Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1095

Search results for: soft actuator

1095 Identification and Force Control of a Two Chambers Pneumatic Soft Actuator

Authors: Najib K. Dankadai, Ahmad 'Athif Mohd Faudzi, Khairuddin Osman, Muhammad Rusydi Muhammad Razif, IIi Najaa Aimi Mohd Nordin

Abstract:

Researches in soft actuators are now growing rapidly because of their adequacy to be applied in sectors like medical, agriculture, biological and welfare. This paper presents system identification (SI) and control of the force generated by a two chambers pneumatic soft actuator (PSA). A force mathematical model for the actuator was identified experimentally using data acquisition card and MATLAB SI toolbox. Two control techniques; a predictive functional control (PFC) and conventional proportional integral and derivative (PID) schemes are proposed and compared based on the identified model for the soft actuator flexible mechanism. Results of this study showed that both of the proposed controllers ensure accurate tracking when the closed loop system was tested with the step, sinusoidal and multi step reference input through MATLAB simulation although the PFC provides a better response than the PID.

Keywords: predictive functional control (PFC), proportional integral and derivative (PID), soft actuator, system identification

Procedia PDF Downloads 278
1094 Analysis of Bending Abilities of Soft Pneumatic Actuator

Authors: Jeevan Balaji, Shreyas Chigurupati

Abstract:

Pneumatic gripper use compressed air to operate its actuators (fingers). Unlike the conventional metallic gripper, a soft pneumatic actuator (SPA) can be used for relocating fragile objects. An added advantage for this gripper is that the pressure exerted on the object can be varied by changing the dimensions of the air chambers and also by the number of chambers. SPAs have many benefits over conventional robots in the military, medical fields because of their compliance nature and are easily produced using the 3D printing process. In the paper, SPA is proposed to perform pick and place tasks. A design was developed for the actuators, which is convenient for gripping any fragile objects. Thermoplastic polyurethane (TPU) is used for 3D printing the actuators. The actuator model behaves differently as the parameters such as its chamber height, number of chambers change. A detailed FEM model of the actuator is drafted for different pressure inputs using ABAQUS CAE software, and a safe loading pressure range is found.

Keywords: soft robotics, pneumatic actuator, design and modelling, bending analysis

Procedia PDF Downloads 116
1093 Plasma Actuator Application to Control Surfaces of a Model Aircraft

Authors: Yuta Moriyama, Etsuo Morishita

Abstract:

Plasma actuator is very effective to recover stall flows over an upper airfoil surface. We first manufacture the actuator, test the stability of the device by trial and error basis and find the conditions for steady operations. We visualize the flow around an airfoil in the smoke tunnel and observe the stall recovery. The plasma actuator is stationary device and has no moving parts, and it might be an ideal device to control a model aircraft. We can use the actuator not only as a stall recovery device but also as a spoiler. We put the actuator near the leading edge of an elevator of a model aircraft as a spoiler, and measure the aerodynamic forces by a three-component balance. We observe the effect of the plasma actuator on the aerodynamic forces and the device effectiveness changes depending on the angle of attack whether it is positive or negative. We also visualize the flow caused by the plasma actuator by a desk-top Schlieren photography which is otherwise very difficult in a low-speed wind tunnel experiment.

Keywords: aerodynamics, plasma actuator, model aircraft, wind tunnel

Procedia PDF Downloads 317
1092 Developing a Comprehensive Model for the Prevention of Tension Neck Syndrome: A Focus on Musculoskeletal Disorder Prevention Strategies

Authors: Behnaz Sohani, Ifeoluwa Joshua Adigun, Amir Rahmani, Khaled Goher

Abstract:

This paper provides initial results on the efficacy of the designed ergonomic-oriented neck support to mitigate and alleviate tension neck syndrome musculoskeletal disorder. This is done using both simulations and measurements. Tension Neck Syndrome Musculoskeletal Disorder (TNS MSD) causes discomfort in the muscles around the neck and shoulder. TNS MSD is one of the leading causes of early retirement. This research focuses on the design of an adaptive neck supporter by integrating a soft actuator massager to help deliver a soothing massage. The massager and adaptive neck supporter prototype were validated by finite element analysis prior to fabrication to envisage the feasibility of the design concept. Then a prototype for the massager was fabricated and tested for concept validation. Future work will be focused on fabricating the full-scale prototype and upgrading and optimizing the design concept for the adaptive neck supporter.

