WorldWideScience

Sample records for water wheels

  1. CFD simulations to optimize the blade design of water wheels

    Science.gov (United States)

    Quaranta, Emanuele; Revelli, Roberto

    2017-05-01

    At low head sites and at low discharges, water wheels can be considered among the most convenient hydropower converters to install. The aim of this work is to improve the performance of an existing breastshot water wheel by changing the blade shape using computational fluid dynamic (CFD) simulations. Three optimal profiles are investigated: the profile of the existing blades, a circular profile and an elliptical profile. The results are validated by performing experimental tests on the wheel with the existing profile. The numerical results show that the efficiency of breastshot wheels is affected by the blade profile. The average increase in efficiency using the new circular profile is about 4 % with respect to the profile of the existing blades.

  2. Model Design for Water Wheel Control System of Heumgyeonggaknu

    Science.gov (United States)

    Kim, Sang Hyuk; Ham, Seon Young; Lee, Yong Sam

    2016-03-01

    Heumgyeonggaknu (????) is powered by a water-hammering-type water wheel. The technique that maintains the constant speed of the water wheel is assumed to be the one used in the Cheonhyeong (???) apparatus in Shui Yun Yi Xiang Tai (???) made by the Northern Song (??) dynasty in the 11th century. We investigated the history of the development and characteristics of the Cheonhyeong apparatus, and we analyzed ways to transmit the power of Heumgyeonggaknu. In addition, we carried out a conceptual design to systematically examine the power control system. Based on the conceptual design, we built a model for a water wheel control system that could be used in experiments by drawing a 3D model and a basic design.

  3. Model laws for water wheels and their application to overshot water wheels; Modellgesetze fuer Wasserraeder und ihre Anwendung auf das oberschlaechtige Wasserrad

    Energy Technology Data Exchange (ETDEWEB)

    Nuernbergk, Dirk M.

    2009-07-01

    For several years, water wheels as a technological drive increasingly gain attention. Water wheels with goitre drain and overshot water wheels have an efficiency of up to 80 %. The question of how this can be exploited on a real location rises. Furthermore, the question of conversion rules rises, if one calculates back a model wheel to a particular location. The required model laws are be derived again in the contribution under consideration. The application of these model laws on the overshot water wheel are explained.

  4. Using of abrasive water jet for measurement of residual stress in railway wheels

    OpenAIRE

    Hlaváček, P. (Petr); Brumek, J.; Horsák, L.

    2012-01-01

    The paper provides a general introduction to methods of measurement of residual stresses on railway wheels. Determination of residual stress distribution is necessary for the prediction of wheel service life and possible catastrophic failure. Therefore experimental section is devoted to residual stress measurement using strain gauges according to standard EN 13262 + A1. During measurement, several segments of tested wheel were cut by abrasive water jet to detect changes of residual stresses o...

  5. Explore, Synthesize, and Repeat: Unraveling Complex Water Management Issues through the Stakeholder Engagement Wheel

    Directory of Open Access Journals (Sweden)

    Kelly E. Mott Lacroix

    2016-03-01

    Full Text Available Effective stakeholder engagement is fundamental to water management, yet there are as many approaches to consultation as there are efforts. This paper provides an evaluation of, and lessons learned from three water management engagement processes, and uses this assessment to offer a framework for stakeholder engagement. The Stakeholder Engagement Wheel framework is centered on a bridging organization that ensures that the process continues to move forward, and a steering committee that guides and changes activities according to stakeholder interests and concerns. Around the Stakeholder Engagement Wheel are four steps designed to examine iteratively the water management issue driving the engagement process and expand the sphere of interests involved. Many engagement processes have limited effectiveness because of: (1 paucity of time; (2 complexity of water resources management; (3 difficulty of engaging diverse stakeholders; and (4 lack of methods for engagement that are centered on empowerment, equity, trust, and learning. In this study, we have encountered all four of these issues and have addressed all but the first through a deliberate, iterative, and flexible approach. By cycling through activities and actions as proposed in the Stakeholder Engagement Wheel, we can build a community of practitioners with the nuanced and shared understanding needed for cohesive action and robust decisions in the face our considerable challenges.

