bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent Progress in Mixed Objective Control Synthesis With ℓ1 and ℋ2 Norms
Authors: Salapaka Murti V. , Khammash Mustafa , Dahleh Mohammed 
Published: January 2022

Abstract
In this paper recent progress in the design of controllers that meet multiple criteria is reviewed. It is well-known that optimization with respect to a single measure may compromise other important closed-loop properties. The ℋ2 norm has been successfully used to design controllers with good nominal performance, and ℓ1 has been very effective in addressing time-domain and robustness requirements. Therefore, the ℋ2/ℓ1 robust synthesis problem combines the features of these two norms and can be very effective as a design tool. In this paper we survey the different approaches to this problem. A new efficient solution method for designing optimal ℋ2/ℓ1 controllers is presented. Also the status of the robust performance problem in this setting is given.
Robust Performance Repetitive Control Design Using Structured Singular Values and its Implementation
Authors: Li Jianwu , Tsao Tsu-Chin 
Published: January 2022

Abstract
This paper converts the design of robust repetitive controller into a standard problem. In order to handle the large delay in the internal model structure of repetitive controller, a new framework, which utilizes Structured Singular Values method (μ synthesis) for solution, is proposed. It is shown that the μ value of the new framework is a tight upper bound of the μ value of the standard problem. Under this framework, the conditions of robust stability and robust performance can be incorporated and analyzed. The designed repetitive controller preserves a special low-order filter structure for efficient real-time implementation. The robust performance can be achieved not only to the periodic signals of the fundamental frequency and its harmonics as the existing repetitive controller did, but also to asynchronous periodic and non-periodic signals by choosing appropriate performance weighting function. The design procedure is more systematic and less conservative than conventional methods. A robust repetitive controller designed using this method is implemented on a hydraulic servo for noncircular cutting. Experimental results are presented to illustrate the control system synthesis procedure and performance.
Discrete Variable Structure Control for Linear Multivariable Systems: The Output Feedback Case
Authors: Tang Choon Yik , Misawa Eduardo A. 
Published: January 2022

Abstract
This paper presents an observer-based discrete variable structure controller for linear multivariable systems with unmatched additive uncertainties, an extension of the results reported in [12] to the output feedback case. It is shown that the incorporation of a prediction observer with uncertainty estimation into the controller guarantees the attractiveness and invariance of the estimated boundary layer, which is dynamic and parallel to the sliding hyperplane, after a transient. As in the state feedback case1, linear control design strategies are applicable to the tracking error dynamics design inside the estimated boundary layer under an eigenvalue constraint. A numerical example is used to illustrate the proposed technique.
Reconfigurable Software for Servo-Controlled Motion
Authors: Birla Sushil K. , Shin Kang G. 
Published: January 2022

Abstract
The motivation for this research is to reduce the cost of servo-motion control software through efficient reuse, adaptation, and integration of generic components across a variety of applications, subject to a variety of reconfigurations over their useful life, e.g., reconfigurable manufacturing systems for machining automotive powertrain components. Future configurations (changes and add-ons) cannot always be identified and designed into the initial configuration, and hence the system design and architecture must have flexibility and adaptability in anticipation. This experimental research explores the application of two well-known paradigms in computer science, object-orientation and finite state machines, in a domain-specific software architecture, to understand the effectiveness of the software engineering approach. The software approach was applied to a laboratory testbed machine tool consisting of multiple servo-controlled axes of motion, with focus on investigating software issues in controlling individual axes.
An Analytical Stability Solution for the Turning Process With Depth-Direction Dynamics and Corner-Radiused Tooling
Authors: Ozdoganlar O. Burak , Endres William J. 
Published: January 2022