Keywords: adaptive neck supporter, tension neck syndrome, musculoskeletal disorder, soft actuator massager, soft robotics

Procedia PDF Downloads 59
1091 On the Representation of Actuator Faults Diagnosis and Systems Invertibility

Authors: F. Sallem, B. Dahhou, A. Kamoun

Abstract:

In this work, the main problem considered is the detection and the isolation of the actuator fault. A new formulation of the linear system is generated to obtain the conditions of the actuator fault diagnosis. The proposed method is based on the representation of the actuator as a subsystem connected with the process system in cascade manner. The designed formulation is generated to obtain the conditions of the actuator fault detection and isolation. Detectability conditions are expressed in terms of the invertibility notions. An example and a comparative analysis with the classic formulation illustrate the performances of such approach for simple actuator fault diagnosis by using the linear model of nuclear reactor.

Keywords: actuator fault, Fault detection, left invertibility, nuclear reactor, observability, parameter intervals, system inversion

Procedia PDF Downloads 352
1090 Dynamics Characterizations of Dielectric Electro- Active Polymer Pull Actuator for Vibration Control


Authors: Abdul Malek Abdul Wahab, Emiliano Rustighi

Abstract:

The elastomeric dielectric material has become a new alternative for actuator technology recently. The characteristic of dielectric elastomer that induces significant strain by applying voltage attracts the attention of many researchers to study this material in actuator technology. Thus, for a couple of years, Danfoss Ventures A/S has established their dielectric electro-active polymer (DEAP), which called Polypower. The main objective of this work was to investigate the characterization of PolyPower folded actuator as a ‘pull’ actuator for vibration control. A range of experiment was carried out on folded actuator including passive (without electrical stimulate) and active (with electrical stimulate) testing. For both categories static and dynamic testing have been done to determine the behavior of folded DEAP actuator. Voltage-Strain experiment determines that DEAP folded actuator is the non-linear system. The voltage supplied has no effect on the natural frequency which shows by ongoing dynamic testing. Finally, varies AC voltage with different amplitude and frequency has been provided to DEAP folded actuator. This experiment shows the parameter that influences the performance of DEAP folded actuator. As a result, the actuator performance dominated by the frequency dependence of the elastic response and was less influenced by dielectric properties.

Keywords: elastomeric dielectric, dielectric electro-active polymer, folded actuator, voltage-strain

Procedia PDF Downloads 283
1089 Soft Pneumatic Actuators Fabricated Using Soluble Polymer Inserts and a Single-Pour System for Improved Durability

Authors: Alexander Harrison Greer, Edward King, Elijah Lee, Safa Obuz, Ruhao Sun, Aditya Sardesai, Toby Ma, Daniel Chow, Bryce Broadus, Calvin Costner, Troy Barnes, Biagio DeSimone, Yeshwin Sankuratri, Yiheng Chen, Holly Golecki

Abstract:

Although a relatively new field, soft robotics is experiencing a rise in applicability in the secondary school setting through The Soft Robotics Toolkit, shared fabrication resources and a design competition. Exposing students outside of university research groups to this rapidly growing field allows for development of the soft robotics industry in new and imaginative ways. Soft robotic actuators have remained difficult to implement in classrooms because of their relative cost or difficulty of fabrication. Traditionally, a two-part molding system is used; however, this configuration often results in delamination. In an effort to make soft robotics more accessible to young students, we aim to develop a simple, single-mold method of fabricating soft robotic actuators from common household materials. These actuators are made by embedding a soluble polymer insert into silicone. These inserts can be made from hand-cut polystyrene, 3D-printed polyvinyl alcohol (PVA) or acrylonitrile butadiene styrene (ABS), or molded sugar. The insert is then dissolved using an appropriate solvent such as water or acetone, leaving behind a negative form which can be pneumatically actuated. The resulting actuators are seamless, eliminating the instability of adhering multiple layers together. The benefit of this approach is twofold: it simplifies the process of creating a soft robotic actuator, and in turn, increases its effectiveness and durability. To quantify the increased durability of the single-mold actuator, it was tested against the traditional two-part mold. The single-mold actuator could withstand actuation at 20psi for 20 times the duration when compared to the traditional method. The ease of fabrication of these actuators makes them more accessible to hobbyists and students in classrooms. After developing these actuators, they were applied, in collaboration with a ceramics teacher at our school, to a glove used to transfer nuanced hand motions used to throw pottery from an expert artist to a novice. We quantified the improvement in the users’ pottery-making skill when wearing the glove using image analysis software. The seamless actuators proved to be robust in this dynamic environment. Seamless soft robotic actuators created by high school students show the applicability of the Soft Robotics Toolkit for secondary STEM education and outreach. Making students aware of what is possible through projects like this will inspire the next generation of innovators in materials science and robotics.

