Automation of handling and assembly, which are complex technological processes, requires qualified solutions. The longterm development goals are decreasing cycle-times and increasing quality of processing. These goals can be achieved by means of innovative concepts based on parallel kinematics which enable higher velocity and acceleration while maintaining at least the same accuracy as compared to conventional systems. Principally, parallel kinematics are better suited for high accelerations than serial structures because the drive units can be mounted on the frame without the need to move their high masses. Additionally, parallel structures are stiffer than their serial counterparts. Two key features of the innovative concepts introduced in the paper are lightweight structural components which allow to reach even higher accelerations and integrated smart actuators and sensors to control the vibrations induced by the high accelerations. This paper discusses modelling of parallel kinematics, control-strategies for the vibration suppression, and design-criteria for active rods. These active rods have built-in piezoceramic stacks serving as both sensors and actuators that provide the means to supresss the vibrations. A two-degree-of-freedom parallel structure with active rods is used as test-case and experimental results confirming the potential of smart parallel kinematics are shown. An outlook to the ongoing research in the field of parallel robots is given.

Membrane masks are thin (2 micron x 35 mm x 35 mm) structures that carry the master exposure patterns in proximity (X-ray) lithography. With the continuous drive to the printing of ever-finer features in microelectronics, the reduction of mask-wafer overlay positioning errors by passive rigid body positioning and passive stress control in the mask becomes impractical due to nano and sub-micron scale elastic deformations in the membrane mask. This paper describes the design, mechanics and performance of a system for actively stretching a membrane mask in-plane to control overlay distortion. The method uses thermoelectric heating/cooling elements placed on the mask perimeter. The thermoelectric elements cause controlled thermoelastic deformations in the supporting wafer, which in turn corrects distortions in the membrane mask. Silicon carbide masks are the focus of this study, but the method is believed to be applicable to other mask materials, such as diamond. Experimental and numerical results will be presented, as well as a discussion of the design issues and related design decisions.

High-precision machines are usually designed according to a limited number of well-known design principles. The dynamic behaviour is optimised mainly by means of proper stiffness management: the design of the mechanical structure is aimed at minimisation of the mass, and maximisation of the stiffness. Damping management is not yet a mature design principle. This is due to the difficulties in designing passive damping mechanisms that do not endanger accuracy. As an example of a vibration problem within an industrial high-precision application, in this paper the need for active damping management in a microlithography machine is discussed. In future, vibrations of the lenses of this machine may pose a practical limit to the accuracy of the lithography process. For that reason, active structural elements have been developed for supporting the lenses. The active elements, consisting of a piezoelectric actuator and a collocated piezoelectric force sensor, are especially suited for implementing robust active damping. The purpose of the present paper is to discuss the conflicting requirements in the mechanical design of the active elements. The discussion is illustrated by means of experimental active damping results that have been obtained on the microlithography machine.

In recent years, there has been a significant interest in, and move towards using highly sensitive, precision payloads on space vehicles. In order to perform tasks such as communicating at extremely high data rates between satellites using laser cross-links, or searching for new planets in distant solar systems using sparse aperture optical elements, a satellite bus and its payload must remain relatively motionless. The ability to hold a precision payload steady is complicated by disturbances from reaction wheels, control moment gyroscopes, solar array drives, stepper motors, and other devices. Because every satellite is essentially unique in its construction, isolating or damping unwanted vibrations usually requires a robust system over a wide bandwidth. The disadvantage of these systems is that they typically are not retrofittable and not tunable to changes in payload size or inertias. During the Phase I MVIS program, funded by AFRL and DARPA, a hybrid piezoelectric/D-strut isolator was built and tested to prove its viability for retroffitable insertion into sensitive payload attachments. A second phase of the program, which is jointly funded between AFRL and Honeywell, was started in November of 2002 to build a hexapod and the supporting interface electronics and do a flight demonstration of the technology. The MVIS-II program is a systems-level demonstration of the application of advanced smart materials and structures technology that will enable programmable and retrofittable vibration control of spacecraft precision payloads. This paper describes the simulations, overall test plan and product development status of the overall MVIS-II program as it approaches flight.

The cost of performing any mission on orbit is a strong function of the cost of getting the mass into orbit and the mass of a spacecraft is driven by the launch loads that the components must be deigned to survive. Additionally, these design loads vary between launch vehicles so if circumstances arise that require a change in launch vehicle significant time and money can be spent in modifying and testing to meet different requirements. Technologies that reduce both the vibration and acoustic environments during launch have the potential to both reduce the design load levels, and eventually equalize them between boosters. To this end the Air Force Research Laboratory, Space Vehicles Directorate in cooperation with the Space Test Program, Boeing SVS, CSA Engineering, and Delta Velocity have been investigating methods to decrease the acoustic and vibration loads induced on payloads by the launch environment and demonstrating them on a sounding rocket launch. The Vibro-Acoustic Launch Protection Experiment (VALPE) mission included an acoustically designed Chamber-Core skin, two passive/active vibration isolation experiments, a passive/active acoustic damping experiment, and an energy recovery experiment integrated onto a Terrier-Improved Orion sounding rocket and launched from NASA Wallops Island. A description of the overall mission, experiments, and general results from the flight test are discussed.