Abstract
An analytical stability solution is developed for the turning process. The solution allows the dominant structural vibration mode to be misaligned relative to the feed direction. It also accounts for the effects of corner radius and lead angle on the chip area to which the process force is proportionally modeled. A general form of the chip area is derived to include overlap factors for each of the feed and depth directions. Mapping the feed and depth directions into the single vibration mode of interest yields the usual form of the equation of motion having a single overlap factor and process gain. The final solution for limiting depth of cut is, unlike past solutions, an explicit function of feed rate, corner radius, lead angle and mode orientation. The analytical solution is validated through comparison to numerical simulation and then exercised to clearly demonstrate the important influence of these four parameters, the presence of which are characteristic of most real turning processes.
Optimal Control of FES Assisted Standing-up in Paraplegia Using Genetic Algorithms
Authors: Davoodi Rahman , Andrews Brian J. 
Published: January 2022

Abstract
A genetic algorithm (GA) optimization method was used to automate the task of tuning the controller parameters in FES assisted standing-up in paraplegia. The method can be applied to any controller with adjustable parameters but we used it to design fuzzy logic (FL) and gain scheduling PID controllers of the knee and hip joint muscles during sit-to stand motion. The genetic algorithm designed controllers, GA-FL and GA-PID were found effective in coordinating volitional and FES control according to formulated criteria. The latter was based on the deviations from the desired trajectory of the knee and hip joints and the magnitude of the voluntary arm forces. The new controllers had improved performance and safety over the standard PID control and the open-loop control commonly practiced in FES clinics.
Neural Network Model of the Voluntary Arm Forces During FES Assisted Standing-up in Paraplegia
Authors: Davoodi Rahman , Andrews Brian J. , Kamnik Roman , Bajd Tadej 
Published: January 2022

Abstract
To gain insight into the way paraplegic subjects voluntarily control their arms during the FES assisted standing-up, we developed a neural network model to predict the arm forces.
The training data were collected from eight paraplegic subjects during the FES-assisted standing-up and divided into two categories for training and validation. In all the cases, it was possible to develop models that followed closely the observed behavior of the subjects. The test on validation data showed that the models could generalize well to the unseen situations. It also proved that each subject has developed a unique voluntary control strategy, which is consistent. The subjects with more experience in the use of FES were more consistent in the use of their arms from trial to trial when compared to older, heavier or high lesion subjects. Comparison of the models in different subjects showed that in addition to the unique features adopted by each subject, there are also general rules that are common in the control strategies adopted by all the subjects.
Measuring Deflection Rate With an Array of Strain Sensors
Authors: Sumali Hartono 
Published: January 2022

Abstract
This paper presents a simple measurement technique for measuring the translational and rotational velocities of flexible continuous structures. The technique uses segments of strain-sensitive materials as transducers. The proposed sensor measures velocity with very little loading compared to conventional means such as linear variable differential transformers (LVDT’s). This technique can be much less costly more practical than other translational velocity measurement.
In one realization, segments of piezoelectric film convert strains on the surface of a beam into electrical outputs. These outputs are connected to signal conditioners with very low impedance. The resulting spatially-discrete signals are then interpolated with a weighting vector that incorporates Lagrange polynomials, specified boundary conditions, and the desired location(s) of measurement. The whole signal processing can be done with a simple analog circuit. Numerical simulations show that the circuit can be used to estimate translational and rotational velocities very accurately.
A Simplified Piston-Ring Assembly Friction Model
Authors: Stanley Richard E. , Taraza Dinu , Henein Naeim A. , Bryzik Walter 
Published: January 2022

Abstract
This paper presents a simplified and efficient piston ring assembly (PRA) friction model of the piston ring pack. The model, which considers both mixed and hydrodynamic lubrication, uses the Reynold’s equation as a governing equation and simplified assumptions to include mixed lubrication. Unique Stribeck curves are generated for a given ring’s geometry and inter ring starvation effects are introduced by varying the boundary conditions, as appropriate. The model is validated by measurements made on a single cylinder diesel engine.
Longitudinal Control of Platoon Treated as One Dynamic System
Authors: Omae Manabu , Fujioka Takehiko 
Published: January 2022

