Experimental Characterization and Static Modeling of McKibben Actuators

Aerospace ◽  
2006 ◽  
Author(s):  
Curt S. Kothera ◽  
Mamta Jangid ◽  
Jayant Sirohi ◽  
Norman M. Wereley
Keyword(s):  
Energy Storage ◽  
Elastic Energy ◽  
Weight Ratio ◽  
Rubber Tube ◽  
Force Output ◽  
Static Behavior ◽  
Series Of Experiments ◽  
Mckibben Actuators ◽  
Improved Model ◽  
The Impact

McKibben actuators are pneumatic actuators with very high force to weight ratio. Their ability to match the behavior of biological muscles better than many other actuators has motivated much research into characterization and modeling of these actuators. The purpose of this paper is to experimentally characterize the behavior of McKibben artificial muscles with basic geometric parameters and present a model that is able to predict the static behavior correctly in terms of blocked force and free displacement. A series of experiments aimed at understanding the static behavior of the actuators was conducted. The results for three different lengths (4, 6, 8 in), three diameters (1/8, 1/4, 3/8 in) and two wall thicknesses (1/32 and 1/16 in) at pressures ranging from 10 psi to 60 psi show the expected trends (for example, block force increasing with diameter) as predicted by models presented in the literature. However, these models do not accurately predict static behavior. Corrections to the Gaylord equation are explored in order to obtain a more accurate model. Consideration of elastic energy storage in the rubber tube has been shown to significantly improve the models. Apart from this, the effect of non-cylindrical tips and elastic energy storage in the braid are also considered. To increase model accuracy, another set of experiments was used to characterize the elasticity of the rubber tubes and fibers of the braid. The improved model is able to predict static behavior correctly. Incorporating, various corrections, a model is presented that is more accurate in predicting the static behavior. Finally, in order to possibly obtain larger force output from the McKibben actuators, a series of experiments were performed to study the impact of an applied pre-strain. The results presented show large increases in blocked force with pre-strain. For the largest diameter actuator of 6 inch length, the blocked force at 12% pre-strain is as high as 270 N, while the amplification is higher at lower pressures. The model is tested to predict the pre-strain characteristics. A number of factors are identified that may improve the model and incorporate dynamic behavior.

Experimental Characterization and Static Modeling of McKibben Actuators

2009 ◽  
Vol 131 (9) ◽  
Author(s):  
Curt S. Kothera ◽  
Mamta Jangid ◽  
Jayant Sirohi ◽  
Norman M. Wereley
Keyword(s):  
Artificial Muscles ◽  
Static Behavior ◽  
Model Accuracy ◽  
Pneumatic Actuators ◽  
Static Modeling ◽  
Series Of Experiments ◽  
Mckibben Actuators ◽  
Improved Model ◽  
Very High ◽  
Better Than

McKibben actuators are pneumatic actuators with very high force to weight ratios. Their ability to match the behavior of biological muscles better than any other actuators has motivated much research into the characterization and modeling of these actuators. The purpose of this paper is to experimentally characterize the behavior of McKibben artificial muscles with basic geometric parameters, and present a model that is able to predict the static behavior accurately in terms of blocked force and free displacement. A series of experiments aimed at understanding the static behavior of the actuators was conducted. The results for three different lengths (4 in., 6 in., and 8 in.), three diameters (1/8 in., 1/4 in., and 3/8 in.), and one wall thickness (1/16 in.) at pressures ranging from 10 psi to 60 psi illustrate the key design trends seen in McKibben actuator geometry. While existing models predict this static behavior, there are varying degrees of accuarcy, which motivates the present study. Using knowledge gained from the experimental study, improvements for the two modeling approaches were explored, including effects from elastic energy storage, noncylindrical shape, and variable thickness. To increase model accuracy, another set of experiments was used to characterize the elasticity of the rubber tubes and fibers of the braid. Comparisons of the measured data to the improved model indicate that the ability to accurately predict the static behavior of McKibben actuators has increased.

Recent Advances and Need of Green Synthesis in Two-Dimensional Materials for Energy Conversion and Storage Applications

2021 ◽  
Vol 16 ◽  
Author(s):  
Joice Sophia Ponraj ◽  
Muniraj Vignesh Narayanan ◽  
Ranjith Kumar Dharman ◽  
Valanarasu Santiyagu ◽  
Ramalingam Gopal ◽  
...  
Keyword(s):  
Energy Storage ◽  
Green Synthesis ◽  
2D Materials ◽  
Synthesis Method ◽  
Energy Storage And Conversion ◽  
Two Dimensional ◽  
Severe Problem ◽  
Energy Conversion And Storage ◽  
Energy Application ◽  
The Impact

: Increasing energy crisis across the globe requires immediate solutions. Two-dimensional (2D) materials are in great significance because of its application in energy storage and conversion devices but the production process significantly impacts the environment thereby posing a severe problem in the field of pollution control. Green synthesis method provides an eminent way of reduction in pollutants. This article reviews the importance of green synthesis in the energy application sector. The focus of 2D materials like graphene, MoS2, VS2 in energy storage and conversion devices are emphasized based on supporting recent reports. The emerging Li-ion batteries are widely reviewed along with their promising alternatives like Zn, Na, Mg batteries and are featured in detail. The impact of green methods in the energy application field are outlined. Moreover, future outlook in the energy sector is envisioned by proposing an increase in 2D elemental materials research.

