bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Material Synergy for High-Performance Actuator Components
Authors: Adley J. , Jones M. , Stole S. , Perettie D. , Fox R. 
Published: January 2022

Abstract
The continuing magnetic disk drive storage industry goals of higher recorded data densities will require increases in tracks per inch (TPI) which will ultimately demand changes in designs/or materials. Rotary actuators represent one application whose configuration and material composition can influence disk drive performance through projected enhancements in tracking accuracy. Ceramic-metal composites allow specific component geometries to be altered to take advantage of the new material properties. This synergistic approach to design and materials allows a much greater improvement to the mechanical performance of actuator components than either material or design substitution alone would allow. This work describes both the fabrication of Aluminum-Boron Carbide reacted metal matrix materials and their practical implementation with specific design strategies developed through numerical models to achieve high performance head/suspension/actuator structure assemblies. Improvements in the overall frequency response behavior of the head support structure are contrasted with equivalent example configurations of conventional materials through simulations which have been experimentally verified.
Implementing Both a Disturbance Observer and a Repetitive Controller for Track Following in a HDD With Emphasis on the Disturbance Observer Design
Authors: Mok Chun-Ho Michael , Bickel Robert J. , Saitoh Mitsuhide , Okuya Hiroaki 
Published: January 2022

Abstract
It is important to provide good tracking for a hard disk drive actuator, since good tracking can allow us to minimize the track pitch and thus increase the data storage capacity of a hard disk drive. Repeatable disturbances, such as disk vibration, and non-repeatable disturbances, such as shocks, are major problems in tracking control of a hard disk drive. It has been shown that a combination of a disturbance observer and a repetitive controller can effectively solve these two problems. In this research, these two controllers are implemented on a real computer hard disk drive, and design of the disturbance observer is emphasized.
Solution of the One Dimensional Foil Bearing Problem Using Matched Asymptotic Expansions
Authors: Renshaw Anthony A. 
Published: January 2022

Abstract
The foil bearing problem describes a longitudinally translating, flexible, tensioned, magnetic tape that rides on a thin film of air as it partially wraps around a stationary recording head. Equilibrium and linear, harmonic vibration analyses of the one dimensional formulation of this problem are performed using matched asymptotic expansions including the effects of tape bending stiffness, compressibility, and molecular slip as regular perturbations. Simple analytic expressions are derived for the nominal film thickness and the vibration frequencies of the free spans. These expressions give designers sharper insight into the usefulness of potential design changes that normally would be evaluated using extensive numerical computations.
Dynamics for Micromachined Silicon Dual Negative Pressure Slider Bearings With an Integrated Microsuspension Mechanism in Proximity Magnetic Recording
Authors: Tagawa Norio , Mori Atsunobu , Kajitani Hiroshi , Hashimoto Masanobu 
Published: January 2022

Abstract
This paper describes head/disk interface dynamics for micromachined silicon dual negative pressure slider bearings with an integrated microsuspension mechanism which we proposed, at steady state flying in proximity magnetic recording. The authors first indicated the analitycal model for air bearing dynamics of dual structure mother ship slider mechanisms, and the advantages of this mechanisms were discussed from the dynamics points of view, compared with conventional flying head slider mechanisms. Furthermore, the effects of stiffness and damping characteristics of an integrated microsuspension mechanism on mother ship slider system dynamics were also analyzed numerically. Considering those numerical simulation results, optimum design method for microsuspension gimbals was established to suppress the coupled vibration between primary and secondary sliders, caused by secondary slider’s piggy-backed structure. It became clear that micromachined integrated microsuspension mechanisms have to be designed not only from the static and silicon micromachined process points of view, but also from the mother ship slider dynamics points of view, in order to achieve head/disk interface reliability in high density proximity magnetic recording.
Optimal Shape Design of Three Dimensional MEMS With Applications to Electrostatic Comb Drives
Authors: Ye Wenjing , Mukherjee Subrata 
Published: January 2022

Abstract
A methodology for solving inverse problems in Micro-electromechanical (MEM) systems is proposed in this paper. Design of variable shape electrostatic comb drives (shape motors), in order to obtain desired force profiles, is presented as an application of the general methodology. This analysis includes simulation, sensitivity analysis and optimization.
A comb drive is one of the most important microactuators in MEM systems. In a standard comb drive, the capacitance varies linearly with displacement, resulting in an electrostatic driving force which is independent of the position of the moving fingers (relative to the fixed ones) except at the ends of the range of travel. It is of interest in some applications to have force profiles such as linear, quadratic or cubic. Such shaped comb drives could be useful, for example, for electrostatic tuning or to get actuators with longer ranges of travel than those of standard comb drives.
The present paper addresses the issues of simulation, sensitivity analysis, and then design (inverse problem) of comb drives with variable height profiles. Three-dimensional simulations of the exterior electrostatic field, and the resultant forces on the comb drive, are carried out with the exterior, indirect, boundary element method. Following direct simulation, sensitivity analysis is carried out by the direct differentiation approach. The variable of interest is the driving force while the design variables are parameters that determine the shape of the moving fingers. Next, an inverse problem is posed as follows: determine the height profile of the moving fingers such that the driving force is a desired function of the displacement of the comb drive. Comb drives of appropriate shapes, that produce desired force profiles, are obtained by this approach. Numerical results are given for shape motors that produce linear or cubic force profiles as functions of travel. The optimization code “E04UCF”, from the NAG package, is used for this phase of the work.
Fatigue Crack Propagation Under Variable-Amplitude Load: Part I — A Deterministic State-Space Model
Authors: Patankar Ravindra , Ray Asok 
Published: January 2022