Payloads delivered to orbit by expendable launch vehicles experience high levels of vibration. This vibration can cause component failures, or more frequently, lead to extra weight that would otherwise be useful for added functions on orbit. Vibration isolation systems have been flown to protect various components as well as entire spacecraft, dramatically reducing launch loads and saving costs in redesign and tests. Future spacecraft and components may benefit from further load reduction through the use of higher performance active isolation systems. These active systems are capable of introducing compliance in selected axes, while maintaining required rigidity in others. They can also produce excellent isolation without large amplification. Passive and active vibration isolation systems were developed for the Vibro Acoustic Launch Protection Experiment (VALPE) and flew aboard sounding rockets. The paper describes the design and development of the isolation systems, actuation and isolation architectures and control strategies. Integration of two flight experiments is summarized. Ground test results are presented for passive and active systems. Results of the experiments are provided, and recommendations for active vibration isolation are offered.

There is no reported research of using shape memory alloy (SMA) actuators for variable area exhaust nozzle for a jet engine in the literature, to the authors' best knowledge. SMA actuators have the advantages of high power-to-weight ratio and can result in dramatic weight reduction as compared to hydraulic systems. However, the difficulty of using SMA actuators for controlling variable area exhaust nozzle lies in the fact that the temperature near exhaust nozzle is far higher than the transformation temperature of an SMA actuator. Due to the flexibility and small volume of SMA wire actuators, they can be remotely replaced in a region where temperature is lower than that of its transformation temperature. By exploiting this fact, this paper presents a novel design of a proof-of-concept variable area exhaust nozzle using shape memory alloy wire actuators. The SMA actuators are remotely placed away from the exhaust nozzle area so that the environmental temperature is below their transformation temperature. By electrically heating the SMA actuators, the exhaust nozzle will experience an area reduction of up to 40%. Bias springs will apply forces to return the fan nozzle to the open-up configuration. A feedback controller based sliding mode method is used to regulate the SMA actuators' position. Experimental results demonstrate that the proposed design meets the desired area variation specifications and show the promise of a lightweight and simple exhaust nozzle design by using shape memory alloy actuators.

Cornerstone Research Group, Inc. (CRG) has developed processes to make molds for casting and mandrels for filament winding composite parts from novel shape memory polymers (SMPs). For external molding, the SMP tooling system is capable of being thermally formed into a precise negative image of a master part, cooled, and made to retain the new shape. For filament winding mandrels, internal SMP mandrels can be used and easily extracted after curing. CRG has developed the ability to fabricate SMP materials from a wide range of polymer systems. Veriflex, the trademark name for CRG's shape memory polymer resin systems, functions on thermal activation customizable from -20°F to 520°F. These materials can withstand the elevated temperatures that are needed to cure composite parts without deformation and offer a gentle, simple demolding process. After the composite part has cured, the mold is raised above the Tg, which allows it to retract to its memory shape. SMP tooling processes provide the opportunity to mitigate the drawbacks of traditional fabrication techniques for advanced composite parts. This tooling system also possesses versatility in size variations, including being capable of micro (nanometers) to macro (meters) replication.

The successful and practical application of shape memory alloy (SMA) torque tube actuators has frequently been hindered by an incomplete understanding of the effects of manufacturing and processing variables, particularly when working with large-scale systems producing high force and large displacements. Recently the authors have developed data for NiTinol SMA torque tubes subjected to a variety of processes routinely encountered in everyday industrial practice, with the objective of developing a robust and reliable high-energy actuator. Data are presented for more than 25 NiTinol torque tubes 5.5" long by 0.4" in diameter. The tubes were tested over a range of steady and variable loads exceeding 150 in-lbs of torque, with angular displacements of more than 60 degrees, and for durations exceeding 10,000 thermal cycles. Each tube's performance is characterized as a function of material source, level of cold work, heat treatment, tube fabrication technique, and training regime, and the results are shown. Changes in mechanical and shape memory property were also tracked, and they are reported. Application of NiTinol characteristics to practical design and fabrication of SMA actuators meeting a wide range of angular displacement and torque requirements will also be discussed.

The DARPA Sponsored Compliant Surface Robotics (CSR) program pursues development of a high mobility, lightweight, modular, morph-able robot for military forces in the field and for other industrial uses. The USTLAB and University of Washington Center for Intelligent Materials and Systems (CIMS) effort builds on USTLAB proof of concept feasibility studies and demonstration of a 4, 6, or 8 wheeled modular vehicle with articulated leg-wheel assemblies. A collaborative effort between USTLAB and UW-CIMS explored the application of Shape Memory Alloy Nickel Titanium Alloy springs to a leg extension actuator capable of actuating with 4.5 Newton force over a 50 mm stroke. At the completion of Phase II, we have completed mechanical and electronics engineering design and achieved conventional actuation which currently enable active articulation, enabling autonomous reconfiguration for a wide variety of terrains, including upside down operations (in case of flip over), have developed a leg extension actuator demonstration model, and we have positioned our team to pursue a small vehicle with leg extension actuators in follow on work. The CSR vehicle's modular spider-like configuration facilitates adaptation to many uses and compliance over rugged terrain. The developmental process, actuator and vehicle characteristics will be discussed.

A comparison of different commercially available packaged piezoelectric actuators is presented. The comparisons are based on force, stress and strain performance at similar field densities. A new metric of comparison, based on energy efficiency, is introduced. This paper provides designers with useful information on actuators and actuator performance for industrial applications. The QuickPack and PowerAct actuators remain the only packaged piezoelectric actuators to be produced in high volume and to feature in commercial applications.

