bluuebunny/crossref_metadata_2025 huggingface dataset:
Varying Lifecycle Lengths Within a Product Take-Back Portfolio
Authors: Zhao Yuan , Pandey Vijitashwa , Kim Harrison , Thurston Deborah
Published: September 2010

Product take-back and reuse is sometimes at odds with the rapidly evolving desires of some customers. For other customers, the environmental benefits of reuse more than compensate for minor drawbacks. “Selling a service” (rather than a product) through leasing enables the manufacturer to control the timing and quality of product take-back but current methods assume a fixed leasing period. What is needed is a method for fine tuning the time span of customers’ life cycles in order to provide each market segment the combination of features it most desires. This paper presents a new method for performing long range product planning so that the manufacturer can determine optimal take-back times, end-of-life design decisions, and number of lifecycles. The method first determines a Pareto optimal frontier over price, environmental impact and reliability using a genetic algorithm. Then, a multiattribute utility function is employed to maximize utility across different segments of the market and also across different lifecycles within each segment. Post-optimal studies help determine feasibility of component redesign in addition to parts consolidation. The proposed method is illustrated through an example involving personal computers.
A Conceptual Design Tool for Resolving Conflicts Between Product Functionality and Environmental Impact
Authors: Fitzgerald Daniel P. , Herrmann Jeffrey W. , Schmidt Linda C.
Published: September 2010

Product development organizations are unwilling to compromise product functionality, unit cost, or time to market in order to create products that have less environmental impact than that required by regulations. Thus, designers may face a conflict between improving product functionality and reducing environmental impact. The design for environment (DfE) tools currently available are inadequate with respect to helping designers determine how to resolve this conflict during the conceptual design phase. Design-by-analogy is a promising conceptual design approach for this problem. Examples of products that simultaneously reduce environmental impact and improve product functionality can inspire designers to do likewise. The challenges are to generate the relevant knowledge and to organize it in an accessible DfE tool. This paper describes an approach for generating and organizing this knowledge, an analysis of successful products, and a table of successful designs.
Integrating Life Cycle Assessment Into the Conceptual Phase of Design Using a Design Repository
Authors: Bohm Matt R. , Haapala Karl R. , Poppa Kerry , Stone Robert B. , Tumer Irem Y.
Published: September 2010

This paper describes efforts taken to further transition life cycle assessment techniques from the latter, more detailed phases of design to the early-on conceptual phase of product development. By using modern design methodologies such as automated concept generation and an archive of product design knowledge, known as the Design Repository, virtual concepts are created and specified. Streamlined life cycle assessment techniques are then used to determine the environmental impacts of the virtual concepts. As a means to benchmark the virtual results, analogous real-life products that have functional and component similarities are identified. The identified products are then scrutinized to determine their material composition and manufacturing attributes in order to perform an additional round of life cycle assessment for the actual products. The results of this research show that sufficient information exists within the conceptual phase of design (utilizing the Design Repository) to reasonably predict the relative environmental impacts of actual products based on virtual concepts.
Hierarchical Decomposition and Multidomain Formulation for the Design of Complex Sustainable Systems
Authors: Alfaris Anas , Siddiqi Afreen , Rizk Charbel , de Weck Olivier , Svetinovic Davor
Published: September 2010

Designing a large-scale complex system, such as a city of the future, with a focus on sustainability requires a systematic approach toward integrated design of all subsystems. Domains such as buildings, transportation, energy, and water are all coupled. Designing each one in isolation can lead to suboptimality where sustainability is achieved in one aspect but at the expense of other aspects. Traditional ad hoc allocations of design parameter precedence and dependence cannot be used for cases where new (instead of only mature) architectures are to be explored. A methodology is introduced for addressing design problems of complex sustainable systems that is comprised of, on the one hand, a hierarchical decomposition that includes multilevel abstraction and design parameter identification, and on the other hand, a multidomain formulation, which includes parameter dependency identification, design cycle identification and decision structuring, and scoping. The application of the methodology for the design of a new urban development, Masdar City in Abu Dhabi, with over 220 different form and behavior parameter sets is shown.
Dynamic Systems With SES Process for Vehicle Integration
Authors: Chang Kevin , Kwon Sung , Naghshineh Kasra
Published: September 2010

This paper describes an integrated engineering environment developed by BAE Systems which combines an integration and test process called Simulation-Emulation-Stimulation (SES) using physics-based high-fidelity dynamic simulation models. This environment creates real-time vehicle simulations of system and electrical control behavior that enable the visibility of electronic component messages and signals at subsystem and system level. It is used to integrate tactical software and electronic components as well as to test and verify vehicle subsystem and system level requirements and performance. To further enhance the SES environment capability, high fidelity electronics simulation models utilized during integration to extend internal signal visibility and aid troubleshooting. With this integrated environment, vehicle electronics and software integration issues can be identified and resolved in a lab before on-vehicle integration occurs. This significantly reduces overall project risk to both schedule and cost.
A Hybrid Optimal Control Strategy for a Smart Prosthetic Hand
Authors: Chen Cheng-Hung , Naidu D. Subbaram , Perez-Gracia Alba , Schoen Marco P.
Published: September 2010

