bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optical Sensor for Precision Small-Angle Measurement
Authors: Huang Peisen S. , Zhang Aiyu 
Published: December 2021

Abstract
A novel optical sensor for precision small-angle measurement is proposed. It is based on the total internal reflection effect of a light beam at a glass prism. Angular displacement of the light beam is measured by detecting the intensity change of the reflected beam as a result of the relative phase shift between the s- and p-polarized beams. A differential method is developed in which the light beam is equally split into two, each reflected at a prism and detected by a photodiode. The output is the difference of the two detected intensities divided by their sum. It was found that this differential method significantly improves the linearity of sensor output. Both theoretical and experimental results are presented.
A Shear-Force Sensitive Silicon Sensor
Authors: Wang Lin , Beebe David J. 
Published: December 2021

Abstract
A shear-force sensitive silicon sensor is developed using microfabrication technology. Four ion implanted piezoresistive resistors are embedded in a silicon diaphragm and used as independent strain gauges. An epoxy mesa is added on top of the diaphragm to transmit force from the load to the diaphgram. Both the shear and normal components of an applied force can be resolved by measuring the resistance variations of the four resistors. The sensor is tested when a 0-3 N variant force is applied at elevation angles of 0° (normal), 30°, 45° and 60°. At each elevation angle, the sensor rotates from 0° to 360° at an increment of 30°. Good linearity (R &gt; 0.98) and high repeatability (standard deviation &lt; 8 %) are observed. Both normal and shear sensitivities are measured. The shear sensitivity is characterized in terms of both magnitude and direction of the applied force. The results show that the sensor has a high sensing ability to both normal and shear forces (compared to commercial load cell). In this paper, the sensor design, fabrication and testing are described. The sensor characterization and shear sensing ability are discussed.
The Degree of Translational-Rotational Coupling of a Spatial Stiffness
Authors: Huang Shuguang , Schimmels Joseph M. 
Published: December 2021

Abstract
Previously, we have shown that, to realize an arbitrary spatial stiffness matrix, spring components that couple the translational and rotational behavior along/about an axis are required. We showed that, 3 such coupled components and 3 uncoupled components are sufficient to realize any full-rank spatial stiffness matrix and that for some spatial stiffness matrices 3 coupled components are necessary. In this paper, we show how to identify the minimum number of components that provide translational-rotational coupling required to realize an arbitrarily specified spatial stiffness matrix. This number is defined as the “degree of translational-rotational coupling” (DTRC). We show that the DTRC of a stiffness matrix is uniquely determined by the spatial stiffness mapping and is obtained by evaluating the eigenstiffnesses of the spatial stiffness matrix. In addition, the relationships between the DTRC and other properties identified in previous investigations of spatial stiffness behavior are discussed.
Design of the NASA Robonaut Hand
Authors: Lovchik C. S. , Aldridge H. A. , Diftler M. A. 
Published: December 2021

Abstract
The design of a highly anthropomorphic human scale robot hand for space based operations is described. This five finger hand combined with its integrated wrist and forearm has fourteen independent degrees of freedom. The device approximates very well the kinematics and required strength of a space suited astronaut’s gloved hand. The mechanisms used to meet these requirements are explained in detail along with the design philosophy behind them. Integration experiences reveal the challenges associated with obtaining the required capabilities within the desired size. The initial finger control strategy is presented along with examples of obtainable grasps.
The Manta and the Kanuk: Novel 4-DOF Parallel Mechanisms for Industrial Handling
Authors: Rolland Luc H. 
Published: December 2021