Aerospace and underwater applications typically require actuators capable of large displacements, precise positioning, and fast response times. To meet these requirements, several classes of actuators based on low-voltage piezoelectric materials have been developed, and, in the case of the Amplified Piezoelectric Actuators (APA series), space qualified. The APA actuators offer large displacements (up to 1mm), large deformations (up to 3%), and large forces (up to 1kN) at low electrical power. These actuators can withstand large external forces and have successfully passed severe qualification tests such as centrifugal accelerations and vibration forces encountered during space launch. Aerospace applications of APAs include scientific instrumentation, such as telescopes and microscopes, microsatellite propulsion valves, and structural vibration control. Aeronautical applications include active flap control in aircraft wings and helicopter blades. Underwater applications focus on the silencing of ships, the piezodiagnostic (NDE) of structural defects in pipelines and hulls, and guidance systems of unmanned vehicles. This paper reviews the use of piezoelectric actuators, in particular APAs, in such applications. Qualification results, when available, are presented and discussed.

Systems that require multiple actuators for range and precision, such as adaptive optics, large optical beam control, photonics metrology, and semiconductor test-measurement, are candidates for this evolving actuator system. Designers can now consider one system to provide over 100 N force in nanometer steps at up to 50 mm/s with features such as, greater than 20 millimeter travel, power-off hold, high acceleration, and high stiffness. High mechanical power density is beneficial whether fitting an actuator into limited real estate or minimizing total mass for launch or inertia considerations. Smaller mechanical systems benefit from higher stiffness and are less susceptible to environmental transients. The actuator design uses sets of three piezoelectric elements. These constitute 1100 nF of load driven at up to 2500 Hz. In addition to the mechanical actuator, a new high efficiency amplifier and controller are being developed. Total system power density benefits will be noted and clamp design detail is presented.

Mide Technology Corporation, under the supervision of the U.S. Army, is developing fast hydraulic valve technologies for fuel injection systems. Mide aims to address the Army's 21st Century Vehicle programs by providing the flexibility to achieve economic, environmentally friendly, and power dense diesel operation from a single platform. The technology couples a highly efficient gained piezoelectric actuator to a diesel unit injector's control valve spool. Piezoelectric actuation enables proportional authority over the injector's control valve, as opposed to traditional digital (on/off) operation. This authority allows the integrated device to provide electronically controlled fuel injection rate shaping capability. Each injection event profile may be independently shaped to govern diesel engine operation in one of three selectable modes: Lean, for fuel efficiency; Clean, for reduced emissions; Mean, for improved battlefield performance. To date, Mide has shown injection rate shaping capability in the laboratory using the industry standard "rate tube test" to measure injection profiles. Future development will focus on an engine demonstration of Lean, Clean, and Mean operating mode flexibility using rate shaping technology.

One of the major issues facing increasing miniaturization of small launched flight systems for reconnaissance or weapons delivery is the issue of sufficient actuation. Such systems cannot afford conventional servo designs as being far too heavy and volumetric as to be practical. One of the approaches that the flight dynamics community has taken is to investigate possible use of smart materials based approaches. Until now the dilemma has been that the actuators providing sufficient force do not deliver sufficient angular displacement or conversely, actuators provisioning sufficient angular displacement do not yield sufficient force. QorTek has developed a new concept in piezoactuation that can deliver both the necessary force and displacement necessary for many of the miniaturized flight munition, reconnaissance, or other area dominance needs. The new QT Bimorph design builds upon the work by NASA and FACE Corporation in using laminate structures in an autoclave process as to yield a high-performance actuation capability. Unlike these prior actuators the new design has two very important distinctions that make it suitable for miniaturized flight control authority applications. The new piezo-actuator functions in a bimorph - as to unimorph rainbow, Thunder etc. devices. The new device is fabricated as a multilayer device with varying length layers. The first advance enables implementation of such technology to flat structures such as fins, canards, ailerons etc. The second advance enables geometric patterning to form fit the available space within such aerodynamic control activation mechanisms.

Although many subscale aircraft regularly fly with adaptive materials in sensors and small components in secondary subsystems, only a handful have flown with adaptive aerostructures as flight critical, enabling components. This paper reviews several families of adaptive aerostructures which have enabled or significantly enhanced flightworthy uninhabited aerial vehicles (UAVs), including rotary and fixed wing aircraft, missiles and munitions. More than 40 adaptive aerostructures programs which have had a direct connection to flight test and/or production UAVs, ranging from hover through hypersonic, sea-level to exo-stratospheric are examined. Adaptive material type, design Mach range, test methods, aircraft configuration and performance of each of the designs are presented. An historical analysis shows the evolution of flightworthy adaptive aerostructures from the earliest staggering flights in 1994 to modern adaptive UAVs supporting live-fire exercises in harsh military environments. Because there are profound differences between bench test, wind tunnel test, flight test and military grade flightworthy adaptive aerostructures, some of the most mature industrial design and fabrication techniques in use today will be outlined. The paper concludes with an example of the useful load and performance expansions which are seen on an industrial, military-grade UAV through the use of properly designed, flight-hardened adaptive aerostructures.

Direct structural deformation to achieve aerodynamic benefit is difficult because large actuators must supply energy for structural strain and aerodynamic loads. This ppaer presents a mechanism that allows most of the energy required to twist or deform a wing to be stored in descrete springs. When this device is used, only sufficient energy is provided to control the position of the wing. This concept allows lightweight actuators to perform wing twisting and other structural distortions, and it reduces the onboard mass of the wing-twist system. The energy shuttle can be used with any actuator and it has been adapted for used with shape memory alloy, piezoelectric, and electromagnetic actuators.

