bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stable User-Specific Haptic Rendering of the Virtual Wall
Authors: Gillespie R. Brent , Cutkosky Mark R. 
Published: July 2023

Abstract
Efficient control algorithms are developed to implement stiff virtual walls without chatter. An analysis of the complete coupled system comprising controller, interface device, and user’s finger underlies the design of a wall algorithm, thus each virtual wall is tailored to a specific user impedance. The finger is modeled as a static second order impedance with justification drawn from empirical studies of limb dynamics available in the literature and from observations of the disparity in time scales between contact instability and volitional control. Compensation is incorporated for the destabilizing effects of the zero order hold using either model based prediction or design in the digital domain. The destabilizing effects of asynchronous wall on/off switching times and sampling times are tracked by a special watchdog while deadbeat control is used to periodically eliminate these effects. Extensions are discussed, including on-the-fly system identification of the user impedance.
Force Shading for Haptic Shape Perception
Authors: Morgenbesser Hugh B. , Srinivasan Mandayam A. 
Published: July 2023

Abstract
This paper proposes a novel haptic rendering algorithm and describes a perceptual experiment that demonstrates its effectiveness in causing humans to perceive shapes during manual interactions with virtual environments. The algorithm, called “Force Shading” (analogous to Phong Shading for visual displays), refers to a controlled variation in the direction of the force vector displayed by the haptic renderer for the purpose of creating the illusion of a non-flat shape on a nominally flat surface. Experiments on shape perception were done on 5 subjects using the Phantom as the haptic interface device. In these experiments, subjects manually explored the haptic display of various virtual polyhedral approximations of a circular cylindrical bump, with or without force shading. They then indicated the perceived shape by selecting one from a menu of shapes displayed on a computer monitor. Without force shading, the subjects accurately identified the polyhedral nature of the virtual bumps. With force shading, however, the subjects identified the polyhedral approximations as feeling closer to that of a smooth cylinder. The higher the number of polygons, the higher was the percentage of trials in which the shape was identified with a smooth cylinder.
Touching Multiresolution Curves
Authors: Pai Dinesh K. , Reissell L.-M. 
Published: July 2023

Abstract
We describe a multiresolution representation of parametric curves that is well suited to haptic interaction. Our approach has been implemented on an embedded controller for the Pantograph haptic device, and has been used for haptic exploration of boundary curves obtained from images. The resolution of the representation can be dynamically adapted to the task and hardware limitations.
Specifically, we use wavelet multiresolution, using biorthogonal wavelets with good approximation properties. In addition to the multiresolution representation, we maintain a hierarchy of error bounding boxes at each resolution level that is then used for fast, “anytime” collision detection.
Design of a Hemispherical Magnetic Levitation Haptic Interface Device
Authors: Berkelman Peter J. , Butler Zack J. , Hollis Ralph L. 
Published: July 2023

Abstract
We are currently fabricating a haptic interface device to enable direct physical interaction with dynamic simulated three-dimensional environments by exerting and reacting to forces and motions between the user’s hand and a magnetically levitated object. Our device uses magnetic levitation rather than a motorized linkage so that the dynamics are simple and actuator nonlinearities such as hysteresis, backlash and static friction are eliminated. Magnetic levitation haptic interaction was previously demonstrated using a fine motion robot wrist. A new magnetic levitation device was then designed specifically to address the requirements of realistic tool-based haptic interaction. A hemispherical device shape was adopted to maximize the ranges of translation and rotation and the ratio of actuator surface area to the levitated mass while enabling the user to grip a tool handle at the hemisphere center, near the center of mass, where translation, rotation, force, and torque ranges are the same in all directions. The new device will have a motion range of at least ±12 mm and ±7°, position sensing resolution within 3 μm, and will be capable of generating peak forces up to 60 N. Preliminary results from testing of position sensors and actuator assemblies support the performance data obtained from model analysis.
Task and Motion Analyses in Endoscopic Surgery
Authors: Cao Caroline G. L. , MacKenzie Christine L. , Payandeh Shahram 
Published: July 2023

