Application of these aspects is illustrated through case studies resulting from our own sma designs. Shape memory alloy actuators deliver high forces while being compact and reliable, making them ideal for consideration in aerospace applications. A largestroke shape memory alloy spring actuator using doublecoil configuration seungwon kim, jonggu lee, sungmin an et al. Proceedings of the 2000 design engineering technical conference, baltimore, md, 10 september. Design of a variable stiffness actuator using shape memory. Performance of the shape memory alloy sma coil spring actuator in cyclic actuation as an artificial muscle is strongly related to the mechanical design of the coil geometry. An electric circuit was constructed as shown in figure 2. The kinitics controller interfaces with a standard plc using discrete io and an analog 420ma input for complex control using a number of possible feedback strategies. Pdf on the design of a shape memory alloy spring actuator using. This paper proposes a practical design method for improving the frequency and efficiency of the sma coil spring actuator.
Shape memory alloys have a large amount of hysteresis as well as moderate response. Composable flexible small actuators built from thin shape. Firstly a deformation is imposed by a compression spring in the actuator. In order to design sma actuator properly, the necessary actuation force is measured. On the design of a shape memory alloy spring actuator using. Design of shape memory alloy spring actuator for pinch valve. On the design of a shape memory alloy spring actuator using thermal analysis sonia degeratu, nicu g. If these materials subjected to an appropriate thermomechanical process, they have. Shape memory alloys sma are lightweight, can produce a large force and consequently large deflections. The implementation of shape memory alloys for large.
Design of shape memory alloy coil spring actuator for. Shape memory actuators for automotive applications stoeckel. Shape memory alloys smas have been used for a wide variety of applications in various fields such as robotics. Design of shape memory alloy actuator with high strain and. Experimental design validation of tilting calibration. This paper presents a novel compliant differential shape memory alloy sma actuator, which is composed of two antagonistic sma wires and a mechanical joint coupled with a torsion spring. Pdf design and analysis of artificial muscle robotic. Systemlevel design of a shape memory alloy actuator for. Shape memory alloys for aerospace, recent developments. Grippers for the micro assembly containing shape memory. This special behavior attracts the use of smas as efficient strokeforce actuators.
High performance force control for shape memory alloy. The design approach described herein will provide a practical and convenient method for use in the design of shape memory alloy actuators. Now, one new actuator uses bundles of sma wire made of specialty nickeltitanium alloy for reliable linear motion. Mikova et al application of shape memory alloy sma as actuator references 1 k. The present invention discloses and teaches a unique, remote optically controlled micro actuator particularly suitable for aerospace vehicle applications wherein hot gas, or in the alternative optical energy, is employed as the medium by which shape memory alloy elements are activated. The first involves a switching control input creating a sliding mode in conjunction with a linear control activated within a boundary layer in the vicinity of. Some truly helpful comments about applications of shape memory alloys and multidisciplinary system optimization also came from professor. Development of advanced actuators using shape memory. Pdf due to their unique properties and behavior, the shape memory alloys smas play an increasingly important role in the intelligent systems. The design of shape memory actuators is generally based on the different stressstrain curves of the material in its austenitic and martensitic condition. Finally, sma actuator and the proposed mechanism are integrated. One form of separation device, the frangibolt, has been used on numerous space missions. Control system design for a morphing unmanned air vehicle.
Design, measurement experiments and application of a. The actuators based on shape memory alloys are described in the paper. The design approach includes coupling between the onedimensional thermomechanical constitutive relations and a lumped capacitance transient thermal analysis. Most of the engineering applications require helical springs as actuators and proper design of sma helical. Shape memory alloys are new, functional materials used in actuator applications with their high power to weight ratio. However, its nonlinear behavior proves to be a major challenge in the development of the controller. The two most prevalent shape memory alloys are copperaluminiumnickel and nickeltitanium, but smas can also be created by alloying zinc, copper, gold and iron. In gas turbine powered aircraft the source of the hot gas may be the turbine engine compressor or turbine. Engineering design framework for a shape memory alloy coil. Fabrication and modeling of shape memory alloy springs b heidari, m kadkhodaei, m barati et al. Application of shape memory alloy sma as actuator received primljeno.
This paper deals w ith actuators based on shape memory alloys. Shape memory alloys and their application to actuators for. However, the inclusion of a bias element with which to cycle the sma actuator becomes di. Variable geometry jet nozzle using shape memory alloy actuators. The second robot, whose motion is controlled using shape memory alloy actuators, is designed to be easily scaled down for microscale applications. Design and control of a novel compliant differential shape. Some of these models are defined by cyclic functions trigonometric functions which they become complex to control when they are.
