Design and Experimental Validation of a Shape Memory Alloy Actuator for Linear Motors

2015 ◽  
Vol 783 ◽  
pp. 69-75 ◽  
Author(s):  
Francesco Aggogeri ◽  
Nicola Pellegrini
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Experimental Validation ◽  
Closed Loop ◽  
Cooling System ◽  
Air Cooling ◽  
Cooling Systems ◽  
Linear Motors ◽  
Forced Air ◽  
The Mathematical Model

This paper presents an innovative mechanical actuator using a shape memory alloy (SMA) with a cooling system based on combined thermoelectric effect and forced air cooling systems. The main advantages of using SMAs include the reduction of the system weight, the ease and reliability in application, and a simple control strategy. This study focuses on the development of the system highlighting the mathematical model of the actuator, and an experimental prototype was implemented. Several experiments are used to validate the model and to identify best SMA actuator configuration parameters. Experiments were used to evaluate the actuator closed-loop performance, stability, and robustness properties.

Energieautarke Kühlung von Lineardirektantrieben*/Experimental investigation of self-sufficient cooling systems for linear direct drives of machine tools - Recuperation of the thermal losses in linear motors with thermoelectric generators

2017 ◽  
Vol 107 (05) ◽  
pp. 359-365
Author(s):  
E. Prof. Uhlmann ◽  
S. Salein
Keyword(s):  
Energy Harvesting ◽  
Machine Tools ◽  
Cooling System ◽  
Electric Energy ◽  
Electrical Energy ◽  
Efficient Solutions ◽  
Air Cooling ◽  
Thermoelectric Generators ◽  
Cooling Systems ◽  
Linear Motors

Das wachsende Bewusstsein für eine umweltgerechte und damit nachhaltige Fertigung sowie steigende Energiepreise führen zur erhöhten Nachfrage nach energieeffizienten Lösungsansätzen für langlebige Produktionsmittel. Die Energierückgewinnung von thermischen Verlusten durch thermoelektrische Generatoren stellt hierfür einen innovativen Ansatz dar. Das als Energy Harvesting bekannte Konzept wird am Institut für Werkzeugmaschinen und Fabrikbetrieb (IWF) der Technischen Universität Berlin auf seine Eignung zur Erhöhung der Energieeffizienz von hochdynamischen Werkzeugmaschinen untersucht. Der Fachbeitrag präsentiert experimentelle Ergebnisse zur Rückgewinnung von thermischen Verlusten eines Linearmotors. Die im Wärmefluss platzierten thermoelektrischen Generatoren generieren eine elektrische Leistung, die direkt zur Versorgung des Motorkühlsystems genutzt wird. Die Ergebnisse zeigen, dass die elektrischen Verbraucher eines Wasser- und Luftkühlsystems aus der rückgewonnenen Energie der thermoelektrischen Module betrieben werden können.   The growing awareness for environmentally friendly and sustainable production as well as the increase of energy costs leads to a rising demand for energy efficient solutions for long-life production facilities. An innovative approach in this field is the recuperation of energy from thermal loss through thermoelectric generators. The proof of applicability to use an energy harvesting concept in order to increase the energy efficiency of highly dynamic machine tools with linear direct drives is part of a research objective at the Institute for Machine Tools and Factory Management (IWF) of the Technische Universität Berlin. The present paper investigates experimentally the recuperation of thermal losses in linear direct drives. Thermoelectric generators are placed in the heat flow to convert heat into electric energy which is directly supplied to the cooling system of a device. Experimental results show the feasibility to operate the electrical loads of water and air cooling systems by the electrical energy harvested from thermoelectric generators.

Forced Air Cooling of Shape-Memory Alloy Actuators for a Prosthetic Hand

2016 ◽  
Vol 16 (4) ◽  
Author(s):  
Fergus Taylor ◽  
ChiKit Au
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Control Experiment ◽  
Position Control ◽  
Prosthetic Hand ◽  
Air Cooling ◽  
Actuation Frequency ◽  
Hand Shape ◽  
Forced Air ◽  
Array Position

This research paper presents the development of nonconventional actuation technology for use in a prosthetic hand. Shape-memory alloy (SMA) is used for the actuation. SMA is a material which contracts when heated and relaxes when cooled and has a work density 25 times greater than traditional electric motor actuators. A compact SMA actuator array, position sensors, and power electronics are developed. A proportional-integral-derivative (PID) controller is used to control the contraction of the actuators. Forced air cooling is implemented to improve actuation frequency. The performance of an actuator is demonstrated in dynamic and static position experiments. The static position control of the actuator is found to remain within 0.7% (70 μm) of the setpoint during initial oscillation and then within 0.15% (15 μm) after oscillations subside. The dynamic position control experiment finds that the forced air cooling reduces actuation frequency from 9.5 s to 3.5 s. This results in an actuation frequency comparable to current commercial prosthetics. When compared with the most advanced commercial devices, this actuator array provides improvements in terms of cost, noise, and weight. All of which are important acceptance criteria for prosthetic hand users.