Keywords: pneumatic actuator fabrication, soft robotic glove, soluble polymers, STEM outreach

Procedia PDF Downloads 88
1088 Dynamics Characterizations of Dielectric Electro- Active Polymer Pull Actuator for Vibration Control

Authors: A. M. Wahab, E. Rustighi

Abstract:

Elastomeric dielectric material has recently become a new alternative for actuator technology. The characteristics of dielectric elastomers placed between two electrodes to withstand large strain when electrodes are charged has attracted the attention of many researcher to study this material for actuator technology. Thus, in the past few years Danfoss Ventures A/S has established their own dielectric electro-active polymer (DEAP), which was called PolyPower. The main objective of this work was to investigate the dynamic characteristics for vibration control of a PolyPower actuator folded in ‘pull’ configuration. A range of experiments was carried out on the folded actuator including passive (without electrical load) and active (with electrical load) testing. For both categories static and dynamic testing have been done to determine the behavior of folded DEAP actuator. Voltage-Strain experiments show that the DEAP folded actuator is a non-linear system. It is also shown that the voltage supplied has no effect on the natural frequency. Finally, varying AC voltage with different amplitude and frequency shows the parameters that influence the performance of DEAP folded actuator. As a result, the actuator performance dominated by the frequency dependence of the elastic response and was less influenced by dielectric properties.

Keywords: dielectric electro-active polymer, pull actuator, static, dynamic, electromechanical

Procedia PDF Downloads 218
1087 Design of Torque Actuator in Hybrid Multi-DOF System with Taking into Account Magnetic Saturation

Authors: Hyun-Seok Hong, Tae-Chul Jeong, Huai-Cong Liu, Ju Lee

Abstract:

In this paper, proposes to replace the three-phase SPM for tilting by a single-phase torque actuator of the hybrid multi-DOF system. If a three-phase motor for tilting SPM as acting as instantaneous, low electricity use efficiency, controllability is bad disadvantages. It uses a single-phase torque actuator has a high electrical efficiency compared, good controllability. Thus this will have a great influence on the development and practical use of the system. This study designed a single phase torque actuator in consideration of the magnetic saturation. And compared the SPM and FEM analysis and validation through testing of the production model.

Keywords: hybrid multi-DOF system, SPM, torque actuator, UAV, drone

Procedia PDF Downloads 562
1086 Sliding Mode Control for Active Suspension System with Actuator Delay

Authors: Aziz Sezgin, Yuksel Hacioglu, Nurkan Yagiz

Abstract:

Sliding mode controller for a vehicle active suspension system is designed in this study. The widely used quarter car model is preferred and it is aimed to improve the ride comfort of the passengers. The effect of the actuator time delay, which may arise due to the information processing, sensors or actuator dynamics, is also taken into account during the design of the controller. A sliding mode controller was designed that has taken into account the actuator time delay by using Smith predictor. The successful performance of the designed controller is confirmed via numerical results.

Keywords: sliding mode control, active suspension system, actuator, time delay, vehicle

Procedia PDF Downloads 364
1085 A Study on the Small Biped Soft Robot with Two Insect-Like Nails

Authors: Mami Nishida

Abstract:

This paper presented a study on the development and control of a small biped soft robot using shape memory alloys (SMAs). Author proposed a flexible flat plate (FFP) actuators consisting of a thin polyethylene plate and SMAs. This actuator has a nail like an insect. This robot moves from the front to back and from left to right using two nails. The walking robot has two degrees of freedom and is controlled by switching the ON-OFF current signals to the SMA based FFPs. The resulting small biped soft robot weighs a mere 4.7 g (with a height of 67 mm). The small robot realizes biped walking by transferring the elastic potential energy (generated by deflections of the SMA based FFPs) to kinematic energy. Experimental results demonstrated the viability and utility of the small biped soft robot with the proposed SMA-based FFPs and the control strategy to achieve walking behavior.

Keywords: biped soft robot with nails, flexible flat plate (FFP) actuators, ON-OFF control strategy, shape memory alloys (SMA)

Procedia PDF Downloads 468
1084 Aerodynamic Devices Development for Model Aircraft Control and Wind-Driven Bicycle

Authors: Yuta Moriyama, Tsuyoshi Yamazaki, Etsuo Morishita

Abstract:

Several aerodynamic devices currently attract engineers and research students. The plasma actuator is one of them, and it is very effective to control the flow. The actuator recovers a separated flow to an attached one. The actuator is also inversely applied to a spoiler. The model aircraft might be controlled by this actuator. We develop a model aircraft with the plasma actuator. Another interesting device is the Wells turbine which rotates in one direction. The present authors propose a bicycle with the Wells turbine in the wheels. Power reduction is measured when the turbine is driven by an electric motor at the exit of a wind tunnel. Several Watts power reduction might be possible. This means that the torque of the bike can be augmented by the turbine in the cross wind. These devices are tested in the wind tunnel with a three-component balance and the aerodynamic forces and moment are obtained. In this paper, we introduce these devices and their aerodynamic characteristics. The control force and moment of the plasma actuator are clarified and the power reduction of the bicycle is quantified.