Abstract
We present here task and motion analyses, part of a larger study on users, tasks and tools in endoscopic surgery. Expert and novice surgeons’ performance of laparoscopic surgery in training workshops was captured on video and analyzed. Four basic surgical tasks were identified: dissecting tissue, suturing, tying knots, and cutting suture. Each task was decomposed into subtasks with operational beginnings and endings. Subtasks were further analyzed into component motions. Here we discuss: differences between novice and expert surgeons; task constraints that might account for the pattern of results across the different tasks, including precision and safety constraints; differences in manipulation of the same endoscopic tool as a function of the target object; the large number of “additional” motions; difficulties in positioning and orientation of tools to perform the surgical tasks; and the serial execution of reach and grasp movements in endoscopic surgery, compared to their parallel execution in natural prehension.
Engineering Icons for Multidisciplinary Systems
Authors: Rosenberg Ronald C. , Hales Michael K. , Minor Mark A. 
Published: July 2023

Abstract
Many modern engineering systems are multidisciplinary, in that they incorporate energy effects from a variety of domains. Iconic representations of components have been standardized for different disciplines in order to provide a consistent set of conceptual modeling tools and to facilitate communication. In this paper we propose a generic multiport icon (GMI) for unifying conceptual reasoning and communication about multidisciplinary engineering system models. We show how the GMI can be used to represent existing icons from electrical, mechanical, fluid power, bond graph, and block diagram domains in a compatible manner. We show that hierarchical modeling is supported. We discuss the concept of icon loading, which is an important issue in the design of icon-based model libraries. The development is structured throughout with reference to the four levels of modeling abstraction introduced by the Twente research group.
Development of a Six-Component Miniature Force Sensor for Robotic Applications
Authors: Jin W. L. , Mote C. D. 
Published: July 2023

Abstract
A six-component miniature force sensor (5 × 5 × 5 mm3) is developed using micro-fabrication and conventional precision machining technologies. High sensitivity and high stiffness are obtained simultaneously with a novel silicon sensing element design. Fair agreement between predicted and measured sensitivities is obtained.
Adaptive Control Using Multiple Models and Model Weighting
Authors: Rajagopal A. , Krishnamurthy K. 
Published: July 2023

Abstract
A general methodology for the identification and control of dynamical systems with several operating environments and possessing a high degree of uncertainty is presented. Neural networks are used to create multiple models to capture the dynamics of the various environments of the system. Control is effected by combining these models by using an evolutionary strategy. The methodology is applied to the problem of controlling a two-link robotic manipulator in the presence of disturbances and varying load conditions. Simulated results presented show that the proposed methodology yields better results compared to the ones obtained by using a single model or by using multiple models but switching to and tuning the model with the smallest tracking error.
An Approach Using Neural-Fuzzy With Modified Fuzzy Associative Memory for System Identification
Authors: Chang Hsin-chi , Lu Wen F. 
Published: July 2023

Abstract
In this paper, a Neural-Fuzzy with modified fuzzy associative memory (NFFAM) approach is developed for the system identification. This approach contains two mechanisms: modified fuzzy associative memory (FAM) and neural-fuzzy. It combines the learning capability of the neural networks and the linguistic characteristic of fuzzy rules. The modified FAM is used to define the initial structure and initial parameters of the rule base, while neural-fuzzy is used to adjust the rules defined by modified FAM. The simulation results show that for a Mackey-Glass time series prediction problem, the proposed NFFAM itself only implements 61 fuzzy rules to simulate the system, and the learning rate is faster than the Back Propagation Neural Network (BPNN). Besides the advantages of a faster learning rate and self-organization, the NFFAM is a rule-based reasoning approach. Being able to recognize the characteristics of the system from rules was the reason for developing this approach.
Contact Transition Control of Nonlinear Mechanical Systems Subject to Unilateral Constraints
Authors: Pagilla Prabhakar R. , Tomizuka Masayoshi 
Published: July 2023