This paper presents a hybrid of a soft computing or control technique of adaptive neuro-fuzzy inference system (AN-FIS) and a hard computing or control technique of the hybrid finite-time linear quadratic optimal control for a two-fingered (thumb and index) prosthetic hand. In particular, the ANFIS is used for inverse kinematics, and the optimal control is used to minimize tracking error utilizing feedback linearized dynamics. The simulations of this hybrid controller, when compared with the proportional-integral-derivative (PID) controller showed enhanced performance. Work is underway to extend this methodology to a five-fingered, three-dimensional prosthetic hand.
An Autonomous Pneumotronic System for Enhancing the Braking Capability of Long Freight Trains
Authors: Jacazio Giovanni , Gastaldi Laura
Published: September 2010

Trains brakes are pneumatically actuated and use the same pneumatic line for power and signal transmission. This simple architecture presents limits for long trains since the last vehicles brakes receive a very delayed command and the train speed must be limited. Solutions were proposed using a signal transmission line parallel to the pneumatic line. These systems, though effective, present drawbacks and are of difficult implementation as retrofits. A solution is described, which leaves the braking system unchanged, but reduces the time delay in the signal transmission by adding a pneumotronic unit at the pneumatic line end. This unit analyzes the pressure time history, recognizes the precursors of new braking commands and issues inputs to a valve at the pneumatic line end mirroring the commands to the master valve. The rapidity of the braking action is enhanced, thereby allowing a more uniform braking and a speed increase of long freight trains.
Evaporator Superheat Regulation via Emulation of Semi-Active Flow Control
Authors: Elliott Matthew , Rasmussen Bryan P.
Published: September 2010

Proper regulation of evaporator superheat is essential to ensuring safe and efficient operation of vapor compression cooling systems. Typical mechanical control devices may behave poorly under transient disturbances or as operating conditions vary, degrading system performance. Electronic expansion valves partially alleviate these problems by allowing more sophisticated control approaches, but frequent valve adjustments raise concerns about device longevity. A cascaded control approach to superheat regulation has been shown to provide significant improvements in superheat control, utilizing a hybrid of mechanical (passive) and electronic (active) feedback devices. This paper examines the emulation of a semi-active flow control device using a MEMs based actuator with high bandwidth, few moving parts, and no risk of fatigue failure. Experimental evaluation reveals this to be a comparable approach to the hybrid valve design. Moreover, further examination reveals that actuator characteristics are the limiting factor in achieving similar levels of performance using standard electronic valves.
Simulation and Experimental Tests of a Safety Braking System for Aerial Tramways
Authors: Strada Roberto , Forlani Mauro
Published: September 2010

Aerial tramways are a fast and efficient mean of transportation, especially found in mountainous regions where the ability of clearing steep inclines makes them a preferred solution. Often non-autonomous, these types of cabin have little or no power installed and thus must be drawn by the haulage rope. In case of failure, a safety braking system must prevent the cabin from rolling back along the track rope. The braking system under investigation is a fail-safe device composed by two braking units that clamp the track rope in case of failure. The aim of the present study was to estimate the braking time. Given the complexity and costs related to on-field experimental tests, simulations and laboratory tests were carried out. The braking unit was modelled in MSC ADAMS, making use of the MSC ADAMS/Hydraulics plug-in. Simulations and experiments were in a very good agreement, evidencing the system’s compliance to Italian regulation.
Control and Validation of Automated Lane Centering and Lane Changing Maneuver
Authors: Lee Jin-Woo , Litkouhi Bakhtiar
Published: September 2010

This paper describes an automated lane changing control system that has been developed at General Motors Research and Development. This system uses a single monochrome camera to recognize lane markings on the road ahead and uses multiple short range radars to detect surrounding traffic and objects. A sensing unit calculates the host vehicle’s lateral displacement and the heading angle from the center of its lane as well as the relative distance and relative speed of each object. Since the smoothness and comfort of lane change maneuvering are important measures of the control performance, the vehicle dynamic model is integrated into the desired path generation and vehicle’s controller design to reduce the vehicle lateral acceleration and the lateral offset overshoot during the lane change maneuvering. To avoid heavy computation, a simplified model predictive control algorithm is proposed. The control algorithm calculates a steering angle command at the current time step to drive the vehicle to the desired path. The control method and algorithms are implemented on a demonstration vehicle and validated at straight roads and various curve roads of up to 0.001 [1/m] curvature for different vehicle speeds up to 100 [km/hr]. The results show that lane change maneuvering is successfully completed with lateral offset error less than 20 cm.
Nonlinear Modeling and Control of a Dual-Stage Hybrid Ride-by-Wire Throttle Body for a Sport Motorbike
Authors: Corno Matteo , Panzani Giulio , Maggio Giorgio , Mazzocchi Paolo , Goggi Andrea , Savaresi Sergio M.
Published: September 2010