A morphing aircraft can be defined as an aircraft that changes configuration to maximize its performance at radically different flight conditions. These configuration changes can take place in any part of the aircraft, e.g. fuselage, wing, engine, and tail. Wing morphing is naturally the most important aspect of aircraft morphing as it dictates the aircraft performance in a given flight condition, and has been of interest to the aircraft designers since the beginning of the flight, progressing from the design of control surfaces to the variable-sweep wing. Recent research efforts (mainly under DARPA and NASA sponsorships) however, are focusing on even more dramatic configuration changes such as 200% change in aspect ratio, 50% change in wing area, 5o change in wing twist, and 20o change in wing sweep to lay the ground work for truly multi-mission aircraft. Such wing geometry and configuration changes, while extremely challenging, can be conceptually achieved in a variety of ways - folding, hiding, telescoping, expanding, and contracting a wing, coupling and decoupling multiple wing segments, etc. These concepts can be classified under a few 'independent' categories and sub-categories so as to permit a systematic evaluation of benefits and challenges. This paper presents: 1) a review of prior work leading to current R&D efforts, 2) classification of morphing designs, and 3) a summary of technical challenges encountered in designing a morphing aircraft.

Cornerstone Research Group, Inc. (CRG), with specific no-cost guidance and support from Lockheed Martin, proposed to significantly increase the capability of loitering Unmanned Air Vehicles (UAVs) by developing a unique adaptive wing structure. This technology will offer significant operational benefit to air vehicles of this type currently under development. The development of this adaptive wing structure will enable such aircraft to adapt their wing configuration to maximize efficiency in each flight regime experienced during their mission. Additionally, the benefits of this development program will enhance the agility and maneuverability of the vehicle; therefore increasing its mission capability. The specific morphing ability CRG proposed to develop was a controlled expansion and contraction of the wing chord, which increases the wing planform area and therefore the lift produced. CRG proved feasibility of this concept and developed a sub-scale prototype integrating smart materials developed at CRG.

Several corporations including QorTek and Boeing have both independently proposed variable sweep primary structures for future adaptive airframe structures as to enable miniaturized area dominance munitions and UAVs. Various new vehicle concepts must insert a high power actuator to overcome low speed aerodynamic forces within a limited packaging availability. In order to meet requirements for this and other UAV/UCAV/MMT missions, require a re-thinking on how to accomplish large motor torque/lb (rather than energy/lb) while integrating the speed and torque capability in a small package. The difficulty is highlighted by considering that piezo devices are nicely compact but can only deliver is typically 1-2ft-lb/lb; whereas SMA has potential of being lighter solution and can deliver 100-200 ft-lb/lb but has two problems: slow recovery and large weight penalty for thermal components. Fortunately, some munition applications have relatively modest control surface actuation bandwidth requirements. However, until now, the thermal aspect has been prohibitive. QorTek will present a new SMA-based motor that provides high torque/lb for UAV/UCAV/MMT systems. This unique motor design has eliminated the need for additional power components for thermal excitation (transient heating) of the SMA elements as to accomplish phase transition. The resulting package is the desirable lightweight and compact packaged solution to many air vehicle and munition needs. Moreover, the design eliminates the undesirable "snapping" action associated with SMA phase transition.

Current efforts to extend the mission profile of Unmanned Aerial Vehicles (UAVs) have highlighted the need for scalable linear actuators. Typically, electrical power and control are specified for their high specific performance and ease of maintenance and replacement. Electro-Hydraulic Actuators (EHAs) provide the advantages of electrical power and control along with the proven reliability, robustness and graceful failure modes of hydraulic actuation. Current EHA technology, however, is not scalable to the degree required for projected UAVs and extension to other markets and applications. This paper will describe the measured and theoretical performance of a magnetostrictive hydraulic pump developed for one such EHA as part of the DARPA Compact Hybrid Actuator Program (CHAP). This work will focus on prototype pump designs utilizing a resonant magnetostrictive piston driver. The numerous design and operational parameters that have been tested and studied in an effort to produce an optimized pump design will be discussed. In particular, the measured and predicted performance of the resonant structure and fluidics will be compared and contrasted for several pump designs. The paper will also examine the interdependence of pump parameters and the balance required to produce a viable design with the required performance characteristics.

UAV's, UCAV's, miniaturized munitions and smart bombs have a variety of objectives clamoring for easement of weight/volume restrictions. These include anti-jam, explosive, servo control, electronics packaging, GPS and other required functions. The possibility of freeing up valuable real estate in the missile itself is most attractive for such applications. QorTek has developed the first self-contained high authority control surface to replace externally activated steering fins or canards. These flight actuation systems require only external control signal and power. Moreover, the technology easily scales to micro munitions. Because of their unique composite structure, these powerful solid-state devices offer exceptional performance in a durable package suitable for miniature munitions. The purpose of this paper is to discuss new breakthroughs in piezo-actuated technology that minimize vol./weight enabling a self-contained flight control actuation system that eliminates the need for servo controls. The presentation will focus on the new design that enables integration into high angular displacement actuation into a graphite epoxy fabricated RALA flight control actuator that can handle the aerodynamic loading conditions.