Abstract
In this paper, contact transition control of mechanical systems subject to unilateral constraints is presented. A systematic way is proposed for designing the control laws for unilaterally constrained mechanical systems. Three phases of motion (inactive, transition, active) are formulated depending on the activation/deactivation of the constraints. Our framework describes the complete behaviour of the mechanical system under the action of unilateral constraints. We propose stable control laws for all the phases of the system. Of special interest is the contact transition problem. During this phase the dynamics is discontinuous. Stability analysis of the transition phase is conducted using nons-mooth Lyapunov stability theory. The transition phase is shown to be exponentially stable. The proposed method is successfully implemented on robots interacting with an environment, and we present results of those experiments.
Stability Analysis of Healthy Greyhounds via Lyapunov Exponents
Authors: Marghitu Dan B. , Nalluri Prasad 
Published: July 2023

Abstract
This paper evaluated the applicability of a mathematical technique of computing Lyapunov exponents for nonlinear systems to describe and define normal greyhound gait. A commercially available video based, 2-dimensional motion analysis system was utilized to acquire kinematic data from healthy greyhounds being led at trot. The removal of noise from the time series data obtained from measurements was accomplished with B-spline wavelets. Lyapunov exponents of five normal subjects were computed from the kinematic data. For the steady state animal locomotion one of the Lyapunov exponents was always zero and all other exponents were negative. Lyapunov exponents provided a useful characterization of the given experimental data set.
A Proper Orthogonal Decomposition Approach to Coupled Structural-Mechanical Systems
Authors: Georgiou Ioannis T. , Schwartz Ira B. 
Published: July 2023

Abstract
This work applies the proper orthogonal decomposition method to identify the asymptotic dominant degrees-of-freedom of a parametrically driven pendulum coupled to a vertical linear viscoelastic rod. Most of the energy of the system is carried by one slow degree-of-freedom whenever the fundamental frequency of the rod is sufficiently larger than that of the pendulum. For certain ranges of physical parameters, the dynamics of the coupled system becomes very large, spreading the energy among many degrees-of-freedom.
Control of Two Coupled Pendula With Zero Energy Change
Authors: Quinn D. Dane 
Published: July 2023

Abstract
We study a system of two identical forced pendula, coupled with a linear torsional spring. Using the idea of energy transfer between the two oscillators, we derive a nonlinear control law to stabilize the in-phase motion. Trajectories of the controlled system are required to remain on the constant energy surface of the Hamiltonian.
Analysis of the Forced Response of Dry-Friction Damped Structural Systems Using an Efficient Hybrid Frequency-Time Method
Authors: Guillen J. , Pierre C. 
Published: July 2023

Abstract
The steady-state response to periodic excitation of dry friction damped structural systems is studied. The general model considered is a linear structure with one flexible dry friction damper connected to ground — representing, for example, a blade with an attached friction damper in a turbomachinery rotor stage. A full hysteretic model of the dry friction force is considered, which involves no further approximation of Coulomb’s law. Namely, the relative slip velocity at the frictional interface is taken to vanish when the damper is stuck, unlike the often-assumed piecewise linear relation between friction force and slip velocity. The solution procedure used is a hybrid frequency-time domain algorithm, which is largely based upon the incremental multi-harmonic balance method. The method is significantly improved by the use of several efficient numerical techniques, such as Fast Fourier Transforms and Toeplitz Jacobian Matrices. In addition, new features are developed to achieve the fast generation of frequency responses, namely, adaptive step size and line search algorithms for automatic sweeps in amplitude and frequency. The resulting solution procedure is highly performant and gives reliable and accurate results for a wide range of system parameters. It allows for the fast and automatic generation of steady-state frequency responses. Results are obtained for both a single-degree of freedom, dry friction damped system and for a beam with one friction damper attached. Interesting features of the non-linear response are revealed.
Bifurcation and Chaos in Parametrically Excited Contact Vibrations
Authors: Narayanan S. , Sekar P. 
Published: July 2023