Abstract
Two novel 4-DOF very fast parallel robots were designed. This paper introduces the new parallel mechanism designs which are named the Manta and the Kanuk. In order to reduce manipulator overall costs, the actuator and encoder numbers are minimized to the exact effective degrees-of-freedoms (DOF) which is usually not the case in most parallel robot designs. The robots allow end-effector displacements along the three Cartesian translations and one platform transversal rotation. The two remaining rotations are blocked by the intrinsic mechanical structure including the rotation along the platform normal which is always limited in range. The main advantages are high stiffness through the multiple kinematic chain structure which allow for low mass designs. Moreover, they feature simple mechanical construction. Thus, it shall be possible to achieve very high throughput since high accelerations are feasible. To circumvent the known workspace limitations, the actuators were selected to be prismatic along linear axes. The applications are automated warehouse manipulation, mediatheque manipulation, machine tool tool changers, loading and unloading.
Sensorless Velocity Estimation for Control of a Compliant Mechanism Based Micromanipulator
Authors: Fite Kevin , Goldfarb Michael 
Published: December 2021

Abstract
A classical state observer-based approach to velocity estimation for the position control of a robot manipulator is compared with a self-sensing approach. The former is essentially an analog differentiator, while the latter utilizes a model of the actuator to reconstruct the velocity signal. The two methods of velocity estimation are compared in two common robot control schemes implemented on a compliant-mechanism-based small-scale robot manipulator. Specifically, both the state-observer-based and the self-sensing velocity estimates are utilized in the PD-control and in the sliding-mode control of the manipulator motion. Experimental results indicate that the self-sensing approach offers better control performance than does the state-observer-based approach, especially in the sliding-mode controller. The results are particularly useful in the motion control of micromanipulators, since the small scale constrains the size and number of sensors on the manipulator.
Emulation of Biological Motor Primitives in an Artificial System: The Generation of Static Force Fields
Authors: Lee Chae J. , Reger Bernard D. , Tresch Matthew C. , Colgate J. Edward , Mussa-Ivaldi Ferdinando A. 
Published: December 2021

Abstract
We have used observations of posture and movements in biological limbs to derive a controller for an artificial mechanism. The controller architecture emulates some of the known relations between spinal cord circuitry and the musculoskeletal system of vertebrates and, specifically, of the rat. This work relates to recent experiments suggesting that the neural circuitry of the spinal cord may be partitioned into a small set of functional modules. Activation of these modules, each connected to a set of limb muscles, resulted in force fields that have been measured at the endpoint of a limb. These force fields map each position of the foot into a corresponding static force vector. The force fields have been found to converge toward equilibrium positions located inside the leg’s workspace. The experimental observation that vector fields induced by multiple stimulations add vectorially, suggested that convergent force fields form a system of building blocks (or “primitives”) for the generation of stable postures and movements. To emulate this biological mechanism in the control of an artificial two-joint limb, we established relationships among three hierarchical levels — spinal modules, muscles, and actuators — by deriving the mappings among the respective output fields. These mappings are used in combination with an inverse model of the actuators to calculate the actuator commands that generate a desired force field. We tested the ability of this control system to reproduce the force fields generated by the leg muscles of the rat and a set of force fields with significant geometrical features. Our results show that we can successfully and reliably transfer to our artificial system the features of muscle force fields. In addition, we exploited the same principle of vector summation observed in the biological system to combine these muscle fields into a variety of force field patterns, including the gradients of Gaussian potentials and locally parallel fields. We consider this a first step in the generation of a biomorphic motor control system. This work is supported by ONR grant N00014-95-1-0571 and NIH grant MH48185.
Design and Development of a Variable Geometry Prototype Manipulator
Authors: Chu M. , Modi V. J. , de Silva C. W. , Misra A. K. 
Published: December 2021

Abstract
The paper focuses on design, dynamical simulation, operation and performance evaluation of a variable geometry manipulator. The system is composed of a mobile base supporting two modules connected in a chain topology. Each module consists of two links: one free to slew while the other is permitted to deploy. The governing equations of motion for the planar dynamics of the manipulator system are obtained using the Lagrangian procedure. Results indicate that the coupling effects together with the flexibility at the revolute joints have significant impact on the manipulator’s performance. Obviously, this will affect the desired trajectory tracking by the end-effector, suggesting a need for a suitable control algorithm. This is achieved through the classical Proportional-Integral-Derivative (PID) control strategy. The numerically predicted results are compared with the prototype performance. The remarkable agreement tends to substantiate integrity of the prototype design and effective implementation of the controller.
On Crack Extension in TSD Specimen With Foam Core
Authors: Li Xiaoming , Carlsson Leif A. 
Published: December 2021