In propeller driven aircraft the main source for internal noise are tonal disturbances caused by the propeller blades that are passing the fuselage. In a certain four propeller military transport aircraft the maximum sound level in the cabin can reach up to 110 dB(A), not taking into account any noise control treatments. Inside the semi closed loadmaster working station (LMWS) the sound level must be reduced down to 86 dB(A). It is proposed to reach this goal with an active noise control system, because passive solutions are to heavy at low frequencies. Optimal positions of the loudspeakers are found by finite element calculations. These positions have been realized in a full-scale test bed. A reduction of the sound pressure level of more than 30dB within a specified volume was achieved at a frequency of 100 Hz. HiFi speakers are used as secondary actuators in this test bed. These speakers are heavy and have unsuitable geometric dimensions for an aircraft. Therefore, other actuators, e.g. flat panel speakers, will be investigated with respect to the application in a mock-up of the LMWS.

Modern high performance aircraft fly at high speeds and high angles of attack. This can result in "buffet" aerodynamics, an unsteady turbulent flow that causes vibrations of the wings, tails, and body of the aircraft. This can result in decreased performance and ride quality, and fatigue failures. We are experimenting with controlling these vibrations by using piezoceramic actuators attached to the inner and outer skin of the aircraft. In this project, a tail or wing is investigated. A "generic" tail finite element model is studied in which individual actuators are assumed to exactly cover individual finite elements. Various optimizations of the orientations and power consumed by these actuators are then performed. Real coded genetic algorithms are used to perform the optimizations and a design space approximation technique is used to minimize costly finite element runs. An important result is the identification of a power consumption threshold for the entire system. Below the threshold, vibration control performance of optimized systems decreases with decreasing values of power supplied to the entire system.

The present paper considers a design of fish fin actuators based on shape memory alloy composites composed of a couple of plates with the opposite functions. Both SMA plates, whose microstructure is either martensite or austenite, are individually arranged in parallel and operated as a bias to each other. The actuation mechanism is based on change in elastic constant, from stiff to soft during austenite to martensite transformation. First, a preliminary model of the elastic and superelastic deformation is proposed for prediction of the optimum curvature of SMA plates, which enable us to control the steering of an underwater object. The analytical model provides the relationship between the bending moment and the curvature for the composite plates in each deformation range. For a given velocity of a moving fish robot, the underwater curvature and bending moment of its plates is successfully obtained. We design such a fish fin actuator made of a set of different types of SMA composite plates which are embedded in an elastometer matrix to form a fish tail fin.

There is growing evidence for ice and fluids near the surface of Mars with potential discharge of brines, which may preserve a record of past life on the planet. Proven techniques to sample Mars subsurface will be critical for future NASA astrobiology missions that will search for such records. The required technology studies are underway in the McMurdo Dry valleys, Antarctica, which is serving as a Mars analog. The ice layer on Lake Vida in the dry valleys is estimated to be 20-meter thick where below 16-m depth there is a mix of ice and brine, which has never been sampled directly due to logistical constraints. A novel light weight, low power ultrasonic/sonic driller/corer (USDC) mechanism was developed that overcomes the need for high axial loads required by drilling via conventional techniques. The USDC was modified to produce an Ultrasonic/Sonic Gopher that is being developed to core down to the 20-m depth for in situ analysis and sample collection. Coring ice at -20°C as in Lake Vida suggests that it is a greater challenge and current efforts are focused on the problems of ice core cutting, ice chip handling and potential ice melt (and refreezing) during drilling. An analytical model and a prototype are being developed with an effort to optimize the design while addressing the thermal issues, drilling rate, power, mass and the electromechanical behavior.

Lost Foam Casting (LFC) enables metal casters to produce complex parts by making foam patterns having the same geometry as the desired finished parts. Among the greatest strengths of LFC process is that it allows designers to consolidate parts, reduce machining and minimize assembly operations. One of the key steps in the LFC process takes place in the compaction box, where the foam pattern is suspended in a steel container that is vibrated while sand is added to surround the pattern. The sand provides the mechanical support to the pattern as molten metal is poured into the mold. Discussed in this paper will be the development of an advanced sensor array for the measurement and control of the sand compaction stage. Compaction of the sand is key in controlling casting distortion and is instrumental in the efficiency rating of the LFC process. Too much compaction can cause the foam part to distort or even get crushed. Too little compaction can lead to a defective final product due to inadequate support of the foam part or lack of sand flow into small cavities in the foam part. To understand and control the behavior of the sand compaction stage, the key parameters that must first be measured are: (1) Energy imparted on the compaction box, sand and foam part, (2) compaction of the sand in the casting box, and (3) distortion of the foam part. The sensor array is to be placed inline in order to give direct feedback that can then be used in both passive and active process control.

In-situ sampling and analysis is one of the major objectives of future NASA exploration missions. Existing drilling techniques are limited by the need for large axial forces, holding torques, and high power consumption. Lightweight robots and rovers have difficulties accommodating these requirements. These requirements are becoming increasingly tougher to meet as the need for drilling techniques is expanding to reach deeper into the subsurface. To address these key challenges to the NASA objective of planetary in-situ rock sampling and analysis, a drilling technology called ultrasonic/sonic driller/corer (USDC) was developed. The USDC uses a novel driving mechanism, transferring ultrasonic vibration to sonic frequency impacts with the aid of a free-flying mass block (free-mass). The free mass then drives the drill bit. The actuator consists of a stack of piezoelectric disks with a horn that amplifies the induced vibration amplitudes. To meet the need for deep driller the USDC was modified to form the Ultrasonic/Sonic Gopher. Drilling to the depth of several meters in ice or hard rocks requires the optimization of the amplification of the vibration displacement and velocity that are generated by the piezoelectric materials. For this purpose, various horn designs were examined analytically. Conventional and new designs of the horn were analyzed using finite element modeling and the results allow for the determination of the control parameters that can enhance the tip displacement and velocity. The results of the modeling are described and discussed in this paper.