Abstract
The rolling contact problem between two contacting cylinders is analysed. The contact force between the bodies is assumed to be given by the Hertzian contact law. The equation of motion is derived in nondimensional form which is nonlinear and contains harmonic parametric excitation terms induced by the surface corrugations and the relative rotation between the cylinders. The periodic solutions are obtained by a numeric-analytical algorithm based on FFT and Galerkin error minimization. An arc length based path following technique in conjunction with a stability analysis is used to obtain the response curves and the bifurcation points. Flip bifurcation boundaries are obtained for different values of surface waviness amplitude in a two dimensional parametric plane consisting of damping and rotational speed parameter. For low values of damping and high values of amplitude of surface waviness, the system exhibits chaotic behaviour attained through a period doubling route.
Self-Scheduled H∞ Controllers for Magnetic Bearings
Authors: Tsiotras Panagiotis , Mason Stephen 
Published: July 2023

Abstract
In this paper we present a design procedure for disturbance attenuation with internal stability of a rotor supported by magnetic bearings, over the whole interval of the rotor operating speeds. The nonlinear gyroscopic equations can be simplified to a set of linear, time-varying differential equations, owing to the linear dependence of the rotor speed in the plant dynamics. For rotors operating in high speeds, even small unbalanced masses can create large synchronous disturbances. To alleviate the forces produced due to imbalance the controller automatically balances the rotor for each operating speed. The proposed methodology addresses both the gyroscopic compensation problem due to change of the rotor speed as well as the automatic balancing problem. The approach is based on the recently developed theory of self-scheduled H∞ controllers. Owing to the linear dependence of the equations on the rotor speed, the computation of the controller can be done very efficiently using convex optimization and Linear Matrix Inequalities (LMIs).
Nonlinear Filtering of Signals Exhibiting Large Fluctuations in Strength
Authors: Jayasuriya Suhada , Langari Reza 
Published: July 2023

Abstract
Considered in this paper is the following filtering problem: Given a signal which has a certain frequency spectrum (|ω| ≤ Ω) and a wide range of strength over that spectrum including such low levels which may not be distinguishable from noise and high levels that could distort the signal due to, say, inherent nonlinearities in the sensors over those ranges, (i) would it be possible to identify the signal correctly?, and (ii) how could it be done? Proposed is a scheme in which the original signal is first distorted by a mono-tonic function and is then passed through an ideal low-pass linear filter resulting in a filtered version of the distorted signal. It is shown that the original signal may be uniquely recovered from the ultimate filtered version of the distorted signal.
The Modal Diagnostics of Rotors With Cracks
Authors: Goldman Paul , Bently Donald E. , Muszynska Agnes 
Published: July 2023

Abstract
This report provides insight into the synchronous response of a cracked multimodal rotor during transient processes of startups or shutdowns. The transversal crack on the rotor is treated as a structure singularity which provides an additional local flexibility and mass reduction. The influence of it on the global rotor behavior is estimated. The rotor lateral response synchronous component is investigated from the mode shape stand point. The results are formulated as suggestions for the vibrational diagnostics strategy improvements.
A Finite Element Method for Separable HRR Solutions in Bi-Material Systems
Authors: Zhang Ningsheng , Joseph Paul F. , Kaya Ahmet C. 
Published: July 2023

Abstract
Separablesingular eigensolutions at points of geometric and/or material discontinuity are determined by the finite element method. The method is applicable to n-material anisotropic elastic behavior as shown by Pageau et al. (1995), and to n-material isotropic power-law hardening behavior, including the case of complex eigenvalues for plane stress, as shown by Zhang and Joseph (1996a,b,c). Separable HRR solutions for the nonlinear problem are limited to cases whereall materials have the same hardening exponent. This paper demonstrates these capabilities with several examples that have relevance to ceramic coatings on metal substrates. The examples include the elastic case of a crack touching an isotropic-orthotropic interface, and several power-law hardening cases for bi-material systems. Both plane strain and plane stress solutions are considered.
Micromechanical Study of Particulate Reinforced Composites
Authors: Choi D. K. , Nomura S. 
Published: July 2023

