prior or subsequent to the SSO step. It is shown that the mixed structures combining BDM and NBDM resulting from the new coupled TO-SSO approach outperform pure BDM based structures.

Design and analysis of a deployable grasping mechanism for capturing non-cooperative space targets

Space targets capture is an essential issue for space missions. This paper proposes a novel deployable grasping mechanism (DGM) that can be folded into a compact configuration for convenient transportation and deployed into an extensive configuration for grasping non-cooperative space targets. The DGM mainly consists of a series of serially connected basic deployable modules (BDMs). Each BDM is designed with a scissor mechanism and two parallelogram mechanisms. In order to deploy the BDMs synchronously, a unique connection mechanism is designed. The decoupled deployment motion and grasping motion enables the DGM to perform the capture operation at any motion state. For the proposed DGM, mobility, kinematics and stiffness analysis are performed. The characteristics and performance studied in this paper provide a basis for further investigation of the DGM in the area of space applications.

Numerical investigation on improvement of energy transfer in solar power satellite

Solar power satellite (SPS) normally collects sunlight through concentrating solar collectors give to PV cells which convert it to electric power and then transmitted it to the earth by microwave energy. SPS-ALPHA Mark-Ⅱ applies conical structural as the whole frame composed by several thousands of hexagonal “Reflectors and Deployment Modules” (RDM) that enables extremely high modularity and low cost of machining/space transport. SPS-ALPHA system, on the whole, can be treated a dense array concentrated photovoltaic (DA-CPV) system. The blocking shadow effect and cosine effect of ray path exist that make the optical efficiency fluctuate with different tracking angles, resulting the trade-off exists between optical efficiency and irradiance uniformity. The current study aims to find a compromise solution: a high optical efficiency with stable irradiance distribution for effective PV layout design. To meet this target, Ant Colony Optimization (ACO) algorithm combined with dynamic source-target mapping was adopted to find suitable aiming vectors of modular reflectors. The optical transmission characteristics were investigated using Monte-Carlo ray tracing (MCRT) method. Using above method, this article will focus on the effects of tracking conditions, structural and RDM parameters of SPS-ALPHA Mark-Ⅱ thereby provide basic data and reference for engineering constructions in next step.

Optical study of a cocktail structural Space-based Solar Power Station

SPS-ALPHA as the most innovative and practical concept of Solar Power Satellite (SPS), has been widely concerned in the world. It adopts axisymmetric sigmoid curve-based/cocktail shape as the entire structure composed by several thousands of hexagonal “Reflectors and Deployment Modules” (RDM) that enables extremely high modularity and low cost of machining/space transport. SPS-ALPHA system, on the whole, can be treated as a dense array concentrated photovoltaic (DA-CPV) system. The blocking shadow effect and cosine effect of ray path exist that make the optical efficiency fluctuate with different tracking angles, resulting the trade-off exists between optical efficiency and irradiance uniformity. The current study aims to find the optimal design parameters of RDM when high optical efficiencies and stable irradiance distribution are both achieved for effective PV layout design. To meet this target, Ant Colony Optimization (ACO) algorithm combined with dynamic source-target mapping was adopted to find suitable aiming vectors of modular reflectors. The optical transmission characteristics under different incident degrees were investigated using a two-step Monte-Carlo ray tracing (MCRT) method. Afterwards the optimized results and sensitivity analysis for RDM would be undertook. The article can provide basic data and reference for engineering constructions of SPS-ALPHA in next step.

Research on Accelerating Application Technology of Centralized ERP System Based on HANA

In order to effectively improve the processing speed of centralized deployment in enterprises, this paper proposes a research based on HANA to accelerate the application technology of centralized deployment of ERP system. By optimizing the configuration of data processor unit in ERP physical deployment module, the running efficiency of the system is accelerated. The optimized data processor is used to calculate the parameter index of centralized deployment acceleration authority. According to the parameter index, the deployment role framework of each department of the enterprise is reasonably allocated, so as to reduce the centralized deployment operation time, achieve the goal of accelerating the system operation, and finally realize the effective application of the centralized deployment ERP system acceleration technology. Finally, through comparative experimental tests, it is confirmed that the actual application effect of the HANA - based accelerated application technology for centralized deployment of ERP system can reach more than 90 %, which is significantly improved compared with the traditional centralized deployment accelerated technology.

Cloud Resource Adaptive Scheduling Framework and Optimization Strategy Based on Swarm Intelligence

Resource scheduling framework is very important for the overall cloud service efficiency and service quality,which is the core module of cloud computing. This paper proposes an adaptive cloud computing resource scheduling framework based on swarm intelligence. The proposed adaptive framework includes resource deployment module, scheduling module, recommendation module, optimization module, and monitoring module.The simulation results show that the proposed framework is more efficient than the traditional framework in terms of task execution time, system load balancing and resource service quality, and can improve the service quality of cloud applications while improving resource utilization.