Abstract
The Tilted Sandwich Debond (TSD) specimen has recently been introduced for characterization of debond fracture of sandwich structure. A precracked sandwich is attached to an incline, and debonding is achieved by loading the partially debonded top face until further crack propagation occurs. In this paper we present numerical finite element analysis of stress intensity factors for several configurations of the TSD specimen, viz. crack in a homogeneous specimen, crack located at the face/core interface, and crack located slightly below the face/core interface. The tendency for crack kinking is examined over a range of tilt angles. The stress intensity factors and mode mixty displayed very little dependency on the tilt angle, but the results were shown to depend on the exact crack configuration.
Stability of Long Cylindrical Sandwich Shells With Dissimilar Facings Subjected to a Lateral Pressure
Authors: Birman Victor , Simitses George 
Published: December 2021

Abstract
The paper presents the analysis of buckling and initial postbuckling behavior of long cylindrical sandwich shells subjected to a lateral pressure. The shells considered in the paper have dissimilar facings reflecting a demand to enhance impact resistance and damage tolerance of the facing exposed to external loads and hostile environments that are typical in applications. The shell being long, its central section remains in the state of plane strain prior to and after buckling. The solution includes the analysis of prebuckling deformations and linear and nonlinear buckling problems. It is shown that prebuckling deformations affect postbuckling shell behavior but they do not affect the linear (upper) buckling pressure. Numerical results presented in the paper illustrate that a moderate redistribution of the layers between the facings results in a limited reduction of the buckling pressure compared to the case of symmetric facings.
Particulate Enhanced Damping in Sandwich Structures
Authors: Maley Scott , Sun C. T. 
Published: December 2021

Abstract
This paper investigates the damping effect of loose particulate within the core of sandwich structures. Beam specimens fabricated from aluminum honeycomb core and IM7 carbon fiber face sheets with various amounts of loose particulate are experimentally examined. Both free vibration and forced vibration tests are performed. It is shown that a moderate amount of particulate can cause a large increase in damping. The effect of varying amounts of particulate is also investigated. Plate equations of motion with damping and inertia terms are derived to model the beam and compare with experimental results. Effective mass and effective viscous damping are generated by matching the theoretical model to the experimental data.
New Formulation for Composite Sandwich Shell Finite Element
Authors: Tabiei Ala , Tanov Romil 
Published: December 2021

Abstract
Sandwich shell finite element formulation is developed and presented. The sandwich shell element formulation allows for orthotropic faces and core material. The sandwich shell element is based on first shell order shear deformable theory utilized by most shell finite elements for isotropic materials. Consequently, the presented procedure can be adopted for any shell element available in commercial finite element packages. The formulation is based on the equalities of stress and moment resultants between a sandwich shell element and a typical homogenous shell element. The developed element is implemented in the nonlinear finite element code DYNA3D to validate and check its accuracy, efficiency and overall performance. The predicted results show good agreement with results obtained from far more complicated and computationally intensive 3-D analyses.
Past, Present and Future Composite Structures Applications in Rotorcraft
Authors: Rousseau Carl , Dobyns Al , Minguet Pierre 
Published: December 2021