  6. From the water wheel to turbines and hydroelectricity. Technological evolution and revolutions

    Science.gov (United States)

    Viollet, Pierre-Louis

    2017-08-01

    Since its appearance in the first century BC, the water wheel has developed with increasing pre-industrial activities, and has been at the origin of the industrial revolution for metallurgy, textile mills, and paper mills. Since the nineteenth century, the water wheel has become highly efficient. The reaction turbine appeared by 1825, and continued to undergo technological development. The impulsion turbine appeared for high chutes, by 1880. Other turbines for low-head chutes were further designed. Turbine development was associated, after 1890, with the use of hydropower to generate electricity, both for industrial activities, and for the benefits of cities. A model ;one city + one plant; was followed in the twentieth century by more complex and efficient schemes when electrical interconnection developed, together with pumped plants for energy storage.

  7. Well-to-Wheels Water Consumption: Tracking the Virtual Flow of Water into Transportation

    Science.gov (United States)

    Lampert, D. J.; Elgowainy, A.; Hao, C.

    2015-12-01

    Water and energy resources are fundamental to life on Earth and essential for the production of consumer goods and services in the economy. Energy and water resources are heavily interdependent—energy production consumes water, while water treatment and distribution consume energy. One example of this so-called energy-water nexus is the consumption of water associated with the production of transportation fuels. The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model is an analytical tool that can be used to compare the environmental impacts of different transportation fuels on a consistent basis. In this presentation, the expansion of GREET to perform life cycle water accounting or the "virtual flow" of water into transportation and other energy sectors and the associated implications will be discussed. The results indicate that increased usage of alternative fuels may increase freshwater resource consumption. The increased water consumption must be weighed against the benefits of decreased greenhouse gas and fossil energy consumption. Our analysis highlights the importance of regionality, co-product allocation, and consistent system boundaries when comparing the water intensity of alternative transportation fuel production pathways such as ethanol, biodiesel, compressed natural gas, hydrogen, and electricity with conventional petroleum-based fuels such as diesel and gasoline.

  8. Bicycle Wheel

    Science.gov (United States)

    1991-01-01

    An aerodynamic bicycle wheel developed by two DuPont engineers and a California company incorporates research into NASA airfoils. Computer modeling was accomplished with MSC/NASTRAN. Each of the three spokes in the wheel is, in effect, an airfoil, maximizing aerodynamic efficiency for racing.

  9. Effects of high doses of magnesium in drinking water and voluntary wheel running on magnesium and calcium concentrations in rats.

    Science.gov (United States)

    Meludu, S C; Nishimuta, M; Aboh, N A; Okonkwo, C; Dioka, C E

    2002-12-01

    The effect of high magnesium intake in addition to supplementation and voluntary wheel activity on magnesium and calcium homeostasis was investigated in rats. Thirty-six 5-week-old male Wistar rats were divided into four groups (n = 9). Groups 2 and 4 received five hundred ppm of elemental magnesium as MgCl2 provided in drinking water. After 1 week of acclimatization and 4 weeks of supplement and/or exercise, the animals were fasted and sacrificed. It appears that magnesium supplementation as well as exercise played some significant role in the homeostatic changes of magnesium and calcium. This could be of great significance in better understanding of mineral homeostasis particularly in sports medicine.

  10. Word wheels

    CERN Document Server

    Clark, Kathryn

    2013-01-01

    Targeting the specific problems learners have with language structure, these multi-sensory exercises appeal to all age groups including adults. Exercises use sight, sound and touch and are also suitable for English as an Additional Lanaguage and Basic Skills students.Word Wheels includes off-the-shelf resources including lesson plans and photocopiable worksheets, an interactive CD with practice exercises, and support material for the busy teacher or non-specialist staff, as well as homework activities.

  11. Mouse genetic differences in voluntary wheel running, adult hippocampal neurogenesis and learning on the multi-strain-adapted plus water maze.