Abstract
The two-part paper addresses modeling of fatigue crack damage in metallic structures for on-line diagnostics and health monitoring of operating machinery. This paper which is the first part presents a dynamical model of fatigue crack propagation in the deterministic state-space setting based on the crack closure concept under cyclic stress excitation of variable-amplitude loading where the model state variables are crack length and crack opening stress. The second part which is a companion paper extends the deterministic model to formulate a stochastic state-space model of fatigue crack propagation under both constant-amplitude and variable-amplitude load. The state-space model is capable of capturing the effects of stress overload and underload on crack retardation and sequence effects, and the model predictions are in fair agreement with experimental data on the 7075-T6 aluminum alloy. Furthermore, the state-space model recursively computes the crack opening stress via a simple functional relationship and does not require a stacked array of peaks and valleys of stress history for its execution. Therefore, savings in both computation time and memory requirement are significant. As such, the state space model of fatigue crack propagation allows real-time execution of decision algorithms for diagnostics, risk analysis, and life prediction on inexpensive platforms such as a Pentium processor.
Controls Education on the WWW: Using MATLAB for Control Design, Simulation and Visualization
Authors: Tilbury Dawn , Messner William 
Published: January 2022

Abstract
The rapid growth of the World Wide Web (WWW) has given educators unprecedented opportunities to provide information to students not only within their own classes, but also around the world. We are developing software which uses the WWW to distribute tutorials to students studying control systems. These tutorials provide students with information from diverse sources in a useful form when and where they need it. Animations are included so students can simulate the control systems which they design and can visualize their results on a physical system model.
Finger Touch Sensors Using Instrumented Nails and Their Application to Human-Robot Interactive Control
Authors: Mascaro Stephen , Chang Kuo-Wei , Asada H. Harry 
Published: January 2022

Abstract
A new type of touch sensor for detecting contact pressure at human fingertips is presented. Fingernails are instrumented with micro LEDs and photodetectors in order to measure changes in the nail color when the fingers are pressed against a surface. Unlike traditional electronic gloves, in which sensor pads are placed between the fingers and the environment surface, this new sensor allows the fingers to directly contact the environment without being impeded by any object between the finger and the environment. The finger force is detected by measuring changes in the nail color; hence the sensor is mounted on the nail side rather than the finger pad. The technique termed “photoplethysmography” is used for measuring the nail color. A prototype sensor is built and tested, and is used to create a new “free-fingered” electronic glove. The new sensor system is applied to the interface of a cooperative human-robot control system. The information acquired from the finger touch sensors is interpreted within the context of a given task description, and the robot motion is coordinated with the human motion based on the interpreted human behavior. This method is applied to a collaborative task in which a robot equipped with a powered screwdriver assists the human by observing the human hand assembling cable connectors.
Inertial Force Feedback for a Locomotion Interface
Authors: Christensen Robert R. , Hollerbach John M. , Xu Yangming , Meek Sanford G. 
Published: January 2022

Abstract
Inertial force feedback was implemented for a locomotion interface, the Treadport. The purpose was to make locomotion on the Treadport more like locomotion on the ground. The feedback force was applied to the user by a mechanical tether. Psychophysical experiments were performed to determine whether users preferred inertial force feedback to other types of control for the case of accelerating from rest. The results showed that all eleven subjects preferred inertial force feedback when compared to a spring force or no force.
Feeling Through a Probe
Authors: Lederman Susan J. , Klatzky Roberta L. 
Published: January 2022