Abstract
In this paper, longitudinal control for a platoon as one dynamic model is investigated by simulation. Difficulty of treating a platoon as one dynamic model is due to non-linearity and uncertainty included in the characteristic of tractive and brake force. A robust model-matching controller is developed for solving the above problem. The characteristic of the tractive and brake force is equivalent to those of a specific transfer function by the model-matching controller. A longitudinal controller for platooning is developed with assumption that the model-matching controller works on each constituent of the platoon. Velocity of the leading vehicle and each spaces between the constituents can be controlled independently and smoothly by the longitudinal controller. The proposed control system is suitable for changing space as well as fixing space, and enables the platoon to execute intelligent tasks according to the various kinds of situations.
Design and Simulations of a Traffic-Friendly Adaptive Cruise Control Algorithm
Authors: Liang Chi-Ying , Peng Huei 
Published: January 2022

Abstract
This paper presents a synthesis method for the design of Adaptive Cruise Control (ACC) algorithms. The control design is obtained on the premise that individual vehicle’s maneuver should produce minimum negative impact on surrounding vehicles. This traffic-friendliness characteristic is achieved by considering the performance of the whole vehicle string. The performance of the proposed ACC algorithm is examined on a microscopic simulation program, the architecture and basic functions of which will also be described in this paper. Both time-domain signals and statistical data are presented.
Integrated Safety Management and Work Smart Standards
Authors: Sturdivant Maggie , Carnes William E. 
Published: January 2022

Abstract
The Department of Energy developed the Work Smart Standards (WSS) concept to provide a work-centered approach for tailored sets of standards to promote improvements in environment, safety and health. As a number of DOE sites were applying the Work Smart approach, the Department also issued requirements for DOE contractors to develop Integrated Safety Management (ISM) Systems. This paper describes how WSS and ISM together are resulting in emerging new understandings about Doing Work Safely. Suggestions are also provided for new ways in which WSS concepts can be applied to implement ISM requirements.
Basaltic Magmatic Intrusion at Yucca Mountain
Authors: Margulies Tim 
Published: January 2022

Abstract
The radiological doses and risks of a probable magmatic event at the Yucca Mountain Nevada waste repository site for spent fuel from commercial power reactors have been estimated. The valuation ($ 2000 per person-rem) of the societal doses with a Poisson stochastic formulation is used to calculate potential resources to avert these risks.
Reasonably Foreseeable Use
Authors: Barnett Ralph L. 
Published: January 2022

Abstract
All technologists design products for an expected use; this use is the goal of the designer. Clearly, the actual use of products by their community of users is broader than the expected use; indeed, the original use contemplated by the designer may be expanded by marketers before the first prototype is finished. Tort law mandates that products be safely designed for their reasonably foreseeable use which includes not only their expected and expanded uses but also their reasonably foreseeable misuses. The concept of reasonably foreseeable use has a literal meaning in technology and this paper explores its impact as a design constraint.
Safety Analysis of Roller Compactors Exposed to Rollover
Authors: Brickman Dennis B. , Barnett Ralph L. 
Published: January 2022

Abstract
Roller compactors exhibit a high resistance to rollover which may be attributed to their low center of gravity, full width rollers, low speed, responsive braking system, high visibility, and operator profile. Tilt table testing of an Ingram pneumatic roller compactor demonstrates that its lateral stability normally exceeds or is comparable to other workplace vehicles. To eliminate or mitigate injuries resulting from roller compactor rollover excursions, a rollover protective structure (ROPS) and seat belt system has been widely debated as a proper countermeasure. Clearly, the roller compactor accident statistics demonstrate the potential of unbelted operators to suffer serious injuries inflicted by the ROPS safety device itself. In the face of reported low seat belt usage, the utilization of the ROPS and seat belt as standard equipment on a roller compactor is not straightforward and value systems are struggling with this dilemma.
Progress in Railroad Freight Car Engineering
Authors: Punwani Swamidas K. 
Published: January 2022