    Science.gov (United States)

    Merritt, Jennifer R; Rhodes, Justin S

    2015-03-01

    Moderate levels of aerobic exercise broadly enhance cognition throughout the lifespan. One hypothesized contributing mechanism is increased adult hippocampal neurogenesis. Recently, we measured the effects of voluntary wheel running on adult hippocampal neurogenesis in 12 different mouse strains, and found increased neurogenesis in all strains, ranging from 2- to 5-fold depending on the strain. The purpose of this study was to determine the extent to which increased neurogenesis from wheel running is associated with enhanced performance on the water maze for 5 of the 12 strains, chosen based on their levels of neurogenesis observed in the previous study (C57BL/6 J, 129S1/SvImJ, B6129SF1/J, DBA/2 J, and B6D2F1/J). Mice were housed with or without a running wheels for 30 days then tested for learning and memory on the plus water maze, adapted for multiple strains, and rotarod test of motor performance. The first 10 days, animals were injected with BrdU to label dividing cells. After behavioral testing animals were euthanized to measure adult hippocampal neurogenesis using standard methods. Levels of neurogenesis depended on strain but all mice had a similar increase in neurogenesis in response to exercise. All mice acquired the water maze but performance depended on strain. Exercise improved water maze performance in all strains to a similar degree. Rotarod performance depended on strain. Exercise improved rotarod performance only in DBA/2 J and B6D2F1/J mice. Taken together, results demonstrate that despite different levels of neurogenesis, memory performance and motor coordination in these mouse strains, all strains have the capacity to increase neurogenesis and improve learning on the water maze through voluntary wheel running.

  12. Fifth wheel

    Science.gov (United States)

    Albrecht, W. P.; Sparks, R. H. (Inventor)

    1976-01-01

    An improved fifth wheel for a tractor trailer rig, characterized by a first subassembly including a wear plate was developed and modified to be mounted on a downwardly facing surface of a trailer. A king pin projected normally therefrom, and a second subassembly is adapted to be pivotally mounted on an upwardly facing surface of a tractor. The king pin is brought into contiguous relation with the first sub assembly. A receiver for capturing the king pin is included along with a safety means responsive to a failure of the king pin or its latching mechanism for joining the first subassembly with the second subassembly.

  13. Piezoelectric Wheel System

    Science.gov (United States)

    Juang, Puu-An

    2007-10-01

    A piezoelectric wheel system is proposed for used as a microstepping displacement device including a carrier and two displacement members, which are separately pivoted on the carrier. Each displacement member includes two wheels, and which can not rotate. In addition, each wheel includes a wheel sheet and a piezoelectric element embedded on its surface. When the piezoelectricity element generates and transmits power to the wheel sheet, the wheel induces vibration and deformation. Therefore, owing to the wheel sheets and the touched ground involving their relative motion, the displacement device can be moved or can be oriented its motion direction. The wheel system involves direct movement, and has no rotor requirement. In this research, a three-dimensional (3D) mechanical element with an extra electrical degree of freedom is employed to simulate the dynamic vibration modes of the linear piezoelectric, mechanical, and piezoelectric-mechanical behaviours of the piezoelectric wheel.

  14. Effect of Wheel Load on Wheel Vibration and Sound Radiation

    Institute of Scientific and Technical Information of China (English)

    HAN Jian; WANG Ruiqian; WANG Di; GUAN Qinghua; ZHANG Yumei; XIAO Xinbiao; JIN Xuesong

    2015-01-01

    The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation. The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t, the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the effect of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research.

  15. Reimagining the Color Wheel

    Science.gov (United States)

    Snyder, Jennifer

    2011-01-01

    Color wheels are a traditional project for many teachers. The author has used them in art appreciation classes for many years, but one problem she found when her pre-service art education students created colored wheels was that they were boring: simple circles, with pie-shaped pieces, which students either painted or colored in. This article…

  16. The Reaction Wheel Pendulum

    CERN Document Server

    Block, Daniel J; Spong, Mark W

    2007-01-01

    This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

  17. [Two-wheeled cart

    OpenAIRE

    2003-01-01

    205 x 139 mm. A view showing a two-wheeled wooden cart being pulled by two bovine quadrupeds. A man is sitting in the cart and a European man is standing to the side watching. Photograph taken circa 1900.