A rigid platform mounted on four supports is modeled with heave, pitch and roll motions as the three degrees of freedom. The stiffness of each support is varied independently depending upon the condition function. Two stiffness values are possible at each support. As long as the absolute value of the relative velocity across the support is greater than a design value, the actuator is switched off. Spring loaded friction pads are in contact and the two springs act in parallel to increase the stiffness of the support. When the relative velocity is close to zero, the actuator is switched on. The friction pads lose contact and only one spring of the support will be effective. The actuator develops the required force that overcomes the torque produced by the torsion spring. The torsion spring develops the necessary normal force at the friction pads that acts normal to the sliding surfaces of the spring and the base in order to produce the necessary coulomb friction for locking one of the springs with the base thus altering the stiffness. A mathematical model is developed to study the performance of the proposed model. The simulation results show that the proposed scheme is very effective in reducing the vibration levels on the platform for harmonic base inputs.

Skyhook control is an effective control strategy for suppressing vehicle vibration. It is typically classified as on-off skyhook control and continuous skyhook control. In this study, a fuzzy skyhook control is proposed. It combines the fuzzy logic theory with the skyhook principle to improve control performance. In order to compare performance of each control strategy, an experimental study is prepared utilizing a quarter car model of high-mobility multi-purpose wheeled vehicle (HMMWV) with a controllable magneto-rheological fluid (MRF) damper. The experimental results under rough road excitation demonstrate that the fuzzy skyhook control offers more robust suspension performance over the continuous skyhook control while still out performing the on-off skyhook control. The system model-independent fuzzy skyhook control is simpler and provides some robust advantages for real application as compared to the system model-dependent continuous skyhook control.

Magnetorheological or MR fluids have been successfully used to enable highly effective semi-active control systems in automobile primary suspensions to control unwanted motions in civil engineering structures and to provide force-feedback in steer-by-wire systems. A key to the successful use of MR fluids is an appreciation and understanding of the balance and trade-off between the magnetically controlled on-state force and the ever-present off-state viscous force. In all MR fluid applications, one must deal with the fact that MR fluids never fully decouple or go to zero force in their off-state. Magnelok devices are a magnetically controlled compliment to traditional MR fluid devices that have been developed to enable a true force decoupling in the off-state. Magnelok devices may be embodied as linear or rotary dampers, brakes, lockable struts or position holding devices. They are particularly suitable for lock/un-lock applications. Unlike MR fluid devices they contain no fluid yet they do provide a variable level of friction damping that is controlled by the magnitude of the applied magnetic field. Magnelok devices are low cost as they easily accommodate relatively loose mechanical tolerances and require no seals or accumulator. A variety of controllable Magnelok devices and applications are described.

Electrically conductive graphite-polymer coatings on electrically insulated nichrome wires are used as electrical resistors to heat the coating-wire assemblage. Preliminary experiments have demonstrated steady state surface temperatures of about 160 deg C. Further, the electrical power input for the coated wires is almost 1/2 that of the power input for uncoated wires. Experiments and analytical modeling indicate the power reduction is, in large part, due to reduced convective losses to the environment. This work is a first step in the development of efficient electrical resistors for shape memory alloys.

This paper introduces polymer composites with locally micro-tailored electric and thermal conductive properties. We concentrate on specially designed orthotropic composites that have modified thermal properties in one preferable direction. This preferable direction can vary from region to region in the composite part to fulfill design objectives. Required local micro-tailoring and optimization of structure for given thermal applications is achieved by exposing liquid polymer suspensions to an electric field and then curing the obtained structure. We present testing results for epoxy resin with various fillers including graphite, silica etc. Obtained orthotropic composites are tested for mechanical and thermal and electrical properties. Elastic modulus, thermal expansion, and thermal conduction are measured for various compositions, directions and degree of orthotropy. The potential of obtained materials for electronic, aerospace and automotive applications are briefly discussed.

Systems Planning and Analysis, Inc. (SPA) has recently planned, installed, and tested a fiber Bragg grating (FBG) strain sensor system to validate FEM predictions of a new submarine design undergoing American Bureau of Shipping (ABS) certification testing. Fiber optic triaxial, biaxial, and uniaxial gage locations were selected based on the FEM analysis. FBGs were placed on six optical fibers with two fibers (33 sensors) mounted internally to the hull and four fibers (64 sensors) mounted externally. Testing was performed by lowering the submarine to the design depth and recording strain measurements. The optical sensor signals were transmitted directly to the water's surface and monitored by top-side interrogation instrumentation through over 2000 feet of optical cable. Measured temperature-compensated strain values were compared to the FEM predicted strain values with excellent results. To the author's knowledge, this successful test represents the first time that FBG sensors have been used to certify a submarine design and to validate FEM analysis on a large-scale structure.

The objective of the work presented was to develop a suite of sensors for use in high-temperature aerospace environments, including turbine engine monitoring, hypersonic vehicle skin friction measurements, and support ground and flight test operations. A fiber optic sensor platform was used to construct the sensor suite. Successful laboratory demonstrations include calibration of a pressure sensor to 100psi at a gas temperature of 800°C, calibration of an accelerometer to 2.5g at a substrate temperature of 850°C. Temperature sensors have been field tested up to 1400°C, and a skin friction sensor designed for 870°C operation has been constructed. The key advancement that enabled the operation of these novel harsh environment sensors was a fiber optic packaging methodology that allowed the coupling of alumina and sapphire transducer components, optical fiber, and high-temperature alloy housing materials. The basic operation of the sensors and early experimental results are presented. Each of the sensors described here represent a quantifiable advancement in the state of the art in high-temperature physical sensors and will have a significant impact on the aerospace propulsion instrumentation industry.