This paper addresses the dynamics identification and servo-controller design for a dual-stage electronic throttle body (ETB) designed for ride-by-wire applications in racing motorcycles. The dynamics of the system is identified and a model of the friction—which is the main nonlinear phenomenon affecting the control of the mechanism—is identified from experimental data. The identified model is used to design a controller composed of a linear part and a nonlinear friction compensator. Experimental tests are employed to validate the controller design and comparison with a linear controller is carried out in order to quantify the advantages brought by the friction compensation.
A Switched Inertance Device for Efficient Control of Pressure and Flow
Authors: Johnston D. Nigel
Published: September 2010

This paper reports on an initial investigation of a switched inertance device (‘SID’). Using this device, flow and pressure can be varied by a means that does not rely on dissipation of power. The device can provide a step-up or step-down of pressure or flowrate, analogous to a hydraulic transformer. Simulated and experimental results on a prototype device show a promising performance. The device could potentially provide very significant reduction in power consumption over conventional valve-controlled systems, provided that noise issues and some other practical problems can be overcome.
Effects of Remote Control on Usability of Hydraulic Excavator
Authors: Uusisalo Jarno , Huhtala Kalevi , Vilenius Matti
Published: September 2010

Remote control is often considered as a means of utilization when operating hydraulic mobile machines in hazardous environments. However, in some cases remote control may also improve the general usability of the machine, which is a good reason for using remote control also in normal (safe) work tasks. In this paper the effects of remote control on the usability of a hydraulic excavator were studied by means of two experiments. A group of subjects carried out two tasks which were related to digging soil with obstacles and controlling the excavator accurately. A remotely controlled hydraulic mobile machine with an excavator and a hand-held remote control with vibro-tactile haptic feedback were utilized as a test platform. The arrangements for the experiments are introduced and the results presented in this paper. The results show that short-range remote control may improve the usability of the hydraulic excavator significantly in some work tasks.
Modeling and Control of Interconnected Dimensionless Dynamic Systems
Authors: Manwaring Scott , Alleyne Andrew
Published: September 2010

Previous work has found benefit in using dimensional analysis in the modeling and control of dynamic systems. What has not been explored is how multiple dimensionless dynamic systems would interconnect and interact with one another. This work presents an initial investigation into the interconnection of dimensionless dynamic systems, including an analysis of the differences between interconnecting dimensioned and dimensionless systems. A strategy is developed to interconnect dimensionless dynamic systems and explored using models of multiple fluid power components. The interconnection strategy is tested through controller design and simulation, which reveals insight into the dimensionless transformation of the original dynamic systems.
LPV-Based-Method Aiming at a Win-Win Situation for Analytical Control Theories and Intelligent Optimization Methodologies
Authors: Hiramoto Kazuhiko
Published: September 2010

A new collaborative control strategy between time varying design parameters in LPV plants and the feedback controllers is proposed in the present paper. As the feedback control law the gain scheduling control scheme is adopted to guarantee the closed-loop L2 gain performance against the variation of the time varying parameter in the control object. The gain-scheduling controller can be obtained in an analytical manner by solving LMIs. For the closed-loop system with the LPV plant and the gain scheduling controller Genetic algorithm (GA), known as a so-called intelligent optimization method, is applied to optimize the closed-loop response. The proposed control system has a complementary structure between the LMI-based analytical control strategy and the flexible intelligent control method that does not impair their advantages each other. In this sense a win-win situation for the LMI-based gain scheduling control and the GA-based intelligent optimization is realized in the proposed approach. A simple simulation example is presented to show the effectiveness of the proposed method.
On the Hybrid Physical/Dynamic Tire/Road Friction Model
Authors: Yi Jingang
Published: September 2010

We present new development of a hybrid physical/dynamic tire/road friction model for real-time friction estimation and control. We extend the LuGre tire/road friction model by considering the physical model-based deformation distribution on the tire/road contact patch. Relationship between the physical friction model and the LuGre dynamic friction model has been built and developed. We have shown that the LuGre dynamic friction model predicts the similar deformation and stress characteristics of the physical model, and therefore the friction model parameters can be interpreted with physical meaning and estimated experimentally. We demonstrate preliminary model comparison study through the “smart tire” sensor measurements on a mobile robot platform.
Performance Analysis of Fault Tolerant Control Systems Including Time Delay
Authors: Mohammadpour Javad , Grigoriadis Karolos M.
Published: September 2010

