scholarly journals Micro Self-reconfigurable Modular Robot Using Shape Memory Alloy

2001 ◽  
Vol 13 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Eiichi Yoshida ◽  
◽  
Satoshi Murata ◽  
Shigeru Kokaji ◽  
Kohji Tomita ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
3D Model ◽  
Robotic System ◽  
Previous Model ◽  
Modular Robot ◽  
3 Dimensional ◽  
Sma Actuators ◽  
Modular Structures

This paper presents a micro self-reconfigurable modular robotic system using shape memory alloy (SMA) actuators. Composed of identical robotic modules, the system can actively configure various structures. The motion of module is based on 2-dimensional rotation using an actuator mechanism with 2 SMA torsion coil springs. The micro-module measures 2cm cube and weighs 15g, half the size of the previous model. The feasibility of reconfiguration was demonstrated using micro-robotic modules. We also show an extended 3-dimensional (3D) model and discuss a distributed self-reconfiguration algorithm for large modular structures.

A Mechanically Intelligent Crawling Robot Driven by Shape Memory Alloy and Compliant Bistable Mechanism

2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Lingda Meng ◽  
Rongjie Kang ◽  
Dongming Gan ◽  
Guimin Chen ◽  
Lisha Chen ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Robotic System ◽  
Design Parameters ◽  
Reciprocating Motion ◽  
Sma Actuators ◽  
Mechanical Components ◽  
Bistable Mechanism ◽  
Constraint Model ◽  
Electronic Controller

Abstract Mechanical components in a robotic system were used to provide body structure and mechanism to achieve physical motions following the commands from electronic controller. This kind of robotic system utilizes complex hardware and firmware for sensing and planning. To reduce computational cost and increase reliability for a robotic system, employing mechanical components to fully or partially take over control tasks is a promising way, which is also referred to as “mechanical intelligence” (MI). This paper proposes a shape memory alloy driven robot capable of using a reciprocating motion to crawl over a surface without any use of electronic controller. A mechanical logic switch is designed to determine the activation timing for a pair of antagonistic shape memory alloy (SMA) actuators. Meanwhile, a compliant pre-strain bistable mechanism is introduced to cooperate with the SMA actuators achieving reliable reciprocating motion between the two stable positions. The SMA actuator is modeled base on a static two-state theory while the bistable mechanism is described by combining a pseudo-rigid-body model (PRBM) with a Bi-beam constraint model (Bi-BCM). Following this, the design parameters of the bistable mechanism and SMA actuators are determined according to theoretical simulations. Finally, a robotic prototype is fabricated using anisotropic friction on its feet to convert the reciprocating motion of the actuator to uni-directional locomotion of the robot body over a surface. Experiments are carried out to validate the presented design concept and the modeling methods.

Structural fatigue and fracture of shape memory alloy actuators: Current status and perspectives

2021 ◽  
pp. 1045389X2110572
Author(s):  
Md Mehedi Hasan ◽  
Theocharis Baxevanis
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Current Status ◽  
Structural Fatigue ◽  
Sma Actuators ◽  
Empirical Relations ◽  
Fatigue And Fracture ◽  
And Performance ◽  
Commercial Applications ◽  
Crack Growth Rates

Shape Memory Alloy (SMA)-actuators are efficient, simple, and robust alternatives to conventional actuators when a small volume and/or large force and stroke are required. The analysis of their failure response is critical for their design in order to achieve optimum functionality and performance. Here, (i) the existing knowledge base on the fatigue and overload fracture response of SMAs under actuation loading is reviewed regarding the failure micromechanisms, empirical relations for actuation fatigue life prediction, experimental measurements of fracture toughness and fatigue crack growth rates, and numerical investigations of toughness properties and (ii) future developments required to expand the acquired knowledge, enhance the current understanding, and ultimately enable commercial applications of SMA-actuators are discussed.

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.

Shape Memory Alloys in Automotive Applications

2014 ◽  
Vol 663 ◽  
pp. 248-253 ◽  
Author(s):  
Jaronie Mohd Jani ◽  
Martin Leary ◽  
Aleksandar Subic
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
External Force ◽  
Active Element ◽  
Mechanical Design ◽  
Competitive Market ◽  
Automotive Applications ◽  
Market Prices ◽  
Sma Actuators

Shape memory alloy (SMA) actuators have drawn much attention and interest due to their unique and superior properties, and are expected to be equipped in many modern vehicles at competitive market prices. The key advantage is that SMA actuators do not require bulky and complicated mechanical design to function, where the active element (e.g. SMA wire or spring) can be deformed by applying minimal external force and will retain to their previous form when subjected to certain stimuli such as thermomechanical or magnetic changes. This paper describes the SMA attributes that make them ideally suited as actuators in automotive applications and to address their limitations, feasibilities and prospects.