  18. Wheeled hopping robot

    Science.gov (United States)

    Fischer, Gary J [Albuquerque, NM

    2010-08-17

    The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

  19. Small Satellite Reaction Wheel Optimization

    OpenAIRE

    Michaelis, Ted

    1990-01-01

    The very "smallness" of small satellites mandates mass minimization. This paper addresses minimization of overall reaction wheel mass, including the incremental mass of the power subsystem needed to support the reaction wheel. The results are applicable to a wide range of wheel sizes and are suitable for optimization at the configuration level. For an average momentum and torque operating point, the minimization process yields wheel radius and angular velocity, as well as, the masses associat...

  20. Rotating Wheel Wake

    Science.gov (United States)

    Lombard, Jean-Eloi; Xu, Hui; Moxey, Dave; Sherwin, Spencer

    2016-11-01

    For open wheel race-cars, such as Formula One, or IndyCar, the wheels are responsible for 40 % of the total drag. For road cars, drag associated to the wheels and under-carriage can represent 20 - 60 % of total drag at highway cruise speeds. Experimental observations have reported two, three or more pairs of counter rotating vortices, the relative strength of which still remains an open question. The near wake of an unsteady rotating wheel. The numerical investigation by means of direct numerical simulation at ReD =400-1000 is presented here to further the understanding of bifurcations the flow undergoes as the Reynolds number is increased. Direct numerical simulation is performed using Nektar++, the results of which are compared to those of Pirozzoli et al. (2012). Both proper orthogonal decomposition and dynamic mode decomposition, as well as spectral analysis are leveraged to gain unprecedented insight into the bifurcations and subsequent topological differences of the wake as the Reynolds number is increased.

  1. Getting Behind the Wheel

    Institute of Scientific and Technical Information of China (English)

    SEAN; O’CONNER

    2008-01-01

    I took the cramming school,the conveyor belt approach to learning to drive.As a passed and stamped graduate of the Oriental Fashion Driving School,I’m relieved that I no longer have to get up at 5 o’clock for a 7-to-12 seat behind the wheel

  2. 3-D Color Wheels

    Science.gov (United States)

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  3. 3-D Color Wheels

    Science.gov (United States)

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  4. Color Wheel Windows

    Science.gov (United States)

    Leonard, Stephanie

    2012-01-01

    In this article, the author describes a painting and drawing lesson which was inspired by the beautiful circular windows found in cathedrals and churches (also known as "rose windows"). This two-week lesson would reinforce both the concept of symmetry and students' understanding of the color wheel. (Contains 1 online resource.)

  5. The ubiquitous photonic wheel

    CERN Document Server

    Aiello, Andrea

    2016-01-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its \\emph{longitudinal} spin angular momentum density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding \\emph{transverse} spin angular momentum density. Electric field configurations of this kind have been suggestively dubbed "photonic wheels". It has been recently shown that photonic wheels are commonplace in optics as they occur in electromagnetic fields confined by waveguides, in strongly focused beams, in plasmonic and evanescent waves. In this work we establish a general theory of electromagnetic waves {propagating along a well defined direction, which carry} transverse spin angular momentum density. We show th...

  6. Experiments with Electrodynamic Wheels

    Science.gov (United States)

    Gaul, Nathan; Corey, Daniel; Cordrey, Vincent; Majewski, Walerian

    2015-04-01

    Our experiments were involving inductive magnetic levitation. A Halbach array is a system in which a series of magnets is arranged in a manner such that the magnetic field is cancelled on one side of the array while strengthening the field on the other. We constructed two circular Halbach wheels, making the strong magnetic field on the outer rim of the ring. Such system is usually dubbed as an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We demonstrated that these interactions produce both drag and lift forces on the EDW which can theoretically be used for lift and propulsion of the EDW. The focus of our experiments is determining how to maximize the lift-to-drag ratio by the proper choice of the induction element. We will also describe our experiments with a rotating circular Halbach array having the strong magnetic field of about 1 T on the flat side of the ring, and acting as a hovercraft.