Keywords: aerodynamics, model aircraft, plasma actuator, Wells turbine

Procedia PDF Downloads 196
1083 The Various Forms of a Soft Set and Its Extension in Medical Diagnosis

Authors: Biplab Singha, Mausumi Sen, Nidul Sinha

Abstract:

In order to deal with the impreciseness and uncertainty of a system, D. Molodtsov has introduced the concept of ‘Soft Set’ in the year 1999. Since then, a number of related definitions have been conceptualized. This paper includes a study on various forms of Soft Sets with examples. The paper contains the concepts of domain and co-domain of a soft set, conversion to one-one and onto function, matrix representation of a soft set and its relation with one-one function, upper and lower triangular matrix, transpose and Kernel of a soft set. This paper also gives the idea of the extension of soft sets in medical diagnosis. Here, two soft sets related to disease and symptoms are considered and using AND operation and OR operation, diagnosis of the disease is calculated through appropriate examples.

Keywords: kernel of a soft set, soft set, transpose of a soft set, upper and lower triangular matrix of a soft set

Procedia PDF Downloads 298
1082 Prediction of the Performance of a Bar-Type Piezoelectric Vibration Actuator Depending on the Frequency Using an Equivalent Circuit Analysis

Authors: J. H. Kim, J. H. Kwon, J. S. Park, K. J. Lim

Abstract:

This paper has investigated a technique that predicts the performance of a bar-type unimorph piezoelectric vibration actuator depending on the frequency. This paper has been proposed an equivalent circuit that can be easily analyzed for the bar-type unimorph piezoelectric vibration actuator. In the dynamic analysis, rigidity and resonance frequency, which are important mechanical elements, were derived using the basic beam theory. In the equivalent circuit analysis, the displacement and bandwidth of the piezoelectric vibration actuator depending on the frequency were predicted. Also, for the reliability of the derived equations, the predicted performance depending on the shape change was compared with the result of a finite element analysis program.

Keywords: actuator, piezoelectric, performance, unimorph

Procedia PDF Downloads 433
1081 Design, Fabrication and Analysis of Molded and Direct 3D-Printed Soft Pneumatic Actuators

Authors: N. Naz, A. D. Domenico, M. N. Huda

Abstract:

Soft Robotics is a rapidly growing multidisciplinary field where robots are fabricated using highly deformable materials motivated by bioinspired designs. The high dexterity and adaptability to the external environments during contact make soft robots ideal for applications such as gripping delicate objects, locomotion, and biomedical devices. The actuation system of soft robots mainly includes fluidic, tendon-driven, and smart material actuation. Among them, Soft Pneumatic Actuator, also known as SPA, remains the most popular choice due to its flexibility, safety, easy implementation, and cost-effectiveness. However, at present, most of the fabrication of SPA is still based on traditional molding and casting techniques where the mold is 3d printed into which silicone rubber is cast and consolidated. This conventional method is time-consuming and involves intensive manual labour with the limitation of repeatability and accuracy in design. Recent advancements in direct 3d printing of different soft materials can significantly reduce the repetitive manual task with an ability to fabricate complex geometries and multicomponent designs in a single manufacturing step. The aim of this research work is to design and analyse the Soft Pneumatic Actuator (SPA) utilizing both conventional casting and modern direct 3d printing technologies. The mold of the SPA for traditional casting is 3d printed using fused deposition modeling (FDM) with the polylactic acid (PLA) thermoplastic wire. Hyperelastic soft materials such as Ecoflex-0030/0050 are cast into the mold and consolidated using a lab oven. The bending behaviour is observed experimentally with different pressures of air compressor to ensure uniform bending without any failure. For direct 3D-printing of SPA fused deposition modeling (FDM) with thermoplastic polyurethane (TPU) and stereolithography (SLA) with an elastic resin are used. The actuator is modeled using the finite element method (FEM) to analyse the nonlinear bending behaviour, stress concentration and strain distribution of different hyperelastic materials after pressurization. FEM analysis is carried out using Ansys Workbench software with a Yeon-2nd order hyperelastic material model. FEM includes long-shape deformation, contact between surfaces, and gravity influences. For mesh generation, quadratic tetrahedron, hybrid, and constant pressure mesh are used. SPA is connected to a baseplate that is in connection with the air compressor. A fixed boundary is applied on the baseplate, and static pressure is applied orthogonally to all surfaces of the internal chambers and channels with a closed continuum model. The simulated results from FEM are compared with the experimental results. The experiments are performed in a laboratory set-up where the developed SPA is connected to a compressed air source with a pressure gauge. A comparison study based on performance analysis is done between FDM and SLA printed SPA with the molded counterparts. Furthermore, the molded and 3d printed SPA has been used to develop a three-finger soft pneumatic gripper and has been tested for handling delicate objects.