Some sma materials, such as nitinol, allow for strain. The design of some shape memory alloy actuators were focused on. Design and control of a shape memory alloy actuator for flap type aerodynamic surfaces. Stateoftheart of shape memory actuators tini alloy. Issues in the design of shape memory alloy actuators. Design of a humanoid hand using segmented shape memory alloy. Introduction a shape memory alloy sma actuator is widely used as an arti. A tilting calibration mechanism is periodically deployed to view the reference temperature target during onboard calibration of a spaceborne imaging sensor and stowed after calibration. Recent citations geometric constraintbased modeling and analysis of a novel continuum robot with shape memory alloy. Casmart collaborative best practices and case studies article pdf available in international journal of mechanics and materials in design 101 march 2014. It is shown that there is necessity to develop the actuators of compact design with amplified force.
Shape memory alloys smas are popular as actuators for soft bioinspired robots because they are naturally compliant, have high work density, and can be operated using miniaturized on. Position control of shape memory alloy actuators using self tuning fuzzy pid controller kyoung kwan ahn and bao kha nguyen abstract. A preliminary study of a torsional actuator has b een made. Also part of the springerbriefs in computational mechanics book sub series briefscomputat. Shape memory alloy sma materials are widely used as an actuating source for bending actuators due to their high power density. Although ironbased and copperbased smas, such as femnsi, cuznal and cualni, are commercially available and cheaper than niti, nitibased smas are preferable for most applications due to their stability and practicability. Current applications of shape memory actuators use in space was an early predicted application and continues to grow. The solidsolid, diffusionless phase transformations in thermally responsive sma allows them to demonstrate unique characteristics like superelasticity and shape memory effects. Highly dynamic shape memory alloy actuator for fast moving. Lip design doubles the maximum frequency of sma coil actuator with onesixth the mass of the nonlip design. Two variable structure controllers are applied to a pair of antagonist actuators. Pci6284, ni is employed to send the pwm signal via the digital output and measure the voltage vr and vsma via the analog input. Using three electrical connections the two ends of the wire and a contact in the middle of the wire, the two halves of the wire were differentially heated, which.
Linear shape memory alloy thermomechanical actuators. Shape memory alloy engineering introduces materials, mechanical, and aerospace engineers to shape memory alloys smas, providing a unique perspective that combines fundamental theory with new approaches to design and modeling of actual smas as compact and inexpensive actuators for use in aerospace and other applications. It is activated by electrical current and the resultant heating. Although two way shape memory actuators are available, most appli cations use the oneway effect with an external reset force. As sma actuators are scaled down in size, cooling increases and bandwidth improves. In 1958, researchers chang and read demonstrated the shape memory effect at the brussels worlds fair. However, due to the slow actuation speed of smas, there are.
President kinitics automation shapememory alloys smas are those materials that respond to temperature changes by changing form factor. Rotationaldirect pull shape memory actuator is an ideal solution for flap and vent mechanisms and is well suited for ice dispensing and vented areas. This short monograph presents an analysis and design methodology for shape memory alloy sma components such as wires, beams, and springs for different applications. This book provides a systematic approach to realizing niti shape memory alloy actuation, and is aimed at science and engineering students who would like to develop a better understanding of the behaviors of smas, and learn to design, simulate, control, and fabricate these actuators in a systematic approach. Introduction to shape memory alloy actuators springerlink. The struc ill tures of the grippers are fabricated from one single part with well defined elastic regions, the so called flexure hinges. Rau is the expert for shape memory alloys assemblies made of shape memory alloys are used as thermal actuators in the automotive industry as well in further fields of measurement and control technolog, appliance technology, aviation industry as well as medical technology. The general design pro cedure for nitinolbased actuators is summarised. A simplified model for highrate actuation of shape memory. Mechanical engineering the design and development of a linear actuator for macro devices using shape memory alloy sma are desired. Design of shape memory alloy sma actuators springerlink. Rau is the expert for shape memory alloys assemblies made of shape memory alloys are used as thermal actuators in the automotive industry as well in further fields of measurement and control technolog, appliance technology. The shape memory effect is often exploited when smas are used as actuators 6 15. The frangibolt consists of an electric heater surrounding a hollow cylinder of tini and a.
Pdf design and control of a shape memory alloy actuator. Twoway memory is unique in that the material remembers different high temperature and low temperature shapes. A micro rotary actuator using shape memory alloys sciencedirect. The design of smabased soft actuators is often limited by the design of the molds used, and these limitations are even more pronounced for actuators with complex shape memory alloy sma wire.
A new approach to the design of helical shape memory alloy. The high strength or displacement usage of shape memory alloys makes them suitable for direct drive applications, which eliminate use of power transmission elements. The broad aim of this dissertation is also to pro vide a users guide to the design of smabased actuators. Design of an impact drive actuator using a shape memory. It may also be called memory metal, memory alloy, smart metal, smart alloy, or muscle wire. There are only two commercially available groups of shape memory alloys for actuator. Recent applications in structural actuation and sensing. Engineering design framework for a shape memory alloy coil spring actuator using a static twostate model, smart materials and structures 21, pp. The focus of this chapter is laid on the actuating parameters of shape memory alloys. Navy, sma technologies were first commercialized by raychem corp. Shape memory alloys convert thermal energy into m echanical energy by way of a thermally induced microstructural change in the material. Shape memory alloy sma actuators, which have the ability to return to a predetermined shape when heated, have many potential applications such as aeronautics, surgical tools, robotics and so on. Then with crossing the electrical current within the wire, actuator is heated and phase.