The motivation for the reported research was to support NASA space nuclear power initiatives through the development of advanced fiber Bragg grating (FBG) sensors for the SAFE-100 non-nuclear core simulator. The purpose of the combined temperature and strain mapping was to obtain a correlation between power distribution and core shape within the simulator. In a nuclear reactor, core dimension affects local reactivity and therefore power distribution. 20 FBG temperature sensors were installed in the SAFE-100 thermal simulator at the NASA Marshal Space Flight Center in an interstitial location approximately 2.3mm in diameter. The simulator was heated during two separate experiments using graphite resistive heating elements. The first experiment reached a maximum temperature of approximately 800°C, while the second experiment reached 1150°C. A detailed profile of temperature vs. time and location within the simulator was generated. During a second test, highly distributed fiber Bragg grating strain sensors were arrayed about the circumference and along the length of the heated core region. The maximum temperature during this test was approximately 300°C. A radial and longitudinal strain distribution was obtained that correlated well with known power distribution. Work continues to increase the strain sensor operating temperature and sensor multiplexing to allow high-resolution mapping.

This paper presents a part of the research results on a damage monitoring system using PZT actuators/FBG sensors for advanced composite material structures of new-generation aircrafts. To achieve weight reduction of the aircraft structure, these advanced composite materials have gradually been employed for the primary structure. It is expected that when these materials are extensively employed, an efficient bonded structure such as a hat-shaped stringer will be utilized for the aircraft structure. However, these bonded structures have critical problems such as debonding and delamination at the interfaces of the laminate. Further, a single-step molding process of the structure elements is necessary in order to ensure low cost and thus affordability. However, this low-cost process results in an increase in the non-destructive inspection (NDI) cost. Therefore, an innovative damage monitoring system is required for structural health management. In the present study, the authors have developed a hybrid sensor system that can detect the elastic waves launched from the piezo transducer (PZT) actuator using a high-speed and high-accuracy fiber Bragg grating (FBG) sensor to resolve the issues mentioned above. In this study, the conceptual design of an aircraft that can employ this damage monitoring system was carried out. Subsequently, the application area was selected based on cases of certain kinds of damage. Further, the validity of the damage monitoring system for the verification of the structural integrity of the aircraft was discussed. Next, in order to verify the elastic wave detectability of the FBG sensor, it was confirmed that an elastic wave of 300 kHz is detectable at a distance of 5 cm between the PZT actuator and FBG sensor using an aluminum sheet and CFRP cross-ply laminate and also by considering the relationship between sensor length and sensitivity. Through the present research results, the possibility of applying the damage monitoring system to the composite material bonding structure in an aircraft is presented.

An important part of the Navy objectives is to be both more efficient and enable manpower reduction is to reduce maintenance, reduce manpower, and eliminate pollutants through creating a more all-electric ship environment. However, placement of both non-centralized and centralized hydraulic systems for control of heavy machinery, large bay doors, articulated systems such as rudders for controlling air flow to the skirt system (such as in Landing Craft Air Cushion (LCAC) is extremely challenging. At the base of the design approach to a Mechatronic Motion System is the fact that such applications do not require high precision. What is required is that the actuator delivers sufficient thrust power without increasing the existing actuator weight and be a self-contained unit. To address this need, QorTek and PSU have been developing a new concept of an entirely new kind of motion system actuator that has few parts, enormous thrust capability for its compact size, and is amenable to affordable manufacture. The new Quadrature Mechatronic Actuator (QMA) is a hydraulic replacement that will match hydraulic force-displacement capabilities in a fully solid-state design. Quadrature Mechatronic Actuators will look very similar to the existing hydraulic actuators currently used on LCAC. These compact self-contained units represent a one-for-one substitute for existing equipment. The Mechatronic Actuator itself will be lighter and slightly smaller than its hydraulic actuator equivalent and use one or more internal hybrid solid-state drivers that are internally coupled to a linear translator.

One of the greatest challenges to practical implementation of smart structures to defense and aerospace systems is the heavy cost of the power electronics and control. Examples of such devices include those driven by piezoelectric, electrostrictive, or magnetostrictive transducers. Typically, the power + control for such device mechanisms are many times the size and cost of the activation mechanism itself. In many cases, this reduces to impractical the capability of implementing otherwise attractive smart structures solutions. QorTek has developed a completely new kind of power drive system suitable for many aerospace applications where weight and compactness are a premium. This patented new technology is referred to as Zero Net Charge (ZNC) power electronics. Conventional and regenerative Class D electronic topologies require large dc power supply filter capacitors in order to drive transducer-actuated systems. The invention eliminates the need for dc power supply filter capacitors in driving reactive loads thus greatly reducing the peak power handled by the dc power sections. The effective average power requirement to drive such a system becomes very low. The resulting ZNC drive system is extremely compact and low profile. Weighing only a few grams it can deliver drive voltages (V/m) several times in excess of conventional drives - enabling transductive devices to be driven in the higher strain, nonlinear region, which thereby reduces the size requirements of the actuator itself.