Keywords: finite element method, fused deposition modeling, hyperelastic, soft pneumatic actuator

Procedia PDF Downloads 42
1080 Application of Soft Sets to Non-Associative Rings

Authors: Inayatur Rehman

Abstract:

Molodtstove developed the theory of soft sets which can be seen as an effective tool to deal with uncertainties. Since the introduction of this concept, the application of soft sets has been restricted to associative algebraic structures (groups, semi groups, associative rings, semi-rings etc.). Acceptably, though the study of soft sets, where the base set of parameters is a commutative structure, has attracted the attention of many researchers for more than one decade. But on the other hand there are many sets which are naturally endowed by two compatible binary operations forming a non-associative ring and we may dig out examples which investigate a non-associative structure in the context of soft sets. Thus it seems natural to apply the concept of soft sets to non-commutative and non-associative structures. In present paper, we make a new approach to apply Molodtsoves notion of soft sets to LA-ring (a class of non-associative ring). We extend the study of soft commutative rings from theoretical aspect.

Keywords: soft sets, LA-rings, soft LA-rings, soft ideals, soft prime ideals, idealistic soft LA-rings, LA-ring homomorphism

Procedia PDF Downloads 413
1079 Analytical Model of Locomotion of a Thin-Film Piezoelectric 2D Soft Robot Including Gravity Effects

Authors: Zhiwu Zheng, Prakhar Kumar, Sigurd Wagner, Naveen Verma, James C. Sturm

Abstract:

Soft robots have drawn great interest recently due to a rich range of possible shapes and motions they can take on to address new applications, compared to traditional rigid robots. Large-area electronics (LAE) provides a unique platform for creating soft robots by leveraging thin-film technology to enable the integration of a large number of actuators, sensors, and control circuits on flexible sheets. However, the rich shapes and motions possible, especially when interacting with complex environments, pose significant challenges to forming well-generalized and robust models necessary for robot design and control. In this work, we describe an analytical model for predicting the shape and locomotion of a flexible (steel-foil-based) piezoelectric-actuated 2D robot based on Euler-Bernoulli beam theory. It is nominally (unpowered) lying flat on the ground, and when powered, its shape is controlled by an array of piezoelectric thin-film actuators. Key features of the models are its ability to incorporate the significant effects of gravity on the shape and to precisely predict the spatial distribution of friction against the contacting surfaces, necessary for determining inchworm-type motion. We verified the model by developing a distributed discrete element representation of a continuous piezoelectric actuator and by comparing its analytical predictions to discrete-element robot simulations using PyBullet. Without gravity, predicting the shape of a sheet with a linear array of piezoelectric actuators at arbitrary voltages is straightforward. However, gravity significantly distorts the shape of the sheet, causing some segments to flatten against the ground. Our work includes the following contributions: (i) A self-consistent approach was developed to exactly determine which parts of the soft robot are lifted off the ground, and the exact shape of these sections, for an arbitrary array of piezoelectric voltages and configurations. (ii) Inchworm-type motion relies on controlling the relative friction with the ground surface in different sections of the robot. By adding torque-balance to our model and analyzing shear forces, the model can then determine the exact spatial distribution of the vertical force that the ground is exerting on the soft robot. Through this, the spatial distribution of friction forces between ground and robot can be determined. (iii) By combining this spatial friction distribution with the shape of the soft robot, in the function of time as piezoelectric actuator voltages are changed, the inchworm-type locomotion of the robot can be determined. As a practical example, we calculated the performance of a 5-actuator system on a 50-µm thick steel foil. Piezoelectric properties of commercially available thin-film piezoelectric actuators were assumed. The model predicted inchworm motion of up to 200 µm per step. For independent verification, we also modelled the system using PyBullet, a discrete-element robot simulator. To model a continuous thin-film piezoelectric actuator, we broke each actuator into multiple segments, each of which consisted of two rigid arms with appropriate mass connected with a 'motor' whose torque was set by the applied actuator voltage. Excellent agreement between our analytical model and the discrete-element simulator was shown for both for the full deformation shape and motion of the robot.

Keywords: analytical modeling, piezoelectric actuators, soft robot locomotion, thin-film technology

Procedia PDF Downloads 127
1078 A Study on User Authentication Method Using Haptic Actuator and Security Evaluation

Authors: Yo Han Choi, Hee Suk Seo, Seung Hwan Ju, Sung Hyu Han

Abstract:

As currently various portable devices were launched, smart business conducted using them became common. Since smart business can use company-internal resources in an external remote place, user authentication that can identify authentic users is an important factor. Commonly used user authentication is a method of using user ID and Password. In the user authentication using ID and Password, the user should see and enter authentication information him or herself. In this user authentication system depending on the user’s vision, there is the threat of password leaks through snooping in the process which the user enters his or her authentication information. This study designed and produced a user authentication module using an actuator to respond to the snooping threat.