Jul 10, 2018 now, one new actuator uses bundles of sma wire made of specialty nickeltitanium alloy for reliable linear motion. Mosley, mj, mavroidis, c 2000 design and dynamics of shape memory alloy wire bundle actuator. In the present work, we have proposed a new design strategy using a shape memory alloy sma spring as an actuator that provides a failsafe function to prevent the blocking of the main optical path when the. A darlington driver is used as a switching element to control the heating or cooling state of the sma actuator. Progress on shape memory alloy actuator development for active clearance control jonathan decastro qss group, inc. Experimental model of shape memory alloy actuators using modified prandtlishlinskii model 259 fig. Shape memorynitinol alloy springs or nitinol trained wires characteristic to ensure mechanical actions with temperature changes or heated with electrical current, allows the development of simple, more compact and reliable. In this study, possible structures for an smawirebased idm actuator are investigated, and a prototype actuator comprising a main body, an inertia body, an sma wire, and a bias spring is developed.
It is shown that there is not an obvious single, linear route a. High performance force control for shape memory alloy sma actuators. The actuator overcomes the main mechanical drawback of shape memory alloys, that being limited strain. This study focuses on the development of the system highlighting. This alloy was named nitinol nickeltitanium naval ordnance laboratory 4. The ability of shape memory alloys to recover a preset shape upon heating above its transformation temperatures and return to an alternate shape upon cooling is known as twoway memory. The torsion spring with a low stiffness is employed in the actuator design to reduce the total stiffness as well as to increase the compliance of the. An accurately controlled antagonistic shape memory alloy. In order to evaluate performance of the developed non. Using the kinitics controller, the kinitics shape memory alloy actuator products can be used in anything from the simplest to the most elaborate of control strategies. Shape memory alloy application miniactuator youtube.
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. Based on that result, sma actuator is designed and fabricated. The unitcell actuator is built using shape memory alloy sma sheets. The thermally activated changes in crystal structure in nickeltitanium shape memory alloy sma material, which produces transformation strains of an order of magnitude higher than and opposite to the thermal strains, have been described using different models. Depending on the combination of these unitcells, the designer can control the direction of actuation, the amount of force generated, and the expansion stroke of the actuator. Variable area jet nozzle for noise reduction using shape. Pdf shape memory alloy actuators for deployable structures. A shapememory alloy is an alloy that can be deformed when cold but returns to its predeformed remembered shape when heated. Synergistic sma actuators use aiding force to create repetitive motion and are thereby capable of producing increased displacement when compared to the antagonistically biased sma systems.
The simplicity of their actuation principle with respect to the relatively large forces generated and their biocompatibility with other material have made them attractive for. Shape memory alloys smas provide exciting opportunities for miniature actuation systems. Design of shape memory alloy spring actuator for pinch. A new option for positioning july 10, 2018 by lisa eitel leave a comment now, one new actuator uses bundles of sma wire made of specialty nickeltitanium alloy for reliable linear motion. On the design of a shape memory alloy spring actuator. Onedimensional constitutive behavior of shape memory alloys. This paper introduces an impact drive mechanism idm that utilizes the rapid contraction property of shape memory alloy sma wire. The explanation of the differences between thermal and electric applications of shape memory actuators is guided by dynamic and mechanic aspects. Development of advanced actuators using shape memory alloys. Shape memory materials are a suitable candidate for actuators in a morphing wing design as they are easy to install and electrically activated. Design of shape memory alloy spring actuator for pinch valve actuation.
Shape memory alloys smas have emerged in several areas, including robotics, control of spaceborne structures, and control of helicopter rotor blades refs. Thermal shape memory alloys smas have characteristics such as high power density which indicate that they would be ideal actuators for such applications. Design and experimental validation of a shape memory alloy. Abstract this paper describes a new technique of gripper actuator using shape memory alloy spring has been fabricated. A linear translational actuator using synergistically configured shape memory alloy sma actuator wires is designed to work by the principle of variable stiffness actuation. Induction heating of shape memory alloy actuators, specifically tubes that twist about the longitudinal axis, has recently been studied experimentally and computationally using finite element analysis. By applying electric power to the shape memory alloy spring i. The main advantages of using smas include the reduction of the system weight, the ease and reliability in application, and a simple control strategy. To study the strain hysteresis curve with respect to both wires resistance, a testing platform was setup as shown in figure 1a. However, certain characteristics of sma exist which, if left unaddressed, make usage as an actuator impractical. Using three electrical connections the two ends of the wire and a contact in the middle of the wire, the two halves of the wire were differentially heated, which caused repeatable, continuous and directional. Shape memory alloy actuator and pump kinitics automation. Tzes, experimental study of a shape memory alloy actuation system for a novel prosthetic hand, book edited by.
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