bluuebunny/crossref_metadata_2025_split huggingface dataset:
3-Dimensional, Single Marker, Gait Analysis System
Authors: Weir Richard F. ff. 
Published: January 2022

Abstract
There is a wealth of data that can be obtained by recording the 3-D position of a single marker at the approximate level of the body center of mass (BCOM) during walking. Evolving the design of a previous 1-D single marker gait system (Weir & Childress, 1997) we are developing a portable, easy-to-use, real-time system which will measure the position of the BCOM during walking in 3-D. This system will measure instantaneous anterior-posterior, medial-lateral, and vertical displacements of the BCOM. We plan to use these data to measure and estimate gait parameters and symmetry indices.
Development of In-Process Skew and Shift Adjusting Mechanism for Paper Handling
Authors: Shirasawa Satoshi , Otsuki Haruaki 
Published: January 2022

Abstract
We have developed a new type of paper handling mechanism to adjust skew and shift which may cause paper jam. The developed mechanism is compact, highspeed, highly robust, and capable of in-process adjustment of large skew and shift. Until now, in order to adjust skew and shift in-process, the conventional adjusting mechanism is able to adjust either skew or shift and even if it is able to adjust both, it does not have sufficient reliability. To solve this problem, the proposed mechanism uses a ball-actuator as an adjusting mechanism. By clipping paper by two free rotating balls and controlling the ball rotation, the developed mechanism is able to control skew and shift of clipped paper. We estimated performance of the developed mechanism and concluded that it is possible to construct an adjusting mechanism to meet the skew and shift requirements.
Free Vibration and Stability of a Rotating Disk-Spindle System
Authors: Sathe Pushkaraj J. , Parker Robert G. 
Published: January 2022

Abstract
This work examines the free vibration and stability of a rotating flexible disk-spindle system. The extended operator formulation (Parker, 1997) is exploited to discretize the system using Galerkin’s method. The coupled vibration modes of the system consist of disk modes, in which the disk dominates the system deformation, and spindle modes, in which the spindle dominates the system deformation. Both the natural frequencies and vibration modes are strongly affected by disk flexibility. If the membrane stresses associated with disk rotation are neglected then the system exhibits flutter instabilities, but these instabilities are not present when membrane stresses are included. Natural frequency veering between disk and spindle frequencies is prominent at low speeds and substantially affects the spectrum and stability. No veering is observed at high speeds where rotational stress stiffening diminishes disk-spindle coupling and causes the natural frequencies to converge to those of a rotating spindle carrying a rigid disk. Changes to the vibration modes are examined in terms of a strain energy ratio measuring the contribution of the disk strain energy to the total modal strain energy.
Trends and Mechanical Issues in Optical Disk Drives
Authors: Lee Seung-Yop , Kim Sookyung 
Published: January 2022

Abstract
Recent trends and the effect of mechanical vibrations in optical disk drives are reviewed in this paper. The transition from CD drives to high density DVD drives and the development of writable optical disk drives require tighter mechanical tolerance. The demand for faster access time and higher data transfer rate also leads to critical mechanical problems to limit the tracking and focusing servo performances. The current mechanical issues in the optical disk drives and various technologies to overcome the mechanical problems are introduced. Vibrations of disk-spindle system, actuator and suspension designs of the optical pick-up, and general mechanical designs for the fast and stable access mechanism are considered.
Simultaneous Determination of Temperatures, Heat Fluxes, Deformations, and Tractions on Inaccessible Boundaries
Authors: Dennis Brian H. , Dulikravich George S. 
Published: January 2022

Abstract
A finite element method (FEM) formulation for the detection of unknown steady boundary conditions in heat conduction and linear elasticity and thermoelasticity continuum problems is presented. The present FEM formulation is capable of determining displacements, surface stresses, temperatures, and heat fluxes on the boundaries where such quantities are unknown or inaccessible, provided such quantities are sufficiently over-specified on other boundaries. Details of the discretization, linear system solution techniques, and sample results for 2-D problems are presented.
A Method for Defining Gaussian Probability Densities for Forward Modeling in Finite Dimensions Using the Method of Tarantola
Authors: Clutz Christopher J. R. , Maniatty Antoinette M. 
Published: January 2022

Abstract
The inverse problem of recovering an unknown boundary function given some information about the (interior) solution is considered. It is assumed that the forward problem is governed by a linear partial differential equation (PDE) and that homogeneous boundary conditions exist on the rest of the boundary. A method developed by Tarantola (Tar87) is used which is based upon statistical inference on finite dimensional random vectors. Within this framework, a method for constructing Gaussian probability density functions which model the forward problem is proposed.
Identification of the Friction Coefficient for Steady and Unsteady Shallow-Water Flows
Authors: Soulaimani Azzeddine 
Published: January 2022