  7. Periodic roads and quantized wheels

    Science.gov (United States)

    de Campos Valadares, Eduardo

    2016-08-01

    We propose a simple approach to determine all possible wheels that can roll smoothly without slipping on a periodic roadbed, while maintaining the center of mass at a fixed height. We also address the inverse problem that of obtaining the roadbed profile compatible with a specific wheel and all other related "quantized wheels." The role of symmetry is highlighted, which might preclude the center of mass from remaining at a fixed height. A straightforward consequence of such geometric quantization is that the gravitational potential energy and the moment of inertia are discrete, suggesting a parallelism between macroscopic wheels and nano-systems, such as carbon nanotubes.

  8. Reaction Wheel with Embedded MEMS IMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is to embed a MEMS IMU Sensor Chip into a reaction wheel to measure its spin rate as well as wheel attitude rate. We propose to use a reaction wheel...

  9. A Country on Wheels

    Institute of Scientific and Technical Information of China (English)

    小雨

    2007-01-01

    Cars are an important part of life in the United States. Most people feel that they are poor without cars. Though he is poor, he doesn't feel really poor when he has a car. Henry Ford was the man who first started making cars. Maybe, he didn't know how much the car was going to affect(影响) the United States. The cars made the United States a country on wheels(轮子). And they have helped to make the United States rich and modern.

  10. Mechanical Design Engineering Enabler Project wheel and wheel drives

    Science.gov (United States)

    Nutt, Richard E.; Couch, Britt K.; Holley, John L., Jr.; Garris, Eric S.; Staut, Paul V.

    1992-01-01

    Our group was assigned the responsibility of designing the wheel and wheel drive system for a proof-of-concept model of the lunar-based ENABLER. ENABLER is a multi-purpose, six wheeled vehicle designed to lift and transport heavy objects associated with the construction of a lunar base. The resulting design was based on the performance criteria of the ENABLER. The drive system was designed to enable the vehicle to achieve a speed of 7 mph on a level surface, climb a 30 percent grade, and surpass a one meter high object and one meter wide crevice. The wheel assemblies were designed to support the entire weight of the vehicle on two wheels. The wheels were designed to serve as the main component of the vehicle's suspension and will provide suitable traction for lunar-type surfaces. The expected performance of the drive system for the ENABLER was influenced by many mechanical factors. The expected top speed on a level sandy surface is 4 mph instead of the desired 7 mph. This is due to a lack of necessary power at the wheels. The lack of power resulted from dimension considerations that allowed only an eight horsepower engine and also from mechanical inefficiencies of the hydraulic system. However, the vehicle will be able to climb a 30 percent grade, surpass a one meter high object and one meter wide crevice. The wheel assemblies will be able to support the entire weight of the vehicle on two wheels. The wheels will also provide adequate suspension for the vehicle and sufficient traction for lunar-type surfaces.

  11. The outlook for wheeling

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, M.J.

    1990-04-01

    There is a continued national interest in decentralized power sources involving cogeneration and independent power production. But while these issues are debated in the halls of Congress, and the subject of generic rulemaking debate before the FERC, the real action is occurring elsewhere. Key momentum is building in the states ad individual electric utility systems requiring Federal Energy Regulatory Commission (FERC) and state commission review of discrete applications for case by case review. These reflect the pressure of competitive forces building within the industry from other electric utilities, power export marketeers, environmental and siting regulation, and from financial institutions. The underlying intent of PURPA is to encourage and provide incentives for the development of alternate energy sources to provide the efficient use of our nation's natural resources. Under PURPA the Commission can not direct an electric utility to provide transmission services. However, this power can only be exercised after a series of complex findings by the Commission through evidentiary hearings. In addition, PURPA amended other sections of the Federal Power Act to provide various rate incentives and exemptions for cogeneration and small power production facilities including the right for interconnection to the electric utility. The scope of such interconnection rights, and whether they might encompass broader transmission rights for QFs has yet to be tested. This paper describes wheeling rules prior to PURPA, the PURPA amendments governing wheeling; states' views; and the need for a review.

