scholarly journals Experimental and Numerical Investigation of Solar Panels Deployment with Tape Spring Hinges Having Nonlinear Hysteresis with Friction Compensation

2020 ◽  
Vol 10 (21) ◽  
pp. 7902
Author(s):  
Dong-Yeon Kim ◽  
Han-Sol Choi ◽  
Jae Hyuk Lim ◽  
Kyung-Won Kim ◽  
Juwon Jeong
Keyword(s):  
Numerical Investigation ◽  
Test Results ◽  
Solar Panels ◽  
Hysteresis Behavior ◽  
Nonlinear Hysteresis ◽  
Revolute Joints ◽  
User Subroutine ◽  
Path Dependent ◽  
Multi Body ◽  
Deployment Analysis

In this work, experimental and numerical investigation on the deployment of solar panels with tape spring (TS) hinges showing complex nonlinear hysteresis behavior caused by the snap-through buckling was conducted. Subsequently, it was verified by comparing simulation results by multi-body dynamics (MBD) analysis with test results on ground-based deployment testing considering gravity compensation, termed zero-gravity (Zero-G) device. It has been difficult to predict the folding and unfolding behavior of TS hinges because their moment–rotation relationship showed a nonlinear hysteresis behavior. To realize this attribute, an algorithm that checks the sign of angular velocity of the revolute joints was used to distinguish folding from unfolding. The nonlinear hysteresis was implemented in terms of two path-dependent nonlinear moment–rotation curves with the aid of the expression function (a kind of user subroutine) in MBD software RecurDyn. Finally, it was found that the results of the deployment analysis were in excellent agreement with those of the test when the friction torques of the revolute joints were properly identified by an inverse analysis with the test frames, thus validating the MBD model.

scholarly journals Novel Structure and Thermal Design and Analysis for CubeSats in Formation Flying

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 150
Author(s):  
Yeon-Kyu Park ◽  
Geuk-Nam Kim ◽  
Sang-Young Park
Keyword(s):  
Analytical Model ◽  
Formation Flying ◽  
Thermal Environment ◽  
Thermal Analyses ◽  
Thermal Design ◽  
Analytical Models ◽  
Test Results ◽  
Solar Panels ◽  
Novel Structure ◽  
Micro Propulsion

The CANYVAL-C (CubeSat Astronomy by NASA and Yonsei using a virtual telescope alignment for coronagraph) is a space science demonstration mission that involves taking several images of the solar corona with two CubeSats—1U CubeSat (Timon) and 2U CubeSat (Pumbaa)—in formation flying. In this study, we developed and evaluated structural and thermal designs of the CubeSats Timon and Pumbaa through finite element analyses, considering the nonlinearity effects of the nylon wire of the deployable solar panels installed in Pumbaa. On-orbit thermal analyses were performed with an accurate analytical model for a visible camera on Timon and a micro propulsion system on Pumbaa, which has a narrow operating temperature range. Finally, the analytical models were correlated for enhancing the reliability of the numerical analysis. The test results indicated that the CubeSats are structurally safe with respect to the launch environment and can activate each component under the space thermal environment. The natural frequency of the nylon wire for the deployable solar panels was found to increase significantly as the wire was tightened strongly. The conditions of the thermal vacuum and cycling testing were implemented in the thermal analytical model, which reduced the differences between the analysis and testing.

Modeling and simulation of planar flexible link manipulators with rigid tip connections to revolute joints

Robotica ◽  
2004 ◽  
Vol 22 (3) ◽  
pp. 285-300 ◽  
Author(s):  
S. M. Megahed ◽  
K. T. Hamza
Keyword(s):  
Mass Matrix ◽  
Equations Of Motion ◽  
Flexible Link ◽  
Link Length ◽  
Finite Segment ◽  
Revolute Joints ◽  
Body Dynamics ◽  
Lumped Masses ◽  
Multi Body ◽  
Rigid Zones

This paper presents the basis of a mathematical model for simulation of planar flexible-link manipulators, taking into consideration the effect of higher stiffness zones at the link tips. The proposed formulation is a variation of the finite segment multi-body dynamics approach. The formulation employs a consistent mass matrix in order to provide better approximation than the traditional lumped masses often encountered in the finite segment approach. The formulation is implemented into a computational code and tested through three examples; cantilever beam, rotating beam and three-link manipulator. In these examples, the length of the rigid tips at both sides of each link ranges from 0% to 6.25% of the whole link length. The zones of higher stiffness at the link tips are treated as short rigid zones. The effect of the rigid zones is averaged along with some portions of the flexible links, thereby allowing further simplification of the dynamic equations of motion. The simulation results demonstrate the effectiveness of the proposed modeling technique and show the importance of not ignoring the effect of the rigid tips.

scholarly journals Experimental and Numerical Investigations on the Behaviour of Masonry Walls Reinforced with an Innovative Sisal FRCM System

2017 ◽  
Vol 747 ◽  
pp. 190-195 ◽  
Author(s):  
Claudia Brito de Carvalho Bello ◽  
Antonella Cecchi ◽  
Emilio Meroi ◽  
Daniel V. Oliveira
Keyword(s):  
Numerical Investigation ◽  
Compression Test ◽  
Composite System ◽  
Numerical Approach ◽  
Masonry Walls ◽  
Test Results ◽  
Numerical Investigations ◽  
Cementitious Matrix ◽  
Diagonal Compression ◽  
Sisal Fibers

An experimental and numerical investigation on an innovative composite reinforced with sisal fibers for masonry strengthening is presented in this paper. A FEM numerical approach is also developed, based on diagonal compression test results, to simulate the shear in-plane response of unreinforced masonry panels (URM) and masonry strengthened with a Fibre Reinforced Cementitious Matrix (FRCM) composite system made with sisal fibers (RM-SISAL).