InSilc: 3D Reconstruction and plaque characterization tool.

Coronary artery disease (CAD) is the leading cause of mortality in Europe and worldwide. Atherosclerosis is the most common pathologic process that is highly related with CAD, while the implantation of drug-eluting Bioresorbable Vascular Scaffolds (BVS) is the most promising procedure for treating patients with CAD. InSilc is an textbfin silico clinical trial (ISCT) platform for the development and assessment of drugeluting BVS. The InSilc platform provides insight in the performance of drug-eluting BVS in their short term and medium/long term through the Mechanical Modelling Module, the Deployment Module, the Fluid Dynamics Module, the Myocardial Perfusion Module, the Drug-delivery Module and the Degradation Module. In order for the aforementioned modules to be developed, the utilization of the reconstructed patient specific arterial segment and the BVS design are required, which is achieved through the 3D reconstruction and plaque characterization tool.In this study, the overall architecture of the InSilc platform is presented with special emphasis on the 3D reconstruction and plaque characterization tool. The tool will be able to implement different medical image processing workflows. The workflows will require minimum user intervention in order to be used in large scale clinical trials.

MODELS OF MALICIOUS SOFTWARE AND FAULT TOLERANCE OF INFORMATION COMMUNICATION NETWORKS

The aim of this paper is to develop a model that would enable a standardized representation of malicious software’s structure, functions and to get a quantitative estimation of the fault tolerance of information and telecommunication networks affected by malicious software. The paper shows the relevance and importance of the malicious software models and evaluation of the fault tolerance of information and telecommunication networks affected by malicious software. Malicious software refers to software systems able to covertly deploy, establish unauthorized virtual data communication channel, self-propagate, self-modify, conduct unauthorized collection of information on the network and information technology interference against it. The structural and functional model of malicious software developed in this paper is composed of the following set of diagrams and function descriptions: structures of covert deployment and malicious software installation using electronic mail, structural and functional diagram of the main module of malicious software and covert deployment modules, structural and functional diagram of malicious software while implementing malicious functions, malicious software certificate. The diagrams detail the standard functions, operating procedures and information interaction of malicious software modules of the external and internal networks via an unauthorized virtual data communication channel. Primary malicious software modules are considered through the example of the Careto targeted computer attack. The model of fault tolerance of information and telecommunication networks affected by malicious software is described by indicators that characterize the ability of the networks and information security facilities to maintain and recover specified probabilistic and temporal characteristics over the period of malicious software activity. The following indicators are considered: probability that information and telecommunication networks and information security facilities maintain the specified probabilistic and temporal characteristics over the period of malicious software activity, probability that information and telecommunication networks and information security facilities recover the probabilistic and temporal characteristics after the effects of malicious software activity, factor of operation availability of information and telecommunication networks to perform the specified probabilistic and temporal characteristics under malicious software activity at an arbitrary moment in time, mathematical expectation of the duration of malicious software activity, mathematical expectation of the recovery time of the probabilistic and temporal characteristics of information and telecommunication networks and information security facilities. It is assumed that the values of the parameters required for the calculation of the indicators of the fault tolerance model of information and telecommunication networks were obtained as the result of a testbed simulation of the networks affected by malicious software. In the conclusion it is noted that the developed models enable the identification of the general structure of covert deployment and installation of attacking malicious software using electronic mail, structural and functional diagram of the main module of malicious software and covert deployment modules, structural and functional diagram of malicious software while implementing malicious functions, malicious software certificate, as well as evaluate the fault-tolerance of information and telecommunication networks and information security facilities affected by malicious software, quantify the probabilistic and temporal fault tolerance, recoverability and availability characteristics of networks.

Ontology Based Data Access in Statoil

Ontology Based Data Access (OBDA) is a prominent approach to query databases which uses an ontology to expose data in a conceptually clear manner by abstracting away from the technical schema-level details of the underlying data. The ontology is ‘connected’ to the data via mappings that allow to automatically translate queries posed over the ontology into data-level queries that can be executed by the underlying database management system. Despite a lot of attention from the research community, there are still few instances of real world industrial use of OBDA systems. In this work we present data access challenges in the data-intensive petroleum company Statoil and our experience in addressing these challenges with OBDA technology. In particular, we have developed a deployment module to create ontologies and mappings from relational databases in a semi-automatic fashion; a query processing module to perform and optimise the process of translating ontological queries into data queries and their execution over either a single DB of federated DBs; and a query formulation module to support query construction for engineers with a limited IT background. Our modules have been integrated in one OBDA system, deployed at Statoil, integrated with Statoil’s infrastructure, and evaluated with Statoil’s engineers and data.