Keywords: actuator, user authentication, security evaluation, haptic actuator

Procedia PDF Downloads 311
1077 Predictive Functional Control with Disturbance Observer for Tendon-Driven Balloon Actuator

Authors: Jun-ya Nagase, Toshiyuki Satoh, Norihiko Saga, Koichi Suzumori

Abstract:

In recent years, Japanese society has been aging, engendering a labour shortage of young workers. Robots are therefore expected to perform tasks such as rehabilitation, nursing elderly people, and day-to-day work support for elderly people. The pneumatic balloon actuator is a rubber artificial muscle developed for use in a robot hand in such environments. This actuator has a long stroke, and a high power-to-weight ratio compared with the present pneumatic artificial muscle. Moreover, the dynamic characteristics of this actuator resemble those of human muscle. This study evaluated characteristics of force control of balloon actuator using a predictive functional control (PFC) system with disturbance observer. The predictive functional control is a model-based predictive control (MPC) scheme that predicts the future outputs of the actual plants over the prediction horizon and computes the control effort over the control horizon at every sampling instance. For this study, a 1-link finger system using a pneumatic balloon actuator is developed. Then experiments of PFC control with disturbance observer are performed. These experiments demonstrate the feasibility of its control of a pneumatic balloon actuator for a robot hand.

Keywords: disturbance observer, pneumatic balloon, predictive functional control, rubber artificial muscle

Procedia PDF Downloads 405
1076 Design and Fabrication of an Array Microejector Driven by a Shear-Mode Piezoelectric Actuator

Authors: Chiang-Ho Cheng, Hong-Yih Cheng, An-Shik Yang, Tung-Hsun Hsu

Abstract:

This paper reports a novel actuating design that uses the shear deformation of a piezoelectric actuator to deflect a bulge-diaphragm for driving an array microdroplet ejector. In essence, we employed a circular-shaped actuator poled radial direction with remnant polarization normal to the actuating electric field for inducing the piezoelectric shear effect. The array microdroplet ejector consists of a shear type piezoelectric actuator, a vibration plate, two chamber plates, two channel plates and a nozzle plate. The vibration, chamber and nozzle plate components are fabricated using nickel electroforming technology, whereas the channel plate is fabricated by etching of stainless steel. The diaphragm displacement was measured by the laser two-dimensional scanning vibrometer. The ejected droplets of the microejector were also observed via an optic visualization system.

Keywords: actuator, nozzle, microejector, piezoelectric

Procedia PDF Downloads 390
1075 Fuzzy Sliding Mode Control of a Flexible Structure for Vibration Suppression Using MFC Actuator

Authors: Jinsiang Shaw, Shih-Chieh Tseng

Abstract:

Active vibration control is good for low frequency excitation, with advantages of light weight and adaptability. This paper use a macro-fiber composite (MFC) actuator for vibration suppression in a cantilevered beam due to its higher output force to suppress the disturbance. A fuzzy sliding mode controller is developed and applied to this system. Experimental results illustrate that the controller and MFC actuator are very effective in attenuating the structural vibration near the first resonant freuqency. Furthermore, this controller is shown to outperform the traditional skyhook controller, with nearly 90% of the vibration suppressed at the first resonant frequency of the structure.

Keywords: Fuzzy sliding mode controller, macro-fiber-composite actuator, skyhook controller, vibration suppression

Procedia PDF Downloads 355
1074 Design, Modelling, and Fabrication of Bioinspired Frog Robot for Synchronous and Asynchronous Swimming

Authors: Afaque Manzoor Soomro, Faheem Ahmed, Fida Hussain Memon, Kyung Hyun Choi

Abstract:

This paper proposes the bioinspired soft frog robot. All printing technology was used for the fabrication of the robot. Polyjet printing was used to print the front and back limbs, while ultrathin filament was used to print the body of the robot, which makes it a complete soft swimming robot. The dual thrust generation approach has been proposed by embedding the main muscle and antagonistic muscle in all the limbs, which enables it to attain high speed (18 mm/s), and significant control of swimming in dual modes (synchronous and asynchronous modes). To achieve the swimming motion of the frog, the design, motivated by the rigorous modelling and real frog dynamics analysis, enabled the as-developed frog robot (FROBOT) to swim at a significant level of consistency with the real frog. The FROBOT (weighing 65 g) can swim at different controllable frequencies (0.5–2Hz) and can turn in any direction by following custom-made LabVIEW software’s commands which enables it to swim at speed up to 18 mm/s on the surface of deep water (100 cm) with excellent weight balance.