Study of EDLC and its Usage in Stand-Alone Photovoltaic System

2011 ◽  
Vol 335-336 ◽  
pp. 1368-1375 ◽  
Author(s):  
Bao Hua Li ◽  
Xue Song Pan ◽  
Yan Bing He ◽  
Hong Da Du
Keyword(s):  
Electric Double Layer ◽  
Storage System ◽  
Energy Storage System ◽  
Photovoltaic System ◽  
Test Results ◽  
Solar Panels ◽  
Working Mechanism ◽  
Storage Devices ◽  
Double Layer Capacitors ◽  
Hybrid Storage System

In recent years, Electric Double Layer Capacitors (EDLCs) are gradually accepted by people and used in different areas as storage devices. This paper studied the working mechanism of EDLC and discussed two kinds of models of EDLC. Based on the advantages of EDLC, this paper proposed EDLC-battery combine storage system in stand-alone photovoltaic system and designed Energy Control System (ECS). Test results show that the hybrid storage system can collect more energy generated by solar panels, enhance the power output ability of energy storage system and extend battery’s life.

Effects of substituting anthropometric joints with revolute joints in humanoid robots and robotic hands: a case study

Robotica ◽  
2013 ◽  
Vol 32 (4) ◽  
pp. 501-513 ◽  
Author(s):  
Mehdi Mousavi ◽  
Aurelio Somà ◽  
Francesco Pescarmona
Keyword(s):  
Human Body ◽  
Humanoid Robots ◽  
Rotational Axis ◽  
Robotic Hands ◽  
Revolute Joints ◽  
Kinematic Study ◽  
Fixed Axis ◽  
Human Joints ◽  
Multi Body

SUMMARYIn the human body there are many joints whose functions are very similar to revolute joints. To avoid the complexity of these joints, they are usually substituted by revolute joints in many humanoid robots. Revolute joints have purely rotational motion along their fixed axis, while real joints in the human body have Instantaneous Rotational Axis (IRA) due to their configuration. Substitution of this kind of human joints with revolute (hinge) joints in robots changes the kinematics of joints. Knowing the exact characteristics of the moving axis of rotation in human joints is a prerequisite for the kinematic study of a joint. Here the main geometrical difference between these kinds of joints in humans and their simplified (hinge-like) models in robots is described. Then, as a case study, the mechanism of the three joints of the index finger are compared with their hinge-like model using a multi-body code to understand when revolute joints can be substituted for anthropometric joints in hand exoskeletons and robotic hands. Furthermore, the position of IRA and its distance from the center of the condyle of the joint are presented. The concept and the results can be extended for other fingers and all similar joints, and can be used in humanoid robots, hand exoskeletons and robotic hands.

scholarly journals Analisa Perbandingan Kinerja Panel Surya Vertikal Dengan Panel Surya Fleksibel Pada Jenis Monocrystalline

2021 ◽  
Vol 4 (1) ◽  
pp. 77
Author(s):  
Budiyanto Budiyanto ◽  
Hery Setiawan
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Solar Panel ◽  
Test Results ◽  
Solar Panels ◽  
Convex Shape ◽  
Final Project ◽  
Surrounding Environment ◽  
Different Types ◽  
Solar Lighting

Permasalahan utama dari solar cell adalah perbedaan jenis solar cell yang mengakibatkan perbedaan kinerja pada solar cell tersebut. Besarnya daya keluaran yang dihasilkan relatif tidak konstan karena dipengaruhi oleh besarnya intensitas matahari  serta  suhu  lingkungan  di  sekitarnya.  Untuk mengatasi masalah tersebut maka tugas akhir ini dirancang untuk melakukan perbandingan panel surya monocrystalline jenis vertikal dan jenis fleksibel.Pada hasil pengujian dengan pencahayaan matahari panel surya fleksibel menghasilkan efisiensi lebih tinggi dibanding dengan panel surya vertikal, yaitu 20,8774%, sedangkan panel surya vertikal meghasilkan efisiensi sebesar 19,2844%. Dalam penggunaan simulasi pencahayaan lampu panel surya vertikal menghasilkan efisiensi yang cukup tinggi dan lebih tinggi dibanding panel surya fleksibel, yaitu 20,4818% sedangkan panel surya fleksibel menghasilkan efisiensi sebesar 16,4044%. Pada panel surya fleksibel dengan bentuk cembung 25° menghasilkan efisiensi sebesar 15,3200. Pada bentuk cekung 25° menghasilkan efisiensi 15,6265%.The main problem with solar cells is the different types of solar cells that result in differences in the performance of the solar cell. The amount of output power produced is relatively not constant because it is influenced by the intensity of the sun and the temperature of the surrounding environment. To overcome this problem, this final project is designed to compare the vertical and flexible monocrystalline solar panels. In the test results with solar lighting, flexible solar panels produce higher efficiency than vertical solar panels, which is 20.8774%, while vertical solar panels resulted in an efficiency of 19.2844%. In the use of simulated lighting, vertical solar panel lights produce high and higher efficiency than flexible solar panels, namely 20.4818%, while flexible solar panels produce an efficiency of 16.4044%. In a flexible solar panel with a convex shape of 25° it produces an efficiency of 15.3200. In the concave shape of 25° it produces an efficiency of 15.6265%.