The brief instability concept in Linear Parameter Varying (LPV) systems allows the linear system to be unstable for some values of the LPV parameters so that instability occurs only for a short period of time. The present paper takes advantage of an extension of the notion of the brief instability to the LPV systems with time-delay in their dynamics to examine the performance degradation in Fault Tolerant Control (FTC) systems in the presence of false identification of the fault signals. The paper provides tools for the stability and performance analysis of such systems, where performance is evaluated in terms of induced L2-gain. The results presented in the paper demonstrate that stability and performance can be evaluated by examining the feasibility of a parameterized set of Linear Matrix Inequalities (LMIs). The paper provides the analysis conditions to guarantee the asymptotic stability and H∞ performance for FTC systems, in which instability, due to the false identification of the fault signals, is allowed to take place for a short period of time. A numerical example is presented to illustrate the qualifications of the proposed analysis and synthesis conditions for treating brief instability in the delayed FTC systems.
Design and Research on High-Speed On/Off Control Hydraulic Propeller for Underwater Vehicle Propulsion
Authors: Zhu Kangwu , Chen Yuanjie , Cao Jianwei , Li Wei , Chen Jiawang
Published: September 2010

For the unmanned underwater vehicles (UUVs) with power between 20kW and 60kW, the electric motor is too heavy, while the power of variable displacement motor is too high. In this paper, the high speed on/off hydraulic control propulsion system for a UUV is designed. The three main parts of the system, the hydraulic subsystem, the propeller, and the amplifier are described in detail. An integrated valve-manifold is designed, which can be installed in the rear of motor to simplify the structure and to improve the response performance of system. A novel quasi PFM amplifier which can make sure the enough switching time of on/off valve and good propeller control performance in the entire working conditions is developed. Since the propeller is driven in switching mode, the speed fluctuation cannot be avoided. Therefore, the relations between the system parameters and speed fluctuation are analyzed by mathematical method, from which the approximate analytical solutions of speed fluctuation and average speed are obtained. Based on these, a flywheel is added on the propeller shaft for the purpose of filtering the speed fluctuation. To choose the inertia of the flywheel, a trade-off between the fluctuation degree and the response speed has been done. Experimental results prove the system has good dynamic performance that the respond time of on/off valve is only about 3.5ms and the fluctuation degree is 12.55% while the response speed of propeller is quick. Simulation results show that the speed closed-loop control system has satisfactory transient and steady-state performance and good tracking ability.
Accurate Decoupled Linear Modeling for Robust H∞ Control of Multi Axis Shaking Tables
Authors: Ghorashi Ali , Plummer Andrew R. , Edge Kevin A. , Keogh Patrick S.
Published: September 2010

This paper illustrates an improved linear modeling method for multi axis electro-hydraulically actuated servo systems to enable the design of high performance and robust H∞ controllers. The model is validated for a Multi Axis Simulation Table (MAST) located at the University of Bath. The dynamic analysis of the MAST proves the effectiveness of the modeling technique compared with conventional methods. Based on the validated linear model, the uncertainties of the system, as determined from parameter estimation errors and system nonlinearities, are quantified. This leads to the design of an H∞ controller for the MAST. The simulated performance of this controller is then compared with that of a classical PI controller. In this paper, the control potential is demonstrated for horizontal table motion.
On the Roll Angle Estimate via Inertial Sensors: Analysis of the Principal Measurement Axes
Authors: Boniolo Ivo , Panzani Giulio , Savaresi Sergio M. , Scamozzi Alessandro , Testa Luca
Published: September 2010

In this work it is proposed an analysis of the foremost inertial measurements to take into account for the estimate of the lean angle in two-wheeled vehicles. As it is well-known, the roll angle is a crucial variable in the dynamic of a two-wheeled vehicle, since it greatly affects the behaviour of the tire-road contact forces, especially in the lateral direction. Hence, the capability of providing a real time and reliable measure of such quantity allows to evaluate the dynamic properties of the vehicle and its tires and represents the enabling technology for the design of advanced ABS systems and stability control systems. The aim of the analysis proposed in this work is to identify which are the inertial measurements (accelerations and angular rates) that are strongly related to the lean angle and that can be used to estimate it in a urban path. Ideally, the measured lateral acceleration and the vertical angular velocity are the only crucial variables to estimate the tilt angle of a motorcycle, but in a real condition characterized by the presence of slopes, banks and variable speed, also the longitudinal measurement axis becomes relevant.
Second Order Polynomial Model for Fluid Dynamics in High Pressure
Authors: Karjalainen Juho-Pekka , Karjalainen Reijo , Huhtala Kalevi , Vilenius Matti
Published: September 2010

This paper suggests second order polynomials for modeling hydraulic fluid dynamic properties — tangent bulk modulus, density and speed of sound in fluid. Model parameters can be calculated from ISO fluid characteristics data available for every commercial hydraulic fluid. The accuracy of the models is verified with measurements at pressures up to 1500 bar. The measurement results as well as the measuring method are also introduced. Although the models are quite simple, correlation with the measurement results is excellent.
Optimal Neuromuscular Control of Spine Systems
Authors: Xu Yunfei , Choi Jongeun , Reeves N. Peter , Cholewicki Jacek
Published: September 2010