Abstract
Subjects performed a series of haptic perceptual tasks using rigid probes or the bare finger (control). In Part I, they made roughness judgments of raised-dot textured surfaces using small or large rigid probes or the bare finger. Performance was compared using two different psychophysical tasks: magnitude-estimation (Experiment 1: “how rough?”) and roughness comparison (Experiment 2: “which is rougher?”). In Part II, performance with a small probe versus the bare linger was compared in a haptic object identification task (Experiment 3). In Part III, we discuss the applied implications of this work. Overall, our findings indicate the viability of vibratory-based coding of roughness through a rigid link and have implications for designing haptic interfaces for teleoperator and virtual-environment systems. In contrast, a substantial decline in haptic object identification highlights one limitation of using haptic interfaces that effect single-point contact.
The research reported in this paper is drawn from a comprehensive research program that focuses on feeling the world with a probe, (see also Lederman & Klatzky, 1997; in press; in preparation; Klatzky & Lederman, in press). The work addresses fundamental research on psychophysical issues concerning how human roughness perception and common object identification work when the hand contacts the external world via an intermediary link. Such questions are important to address inasmuch as tool use is such a common aspect of our manual interactions with the world. We also explore the implications of this research for the development of haptic interfaces for teleoperator and VE systems that employ point contact.
Three Degree of Freedom Haptic Interface for Precision Manipulation
Authors: Adelstein B. D. , Gayme D. F. , Ho P. , Kazerooni H. 
Published: January 2022

Abstract
We are developing a new portable force-reflecting haptic interface based on the three degree of freedom (dof) kinematic architecture introduced by Adelstein, Ho, and Kazerooni (1996). This new interface is intended specifically to emulate dynamic manual interaction with precision hand tools and allow single-point probing of simulated mechanical environments.
Haptic Interaction Using Magnetic Levitation
Authors: Berkelman Peter J. , Hollis Ralph L. 
Published: January 2022

Abstract
We have developed a system which uses magnetic levitation for high-fidelity haptic interaction with a physically-based realtime simulated environment. With this device, the user grasps a floating rigid body to interact with the system. The dynamics of the grasped handle are controlled so that the user directly feels the motion, shape, solidity, and texture of objects in the simulated environment as if manipulated using a rigid tool. This is the first magnetic levitation device designed specifically for high-performance haptic user interaction.
Cable-Suspended Haptic Interface
Authors: Williams Robert L. 
Published: January 2022

Abstract
A cable-suspended haptic interface (CSHI) concept is presented. The goal is to create an input/output device to provide six-degree-of-freedom (dof) wrench (force and moment) feedback to a human operator in virtual reality or remote applications. Compared to commercially-available haptic interfaces, the present concept is driving for lighter, safer, crisper, more dexterous, and more economical operation. The CSHI concept is presented, along with the required mathematical transformations for use of the device.
Compliant Micromanipulator Design for Scaled Bilateral Telemanipulation of Small-Scale Environments
Authors: Goldfarb Michael , Speich John E. 
Published: January 2022

Abstract
Compliant mechanism design enables the development of revolute joint manipulators without the backlash or Coulomb friction that impede precision position and especially force control. Conventional approaches to compliant mechanism design impose several limitations, however, such as severely limited ranges of motion, poor kinematic behavior, and significant deformation under multi-axis loading. The authors have developed a new type of compliant mechanism that enables the implementation of spatially-loaded revolute joint manipulators with well-behaved kinematic characteristics and without the backlash and stick-slip behavior that would otherwise impede precision control. The design, which is based upon a unique flexure joint, has been incorporated into a small-scale three degree-of-freedom manipulator with an approximately spherical workspace two centimeters in diameter. Data from the small-scale manipulator demonstrates that positioning resolution is limited by digital quantization and sensor noise, and not by more fundamental physical limitations, such as backlash or Coulomb friction.
Stability and Performance of Haptic Displays: Theory and Experiments
Authors: Adams Richard J. , Moreyra Manuel R. , Hannaford Blake 
Published: January 2022

Abstract
In haptic simulation, a human operator kinesthetically explores a virtual environment. To achieve a virtual sense of touch, the human interacts with an active mechanical device, called a haptic display. This paper presents an approach to guarantee that this physical man-machine interface remains stable, while maximizing performance. The key element in ensuring stability is the virtual coupling network, an artificial link between the haptic display and the virtual environment. Considerations of structural flexibility in the haptic device are included in the derivation of design criteria for such networks. Solutions for both the impedance and admittance models of haptic interaction are included. Numerical and experimental results for a two degree-of-freedom haptic display demonstrate the effectiveness of the proposed approach in achieving performance and stability in haptic simulation.
Minimum Mass for Haptic Display Simulations
Authors: Brown J. Michael , Colgate J. Edward 
Published: January 2022

Abstract
This paper addresses the issue of providing stability guarantees during the implementation of multibody simulations for haptic display. Within the framework of the virtual coupling, we discuss the passivity of the haptic display. Previous work has established that, if the numerical methods used in the virtual environment are discrete time passive, it is possible to decouple the stability of the device from the virtual environment simulation. In the present work, we prove that discrete time passive operators must be implicit, making them unlikely candidates for real time implementation. Given restrictions on environment parameters, however, passivity can sometimes be preserved even when using explicit numerical methods. An important benchmark simulation is that of a point mass, and restrictions take the form of a minimum mass that can be simulated passively. This minimum mass is derived for several simple numerical integrator-virtual coupling pairs.
Effects of Shear Stress in Teletaction and Human Perception
Authors: Moy G. , Fearing R. S. 
Published: January 2022

