scholarly journals Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy

10.5772/7228 ◽  
2009 ◽  
Vol 6 (3) ◽  
pp. 29 ◽  
Author(s):  
Hu Bing-Shan ◽  
Wang Li-Wen ◽  
Fu Zhuang ◽  
Zhao Yan-zheng
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
Basic Structure ◽  
Thin Elastic Plate ◽  
Climbing Robots ◽  
Suction Cup ◽  
Sma Actuator ◽  
Suction Cups ◽  
Pressure Suction

Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA) are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME) extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

Design of a 2 DOF Shape Memory Alloy Actuator Using SMA Springs

2021 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Biologically Inspired ◽  
Loop Control ◽  
Actuator System ◽  
Sma Actuator ◽  
Sma Spring ◽  
Two Degree Of Freedom

Abstract In this paper, we developed two degree of freedom shape memory alloy (SMA) actuator using SMA springs. This module can be applied easily to various applications: device holder, artificial finger, grippes, fish robot, and many other biologically inspired applications, where small size and small wight of the actuator are very critical. This actuator is composed of two sets of SMA springs: one set is for the rotation around the X axis (roll angle) and the other set is for the rotation around the Y axis (pitch angle). Each set contains two elements: one SMA spring and one antagonistic SMA spring. We used an inertia sensor (IMU) and two potentiometers for angles feedback. The SMA actuator system is modeled mathematically and then tested experimentally in open-loop and closed-loop control. We designed and experimentally tuned a proportional integrator derivative (PID) controller to follow the set points and to track the desired trajectories. The main goal of the presented controller is to control roll and pitch angles simultaneously in order to satisfy set points and trajectories within the work space. The experimental results show that the two degree of freedom SMA actuator system follows the desired setpoints with acceptable rise time and overshoot.

A simplified analytical model to simulate martensite reorientation and plasticity in shape memory alloy ring couplers

2021 ◽  
pp. 1045389X2110572
Author(s):  
Fabrizio Niccoli ◽  
Valentina Giovinco ◽  
Cedric Garion ◽  
Carmine Maletta ◽  
Paolo Chiggiato
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
High Vacuum ◽  
Ring Expansion ◽  
Particle Accelerators ◽  
European Organization ◽  
Elastic Plastic ◽  
Wide Range ◽  
Martensite Reorientation

Recent studies on Shape Memory Alloy rings have been undertaken at the European Organization for Nuclear Research (CERN) to develop smart and leak-tight couplers for Ultra High Vacuum systems of particle accelerators. A special thermo-mechanical process (training) is needed to provide SMA rings with proper functional properties, that is to allow thermal mounting, dismounting, and leak tight coupling within a given service temperature window. Low temperature ring expansion is a crucial part of the training process as it gives suitable size, shape recovery properties, and thermal stability range to the SMA element. An analytical model, based on simplified elastic-plastic axisymmetric concepts, has been developed and implemented in a commercial software to simulate isothermal SMA rings expansions. It is particularly useful to predict the final size of a martensitic SMA coupler as a function of the initial dimensions and of the pre-deformation parameters. The effectiveness of the model has been demonstrated by analyzing the stress/deformation field occurring in a wide range of ring geometries for different load cases including martensite reorientation and plasticity. The predictions of the analytical model have been systematically compared with those obtained by axisymmetric finite element (FE) analyses based on elastic-plastic constitutive models and experimental measurements.

scholarly journals A Pressing Attachment Approach for a Wall-Climbing Robot Utilizing Passive Suction Cups

Robotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 26
Author(s):  
Dingxin Ge ◽  
Yongchen Tang ◽  
Shugen Ma ◽  
Takahiro Matsuno ◽  
Chao Ren
Keyword(s):  
Experimental Test ◽  
Experimental Results ◽  
Climbing Robot ◽  
Guide Rail ◽  
Test Bed ◽  
Climbing Robots ◽  
Pressing Method ◽  
Suction Cup ◽  
Suction Cups

This paper proposes a pressing method for wall-climbing robots to prevent them from falling. In order to realize the method, the properties of the utilized suction cup are studied experimentally. Then based on the results, a guide rail is designed to distribute the attached suction cup force and implement the pressing method. A prototype of a wall-climbing robot that utilizes passive suction cups and one motor is used to demonstrate the proposed method. An experimental test-bed is designed to measure the force changes of the suction cup when the robot climbs upwards. The experimental results validate that the suction cup can completely attach to the surface by the proposed method, and demonstrate that the robot can climb upwards without falling.

Discrete Preisach Model of a Shape Memory Alloy Actuator

2016 ◽  
Vol 248 ◽  
pp. 227-234
Author(s):  
Waldemar Rączka ◽  
Jarosław Konieczny ◽  
Marek Sibielak ◽  
Janusz Kowal
Keyword(s):  
Mathematical Model ◽  
Shape Memory Alloy ◽  
Parameter Identification ◽  
Shape Memory ◽  
Preisach Model ◽  
Discrete Form ◽  
Nonlinear Characteristics ◽  
Shape Memory Alloy Actuator ◽  
Sma Actuator ◽  
Identification Model

Shape Memory Alloy is a material used to designing actuators. These actuators have many advantages. They are light, strong and silent. They are building in laboratory and tested because beside advantages they have disadvantages too. SMA actuators have nonlinear characteristics with hysteresis loop.In the first part of the paper Shape Memory Alloys are shortly described. Next mathematical model was formulated. In the paper the Preisach model was developed. Discrete form of the model was considered and implemented. After parameter identification model was implemented in LabView. Tests of the model were conducted and results were worked. Obtained characteristics of the SMA actuator are shown in the paper. At the end of the paper the conclusions were formulated.

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.

A Novel Design of a Large-Stroke Shape Memory Alloy Linear Actuator

2019 ◽  
Author(s):  
Fei Yang ◽  
Jian Wang ◽  
Miaoling Han ◽  
Yifan Lu ◽  
Honghao Yue ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Linear Actuator ◽  
Confined Space ◽  
Output Displacement ◽  
Tandem Structure ◽  
In Series ◽  
Sma Actuator ◽  
Application Fields ◽  
Actuation Systems

Abstract The traditional actuation systems such as combustion engines, electro motors, hydraulic and pneumatic machines, have several drawbacks: large volume and weight, huge energy consumption and high cost. To overcome these problems, this paper presents a novel large-stroke linear actuator actuated by shape memory alloy (SMA) wires. Multiple SMA wires are distributed in the space three-dimensionally and connected in series to achieve a larger stroke of the actuator. The tandem structure makes the SMA actuator easy to integrate into a narrow available space with dimension constraints. A theoretical model for bias element selection is developed through analysis of the driving paths. A prototype of the proposed SMA actuator is fabricated and corresponding experiments are conducted to verify the functions and performances. The critical working performances of the SMA actuator such as the output displacement, heating electric current, actuation time and reset time are obtained and investigated. The results prove that the proposed SMA actuator can output an ideal driving stroke and enough actuation force in confined space. This research provides design ideas for the large-stroke SMA actuator in more application fields.

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