The goal of this work is to present methodology to first evaluate the performance of an in vivo spine system and then to synthesize optimal neuromuscular control for rehabilitation interventions. This is achieved 1) by determining control system parameters such as static feedback gains and delays from experimental data, 2) by synthesizing the optimal feedback gains to attenuate the effect of disturbances to the system using modern control theory, and 3) by evaluating the robustness of the optimized closed-loop system. We also apply these methods to a postural control task, with two different control strategies, and evaluate the robustness of the spine system with respect to longer latencies found in the low back pain population. This framework could be used for rehabilitation design as discussed at the end of the paper.
Fluid Flow in the Vicinity of a Vibrating Ionic Polymer Metal Composites: Part 2—Numerical Study
Authors: Abdelnour Karl , Mancia Elisa , Peterson Sean D. , Porfiri Maurizio
Published: September 2010

Ionic Polymer Metal Composite (IPMC) actuators have shown promise as miniature underwater propulsors due to their high flexibility, reduced weight, and low activation voltage and power consumption. In this second of two papers, we discuss numerical simulations of the flow of a viscous fluid generated by a two-dimensional cantilever IPMC actuator vibrating along its fundamental mode shape. We compute the thrust produced by the actuator as a function of its oscillation frequency and maximum tip displacement and show that it is correlated to vortex shedding. We find that vorticity production is prominent at the IPMC tip and increases as the oscillation frequency increases. We analyze the lateral force and the moment exerted by the IPMC on the surrounding fluid. Further, we study the power transferred by the vibrating IPMC to the encompassing fluid. The findings are validated via comparison with the experimental results presented in part 1 of this series.
Design of Observer-Based Feedback Control for Time-Delay Systems With Application to Automotive Powertrain Control
Authors: Yi Sun , Nelson Patrick W. , Ulsoy A. Galip
Published: September 2010

A new approach for observer-based feedback control of time-delay systems is developed. Time-delays in systems lead to characteristic equations of infinite dimension, making the systems difficult to handle with classical control methods. In this paper, a recently developed approach, based on the Lambert W function, is used to address this difficulty and to control time-delay systems by designing an observer-based state feedback controller via eigenvalue assignment. The designed observer provides estimation of the state, which converges asymptotically to the actual state, and is then used for state feedback control. The feedback controller and the observer take simple linear forms and, thus, are easy to implement when compared to nonlinear methods. This new approach is applied, for illustration, to the control of a diesel engine to achieve improvement in fuel efficiency and reduction in emissions. The simulation results show excellent closed-loop performance.
Vibrational AFM-Based Nano-Placing: Modeling and Simulation
Authors: Landolsi Fakhreddine , Ghorbel Fathi H. , Dabney James B.
Published: September 2010

Bottom-up fabrication presents the potential applications of improved materials and highly effective devices. Matter at the microscale can be manipulated using micro-placing techniques that rely solely on surface forces. These techniques can be used on rough substrates and allow for fast manipulation. In the present paper, we will investigate generalizing these techniques to manipulate nanoscale samples. The use of dynamic oscillations of the manipulator is proposed to allow for controlled release at the nanoscale. The effects of the adhesion and sample mass on the manipulation outcome are investigated. Simulations are conducted to help select the amplitude and the frequency of the vibrations and to improve the accuracy of the manipulation.
Multi-Domain TLM Model for Intravascular Ultrasound
Authors: Borji Rafik , Franchek Matthew A.
Published: September 2010

Developed in this paper is the set up of a spatiotemporal (multi-domain) numerical model for intravascular ultrasound (IVUS). The transmission line matrix method (TLM) is used to mimic the propagation of the sound wave through the circular cross-section of an artery. Different propagation scenarios (healthy and abnormal arteries) are illustrated in this work showing how this model captures the behavior of these waves. The model is evaluated by means of regular TLM models established in the literature.
Adaptive Robust Control of Hydraulic Robots With Recursive Least Squares
Authors: Wang Longke , Book Wayne J. , Huggins James D.
Published: September 2010

This paper proposes a robot control approach using a discrete recursive least square algorithm. The scheme shows robustness when the system suffers from measurement noise and has a fast parameter convergence rate. The control algorithm is computationally efficient and numerically stable. Guaranteed trajectory tracking can be achieved by simple parameter design if disturbances are bounded.
The Critical Speed of Slipper Bearings in Axial Piston Swash Plate Type Pumps and Motors
Authors: Borghi Massimo , Specchia Emiliano , Zardin Barbara , Corradini Enzo
Published: September 2010

A stationary model is adopted to determine the critical condition for which the slipper moves away from the swashplate in an axial piston machine. The aim of the analysis is to find the critical speed, i.e. the value of the machine speed for which the slipper moves away from the swashplate; usually this condition may determine bad operating behaviour of the machine, although a retainer plate is used to maintain the slipper sufficiently near to the swashplate. The influences of the pressure transition in the cylinder, the swashplate angle and the radial clearance between piston and cylinder on the critical speed are depicted. Successively, the role of the position of the point of application of the resultant force due to the slipper-retaining plate contact is analyzed.
Model-Free Adaptive On-Off Step Controller for Piezoelectric Micro-Robots
Authors: Hahn Bongsu , Oldham Kenn
Published: September 2010