Abstract
This work presents some recent results on the solution of shallow-water flows using the finite element method and the optimal control method for distributed systems. The objective is to identify the friction coefficient for steady and unsteady flows, such as the numerical solution is close to the measurement data. We investigate the following aspects: the finite element discretization, the regularization of the cost function and the solution algorithms. Several benchmark tests are presented.
A Singular Perturbation Approach for Modeling Differential-Algebraic Systems
Authors: Gordon Brandon W. , Liu Sheng , Asada Haruhiko 
Published: January 2022

Abstract
Dynamic systems described by an implicit mixed set of Differential and Algebraic Equations (DAEs) are often encountered in control system modeling and analysis due to inherent constraints in the system. A key difficulty in control and simulation of DAE systems is that they are not expressed in an explicit state space representation. This paper describes a general approach based on singular perturbation analysis for adding fast dynamics to a system of DAEs so that they can be expressed in an explicit state space form. Conditions for asymptotic convergence and approximation methods are investigated. The approach is illustrated for a model of a two-phase flow heat exchanger.
“Soft” Real-Time Applications Under Windows NT™
Authors: Mattern Duane 
Published: January 2022

Abstract
The Microsoft® Windows NT™ operating system is inappropriate for “hard” real-time applications that require a deterministic response as might be required in a closed-loop control system where safety is an issue. There are third party development packages that extend NT so that it can be used in a “hard” real-time system. These tools cost several times more than the cost of the PC hardware and this is too expensive for most educational purposes. An example of how “soft” real-time applications can be run under Windows NT using only the Visual C compiler is presented in this article. The multimedia timer and the high performance counter are used in the example to provide a user mode “pseudo-interrupt”. The example is an animated, second order, spring-mass-damper system with a frame time of 25 milliseconds. A circular buffer is used for data storage. The example program can be modified for other “soft” real-time applications and access to the source code is provided.
Magnetic Levitation Testbed for Controls Education
Authors: Craig Kevin , Kurfess Thomas , Nagurka Mark 
Published: January 2022

Abstract
This paper describes a magnetically levitated testbed for use in undergraduate and graduate controls education. Key components of the testbed include an electromagnetic coil to create the magnetic field, a ferrous object for levitation, a position sensor for height determination, and a controller for feedback adjustment of the coil current. In this paper the unit’s design, development, and use in educational arenas are discussed.
Display of Friction in Virtual Environments Based on Human Finger Pad Characteristics
Authors: Nahvi A. , Hollerbach J. M. , Freier R. , Nelson D. D. 
Published: January 2022

Abstract
A friction display system is proposed for virtual environments. Since a user’s fingertip is often placed inside a ring or thimble of a haptic interface, the finger pad cannot move relative to the finger structure as freely as it would move in the real world. Thus, it is necessary to imitate the real world movement of the human finger pad in the virtual environment. This paper quantifies the frictional properties of the human finger pad on 9 subjects by simultaneously recording force and movement of the finger pad when it rubs against a rigid plate. Results of such tests and implementation in a virtual environment are reported.
Resolution of Virtual Grating Orientation With 2-DOF and 3-DOF Force Feedback Systems
Authors: Weisenberger Janet M. , Krier Michael J. , Rinker Martha A. 
Published: January 2022

Abstract
The present study describes experiments comparing human observers’ ability to resolve the orientation of grating stimuli presented on a 3-DOF haptic interface (PHANToM) and a 2-DOF haptic interface (Immersion IE2000 joystick). Although the force renderings for the two devices are of necessity quite distinct, both yield surprisingly credible percepts of surface texture. Accordingly, resolution for sinusoidal gratings (3-DOF device) and “square-wave” gratings (2-DOF device) was measured as the minimum spatial period required to determine which of two grating orientations had been presented. For the 3-DOF device, this ability was tested for a range of grating amplitudes. For the 2-DOF device, a range of damping constants was employed. Pilot results showed better performance for the 2-DOF device, most likely attributable to the sharp delineation of “edges” for the gratings presented, as compared to the “edgeless” sinusoidal gratings presented on the 3-DOF device. In addition, observers reported a number of interesting perceptual phenomena when stimuli were close to threshold.
The Future of Robust Control Engineering
Authors: Nwokah O. D. I. 
Published: January 2022