scholarly journals Air circulation in a gastrointestinal light source box and endoscope in the era of SARS-CoV-2 and airborne transmission of microorganisms

2021 ◽  
Vol 09 (03) ◽  
pp. E482-E486
Author(s):  
Stanislas Chaussade ◽  
Einas Abou Ali ◽  
Rachel Hallit ◽  
Arthur Belle ◽  
Maximilien Barret ◽  
...  
Keyword(s):  
Light Source ◽  
Cooling System ◽  
Air Cooling ◽  
Airborne Transmission ◽  
Plastic Tube ◽  
Care Workers ◽  
Air Cooling System ◽  
Forced Air ◽  
Air Circulation ◽  
Closed Environment

Abstract Background and study aims The role that air circulation through a gastrointestinal endoscopy system plays in airborne transmission of microorganisms has never been investigated. The aim of this study was to explore the potential risk of transmission and potential improvements in the system. Methods We investigated and described air circulation into gastrointestinal endoscopes from Fujifilm, Olympus, and Pentax. Results The light source box contains a lamp, either Xenon or LED. The temperature of the light is high and is regulated by a forced-air cooling system to maintain a stable temperature in the middle of the box. The air used by the forced-air cooling system is sucked from the closed environment of the patient through an aeration port, located close to the light source and evacuated out of the box by one or two ventilators. No filter exists to avoid dispersion of particles outside the processor box. The light source box also contains an insufflation air pump. The air is sucked from the light source box through one or two holes in the air pump and pushed from the air pump into the air pipe of the endoscope through a plastic tube. Because the air pump does not have a dedicated HEPA filter, transmission of microorganisms cannot be excluded. Conclusions Changes are necessary to prevent airborne transmission. Exclusive use of an external CO2 pump and wrapping the endoscope platform with a plastic film will limit scatter of microorganisms. In the era of pandemic virus with airborne transmission, improvements in gastrointestinal ventilation systems are necessary to avoid contamination of patients and health care workers.

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.

Influence of selected factors on parameters of a cooling system with a Peltier module and forced air flow

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Krzysztof Posobkiewicz ◽  
Krzysztof Górecki
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Cooling System ◽  
Heat Sinks ◽  
Cooling Power ◽  
Cooling Systems ◽  
Content Type ◽  
Peltier Module ◽  
Peltier Modules ◽  
Forced Air

Purpose The purpose of this study is to investigate the validation of the usefulness of cooling systems containing Peltier modules for cooling power devices based on measurements of the influence of selected factors on the value of thermal resistance of such a cooling system. Design/methodology/approach A cooling system containing a heat-sink, a Peltier module and a fan was built by the authors and the measurements of temperatures and thermal resistance in various supply conditions of the Peltier module and the fan were carried out and discussed. Findings Conclusions from the research carried out answer the question if the use of Peltier modules in active cooling systems provides any benefits comparing with cooling systems containing just passive heat-sinks or conventional active heat-sinks constructed of a heat-sink and a fan. Research limitations/implications The research carried out is the preliminary stage to asses if a compact thermal model of the investigated cooling system can be formulated. Originality/value In the paper, the original results of measurements and calculations of parameters of a cooling system containing a Peltier module and an active heat-sink are presented and discussed. An influence of power dissipated in the components of the cooling system on its efficiency is investigated.

Optimal H∞ Control of Structural Vibrations Using Shape Memory Alloy Actuators

1999 ◽  
Author(s):  
Jian Sun ◽  
Ali R. Shahin
Keyword(s):  
Mathematical Model ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Model Uncertainty ◽  
High Frequency ◽  
Structural Vibrations ◽  
Design Procedures ◽  
Sma Actuators ◽  
Temperature Dynamics ◽  
The Mathematical Model

Abstract This paper investigates robust control problem of structural vibrations using shape memory alloy (SMA) wires as actuators. The mathematical model for these SMA actuators is derived with emphasis in model uncertainty. The linearization of the relation between stress and temperature dynamics of SMA actuators is analyzed for active control. To handle the uncertainties caused by the linearization and the neglected high frequency dynamics, optimal H∞ control was employed to design a controller. An example is used to demonstrate the design procedures and the control system is tested in a nonlinear environment.

Development of a PID Based Closed Loop Controller for Shape Memory Alloy Actuators

2018 ◽  
Author(s):  
T.A.U. Roshan ◽  
B.A.D.J.C.K. Basnayake ◽  
Y.W.R. Amarasinghe ◽  
Dimuthu Wijethunge ◽  
Nuwan D Nanayakkara
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Closed Loop
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