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.

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.

scholarly journals Correction to: Accurate position control of shape memory alloy actuation using displacement feedback and self-sensing system

2021 ◽  
Author(s):  
Ermira Junita Abdullah ◽  
Josu Soriano ◽  
Iñaki Fernández de Bastida Garrido ◽  
Dayang Laila Abdul Majid
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Position Control ◽  
Sensing System ◽  
Accurate Position

Position Control of a Three-link Shape Memory Alloy Actuated Robot

2006 ◽  
Vol 17 (5) ◽  
pp. 381-392 ◽  
Author(s):  
Hashem Ashrafiuon ◽  
Mojtaba Eshraghi ◽  
Mohammad H. Elahinia
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Position Control

Rapid prototyping prosthetic hand acting by a low-cost shape-memory-alloy actuator

2018 ◽  
Vol 21 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Enrique Soriano-Heras ◽  
Fernando Blaya-Haro ◽  
Carlos Molino ◽  
José María de Agustín del Burgo
Keyword(s):  
Shape Memory Alloy ◽  
Rapid Prototyping ◽  
Shape Memory ◽  
Low Cost ◽  
Prosthetic Hand ◽  
Shape Memory Alloy Actuator

Angular control of differential shape-memory alloy spring actuator for underactuated dynamic system

2021 ◽  
pp. 107754632110216
Author(s):  
M Banu Sundareswari ◽  
G Then Mozhi ◽  
K Dhanalakshmi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Fractional Order ◽  
Position Control ◽  
Sliding Mode ◽  
Control Effort ◽  
Control Laws ◽  
Integer Order ◽  
Two Degree Of Freedom ◽  
Outer Primary

This article dwells on two technical aspects, the design and implementation of an upgraded version of the differential shape-memory alloy–based revolute actuator/rotary actuating mechanism for stabilization and position control of a two-degree-of-freedom centrally hinged ball on beam system. The actuator is configured with differential and inclined placement of shape-memory alloy springs to provide bidirectional angular shift. The shape-memory alloy spring actuator occupies a smaller space and provides more extensive reformation with justifiable actuation force than an equally able shape-memory alloy wire. The cross or diagonal architecture of shape-memory alloy springs provides force amplification and reduces the actuator’s control effort. The shape-memory alloy spring–embodied actuator’s function is exemplified by the highly dynamic underactuated custom-designed ball balancing system. The ball position control is experimentally demonstrated by cascade control using the control laws that have been unattempted for shape-memory alloy actuated systems; the ball is positioned with linear (integer-order and fractional-order) proportional–integral–derivative controllers optimized with genetic algorithm and particle swarm optimization at the outer/primary loop. Angular control of the shape-memory alloy actuated beam is obtained with nonlinear (integer-order and fractional-order sliding mode control) control algorithms in the inner/secondary loop.

Adaptive predictive control of a novel shape memory alloy rod actuator

2020 ◽  
pp. 095965182097448
Author(s):  
S Farzaneh Hoseini ◽  
S Ali MirMohammadSadeghi ◽  
Alireza Fathi ◽  
Hamidreza Mohammadi Daniali
Keyword(s):  
Control System ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Predictive Control ◽  
Smart Materials ◽  
Position Control ◽  
Least Square ◽  
Recursive Least Square ◽  
Shape Memory Alloy Actuator ◽  
Hysteresis Nonlinearity

Shape memory alloys are among the highly applicable smart materials that have recently appealed to scientists from various fields of study. In this article, a novel shape memory alloy actuator, in the form of a rod, is introduced, and an adaptive model predictive control system is designed for position control of the developed actuator. The need for such an advanced control system emanates from the fact that modeling and controlling of shape memory alloy actuators are thwarted by their hysteresis nonlinearity, dilatory response, and high dependence on environmental conditions. Real-time identification and dynamic parameter estimation of the model are addressed according to orthogonal Laguerre functions and recursive least square algorithm. In the end, the designed control system is implemented on the experimental setup of the fabricated shape memory alloy actuator. It is observed that the designed control system successfully tracks the variable step and sinusoidal control references with startling accuracy of ±1 μm.

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