Abstract
The Rail Transportation Division (RTD), American Society of Mechanical Engineers (ASME) annually conducts a survey to document progress in the design, construction and use of freight cars and components. This year’s survey brought responses which indicated that 1998 was not a banner year for new developments. The continued evolution of freight equipment in 1998 focused on flexibility and versatility.
Estimation of Residual Stresses in Railroad Commuter Car Wheels Following Manufacture
Authors: Gordon Jeff , Perlman A. Benjamin 
Published: January 2022

Abstract
A finite element simulation is presented for the prediction of residual stresses resulting from the heat treatment of railroad commuter car wheels during manufacture. The quenching and annealing segments of the wheel manufacturing process are simulated using a decoupled heat transfer and stress analysis. A set of baseline parameters which characterize geometry, material properties and quench characteristics is developed which are representative of current rim-quenching practice. Results indicate the formation of a layer of residual circumferential (hoop) compression to a depth of about 4 cm (1.5 inch) from the tread surface. Variations of these parameters which account for expected ranges in the manufacturing process are shown to have little influence on this finding. The as-manufactured net rim compressive residual stress may be reversed when subjected to service loading in railroad commuter operations. This situation is examined in a companion paper. Tensile stresses at the wheel tread create an environment conducive to the formation of surface cracks that may threaten the safety of train operations. The results of the studies presented in this paper are required to define the initial conditions for analyses of how service conditions may act to change the as-manufactured residual stress state.
Effect of Hollow Worn Railroad Wheels on Fuel Use and Track Damage
Authors: Sawley Kevin J. , Oliva-Maal Diana , LoPresti Joseph 
Published: January 2022

Abstract
The work described contributes to the goal of defining an economic-based criterion for removing or re-profiling hollow-worn railroad wheels. Results from a survey of North American freight car wheels indicates that significant numbers of wheels have hollow-worn treads. The effect of hollow wear on rolling resistance and lateral forces has been investigated using a vehicle dynamics model backed by track tests. Results indicate that hollow wheels impose an economic cost, and, by their effect on lateral track forces, increase the risk of derailment. Prediction and test results have been used as input to an economic model to examine the cost benefits of a removal criterion for hollow-worn wheels. The modeling methods used are general in principle, and are not specific solely to the heavy haul environment.
Effect of Different Thermal Cycles on TBC Spallation Lifetime
Authors: Nusier S. Q. , Newaz G. M. , Chaudhury Z. A. , Chen X. , Khan J. M. 
Published: January 2022

Abstract
The effect of different thermal cycle profiles on thermal barrier coating (TBC) spallation lifetime was investigated. Fick’s law was used to describe the thermally grown oxide (TGO) buildup. It was found that Fick’s law can be used to correlate between damage thickness and oxide thickness for different thermal cycle profiles. A critical oxide thickness of 12 μm can be associated with spallation life for the 8 wt% YSZ /PtAl/Rene N5 EB-PVD system. The importance of this correlation is that, for a given thermal cycle profile, the number of cycles to spallation can be predicted analytically using Fick’s law. The effect of maximum temperature, minimum temperature, holding time, and number of cycles were studied. It was found that by using the actual thermal cycle profile, accounting for cumulative oxide buildup throughout the complete cycle, the TBC spallation lifetime can be estimated reasonably well.
Fatigue Behavior and Life Simulation of Torsion Loaded Glass Fiber/Vinylester Tubes
Authors: Himmel Norbert A. , Kienert Michael C. 
Published: January 2022