Abstract
The field of mechanical systems is viewed within and as a subset of general mechanical and electromechanical systems design. Thus, it should address issues of modeling, analysis, measurement and control of complex mechanical systems. Mechanical engineers in particular are comfortable with design theories only if they can validate them experimentally. Furthermore, any newly suggested methodologies must seek to close some technological deficiency gap between what engineers currently do, and what they would like to do, otherwise engineers would not be inclined to buy into the new methodologies. This calls for a metric to measure such a gap. Although control theory is a very mature field, only a relatively small subset of this theory has been found most useful by design engineers. On the other hand it is often the case that some methodologies are discovered by design engineers and in general use before a complete scientific justification for all of its aspects are delineated. While most of the available theory is linear, almost all mechanical systems are nonlinear.
In this paper, we examine the future impact of modeling as well as information technology on the design and control of mechanical systems. It is argued that developments in computer technology and in modeling will have more influence on the future of mechanical systems than corresponding developments in control theory. However, domain specific control theories will emerge, and should prove more significant than control theories of “everything.” The future lies in the smart integration of modeling, computer technology, engineering design and targeted control theory.
Mechatronics in University and Professional Education: Is There Anything Really New Here?
Authors: Craig Kevin 
Published: January 2022

Abstract
Mechatronics is the synergistic combination of mechanical engineering, electronics, control systems and computers. The key element in mechatronics is the integration of these areas through the design process. The essential characteristic of a mechatronics engineer and the key to success in mechatronics is a balance between two sets of skills: modeling / analysis skills and experimentation / hardware implementation skills. Synergism and integration in design set a mechatronic system apart from a traditional, multidisciplinary system. So the answer is YES! There is something new here — in the way mechanical engineers are expected to design and in the way professors must now teach design!
This paper describes the undergraduate program in mechatronics at Rensselaer, i e, two senior-elective courses, Mechatronics (fall semester) and Mechatronic System Design (spring semester), and in particular, the integration of the theory covered in lectures with the laboratory exercises. The hardware systems used in both courses are described. Also discussed are observations from conducting professional training in mechatronics both in industry and for the ASME Professional Development Program.
Controllers or Components: Deciding What (and What Not) to Teach in Mechatronics Courses
Authors: Carryer J. Edward 
Published: January 2022

Abstract
This paper examines the breadth of the field of Mechatronics in the context of determining appropriate content and processes for Mechatronics courses. Issues addressed include the aspects of a uniquely Mechatronics course and the impact of student background, sub-domain of focus and curricular integration on the content of Mechatronics courses. It will be useful for those seeking guidance on appropriate content and the design of new Mechatronics courses. The paper should also prove useful to those involved in evaluating the structure and content of existing courses for the purpose of their improvement.
Meeting Industrial Needs in Mechatronics and Control
Authors: Auslander David M. 
Published: January 2022

Abstract
Widespread use of embedded computing in mechanical and other physical systems has lead to a need for new skills and attitudes on the part of engineers who are leaders and central participants in projects that lead to such products. In this essay I attempt to delineate that skill set, thereby identifying many of the subfields associated with mechatronics. The intent is to provide background for use both in design of curricula for educational institutions interested in mechatronics and control and to focus on research areas that will lead to advances in the art of mechatronics.
A Finite Element Model of Thermally Induced Angular Contact Spindle Bearing Loads
Authors: Gibson Alex O. , Stein Jeffrey L. 
Published: January 2022

Abstract
Thermally induced bearing loads have long been recognized as a key factor impacting the reliability and performance of machine tool spindle systems. This is particularly true for reconfigurable machine tool spindles which may experience a wide range of external loads, processes and spindle speeds. The models of thermally induced bearing load which have been developed thus far have calculated the thermal expansion of the spindle’s components using a classical solution that assumes the spindle is a circular cylinder of infinite length and that the temperature within the cylinder only varies in the radial direction. While this approach to calculating the thermal expansion provides reasonably accurate predictions of the bearing load if the thermal gradients in the axial and radial directions are small, it can result in large errors in the calculated bearing load if the thermal gradients within the spindle become large. The purpose of this paper is to present a new model of thermally induced spindle bearing load that uses a finite element model to calculate the thermal expansion of the spindle components. The model includes the thermally and mechanically induced spindle bearing loads in a back to back angular contact bearing pair that are due to radial and axial thermal expansion as well as the centrifugal forces and moments within the bearings. Simulation results are used to compare and contrast bearing load predictions that are based upon both a finite element and a classical thermal expansion calculation. The results demonstrate that the bearing load predictions based upon the classical thermal expansion calculation substantially under predict the bearing load as the heat load, due to increasing spindle speeds, is increased. As these errors in the predicted bearing load may be high enough to alter important design decisions, it is concluded that a finite element, or equivalent, thermal expansion calculation be used in future thermally induced bearing load models unless the thermal gradients within the spindle are known to be small.
Intelligent Agile Line Boring Station
Authors: Pasek Zbigniew J. , Szuba Phil 
Published: January 2022