  12. Swirls and wheels

    Science.gov (United States)

    Maskit, B.

    1992-02-01

    There are several standard splittings of Kleinian groups using multiple combination theorems; these are the splitting of a function group into basic groups, the more general splitting of an analytically finite group into web groups, and the splitting given by Thurston of a Haken hyperbolic manifold. These splitting all use a finite set of combination theorems, where the order is, in some sense, irrelevant (the first two splittings mentioned above use only one such set; the Thurston splitting uses a finite sequence of these). A general theory of these finite sets of commuting splittings is built in the context of an arbitrary Kleinian group, and a descriptive language for these splittings is constructed. The point is decomposition rather than construction. One needs to be able to say that a given group could have been built up by using a commuting set of combination theorems, from certain subgroups, without specifying the subgroups. The description is given in terms of a system of swirls and wheels. Swirls are simple closed curves with certain additional properties, and wheels are generalized simple closed curves; these will be described. A system of these is a G-invariant collection, where no element of the system crosses any other element of the system, although they may touch at carefully controlled points.

  13. Squeaky Wheel Optimization

    CERN Document Server

    Clements, D P; 10.1613/jair.561

    2011-01-01

    We describe a general approach to optimization which we term `Squeaky Wheel' Optimization (SWO). In SWO, a greedy algorithm is used to construct a solution which is then analyzed to find the trouble spots, i.e., those elements, that, if improved, are likely to improve the objective function score. The results of the analysis are used to generate new priorities that determine the order in which the greedy algorithm constructs the next solution. This Construct/Analyze/Prioritize cycle continues until some limit is reached, or an acceptable solution is found. SWO can be viewed as operating on two search spaces: solutions and prioritizations. Successive solutions are only indirectly related, via the re-prioritization that results from analyzing the prior solution. Similarly, successive prioritizations are generated by constructing and analyzing solutions. This `coupled search' has some interesting properties, which we discuss. We report encouraging experimental results on two domains, scheduling problems that ari...

  14. PHENOMENON OF CARVED DRIVING WHEELS

    Institute of Scientific and Technical Information of China (English)

    LI Xianghua; ZHANG Jianwu

    2007-01-01

    A newly found phenomenon of carved driving wheels of a rea-wheel-drive tractor used in an airport is discussed. The circum of every driving wheel is damaged at three regions, which distribute regularly and uniformly. Everyday, the tractor tows a trailer which are times heavier than the tractor, and moves on the same road in the airport. The phenomenon is explained by the torsional self-excited vibration system of the powertrain. The simplified torsional vibration system is discribed by a 2-order ordinary differential equation, which has a limit circle. Experiments and numerical simulations show the followings: Because of the heavy trailer, the slip ratio of the tractor's driving wheels is very large. Therefore, there is severe torsional self-excited vibration in the tractor's drivetrain, and the self-excited vibration results in severe and regular fluctuations of the rear wheel's velocity. The severe fluctuations in velocity fastens the damage of the driving wheels. At the same time, the time interval in which an arbitrary point in the circum of the driving wheel contacts with the road twice is two times more than the period of the torsional self-excited vibration, and this times explained the existence of three damaged regions. At last, it points out that the phenomenon can be avoided when the torsional damping is large enough.

  15. For each head differences the corresponding turbine. Energy generating water wheels were already known by Greeks and Romans in the ancient world; Fuer jede Fallhoehe die richtige Turbine. Wasserraeder mit dem Vorteil, damit Energie zu erzeugen, kannten in der Antike schon Griechen und Roemer

    Energy Technology Data Exchange (ETDEWEB)

    Krause, W.