An adaptive, model-free on-off controller is described for situations in which a desired step response is to be repeated many times, but there is incomplete information available about the system dynamics. The controller adapts a set of on-off switching transition times as a function of certain objective measurements defined by the designer. While the controller does not utilize any model of the system to perform this adaptation, the effects of the adaptation on known plants can be analyzed to find a range of systems for which the on-off switching times will result meeting desired objectives. This analysis is applied to lightly-damped 2nd-order systems representative of micro-robotic leg joints driven by piezoelectric actuators, and used to identify on-off switching frequencies, sensing frequencies, and adaptation parameters that converge for many plants. This can produce a controller with good robustness to system variation and relatively low switching and sampling frequencies, which can keep power consumption of for piezoelectric servo control very low.
Modelling of Large Deflection of IPMC Plates
Authors: Shahinpoor M.
Published: September 2010

Reported are advances made in connection with modeling of ionic polymeric metal composite (IPMC) plates undergoing large deformation under an imposed dynamic electric field. Analysis, design and prototyping of sensing or/and actuating plates made with IPMCs requires analytical models of the utilized materials and structures. This paper presents recent advances made towards the development of a computational implementation of a general theory for describing such systems in a way that allows accurate prediction of their behavior within their state space. Continuum mechanics, irreversible thermodynamics, and electrodynamics are utilized to derive the general four dimensional multi-physics field equations of materials used for artificial muscle applications. These applications are particularly important in terms of creating data sheets, thin data keyboards as well as flat speakers made with IPMC plates. The system of governing partial differential equations describing the state evolution of large deflection IPMC plates is derived. The system of these electro-hygro-thermally modified Von-Karman non-linear equations are solved numerically through an adaptive finite element approach through perspectives of geometrical and material nonlinearities. The preliminary results are presented for the case of finite deformation of an IPMC plate.
Electro-Thermal Battery Modeling and Identification for Automotive Applications
Authors: Hu Yiran , Yurkovich Benjamin J. , Yurkovich Stephen , Guezennec Yann
Published: September 2010

In this paper, a methodology for modeling and identification of the electro-thermal dynamic behavior of batteries is developed with an equivalent circuit model for use in automotive applications. The developed model has a simple structure but can capture sufficient dynamics under both temperature and state of charge (SoC) variation, thus making it applicable for use with real-time model-based estimation algorithms (for example, in state of charge and state of health estimation). A systematic procedure is outlined for the data acquisition and identification process, and experimental results are presented for an A123 lithiumion iron phosphate battery.
Managing the Hydraulic Characteristics of Control Spool Valves Through Simplified Manufacturing Process
Authors: Marger Thibaut , Pommier-Budinger Valerie , Mare J.-Charles , Malburet Franc¸ois
Published: September 2010

This communication proposes an original method to define a low-cost manufacturing process for hydraulic spool valves in the case of very low production rate. A valve is usually completely defined by three characteristic curves obtained by two tests: a pressure gain test and a flow gain test. The aim is to limit the number of tests and in particular to avoid the flow gain test that is quite long to achieve. The method only uses a single metrology operation and the pressure gain curve to manage the spool flanks grinding while ensuring the specified hydraulic characteristics. The method is established by a model-based approach. It is then validated by experimental tests on two different valves.
Lithium Ion Dynamic Battery Pack Model and Simulation for Automotive Applications
Authors: Yurkovich Benjamin J. , Guezennec Yann
Published: September 2010

In this paper, we introduce a lumped parameter, distributed battery pack dynamic model which allows simulation of the electrical dynamics of all the cells in an arbitrarily configured series/parallel pack typical of those used in automotive applications. The dynamic pack simulator is based on the development of an analytical solution for the dynamic response of a single cell and an analytical development of such elemental solutions into a distributed dynamic pack model which can resolve the dynamics of each cell within the pack. This formulation leads to a computationally efficient simulation tool appropriate for application on large battery packs. This simulation tool is then used to perform Monte Carlo simulations on typical automotive current profiles for packs made of cells with a statistical distribution of parameters. A mild distribution of cell mismatch leads to cell unbalance development and statistical metrics for the growth unbalance, presented and related to both current severity and cell parameter distribution. The tool is ideally suited for studies in Battery Management System (BMS) algorithm development, as well as model-based fault propagation and diagnostics.
Qualitative Principles of Ecology and Their Implications in Quantitative Engineering Systems
Authors: Yedavalli Rama K. , Devarakonda Nagini
Published: September 2010