Keywords: soft robotics, soft actuator, frog robot, 3D printing

Procedia PDF Downloads 63
1073 Numerical Simulation of Plasma Actuator Using OpenFOAM

Authors: H. Yazdani, K. Ghorbanian

Abstract:

This paper deals with modeling and simulation of the plasma actuator with OpenFOAM. Plasma actuator is one of the newest devices in flow control techniques which can delay separation by inducing external momentum to the boundary layer of the flow. The effects of the plasma actuators on the external flow are incorporated into Navier-Stokes computations as a body force vector which is obtained as a product of the net charge density and the electric field. In order to compute this body force vector, the model solves two equations: One for the electric field due to the applied AC voltage at the electrodes and the other for the charge density representing the ionized air. The simulation result is compared to the experimental and typical values which confirms the validity of the modeling.

Keywords: active flow control, flow-field, OpenFOAM, plasma actuator

Procedia PDF Downloads 264
1072 Soft Power: Concept and Role in Country Policy

Authors: Talip Turkmen

Abstract:

From the moment the first beats, the first step into the world mankind finds him in a struggle to survive. Most important case to win this fight is power. Power is one of the most common concepts which we encounter in our life. Mainly power is ability to reach desired results on someone else or ability to penetrate into the behavior of others. Throughout history merging technology and changing political trade-offs caused the change of concept of power. Receiving a state of multipolar new world order in the 21st century and increasing impacts of media have narrowed the limits of military power. With increasing globalization and peaceful diplomacy this gap, left by military power, has filled by soft power which has ability to persuade and attract. As concepts of power soft power also has not compromised yet. For that reason it is important to specify, sources of soft power, soft power strategies and limits of soft power. The purpose of this study was to analyze concept of soft power and importance of soft power in foreign relations. This project focuses on power, hard power and soft power relations, sources of soft power and strategies to gain soft power. Datas in this project was acquired from other studies on soft power and foreign relations. This paper was prepared in terms of concept and research techniques. As a result of data gained in this study the one of important topics in international relations is balance between soft power.

Keywords: soft power, foreign policy, national power, hard power

Procedia PDF Downloads 417
1071 Functionalized Ultra-Soft Rubber for Soft Robotics Application

Authors: Shib Shankar Banerjeea, Andreas Ferya, Gert Heinricha, Amit Das

Abstract:

Recently, the growing need for the development of soft robots consisting of highly deformable and compliance materials emerge from the serious limitations of conventional service robots. However, one of the main challenges of soft robotics is to develop such compliance materials, which facilitates the design of soft robotic structures and, simultaneously, controls the soft-body systems, like soft artificial muscles. Generally, silicone or acrylic-based elastomer composites are used for soft robotics. However, mechanical performance and long-term reliabilities of the functional parts (sensors, actuators, main body) of the robot made from these composite materials are inferior. This work will present the development and characterization of robust super-soft programmable elastomeric materials from crosslinked natural rubber that can serve as touch and strain sensors for soft robotic arms with very high elastic properties and strain, while the modulus is altered in the kilopascal range. Our results suggest that such soft natural programmable elastomers can be promising materials and can replace conventional silicone-based elastomer for soft robotics applications.

Keywords: elastomers, soft materials, natural rubber, sensors

Procedia PDF Downloads 113
1070 A Model-Reference Sliding Mode for Dual-Stage Actuator Servo Control in HDD

Authors: S. Sonkham, U. Pinsopon, W. Chatlatanagulchai

Abstract:

This paper presents a method of sliding mode control (SMC) designing and developing for the servo system in a dual-stage actuator (DSA) hard disk drive. Mathematical modelling of hard disk drive actuators is obtained, extracted from measuring frequency response of the voice-coil motor (VCM) and PZT micro-actuator separately. Matlab software tools are used for mathematical model estimation and also for controller design and simulation. A model-reference approach for tracking requirement is selected as a proposed technique. The simulation results show that performance of a model-reference SMC controller design in DSA servo control can be satisfied in the tracking error, as well as keeping the positioning of the head within the boundary of +/-5% of track width under the presence of internal and external disturbance. The overall results of model-reference SMC design in DSA are met per requirement specifications and significant reduction in %off track is found when compared to the single-state actuator (SSA).