Abstract
The rotorcraft industry is a roughly $5B/year segment of aerospace, with a 4:1 military to civil sales ratio, that delivers on the order of 5000–6000 aircraft per year. The earliest rotorcraft had composite primary structure: bonded wooden main and tail rotor blades. The first advanced composite main rotor (M/R) and tail rotor blades (bonded glass/epoxy D-spars, honeycomb afterbodies, and fabric skins) went into production in the early ’70’s. Thus, the rotorcraft industry has been designing and certifying nonredundant bonded primary composite structure for over 25 years. More recent design innovations for rotor components include 4-inch-thick solid molded bearingless M/R hubs and yokes (joining the blades to the mast) and a 1.5-inch-thick complex curvature fiber placed carbon grip for the Bell/Boeing MV-22 Osprey tiltrotor. With roughly 50% of its empty weight consisting of glass and carbon reinforced composites, the V-22 probably has the highest weight-percentage of composites of any manned military production aircraft. This degree of composites usage will likely be surpased by the Sikorsky/Boeing RAH-66 Comanche scout/attack helicopter when it goes into production. As with the V-22 and RAH-66, composites are also seeing increased usage in civilian rotorcraft airframes. Specifically, the Bell 427 and MD Helicopter MD900 Explorer light twin helicopters feature all-composite fuselages, while the Bell-Agusta BA609 civil tiltrotor will have carbon epoxy wings, fuselage and empennage much like the V-22. In the future, composite structural applications will become more widespread as designers gain insight and confidence. Repair, maintenance and support of these structures will become the focus of much engineering R&D effort.
Breaking the 1:1 Immersion Barrier
Authors: Pimentel Kenneth , Ferneau Mark , Anderson Gavin 
Published: December 2021

Abstract
This paper discusses a combination of techniques that lets stylists and designers experience believable 1:1 interactions with virtual prototypes using immersive environments. The intent is to replace physical prototypes with believable virtual prototypes and then use them as the basis for communicating design intent within formal or informal design reviews. Achieving a reasonable degree of “believability” and natural interaction within this context requires addressing a broad range of problems, including: perception of scale, varying frame-rates, non-intuitive interaction devices and process and data integration just to name a few.
In addition to these challenges, designers and stylists want to examine multiple forms of product data including bitmaps, movies, text information and 3D data within a single visual context. This paper describes an approach for visualizing and interacting with various forms of product data within a fully immersed environment for the purposes of concept design (the phase of product design where the overall functionality and shape of the product is determined [Kraftcheck, 1997]).
A Framework for Augmented Reality Based Collaborative Product Development
Authors: Agarwal S. , Huang C. P. , Liou F. W. , Mitchell O. R. 
Published: December 2021

Abstract
The aim of this paper is develop a framework for a system for collaborative product development using Internet and augmented reality technology. The system allows fruitful interaction between experts at geographically dispersed locations through a flexible environment for sharing of information which could be in the form of live video, computer-aided design, audio, textual or conceptual. This system will provide a new paradigm for flexible interaction between the vendors and/or the domain experts at different stages of the product development cycle in order to reduce turn-around time. Also the system can be used in the classroom as a demonstration tool or in distance learning environment to introduce the concept of distributed collaborative engineering to students.
Comparative Testing of Virtual Environment Display Devices for Conceptual Design Reviews
Authors: Bochenek Grace M. , Ragusa James M. 
Published: December 2021

Abstract
The high cost of designing and prototyping new products and systems, coupled with the need to shrink overall life cycles, requires that organizations become more effective and efficient in managing these processes. To this end, empirical testing of various virtual environment (VE) devices was conducted to evaluate their use during a conceptual design review of a new military vehicle. Test results and analysis indicated that there were significant advantages of some VE technologies during certain phases of the review process, but no single device fully satisfied all individual and team needs. For that reason, a combined technology approach is recommended.
A Computational Acoustic Field Reconstruction Process Based on an Indirect Variational Boundary Element Formulation
Authors: Zhang Zhidong , Vlahopoulos Nickolas , Raveendra S. T. , Allen T. , Zhang K. Y. 
Published: December 2021