A root cause of this inability of USS Cole incident to recover usable portions of its electrical power systems in a timely fashion was due to manual reset requirements of its electrical switching gear. Much of the damage was caused by the arcing or gapping of switch-gear components initiating ship-wide equipment outages and losses. QorTek has developed an entirely new generation 0.5-msec reset or interrupt high power switches that completely eliminate gapping and arcing based upon smart composite materials. Originally developed by Dupont, these composite materials have the ability to change their conductance by 8-10 orders of magnitude as function of applied pressure. Dependent upon materials selection, particulate density, geometry, compliance, such materials can be tailored to vary resistance from 0.1Ω to 10MΩ. QorTek fabricates such smart composite switches with 6.75KVA continuous and 70KVA peak power handling capabilities that require 125psi switching and 50psi hold. Until now, a major challenge has been how to enable such variably applied loads. The main part of this presentation will focus on the new concept of super magnetic (e.g. NdFeB) induced percolation crossing of this family of variably conductive "smart" composite materials. The use of super magnets to load the metallic loaded composites has a further advantage of fully enabling ultrafast remote switching, automatic shut-off in presence of high current rate onset, and remote interrogation of system state. These will be available in compact packaging suitable for integration in future Navy and Aircraft systems.

Composite materials have increased the range of mechanical properties available to the design engineer compared with the range afforded by single component materials, leading to a revolution in capabilities. Nearly all commonly used engineering materials, including these composite materials, however, have a great limitation; that is, once their mechanical properties are set they cannot be changed. Imagine a material that could, under electric control, change from rubbery to rigid. Such composite "meta-materials" with stiffness and damping properties that can be electrically controlled over a wide range would find widespread application in areas such as morphing structures, tunable and conformable devices for human interaction, and greatly improved vibration control. Such a technology is a breakthrough capability because it fundamentally changes the paradigm of composite materials having a fixed set of mechanical properties. These electronically controllable composites may be the basis of discrete devices with tunable impedance. The composites can also be multifunctional materials: They can minimize size and mass by acting not only as a tunable impedance device, but also as a supporting structure or protective skin. Current approaches to controllable mechanical properties include composites with materials that have intrinsically variable properties such as shape memory alloys or polymers, or magnetorheological fluids, or composites that have active materials such as piezoelectrics, magnetostrictives, and newly emerging electroactive polymers. Each of these materials is suitable for some applications, but no single technology is capable of fast and efficient response that can produce a very wide range of stiffness and damping with a high elongation capability, that is, go from rubber to rigid. Such a material would be capable of a change in its maximum elastic energy of deformation of 50,000 J/cm³. No existing material is within three orders of magnitude of this value. Similarly, no material appears capable of going from a very lightly damped to a very heavily damped condition over a wide range of motion. We suggest an approach based on composites whose meso-scale structure can be changed with actuation or change in intrinsic properties. Passive composite meta-materials have been demonstrated, however, such active composite meta-materials have not yet been demonstrated.

The automobile today is primarily a mechanical system focused on the conversion of energy from a variety of forms into mechanical effort and desired motion. Consequently, automobile designers and engineers have traditionally taken mechanically-oriented approaches to solving problems or enhancing the performance and functionality of the automobile. Unfortunately, this way of looking at problems severely limits the options available and has usually led to bulky, massive, inflexible and expensive solutions. Expanding the solution domain beyond the purview of traditional mechanical approaches can enhance the realization of effective solutions. This paper introduces the notion that "Mechamatronics," the integration of mechanical systems, smart materials and electronics, offers new degrees of freedom for achieving this goal.

A full scale Smart Material Actuated Rotor Technology (SMART) system with piezoelectric actuated blade flaps was developed and whirl tower tested. The development effort included design, fabrication, and component testing of rotor blades, trailing edge flaps, piezoelectric actuators, switching power amplifiers, and the data/power system. Simulations and model scale wind tunnel tests have shown that this system can provide 80% vibration reduction, 10dB noise reduction for a helicopter passing overhead, and substantial aerodynamic performance gains. Whirl tower testing of the 34-foot diameter rotor demonstrated the functionality, robustness, and required authority of the active flap system. The program involved extensive development work and risk reduction tests which resulted in a robust, high performance actuator and a tightly integrated actuator, flap, and blade system. The actuator demonstrated excellent performance during bench testing and has accumulated over 60 million cycles under a spectrum of loading conditions. The flight worthy active flap rotor blades were based on a modified design of the FAA certified MD900 Explorer production rotor blade. Whirl tower testing was conducted with full rotor instrumentation and a 5-component balance. The rotor was tested for 13 hours under a range of conditions, including 7 hours of flap operation. Flap inputs included open loop static and dynamic commands. The flaps showed excellent authority with oscillatory thrust greater than 10% of the steady baseline thrust. Various flap actuation frequency sweeps were run to investigate the dynamics of the rotor and the flap system. Limited closed loop tests used hub accelerations and hub loads for feedback. Proving the integration, robust operation, and authority of the flap system were the key objectives met by the whirl tower test. This success depended on tailoring the piezoelectric materials and actuator to the application and meeting actuator/blade integration requirements. Test results demonstrate the feasibility and practicality of applying smart materials for limited authority, active control on a helicopter rotor. Follow-on forward flight demonstrations are needed to quantify the expected significant improvements in vibrations, noise, and aerodynamic performance. Extensions of this technology are a prime candidate for on-blade flight control, i.e. elimination of the swashplate. This program was performed as part of DARPA's Smart Materials and Structures Demonstrations. Funding was provided by DARPA, The Boeing Company, NASA, and the U.S. Army. Additional cost share funds were provided by the University of Maryland, MIT, and UCLA.