scholarly journals Otomasi Sistem Hidroponik DFT (Deep Flow Technique) Berbasis Arduino Android dengan Memanfaatkan Panel Surya sebagai Energi Alternatif

2019 ◽  
Vol 3 (2) ◽  
pp. 30-37
Author(s):  
Eko Agus Suprayitno MT ◽  
Rohman Dijaya M.Kom ◽  
M. Atho’illah ST
Keyword(s):  
Smartphone Application ◽  
Solar Panel ◽  
Maximum Distance ◽  
Test Results ◽  
Solar Panels ◽  
Concrete Wall ◽  
Hydroponic System ◽  
Pump Speed ◽  
Tool Performance ◽  
Communication Module

The application of hydroponic farming methods has been widely applied by the community, the system used is still manual so that it lacks quality, both in terms of humidity and growth. For that we need a system that is able to regulate the time of watering and the provision of nutritional solutions automatically without disturbing the activity. In the design of an automatic DFT hydroponic system using an Android Arduino based solar panel. Where the solar panel system functions as a renewable energy substitute for PLN which will fill the accumulator. The accumulator filling process is equipped with a solar charge controller module, which aims to avoid overcharging the accumulator. The process of watering and administering nutritional solutions is controlled by the Arduino UNO microcontroller which is integrated with the DS1307 RTC module, the HC-05 bluetooth serial communication module and the android smartphone application as the relay module to turn on and turn off the circulation pump according to a predetermined schedule. Test results and tool performance are in accordance with the plan, namely the efficiency of the use of solar panels. This is indicated by scheduling the circulation of the circulating pump for 1 hour from the estimated calculation of the maximum pump speed for 2.38 hours. In testing the transmission of data from bluetooth HC-05 connected to a bluetooth smartphone with unhindered conditions obtained a maximum distance of 15 meters and with a concrete wall obstruction a maximum distance of 5 meters, with plywood walls a maximum distance of 8 meters.

Compactly Folding Rigid Panels With Uniform Thickness Through Origami and Kirigami

2019 ◽  
Author(s):  
Jingyi Yang ◽  
Zhong You
Keyword(s):  
Solar Panels ◽  
Uniform Thickness ◽  
Hamiltonian Circuit ◽  
Aerospace Applications ◽  
Revolute Joints

Abstract In this paper, we investigate and evaluate origami and kirigami patterns that enable folding arrays made from flat rigid panels with uniform thickness into compact stacks. In deployed state, all panels form a completely flat plane; while in folded state, no voids exist within the stack. Two approaches are proposed. The first approach folds an array of identical rectangular panels into compact stacks. By drawing a Hamiltonian circuit over the array, a method of placing revolute joints is presented. By selecting a symmetric Hamiltonian circuit, we show that the array can be folded into two stacks. The second approach is case specific, which folds arrays consisting of square and half square triangular panels into stacks. Three basic units as well as their combinations are proposed, all of which lead to compact folding. Our designs can be applied to package solar panels for aerospace applications.

scholarly journals Two-Dimensional CFD Modeling of Hysteresis Behavior of MR Dampers

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Pengfei Guo ◽  
Jing Xie
Keyword(s):  
Mr Damper ◽  
Cfd Modeling ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
One Dimensional ◽  
Hysteresis Behavior ◽  
Mr Dampers ◽  
Nonlinear Hysteresis ◽  
Mr Fluids ◽  
Dimensional Modeling

So far, most previous studies on the nonlinear hysteresis analysis of ER/MR dampers have been limited to one-dimensional modeling techniques. A two-dimensional (2D) axisymmetric CFD model of MR dampers is developed in this work. The main advantage of the proposed 2D model of MR dampers lies in that it can be used to predict dynamic behavior of MR devices of arbitrary geometries. The compressibility of MR fluids is the main factor responsible for the hysteresis behavior of MR dampers, and it has been rarely investigated in previous multidimensional modeling of MR damper. In our model, the compressibility of MR fluids is taken into account by the two-dimensional constitutive model which is extended from a previous one-dimensional physical model. The model is solved by using the finite element method, and the movement of the piston is described by the moving mesh technique. The MR damper in a reference is simulated, and the model predictions show good agreement with the experimental data in the reference.

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