Design and Control of a Shape Memory Alloy Wire Bundle Actuator

2000 ◽  
Author(s):  
Michael J. Mosley ◽  
Constantinos Mavroidis
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Artificial Muscle ◽  
Linear Displacement ◽  
Nickel Titanium ◽  
Input Shaping ◽  
Joint Rotation ◽  
Revolute Joint ◽  
And Control ◽  
Robotic Applications

Abstract In this paper, the design and control of a novel shape memory alloy (SMA) actuator that possesses impressive payload lifting capabilities are presented. The actuator consists of 48 nickel-titanium SMA wires mechanically bundled in parallel forming one powerful artificial muscle. This new linear actuator can apply up to 100 lbf (445 N), which is approximately 300 times its weight, over a maximum distance of 0.5 in. (1.27 cm). The actuator was tested in two different loading configurations — linear displacement and operation of a revolute joint. A PID based controller with the addition of an input shaping function was developed for each loading configuration with excellent results, maintaining steady state error within ± 0.004 in. (0.1 mm) for linear motion and ± 1° for revolute joint rotation. This powerful, compact, and lightweight actuator shows promise for use in space, medical, and other macro-robotic applications.

Nonlinear Adaptive Control of Dynamic Systems Driven by Shape Memory Alloy (SMA) Actuators

2008 ◽  
Author(s):  
Shuo Chen ◽  
William J. Craft ◽  
David Y. Song
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Composite Structures ◽  
Lyapunov Stability Theory ◽  
Linear Displacement ◽  
Control Algorithms ◽  
Sma Actuators ◽  
Composite Systems ◽  
Set Up ◽  
And Control

This work describes the development and analysis of nonlinear adaptive based control algorithms for composite structures/systems operated with Shape Memory Alloy (SMA) actuators. A mathematical model charactering the motion of the composite systems is established, and by using Lyapunov stability theory, algorithms for linear displacement tracking control are derived. Actuation and control is achieved by adjusting the supply current to the SMA actuators. It is shown that with the proposed strategy for both linear displacement and velocity requires that the desired trajectory is tracked precisely. The novelty of the proposed approach also lies in the fact that it is fairly easy to set up and the computation involved as compared with other strategies. An example is used to verify the validity of the proposed approach. Simulation results using Matlab are presented.

scholarly journals Crystallographic Attributes of a Shape-Memory Alloy

1999 ◽  
Vol 121 (1) ◽  
pp. 93-97 ◽  
Author(s):  
Kaushik Bhattacharya
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Nickel Titanium ◽  
Potential Applications

Shape-memory Alloys are attractive for many potential applications. In an attempt to provide ideas and guidelines for the development of new shape-memory alloys, this paper reports on a series of investigations that examine the reasons in the crystallography that make (i) shape-memory alloys special amongst martensites and (ii) Nickel-Titanium special among shape-memory alloys.

scholarly journals The Role of Nickel-titanium Shape Memory Alloy Embracing Fixator in Determination of the Implantation Angle of Hip Tumor Prosthesis Stem Following Tumor Resection and the Analysis of Its Efficacy: a Retrospective Study

2021 ◽  
Author(s):  
Yang Wang ◽  
Panyu Zhou ◽  
Demeng Xia ◽  
Yunyun Wang ◽  
Sheng Wang ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Tumor Resection ◽  
Hip Dislocation ◽  
Nickel Titanium ◽  
Prosthetic Replacement ◽  
Limb Function ◽  
Tumor Prosthesis

Abstract Background: To explore the role of nickel-titanium(NiTi) shape memory alloy embracing fixator in determination of implantation angle of hip tumor prosthesis stem and analyze its efficacy. Methods: 36 patients with proximal femur tumor were treated with extended tumor resection and prosthetic replacement. 14 patients received prosthetic replacements with the embracing fixators fixing between the junction of the prosthesis stem and the femur temporarily, while the other 22 patients received the same replacements but without the fixators. Following aspects were compared: occurrence of complications, limb function and active hip ROM.Results: There are fewer cases of hip dislocation in the group received prosthetic replacements with the use of embracing fixators. Occurrence of deep infection presented no difference between the two groups. Better limb function and higher active range of motion (ROM) on abduction or flexion were also found in the group using embracing fixators. Conclusion: Ni-Ti shape memory alloy embracing fixator plays a key part in assisting the accurate implantation angle of the prosthesis stem in the prosthetic replacement. The prosthesis stem can be adjusted to the optimal angle with the help of the embracing fixator. Patients have lower chance of dislocation, better limb function, and higher active hip ROM. Trial registration: retrospectively registered.

Nickel–titanium shape memory alloy mechanical components produced by investment casting

2018 ◽  
Vol 29 (19) ◽  
pp. 3748-3757 ◽  
Author(s):  
Jackson de Brito Simões ◽  
Carlos José de Araújo
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Investment Casting ◽  
Mechanical Characterization ◽  
Nickel Titanium ◽  
Compression Tests ◽  
Thermoelastic Martensitic Transformation ◽  
Scanning Calorimetry ◽  
Helical Springs ◽  
Mechanical Components

This work aimed to produce mechanical components of nickel–titanium shape memory alloys using investment casting processes. Then, in order to validate processing, different designs of nickel–titanium shape memory alloy components as staple implants, Belleville springs, meshes, helical springs, screws and hexagonal honeycombs were produced and submitted to thermal and mechanical characterization. Thermoelastic martensitic transformation of the nickel–titanium shape memory alloy parts was determined by differential scanning calorimetry and electrical resistance with temperature, while the superelastic behaviour was verified by cyclic tensile and compression tests. It has been demonstrated that the employed investment casting processes are suitable to manufacture nickel–titanium shape memory alloy mechanical components with simple and complicated designs as well as functional properties related to phase transformation and superelasticity.

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