Abstract
Particulate reinforced composites include functionally graded materials that are to be exposed to extremely high temperatures at one side and extremely low temperature at another side. In this paper, the steady-state temperature field in particulate reinforced composites is derived using the Green’s function expressed by a linear combination of the eigenfunctions for the given geometry and the boundary conditions. The trial functions that are used to construct the Green’s functions are those that warrant continuous temperature and heat flux across the material boundary (heat-flux-conserving trial functions). The solution by the proposed method is compared to the finite element solution for accuracy.
Micromechanical Edge Effects in Glass Matrix Composites
Authors: Tandon G. P. , Kim R. Y. , Dutton R. E. 
Published: July 2023

Abstract
This paper reports on our efforts to demonstrate the significance of free edge effects on the effective response of a unidirectional composite under combined thermal and transverse loading and to validate the predictions of an analytical model through the careful design and testing of composite specimens. Included in this study are the demonstration of potential failure modes and the predictions for the micromechanical stress fields which define damage initiation and the constituent energy release rates governing crack propagation within the constituents and along the interfaces. The theoretical predictions for damage development and propagation are in good agreement with the experimental measurements and observations and demonstrate the importance of free edge stresses in controlling damage initiation and subsequent response.
A Model for the Effusion of Water in Carbon Phenolic Composites
Authors: Sullivan Roy M. , Stokes Eric H. 
Published: July 2023

Abstract
A model is developed for the effusion of water in phenolic composites as the material is heated to moderate temperatures. The model is developed from the theory of the flow of gases through a porous media coupled with the thermodynamics of the evaporation of water from a condensed, binary mixture. The resulting model accounts for the evaporation of water from solid sites in the material to an internal pore network and then the subsequent flow of water vapor through the pore network. The mathematical theory is applied by simulating the effusion behavior of water in a thernogravimetric test. The results obtained from the model compared favorably with the thermogravimetric measurements. The results also showed a close correlation between the permeability of the material and the rate of evaporation of water from the solid sites.
An Approach to Characterize Nonlinear Viscoelastic Material Behavior Using Dynamic Mechanical Tests and Analyses
Authors: Golden H. J. , Strganac T. W. , Schapery R. A. 
Published: July 2023

Abstract
Traditional methods of viscoelastic material characterization have not been able to rapidly characterize nonlinear viscoelastic materials. Dynamic mechanical analysis has been a method in which only linear viscoelastic material properties are rapidly identifying. Herein, dynamic mechanical analysis is extended to provide a method of nonlinear characterization. The proposed method is based on an extension of Schapery’s nonlinear viscoelastic model to dynamic mechanical theory. The oscillatory loading during a dynamic test is accounted for by expanding the nonlinear viscoelastic model on stress. An experimental protocol is established and utilized in the characterization of thin film polyethylene for validation of the nonlinear dynamic mechanical theory.
Fatigue Damage Modeling and Life Prediction of Titanium Matrix Composites
Authors: Wang P. C. , Yang J.-M. , Mal A. K. 
Published: July 2023

Abstract
The evolution of microstructural damage during fatigue loading, which includes matrix cracking, interfacial debonding, and fiber fracture results in the progressive degradation of mechanical properties of the fiber-reinforced titanium matrix composites. A mechanism-based fatigue life prediction methodology was developed to simulate the evolution of fatigue damage, degradation of mechanical properties, and distribution of fatigue lives under various applied stress levels. The simulated matrix crack propagation rates, residual stiffness, residual tensile strength, and fatigue life are also correlated with experimental results.