Soft and smart modular structures actuated by shape memory alloy (SMA) wires as tentacles of soft robots

2016 ◽  
Vol 25 (8) ◽  
pp. 085026 ◽  
Author(s):  
Hu Jin ◽  
Erbao Dong ◽  
Min Xu ◽  
Chunshan Liu ◽  
Gursel Alici ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Soft Robots ◽  
Modular Structures

Modeling and Tracking Control System of Shape Memory Alloy Actuator

2007 ◽  
Author(s):  
B. Y. Ren ◽  
B. Q. Chen
Keyword(s):  
Control System ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Tracking Control ◽  
Fuzzy Controller ◽  
Smart Structures ◽  
Constitutive Law ◽  
Hysteresis Model ◽  
Sma Actuators ◽  
Sma Actuator

The different Shape Memory Alloy (SMA) actuators have been widely used in the fields of smart structures. However, the accurate prediction of thermomechanical behavior of SMA actuators is very difficult due to the nonlinearity of inherence hysteresis of SMA. Therefore, the tracking control accuracy of SMA actuator is very important for the practical application of the SMA actuator. A dynamic hysteresis model of bias-type SMA actuator based on constitutive law developed by Brinson et al. and hysteresis model developed by Ikuta et al. is presented. The control systems composed of the Proportional Integral Derivative (PID) controller as well as a fuzzy controller or a fuzzy-PID composite controller for compensating the hysteresis is proposed. The effort of tracking control system is analyzed according to the simulation on the displacement of SMA actuator with the three kinds of controllers. The result can provide a reference for the application of SMA actuator in the fields of smart structures.

Wet Shape Memory Alloy Actuated Robotic Heart

2009 ◽  
Author(s):  
Joel Ertel ◽  
Stephen Mascaro
Keyword(s):  
Shape Memory Alloy ◽  
Theoretical Analysis ◽  
Shape Memory ◽  
Preliminary Analysis ◽  
Design Concept ◽  
Design Parameters ◽  
Sma Actuators ◽  
Fluid Analysis ◽  
Cold Fluid ◽  
Simulation And Experiment

This paper presents a conceptual design and preliminary analysis for a biomimetic robotic heart. The purpose of the robotic heart is to distribute hot and cold fluid to robotic muscles composed of wet shape-memory alloy (SMA) actuators. The robotic heart is itself powered by wet SMA actuators. A heart design concept is proposed and the feasibility of self-sustaining motion is investigated through simulation and experiment. The chosen design employs symmetric pumping chambers for hot and cold fluid. Analysis of this design concept shows that there exists a range of design parameters that will allow the heart to output more fluid than it uses. Additionally, it is shown that the heartbeat rate decreases as the system increases in size, and that the number of actuators and their length limit the power output of the pump. Experimental results from a prototype heart agree with the predicted trends from theoretical analysis and simulation.

scholarly journals A 3D Printed Implantable Device for Voiding the Bladder Using Shape Memory Alloy (SMA) Actuators

2017 ◽  
Vol 4 (11) ◽  
pp. 1700143 ◽  
Author(s):  
Faezeh Arab Hassani ◽  
Wendy Yen Xian Peh ◽  
Gil Gerald Lasam Gammad ◽  
Roshini Priya Mogan ◽  
Tze Kiat Ng ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Implantable Device ◽  
Sma Actuators ◽  
3D Printed

Shape Memory Alloy Actuator (SMA)

2015 ◽  
Vol 816 ◽  
pp. 9-15
Author(s):  
Oskar Ostertag ◽  
Eva Ostertagová
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Shape Memory Material ◽  
Sma Actuators ◽  
Shape Memory Alloy Actuator ◽  
Memory Material ◽  
Low Weight ◽  
Mechanical Element ◽  
Great Force

Our article deals with the possibility of using shape memory material (SMA − Shape Memory Alloy) to create an actuator of the mechanical element. The biggest advantage of the SMA actuators compared to those made of conventional materials is that they have the ability to generate relatively great force, are of low weight and small size.

Optimization of a Composite Morphing Wing With Shape Memory Alloy Torsional Actuators

2014 ◽  
Author(s):  
Robert Saunders ◽  
Darren Hartl ◽  
Joshua Herrington ◽  
Logan Hodge ◽  
James Mabe
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Structural Design ◽  
Rapid Prototype ◽  
Sma Actuators ◽  
Wing Model ◽  
Induced Drag ◽  
Preliminary Study ◽  
Wing Performance ◽  
Composite Wing

Shape memory alloy (SMA) actuators have recently been developed in the form of torsional tubes that can undergo large twisting deformations. Wing twisting has been investigated as a means to reduce induced drag in cruise conditions in small aircraft, but the actuation hardware required to generate wing twist at larger scales is prohibitively cumbersome. Replacing conventional actuators with SMA torque tubes provides a way to minimize weight of the twisting system but wing structural design then becomes more challenging. This analysis-driven design study examines an SMA torque tube as applied to the twisting wing design problem. A composite skin is considered to maximize wing performance under combined twist and aerodynamic loads. The SMA has been analyzed using a 3-D thermo-mechanical constitutive model while a preliminary study was performed to determine a composite lamina with appropriate unidirectional properties. An optimization was then completed to find an ideal composite layup. This optimization also included the design of a passive torque tube used to properly balance the twist generated by the SMA against that required in the wing. Localized buckling in the twisted wing was also considered and avoided. The product of this optimization was a composite wing that twisted while considering constraints of stress on the SMA. To validate the controllable use of SMA actuators, testing was completed on a scaled wing model fitted with a rapid prototype shell.

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