    2006-07-01

    From simple water wheels, working in the Ancient World, to modern hydraulic turbines like Francis, Pelton and Kaplan turbine, the contribution shows the development of this engines generating clean power. Operating with small heads and high flow rates and velocities a new generation like the tube turbine and in special fields the flow rate turbine are able to generate power still more efficiently. (GL)

  16. The big wheels of ATLAS

    CERN Multimedia

    2006-01-01

    The ATLAS cavern is filling up at an impressive rate. The installation of the first of the big wheels of the muon spectrometer, a thin gap chamber (TGC) wheel, was completed in September. The muon spectrometer will include four big moving wheels at each end, each measuring 25 metres in diameter. Of the eight wheels in total, six will be composed of thin gap chambers for the muon trigger system and the other two will consist of monitored drift tubes (MDTs) to measure the position of the muons (see Bulletin No. 13/2006). The installation of the 688 muon chambers in the barrel is progressing well, with three-quarters of them already installed between the coils of the toroid magnet.

  17. Wheels lining up for ATLAS

    CERN Multimedia

    2003-01-01

    On 30 October, the mechanics test assembly of the central barrel of the ATLAS tile hadronic calorimeter was completed in building 185. It is the second wheel for the Tilecal completely assembled this year.

  18. Wind wheel electric power generator

    Science.gov (United States)

    Kaufman, J. W. (Inventor)

    1980-01-01

    Wind wheel electric power generator apparatus includes a housing rotatably mounted upon a vertical support column. Primary and auxiliary funnel-type, venturi ducts are fixed onto the housing for capturing wind currents and conducting to a bladed wheel adapted to be operatively connected with the generator apparatus. Additional air flows are also conducted onto the bladed wheel; all of the air flows positively effecting rotation of the wheel in a cumulative manner. The auxiliary ducts are disposed at an acute angle with respect to the longitudinal axis of the housing, and this feature, together with the rotatability of the housing and the ducts, permits capture of wind currents within a variable directional range.

  19. Computation of bicycle wheel power

    Institute of Scientific and Technical Information of China (English)

    尚寿亭; 吴龙; 薛立军; 徐吉杰

    2001-01-01

    Presents the model on the drag resistance to overcome discusses the equations used for calculation of spoked and solid wheel power and force, and gives a table of power output under a certain condition for comparison of two types of wheels, and suggests a scheme to estimate power on a specific track, and the speed and the time spent on a certain track are compared to illustrate the functions of parameters.

  20. The ubiquitous photonic wheel

    Science.gov (United States)

    Aiello, Andrea; Banzer, Peter

    2016-08-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its longitudinal spin angular momentum (AM) density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding transverse spin AM density. Electric field configurations of this kind have been suggestively dubbed ‘photonic wheels’. It has been recently shown that photonic wheels are commonplace in optics as they occur in electromagnetic fields confined by waveguides, in strongly focused beams, in plasmonic and evanescent waves. In this work we establish a general theory of electromagnetic waves propagating along a well defined direction, and carrying transverse spin AM density. We show that depending on the shape of these waves, the spin density may be either perpendicular to the mean linear momentum (globally transverse spin) or to the linear momentum density (locally transverse spin). We find that the latter case generically occurs only for non-diffracting beams, such as the Bessel beams. Moreover, we introduce the concept of meridional Stokes parameters to operationally quantify the transverse spin density. To illustrate our theory, we apply it to the exemplary cases of Bessel beams and evanescent waves. These results open a new and accessible route to the understanding, generation and manipulation of optical beams with transverse spin AM density.

  1. Magnetically suspended momentum wheels for spacecraft stabilization

    Science.gov (United States)

    Henrikson, C. H.; Lyman, J.; Studer, P. A.

    1974-01-01

    Magnetic bearings for spacecraft momentum wheels offer the promise of low friction and unlimited life. This paper describes how magnetic bearings work and their advantages and disadvantages. The present status of magnetic bearings is described and examples are shown of the various and widely-different magnetically suspended momentum wheels that have been built to date. These include wheels whose bearings exhibit high stiffness and wheels with zero-power suspensions. The future of magnetically suspended momentum wheels is discussed including the possibility of wheels with neither spokes nor shaft.