In this paper, we briefly review some fundamental qualitative features of ecological sign stability and transform these principles of ecology to a set of mathematical results in matrix theory with quantitative information, which is usually encountered in engineering sciences. This type of cross fertilization of ideas of life sciences and engineering sciences is deemed to be highly beneficial to both fields. In particular, we show in this paper what effect the signs of elements of a matrix have on the matrix properties such as eigenvalues and condition number. Similarly, it is also shown that under some assumptions on the magnitudes of the elements, predator-prey phenomenon in ecology renders some special properties like ‘normality’ to matrices. It is also shown that these predator-prey models have better robustness properties when compared to other matrices. The results presented in this paper can assist in the use of ecological system principles to build highly robust engineering systems.
Modeling and Robust Discrete-Time Sliding Mode Control Design for a Fluid Power Electrohydraulic Actuator (EHA) System
Authors: Lin Yang , Shi Yang , Burton Richard
Published: September 2010

This paper studies the design of a robust discrete-time sliding mode control (DT-SMC) for a high precision electro-hydraulic actuator (EHA) system with nonlinear actuator friction. Nonlinear friction in the hydraulic actuator can greatly influence the performance and accuracy of the hydraulic actuators; however, it is difficult to accurately model nonlinear friction characteristics. In this paper, it is proposed to characterize frictions as an uncertainty in the system matrices. Indeed, the effects of variations of the nonlinear friction coefficients are considered as norm bounded uncertainties that span a bounded region to cover a wide range of real actuator friction. For such a discrete-time dynamic model for the EHA system with system matrices uncertainties and a nonlinear term, a sufficient condition for the existence of stable sliding surfaces is proposed by using the linear matrix inequality (LMI) approach. Based on this existence condition, a discrete-time sliding mode controller is developed such that the reaching motion satisfies the discrete-time sliding mode reaching condition for uncertain systems. Simulation and comparison studies on the EHA system model illustrate the effectiveness of the proposed method. The study is simulation based only as it is important to establish the feasibility and stability of the controller before attempting to apply the controller to a physical system.
LPV Gain Scheduling Control of Hysteresis on an SMA Wire System
Authors: Kilicarslan Atilla , Song Gangbing , Grigoriadis Karolos M.
Published: September 2010

In this work, a Linear Parameter-Varying (LPV) control method is used to compensate the hysteretic behavior of a Shape Memory Alloy (SMA) wire. Controller is implemented on an experimental system which consists of a pre-tension spring and a mass actuated with a thin SMA wire. The hysteretic characteristic of the SMA wire is modeled using the Preisach model and the model is verified both for the major and minor hysteresis loops. The small signal linear gain of the Preisach model is used as a scheduling stiffness variable. The parameter-dependent controller is scheduled based on the real time measurement of the stiffness variable. An H∞ controller is also synthesized by representing the hysteresis as a parametric uncertainty and comparisons are made with LPV gain scheduling controllers using similar weights for both controllers. Experimental trajectory tracking results show that the LPV Gain Scheduling controller has a better response and the hysteresis uncertainty is compensated for the full range of stiffness variability.
Control of Selectable One-Way Clutch in GM Six-Speed Automatic Transmissions
Authors: Lee Chunhao J. , Samie Farzad , Kao Chi-Kuan
Published: September 2010

Automatic transmissions use one-way clutches and regular clutches to control gear shifts. Regular one-way clutch locks in one direction and free spins (freewheeling) in the other direction and thus provides good shift quality. However, a clutch is needed if the freewheeling direction needs to be locked. The advantage of a selectable one-way clutch (SOWC) is that it can be designed to act like a regular one-way clutch, fully freewheels or locks in both directions. In the GM six-speed transmissions, there is one one-way clutch which is accompanied by a clutch CB1R to control between 1st gear and reverse direction. The study is to replace the one-way clutch and CB1R clutch with simply one selectable one-way clutch in GM 6-speed transmissions (1). This will eliminate one transmission clutch, reduce weight and cost, and improve transmission efficiency. The proposed design of transmission is applied to a GM SUV and a GM passenger vehicle. Different from a regular clutch, which can be applied with force/pressure from high slippage to lock-up between two elements, a selectable one-way clutch can only be applied to a lock-up position when the slippage between two elements is near zero speed. Also, an SOWC can only be released when there is no torque or force carried by the clutch while a regular clutch can be easily released by dropping the applied force/pressure. These requirements impose challenges of the control strategies of the SOWC, especially during the scenarios such as 2–1 engine idle downshift (engine braking) and 1–2 upshift (coasting). This paper reviews hardware design, vehicle implementation, and focuses on control of the selectable one-way clutch. Vehicle results demonstrate static and rolling garage shifts, 1–2 upshifts, 2–1 and coast downshifts. Also demonstrated is the successful application of engaging 1st gear engine braking with the SOWC. This control involves coordination between the engine speed and SOWC slip speed, and the apply/release of the device.
A Simulation Study of a Reduced-Gravity Simulator for Simulating Human Jumping and Walking in a Reduced-Gravity Environment
Authors: Lu Qi , McAvoy Jesse , Ma Ou
Published: September 2010