Abstract
The fatigue characterization of resin matrix composite materials is still quite a demanding subject due to the variety of interacting damage mechanisms including matrix cracking, debonding, delamination and fiber fracture rather than one distinguished damage event as in metals. The subject of the present study was the investigation of the torsion fatigue behavior of filament wound glass fiber/vinylester tubular specimens and its fatigue life estimation. To provide the experimental data constant amplitude tests were carried out under torque ratios R = +0.1, −0.4 and −1.0. Two-step R = −1.0 block loading experiments were performed to investigate potential load sequence effects. Finally, a spectrum load profile derived from a real car drive shaft test was applied to elevated length specimens incorporating a realistic loading situation and a structural size level in the study. Parallel to the experiments fatigue life predictions based on the critical element method, the residual strength degradation concept and the linear damage accumulation rule were carried out. The paper presents the relevant experimental results and the comparison with fatigue life predictions.
Simulation of Fatigue Performance of Polymeric Composites for Infrastructure Applications
Authors: McBagonluri Fred , Foster Glenn , Case Scott , Curtin Bill , Lesko John 
Published: January 2022

Abstract
A simulation model which incorporates a fracture mechanics-based residual strength model for glass fiber in the statistical- and numerical-based Lattice Green Function Local Load Sharing Model has be developed. The simulation of the fatigue of glass fiber-reinforced composites is achieved by replacing the constant stress parameter in the model with a sinusoidal wave function. Recognizing Mandell’s stipulation, that fatigue failure in glass fiber-reinforced polymeric composites is a fiber-dominated mechanism with a characteristic slope of 10%UTS/decade, simulation results are shown consistent with available experimental data. The slopes of simulated S-N fatigue curves at three frequencies namely: 2, 5 and 10 Hz are within 12–14 UTS/decade compared with 10.6–13 UTS/decade for unidirectional glass reinforced composites (epoxy and vinyl ester).
Growth of Face-Sheet Delaminations in Sandwich Beams Under Compression or Bending
Authors: Kardomateas G. A. 
Published: January 2022

Abstract
A bending load on a sandwich beam consisting of two fiber-reinforced sheets separated by a low stiffness core is equivalent to a compressive force on one face and a tensile force on the other. Should an interlayer crack in the composite face sheet (delamination) exist on the compressively loaded face, local buckling and subsequently growth of the interface crack may occur. This may also naturally occur under pure compression. In these cases, the composite face rests on an elastic “foundation” (the core), which imposes reaction forces proportional to the deflection of the “foundation”. In this study, the buckling and initial postbuckling behavior is studied through a perturbation procedure. The solution, derived in closed form, is subsequently used to study the growth of the mixed mode crack during the initial postbuckling phase. To this extent, the energy release rate and the Mode I and II stress intensity factors are obtained in terms of the loading and geometric parameters.
Mold Filling Simulation of Sandwich Composite Structures Manufactured by Liquid Molding
Authors: Nedanov Pavel , Advani Suresh G. 
Published: January 2022

Abstract
The mold filling stage in the manufacturing of sandwich composite structures with fiber reinforced foam core was studied with numerical simulations. Three different geometries of sandwich core reinforcement were considered: in the form of fiber layers forming angle 45° or 90° with the facings or in the form of equally spaced separate strands (webs). The influence of variable core and face reinforcement permeability and location of the injecting edge on the flow front progression and filling time was explored. The results suggest that permeability of the core has a significant influence on filling pattern and mold filling time. Experimental and predicted flow front developments for a case of radial injection were compared.
Circular Cylindrical Sandwich Shells With Midplane Asymmetry Subjected to Axially Symmetric Loads
Authors: Preissner Eric C. , Vinson Jack R. 
Published: January 2022

Abstract
Solutions for the displacements and stresses in circular cylindrical shell structures subjected to axially symmetric loads are presented for the cases of the shell construction having a midplane asymmetry. For sandwich constructions this can mean faces of the same material with different thicknesses, faces of different materials, or all of the above. A midplane asymmetry parameter ϕ is used wherein −1 &lt; ϕ &lt; +1 for all physically possible cases, and this parameter facilitates the case of a perturbation solution to the generic problem. By an example it is shown that through such asymmetric construction, bending stresses can be minimized or negated.