Jumping, Climbing and Suspensory Locomotion

2018 ◽  
Keyword(s):  
Energy Storage ◽  
Elastic Energy ◽  
The Core ◽  
Power Amplification ◽  
Core Concepts

Jumping, climbing and suspensory locomotion are specialized locomotor mechanisms used on land and in the air. Jumping is used for rapid launches from substrates. Climbing and suspensory movements enable locomotion up, under and through vertically-structured habitats, such as forests. Elastic energy storage is particularly important for jumping and catapult systems and we address the core concepts of power amplification that are exemplified in nature’s extreme jumpers. We examine the diverse mechanisms of attachment that characterize animals that can grasp and adhere to a diversity of structures. We conclude the chapter by examining the integration of biological capabilities with engineering innovations in these systems.

scholarly journals Controlled Nanostructuration of Cobalt Oxyhydroxide Electrode Material for Hybrid Supercapacitors

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2325
Author(s):  
Ronan Invernizzi ◽  
Liliane Guerlou-Demourgues ◽  
François Weill ◽  
Alexia Lemoine ◽  
Marie-Anne Dourges ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Energy Storage ◽  
Specific Surface ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Hybrid Supercapacitors ◽  
Cobalt Oxyhydroxide ◽  
Precipitation Medium ◽  
The Impact

Nanostructuration is one of the most promising strategies to develop performant electrode materials for energy storage devices, such as hybrid supercapacitors. In this work, we studied the influence of precipitation medium and the use of a series of 1-alkyl-3-methylimidazolium bromide ionic liquids for the nanostructuration of β(III) cobalt oxyhydroxides. Then, the effect of the nanostructuration and the impact of the different ionic liquids used during synthesis were investigated in terms of energy storage performances. First, we demonstrated that forward precipitation, in a cobalt-rich medium, leads to smaller particles with higher specific surface areas (SSA) and an enhanced mesoporosity. Introduction of ionic liquids (ILs) in the precipitation medium further strongly increased the specific surface area and the mesoporosity to achieve well-nanostructured materials with a very high SSA of 265 m2/g and porosity of 0.43 cm3/g. Additionally, we showed that ILs used as surfactant and template also functionalize the nanomaterial surface, leading to a beneficial synergy between the highly ionic conductive IL and the cobalt oxyhydroxide, which lowers the resistance charge transfer and improves the specific capacity. The nature of the ionic liquid had an important influence on the final electrochemical properties and the best performances were reached with the ionic liquid containing the longest alkyl chain.

An improved dynamic load-strength interference model for the reliability analysis of aero-engine rotor blade system

2020 ◽  
pp. 095441002097289
Author(s):  
Bingfeng Zhao ◽  
Liyang Xie ◽  
Yu Zhang ◽  
Jungang Ren ◽  
Xin Bai ◽  
...  
Keyword(s):  
Reliability Analysis ◽  
Dynamic Load ◽  
Rotor Blade ◽  
Engineering Application ◽  
Weight Ratio ◽  
System Component ◽  
Aero Engine ◽  
Blade System ◽  
Improved Model ◽  
Engine Rotor

As the power source of an aircraft, aero-engine tends to meet many rigorous requirements for high thrust-weight ratio and reliability with the continuous improvement of aero-engine performance. In this paper, based on the order statistics and stochastic process theory, an improved dynamic load-strength interference (LSI) model was proposed for the reliability analysis of aero-engine rotor blade system, with strength degradation and catastrophic failure involved. In presented model, the “unconventional active” characteristic of rotor blade system, changeable functioning relationships and system-component configurations, was fully considered, which is necessary for both theoretical analysis and engineering application. In addition, to reduce the computation cost, a simplified form of the improved LSI model was also built for convenience of engineering application. To verify the effectiveness of the improved model, reliability of turbojet 7 engine rotor blade system was calculated by the improved LSI model based on the results of static finite element analysis. Compared with the traditional LSI model, the result showed that there were significant differences between the calculation results of the two models, in which the improved model was more appropriate to the practical condition.

scholarly journals The Impact of Energy Storage along with the Allocation of RES on the Reduction of Energy Costs Using MILP

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3783
Author(s):  
Mateusz Andrychowicz
Keyword(s):  
Energy Storage ◽  
Mixed Integer Linear Programming ◽  
Distribution Systems ◽  
Operating Costs ◽  
Mixed Integer ◽  
Energy Costs ◽  
Power Exchange ◽  
Local Initiatives ◽  
One Year ◽  
The Impact