Abstract
Ideally, a tactile stimulator presents information through control of surface normal stress and surface shear stresses. Psychophysical experiments measured the effect of shear stress information on the perception of static stimuli applied normal to the surface. Wax gratings in two different orientations and various spatial frequencies were used as stimuli. Elastic layers, representing the anti-aliasing filter on a tactile display, were placed over the stimuli. Using an elastic layer which reduces shear stress transmission improved perception compared to standard elastic layers. Spatial resolution differences due to different elastic layers are explained by modulation indices determined from the predicted sub-surface strain using an elastic half-plane model.
Controller Design Using Linear Programming
Authors: Keel L. H. , Bhattacharyya S. P. 
Published: January 2022

Abstract
This paper deals with the problem of designing a feedback controller, of a prescribed order, for a fixed plant, as well as for an uncertain family of plants containing parameter uncertainty, so that stability, robust stability and robust performance are attained. The desired closed loop specifications considered here are given in terms of a target closed loop system. In general point targets are generically unattainable with a fixed order controller. By enlarging the target from a fixed point set to an interval set the solvability conditions with a fixed order controller are relaxed and a solution is enabled. It is shown that it is possible to devise a simple linear programming problem formulation that attempts to meet the desired closed loop specifications. Both transfer function and state space approaches are described. Numerical examples will be given in the presentation.
Utilizing Loop Interaction in Multivariable Regulating Systems
Authors: de Bedout Juan M. , Franchek Matthew A. 
Published: January 2022

Abstract
Presented in this paper is a controller design methodology for a class of square multivariable regulating systems that utilizes loop interaction to achieve output regulation of ill-specified systems. This is accomplished by designing off-diagonal controllers to donate control effort to loops that cannot meet their performance requirements. The class of performance specifications considered are actuator saturation limits and output tolerances. The proposed controller design methodology is a frequency domain approach based on sequential loop closure that incorporates all control elements of previously closed loops into subsequent loop designs. The design of the off-diagonal controllers takes advantage of this recursive technique by isolating the effects of each off-diagonal controller on subsequent loops. The restrictions on the class of multivariable systems are that it must be invertible and the inverted plant must be stable.
Synthesis of an H∞ Controller With Preview Compensation
Authors: Choi Chintae , Tsao Tsu-Chin 
Published: January 2022

Abstract
An optimal preview controller based on the discrete-time H∞ control is presented. The preview controller is synthesized by considering the bounded unknown disturbances as well as pre-viewable commands and disturbances. The controller derivation procedure is analogous to the LQ-based scheme. The designed preview gain matrix has a similar structure as the LQ-based one. As the infinity norm γ of the transfer function matrix tends to ∞, the preview gains obtained by H∞ control method approach to the gains by the LQR. The LQ-based preview gains are verified to be subsets of the H∞-based preview gains.
Modular Control for Machine Tools: Cross-Coupling Control With Friction Compensation
Authors: Chen B.-C. , Tilbury D. M. , Ulsoy A. G. 
Published: January 2022

Abstract
In this paper, we consider the combination of two different types of auxiliary control modules applied to a two-axis machining system. It is known that a cross-coupling control algorithm can reduce the contour error of a two-axis system, and that friction compensation can reduce positioning errors in machining systems. Here, we address the question of how the overall performance of the system is affected when both types of control are applied at the same time. Preliminary results indicate that the performance improvement is multiplicative. That is, if the error is reduced by a factor of Pcc for cross-coupling control, by a factor of Pfc for friction compensation, and by a factor of Pcc,fc when both are applied simultaneously, then Pcc,fc ≈ Pcc · Pfc. Simulation and experimental results are presented.
High Speed Contouring Control Algorithm for CNC Machine Tools
Authors: Erkorkmaz Kaan , Altintas Yusuf 
Published: January 2022

Abstract
A method of estimating contouring error and its minimization using a control law are presented. The contouring error is estimated in real time by projecting the actual tool position on the desired tool path. Sudden deviations in the tool path are considered in evaluating the contouring error, which is decoupled in the axis directions. The tracking error in each axis is first minimized by cascaded zero phase error tracking and pole placement control laws. In addition to axis tracking error, the components of contouring error in each axis are also regulated with PID controllers. Smoothing the axis position commands further enhances the overall system performance, and avoids discontinuities in the velocity and acceleration values in discrete time domain. The proposed method is compared to other methods suggested in literature (ZPETC, CCC) and its effectiveness is verified in simulations and with experiments, performed on a linear d.c. motor driven high speed x-y table.