Abstract
This paper describes efforts leading to the development of a precision, agile line boring station for machining of long bores in automotive applications. A new concept of a “smart” line boring tool is described. The tool is equipped with an on-line compensation mechanism, relying on sensing and intelligence built into the tool itself, for real-time correction of the boring process yielding increased precision. The tool body contains a number of sensors (e.g., laser with multiple detectors and strain gages) and the necessary instrumentation. Using sensor signals, an onboard computer controls the motions of the tool-tip actuated by a mechanism powered by a piezoelectric actuator. To supplement the advantages provided by the “smart” tool, a prototype agile line boring machine was developed. The design integrates multiple new concepts of mechanical structure of the machine with an intelligent controller. Open structure of the controller enabled integration of several error compensation functions enhancing machining precision.
Optimal Velocity Estimation of Slowly Moving Systems With Quantized Position Output
Authors: Jacobsen Michael P. , Tsao Tsu-Chin 
Published: January 2022

Abstract
Feedback control systems and many manufacturing processes can benefit from precise velocity information, although direct measurement of linear velocity is often impractical and/or costly. The accepted procedure of inferring velocity from quantized position measurements can in some instances yield noisy and inaccurate estimates. This paper proposes an optimal velocity estimation scheme incorporating measured acceleration data for use in slowly moving systems. Simulation and experimental results demonstrate improved low speed velocity estimation compared to traditional methods. The optimal velocity feedback is also shown to decrease overshoot in a closed-loop implementation.
Frequency Based Nonlinear Controller Design for Regulating Systems Subjected to Time Domain Constraints
Authors: Glass John W. , Franchek Matthew A. 
Published: January 2022

Abstract
Presented is a nonlinear controller design methodology for a class of regulating systems subjected to quantitative time domain constraints. The output performance specification is an allowable time domain tolerance and the system experiences actuator saturation. The controller design is executed in the frequency domain and is applicable when the frequency response of a linear design cannot satisfy the gain and phase characteristics required by quantitative time domain specifications. A describing function (DF) approach, automated by the Volterra Series, facilitates the nonlinear controller design. The resulting gain and phase distortions associated with the DF of the dynamic nonlinear element are used to achieve the desirable open loop gain and phase characteristics identified by the time domain constraints. The design methodology is illustrated on the idle speed control of a Ford 4.6L V-8 fuel injected engine. The engine input is the by-pass air valve and the regulated output is engine speed. The power steering pump generates the nonmeasureable external torque load.
Desired Compensation Adaptive Robust Control
Authors: Yao Bin 
Published: January 2022

Abstract
A desired compensation adaptive robust control (DCARC) approach is proposed for nonlinear systems having both parametric uncertainties and uncertain nonlinearities. DCARC of nonlinear systems transformable to a normal form is first solved. A DCARC backstepping design is then developed to overcome the design difficulties associated with unmatched model uncertainties. The proposed DCARC has the unique feature that the adaptive model compensation part depends on the reference trajectory and parameter estimates only. Such a structure has several implementation advantages. First, the regressor in the model compensation part can be calculated off-line and on-line computation time may be reduced. Second, the interaction between the parameter adaptation and the robust control law is minimized, which may facilitate the controller gain tuning process considerably. Third, the effect of measurement noise is minimized since the regressor does not depend on actual measurements. As a result, a fast adaptation rate may be chosen in implementation to speed up the transient response and to improve overall tracking performance. These claims have been verified in the comparative experimental studies for the control of robot manipulators.
An Active, Surface Wave Bed for Transporting Humans and Elastic Bodies
Authors: Spano Joseph , Asada Haruhiko H. 
Published: January 2022

Abstract
Bedridden patients and elastic bodies are transported by generating surface waves on an active bed. The motion of each node on the bed surface is coordinated such that it follows a circular trajectory with a certain phase lag from its adjacent nodes. This surface wave actuation allows a bedridden patient to move freely while lying comfortably upon the bed. First, the basic properties of surface waves are investigated. Technical requirements for transporting humans and elastic bodies are obtained. To assure comfort during transport, the stress distribution at the contact area is analyzed based on elasticity theory. Transport speed and efficiency are analyzed as well. A proof-of-concept prototype is designed, built and tested. It is demonstrated that a human is moved along the bed surface while lying on the bed.