The paper shows a method of optimizing local initiatives in the energy sector, such as energy cooperatives and energy clusters. The aim of optimization is to determine the structure of generation sources and energy storage in order to minimize energy costs. The analysis is carried out for the time horizon of one year, with an hourly increment, taking into account various RES (wind turbines (WT), photovoltaic installations (PV), and biogas power plant (BG)) and loads (residential, commercial, and industrial). Generation sources and loads are characterized by generation/demand profiles in order to take into account their variability. The optimization was carried out taking into account the technical aspects of the operation of distribution systems, such as power flows and losses, voltage levels in nodes, and power exchange with the transmission system, and economic aspects, such as capital and fixed and variable operating costs. The method was calculated by sixteen simulation scenarios using Mixed-Integer Linear Programming (MILP).

scholarly journals Computer Model for Financial, Environmental and Risk Analysis of a Wind–Diesel Hybrid System with Compressed Air Energy Storage

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4054 ◽  
Author(s):  
Youssef Benchaabane ◽  
Rosa Elvira Silva ◽  
Hussein Ibrahim ◽  
Adrian Ilinca ◽  
Ambrish Chandra ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Renewable Energy ◽  
Energy Storage ◽  
Environmental Impact ◽  
Hybrid System ◽  
Computer Model ◽  
Net Present Value ◽  
Compressed Air ◽  
Compressed Air Energy Storage ◽  
The Impact

Remote and isolated communities in Canada experience gaps in access to stable energy sources and must rely on diesel generators for heat and electricity. However, the cost and environmental impact resulting from the use of fossil fuels, especially in local energy production, heating, industrial processes and transportation are compelling reasons to support the development and deployment of renewable energy hybrid systems. This paper presents a computer model for economic analysis and risk assessment of a wind–diesel hybrid system with compressed air energy storage. The proposed model is developed from the point of view of the project investor and it includes technical, financial, risk and environmental analysis. Robustness is evaluated through sensitivity analysis. The model has been validated by comparing the results of a wind–diesel case study against those obtained using HOMER (National Renewable Energy Laboratory, Golden, CO, United States) and RETScreen (Natural Resources Canada, Government of Canada, Canada) software. The impact on economic performance of adding energy storage system in a wind–diesel hybrid system has been discussed. The obtained results demonstrate the feasibility of such hybrid system as a suitable power generator in terms of high net present value and internal rate of return, low cost of energy, as well as low risk assessment. In addition, the environmental impact is positive since less fuel is used.

scholarly journals Ultrahigh Ballistic Resistance of Twisted Bilayer Graphene

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 206
Author(s):  
Qing Peng ◽  
Sheng Peng ◽  
Qiang Cao
Keyword(s):  
Weight Ratio ◽  
High Strength ◽  
Bilayer Graphene ◽  
Energy Propagation ◽  
Dynamic Simulations ◽  
Protective Material ◽  
Impact Performance ◽  
Ballistic Resistance ◽  
Twisted Bilayer Graphene ◽  
The Impact

Graphene is a good candidate for protective material owing to its extremely high stiffness and high strength-to-weight ratio. However, the impact performance of twisted bilayer graphene is still obscure. Herein we have investigated the ballistic resistance capacity of twisted bilayer graphene compared to that of AA-stacked bilayer graphene using molecular dynamic simulations. The energy propagation processes are identical, while the ballistic resistance capacity of the twisted bilayer graphene is almost two times larger than the AA-bilayer graphene. The enhanced capacity of the twisted bilayer graphene is assumed to be caused by the mismatch between the two sheets of graphene, which results in earlier fracture of the first graphene layer and reduces the possibility of penetration.

scholarly journals Evaluation of a 1 MW, 250 kW-hr Battery Energy Storage System for Grid Services for the Island of Hawaii

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3367 ◽  
Author(s):  
Karl Stein ◽  
Moe Tun ◽  
Keith Musser ◽  
Richard Rocheleau
Keyword(s):  
Energy Storage ◽  
Data Collection ◽  
Storage System ◽  
Energy Storage System ◽  
Fast Response ◽  
Lessons Learned ◽  
Battery Energy Storage ◽  
Utility Company ◽  
Battery Energy ◽  
The Impact

Battery energy storage systems (BESSs) are being deployed on electrical grids in significant numbers to provide fast-response services. These systems are normally procured by the end user, such as a utility grid owner or independent power producer. This paper introduces a novel research project in which a research institution has purchased a 1 MW BESS and turned ownership over to a utility company under an agreement that allowed the institution to perform experimentation and data collection on the grid for a multi-year period. This arrangement, along with protocols governing experimentation, has created a unique research opportunity to actively and systematically test the impact of a BESS on a live island grid. The 2012 installation and commissioning of the BESS was facilitated by a partnership between the Hawaii Natural Energy Institute (HNEI) and the utility owner, the Hawaiian Electric and Light Company (HELCO). After the test period ended, HELCO continued to allow data collection (including health testing). In 2018, after 8500 equivalent cycles, the BESS continues to operate within specifications. HNEI continues to provide HELCO with expertise to aid with diagnostics as needed. Details about the BESS design, installation, experimental protocols, initial results, and lessons learned are presented in this paper.

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