Keywords: hard disk drive, dual-stage actuator, track following, hdd servo control, sliding mode control, model-reference, tracking control

Procedia PDF Downloads 321
1069 Soft Power in International Politics: Defense and Continued Relevance

Authors: Shivani Yadav

Abstract:

The paper will first elaborate on the concept of soft power as formulated by Joseph Nye, who argues that soft power is as important as hard power in international politics as it replaces coercion with non-coercive forms of co-optation and attraction. The central tenet of the paper is to extrapolate the continued relevance of soft power in international relations in the 21st century. It is argued that the relevance of soft power, in concurrence with hard power, is on the rise in the international system. This is found to be emanating out of two factors. First, the state-centric practice of international relations has expanded to allow other actors to participate in policymaking. This has led to the resources for power generation to become varied, largely move away from the control of governments, and to produce both hard and soft power attributes. Second, as the currency of coercive power seems to be devaluing in global politics, the role of intangible factors like soft power is getting more important in policymaking. The paper will then go on to elaborate on the critiques of the formulation of soft power from various perspectives, as well as the defenses to these critiques presented by soft power proponents. The paper will reflect on the continued relevance of soft power in international politics by giving the example of India, and how soft power has continued to serve its policy objectives over the years. It is observed that even as India is recognized as a rising superpower today, yet it has made a continuous effort in cultivating its soft power resources, which have proven to be its assets in furthering its foreign policy interests. In conclusion, the paper makes the point that soft power, in conjunction with hard power, will shape international politics in the coming times.

Keywords: foreign policy, India’s soft power, international politics, smart power, soft power

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1068 A Robust Model Predictive Control for a Photovoltaic Pumping System Subject to Actuator Saturation Nonlinearity and Parameter Uncertainties: A Linear Matrix Inequality Approach

Authors: Sofiane Bououden, Ilyes Boulkaibet

Abstract:

In this paper, a robust model predictive controller (RMPC) for uncertain nonlinear system under actuator saturation is designed to control a DC-DC buck converter in PV pumping application, where this system is subject to actuator saturation and parameter uncertainties. The considered nonlinear system contains a linear constant part perturbed by an additive state-dependent nonlinear term. Based on the saturating actuator property, an appropriate linear feedback control law is constructed and used to minimize an infinite horizon cost function within the framework of linear matrix inequalities. The proposed approach has successfully provided a solution to the optimization problem that can stabilize the nonlinear plants. Furthermore, sufficient conditions for the existence of the proposed controller guarantee the robust stability of the system in the presence of polytypic uncertainties. In addition, the simulation results have demonstrated the efficiency of the proposed control scheme.

Keywords: PV pumping system, DC-DC buck converter, robust model predictive controller, nonlinear system, actuator saturation, linear matrix inequality

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1067 Single Chip Controller Design for Piezoelectric Actuators with Mixed Signal FPGA

Authors: Han-Bin Park, Taesam Kang, SunKi Hong, Jeong Hoi Gu

Abstract:

The piezoelectric material is being used widely for actuators due to its large power density with simple structure. It can generate a larger force than the conventional actuators with the same size. Furthermore, the response time of piezoelectric actuators is very short, and thus, it can be used for very fast system applications with compact size. To control the piezoelectric actuator, we need analog signal conditioning circuits as well as digital microcontrollers. Conventional microcontrollers are not equipped with analog parts and thus the control system becomes bulky compared with the small size of the piezoelectric devices. To overcome these weaknesses, we are developing one-chip micro controller that can handle analog and digital signals simultaneously using mixed signal FPGA technology. We used the SmartFusion™ FPGA device that integrates ARM®Cortex-M3, analog interface and FPGA fabric in a single chip and offering full customization. It gives more flexibility than traditional fixed-function microcontrollers with the excessive cost of soft processor cores on traditional FPGAs. In this paper we introduce the design of single chip controller using mixed signal FPGA, SmartFusion™[1] device. To demonstrate its performance, we implemented a PI controller for power driving circuit and a 5th order H-infinity controller for the system with piezoelectric actuator in the FPGA fabric. We also demonstrated the regulation of a power output and the operation speed of a 5th order H-infinity controller.

Keywords: mixed signal FPGA, PI control, piezoelectric actuator, SmartFusion™

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1066 Recruitment Model (FSRM) for Faculty Selection Based on Fuzzy Soft

Authors: G. S. Thakur

Abstract:

This paper presents a Fuzzy Soft Recruitment Model (FSRM) for faculty selection of MHRD technical institutions. The selection criteria are based on 4-tier flexible structure in the institutions. The Advisory Committee on Faculty Recruitment (ACoFAR) suggested nine criteria for faculty in the proposed FSRM. The model Fuzzy Soft is proposed with consultation of ACoFAR based on selection criteria. The Fuzzy Soft distance similarity measures are applied for finding best faculty from the applicant pool.

Keywords: fuzzy soft set, fuzzy sets, fuzzy soft distance, fuzzy soft similarity measures, ACoFAR

Procedia PDF Downloads 303