Abstract
The objective of the work presented in this paper is to develop a computational capability based on the indirect variational boundary element method (IVBEM) to evaluate appropriate velocity boundary conditions on an assembly of piston type sources such that they can recreate a prescribed acoustic field. Information for the acoustic pressure of the original acoustic field at certain field points constitutes the input to the developed process. Several new developments associated with the IVBEM are completed within the field reconstruction process. A new formulation for treating irregular frequencies in the IVBEM is developed and implemented in the field reconstruction process. The velocities on the piston type sources are computed from transfer functions between the field points, where the acoustic pressure of the original field is prescribed, and the velocity boundary condition on each element of the generic source. The IVBEM is employed for computing the transfer functions. A singular value decomposition solver is integrated with the IVBEM computations in order to evaluate the velocity boundary conditions from the transfer functions. Finally, an algorithm is developed that identifies the optimum field points where the acoustic pressure of the original field must be prescribed. The optimum field points are selected from a set of prescribed candidate points. The selection of the optimum points is based on the geometric characteristics of the generic source, the frequency of analysis, and the properties of the medium. Several validation and application cases are presented.
Flow Measurements and Analysis for Automotive Blower Noise
Authors: Humbad Niranjan G. , Foss John F. , Prevost Richard J. , Chen Charles C. 
Published: December 2021

Abstract
The climate control air handling system is one of the major contributors to automobile interior noise. The most annoying features can be characterized as low frequency (&lt;= 400 Hz) “rumble”, and “blade passing frequency, BPF tone” noise. This study presents an experimental investigation for two blower scroll assemblies, namely ‘baseline’ and ‘modified’. The baseline assembly is the original scroll which exhibited both tone and rumble noise problems. This assembly was modified to significantly reduce the tone and rumble noise. The velocity power spectral density plots of flow velocity show areas within the blower scroll where the turbulence fluctuations are relatively high for the tone and rumble frequencies, and are lower in magnitude for the modified case. A detailed CFD analysis was performed to compare the mean flow velocity components for the two assemblies. The results are in good agreement with the measurements. CFD analyses, which have been confirmed by experimental data, can be used to predict beneficial geometric alterations to minimize the tonal and rumble noise sources in climate control flow systems.
Influence of Pavement Roughness on Tire Noise
Authors: Ruhala Richard J. , Burroughs Courtney B. 
Published: December 2021

Abstract
In this study, the influence of the levels of pavement roughness on tire noise is examined using Nearfield Acoustical Holography (NAH) to measure noise from single tires mounted on a two-wheel trailer towed over different types of pavements. Contributions to the radiated noise from the leading edge, trailing edge, and sidewall of two tires are identified. Two experimental tires — a blank tire and a monopitch tire — are evaluated on three pavements — smooth asphalt, stud-damaged concrete, and Ellsworth — at 56 km/hr. From the measured complex pressure, acoustic intensity is reconstructed on side plane of the tires using NAH procedures. Additionally, sound power spectra levels are presented. Tire noise generating mechanisms associated with each pavement are inferred from measurements. The experimental results are compared with theories on pavement-induced tire noise available in the literature.
A Hybrid Track Model for Studying Dynamic Track/Sprocket Contact
Authors: Ma Zheng-Dong , Perkins Noel C. 
Published: December 2021

Abstract
Tracked vehicles are propelled by the engagement of track pitches and a drive sprocket. This sprocket, referred to as a tumbler for the large tracked mining vehicles considered herein, may wear quickly under the action of the considerable contact forces that develop with the track. This paper summarizes a model of the track/tumbler seating process and the contact forces that control abrasive wear. A vehicle model is developed that employs a hybrid model for the track. This hybrid model combines a multibody model of the track within the seating region of the tumbler with a continuous model of the track elsewhere in the track circuit. The hybrid model is then employed to simulate the track/tumbler interactions and the associated nonlinear contact phenomena. This new modeling approach promotes accuracy within the track/tumbler contact region with few degrees of freedom outside this region where spatial resolution is less important.