This paper presents a computer-simulation based feasibility study of a passive Reduced Gravity Simulator (RGS), which uses spring-based static gravity-balancing technology to simulate a reduced-gravity environment. The concept of the simulator was developed for providing a potentially low-cost and easy-to-use simulation method for assisting astronauts training. The proposed RGS is capable of compensating full or partial gravitational effect of the trainee, providing a similar experience or feeling as if he/she is in a real reduced-gravity environment. Due to the safety requirements, the proposed technology has to be fully studied by means of simulation and nonhuman experiments before it can be safely tested with a human subject. The work presented here is the result of such a simulation study. In the study, a physical human is modeled as a multibody dynamical system with 54 degrees of freedom. The dynamic responses of a human jumping and walking with the RGS are simulated and analyzed. The simulation results are compared to those of the same human body on free jumping and walking in the same reduced-gravity environment.
On Coupled Flexural and Torsional Oscillations of a Vibrating Beam Gyroscopic System
Authors: Ansari Masoud , Esmailzadeh Ebrahim , Jalili Nader
Published: September 2010

Gyroscopes are commonly used to measure the angle of rotation and its rate of change in several critical systems like airplanes. Therefore, there is a never-ending desire for researchers to increase measurement precision of these devices. In order to achieve this goal, some new gyroscopes have been invented recently. Especially, advent of micro manufacturing has appeared some sophisticated to more pre´cised gyroscopic systems. The widely-used gyroscopes are vibrating beam gyroscopes; however they face a very important drawback, called cross-coupling error. In presence of the secondary base rotations, significant errors will be produced in measurement of the gyroscope output. In order to deal with this issue, this paper addresses a novel gyroscopic system, called rocking-mass gyroscope. It is consist of four beams attached to a rigid substrate, undergoing coupled flexural and torsional vibrations with a finite mass attached in the middle. This configuration is such that, it does not encounter the same problems as vibrating beam gyroscopes. This configuration makes the vibration analysis very complicated. Despite this fact, a thorough analysis is performed in this paper. Using Extended Hamilton’s principle, eight governing partial differential equations of motion along with their corresponding boundary conditions are derived. Further attempt is made to find the closed-form frequency equation of the system. Solving this equation needs high computational costs and gives the natural frequencies of the system. In spite of this fact, the system is analysed in the frequency domain using an exact method in full detail, for two cases of fixed and rotating base support. Furthermore, a detailed parameter sensitivity analysis is carried out to determine the effects of different parameters on the natural frequencies of the system. The contributions of this research are very important from two viewpoints. Firstly, determination of natural frequencies and resonance conditions are essential for design of the system, and design of appropriate control strategies. Secondly, frequency domain analysis forms the basis of time domain analysis, followed by exact mode superposition method.
Internal Leakage Diagnosis in Hydraulic Actuators Using Wavelet Transforms
Authors: Yazdanpanah Goharrizi Amin , Sepehri Nariman , Wu Yan
Published: September 2010

This paper describes experimental evaluation of applying wavelet transform to detect internal leakage in hydraulic actuators due to seal damage. The method analyses pressure signal at one side of the actuator in response to periodic step inputs to the control valve. It is shown that the detailed version of decomposed pressure signal, using discrete wavelet transform, establishes feature patterns that can effectively detect internal leakage and its severity. The method is also capable of detecting changes in the friction property of the actuator, another problem associated with actuator seal damage. Specifically, the root mean square (RMS) of level two detail coefficients, obtained from the measured pressure signal, is used to detect internal leakage. The degree of changes of the RMS value from the one obtained under normal operating condition indicates the severity of leakage fault. Furthermore, it is shown that the RMS of level three detail coefficient values, is sensitive to the changes of the actuator friction. All these observations are made without a need to model the actuator, leakage or friction.
Output Synchronization for Teleoperation of Wheel Mobile Robot
Authors: Miller Patrick , Lee Leng-Feng , Krovi Venkat
Published: September 2010

The potential for use of robotic systems in remote applications arenas has long motivated development of robust and stable means of teleoperated control of slave systems. However, telerobotic systems face challenges stemming from the devices themselves, environmental factors, communication and control complexities. To address these challenges, we will adopt the passivity based synchronization framework [1] and study its applicability to safely synchronize two heterogeneous Lagrangian systems. Within this framework, an adaptive controller identifies and stabilizes the dynamics of the master and slave systems and renders the dynamics passive to a secondary coupling input. The passive mapping used to couple the output states of the master and slave systems and is made insensitive to lossy and delayed communication medium. Specifically, an adaptive passive synchronization teleoperation controller is developed between an Omni haptic device that serves as our master and a differentially driven nonholonomic Wheel Mobile Robot (WMR) as the slave system. A battery of hardware-in-the-loop simulations are used to verify the proposed controller.