  2. Two new wheels for ATLAS

    CERN Multimedia

    2002-01-01

    Juergen Zimmer (Max Planck Institute), Roy Langstaff (TRIUMF/Victoria) and Sergej Kakurin (JINR), in front of one of the completed wheels of the ATLAS Hadronic End Cap Calorimeter. A decade of careful preparation and construction by groups in three continents is nearing completion with the assembly of two of the four 4 m diameter wheels required for the ATLAS Hadronic End Cap Calorimeter. The first two wheels have successfully passed all their mechanical and electrical tests, and have been rotated on schedule into the vertical position required in the experiment. 'This is an important milestone in the completion of the ATLAS End Cap Calorimetry' explains Chris Oram, who heads the Hadronic End Cap Calorimeter group. Like most experiments at particle colliders, ATLAS consists of several layers of detectors in the form of a 'barrel' and two 'end caps'. The Hadronic Calorimeter layer, which measures the energies of particles such as protons and pions, uses two techniques. The barrel part (Tile Calorimeter) cons...

  3. Propulsion Wheel Motor for an Electric Vehicle

    Science.gov (United States)

    Figuered, Joshua M. (Inventor); Herrera, Eduardo (Inventor); Waligora, Thomas M. (Inventor); Bluethmann, William J. (Inventor); Farrell, Logan Christopher (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Winn, Ross Briant (Inventor); Eggleston, IV, Raymond Edward (Inventor); Guo, Raymond (Inventor); hide

    2016-01-01

    A wheel assembly for an electric vehicle includes a wheel rim that is concentrically disposed about a central axis. A propulsion-braking module is disposed within an interior region of the wheel rim. The propulsion-braking module rotatably supports the wheel rim for rotation about the central axis. The propulsion-braking module includes a liquid cooled electric motor having a rotor rotatable about the central axis, and a stator disposed radially inside the rotor relative to the central axis. A motor-wheel interface hub is fixedly attached to the wheel rim, and is directly attached to the rotor for rotation with the rotor. The motor-wheel interface hub directly transmits torque from the electric motor to the wheel rim at a 1:1 ratio. The propulsion-braking module includes a drum brake system having an electric motor that rotates a cam device, which actuates the brake shoes.

  4. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel disturbances are some of the largest sources of noise on sensitive telescopes. Such wheel-induced mechanical noises are not well characterized....

  5. Experimental heat and mass transfer of the separated and coupled rotating desiccant wheel and heat wheel

    Energy Technology Data Exchange (ETDEWEB)

    Enteria, Napoleon; Yoshino, Hiroshi; Mochida, Akashi; Takaki, Rie [Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Satake, Akira [Technical Research Institute, Maeda Corporation, Tokyo 179-8914 (Japan); Yoshie, Ryuichiro [Faculty of Engineering, Tokyo Polytechnic University, Atsugi 243-0297 (Japan); Mitamura, Tiruaki [Faculty of Engineering, Ashikaga Institute of Technology, Ashikaga 326-8558 (Japan); Baba, Seizo [Earth Clean Tohoku Co., Ltd., Sendai 984-0038 (Japan)

    2010-07-15

    The experimental evaluation of the separated and coupled rotating desiccant wheel and heat wheel is reported. The study aims to investigate the performance of the desiccant wheel and of the heat wheel both when operated separately and jointly. The performance evaluation of the desiccant wheel is based on its moisture removal capacity (MRC), moisture removal regeneration (MRR), and moisture mass balance (MMB). In addition, the study used the total energy balance (TEB), sensible coefficient of performance (COP{sub Sensible}), latent coefficient of performance (COP{sub Latent}) and, total coefficient of performance (COP{sub Total}). The performance of the heat wheel is based on its effectiveness. The COP{sub Sensible}, COP{sub Latent} and, COP{sub Total} are used in the performance evaluation of the coupled desiccant wheel and heat wheel. The general results of the study show that the MRC, MRR and MMB coupled with the TEB, COP{sub Latent}, COP{sub Sensible} and COP{sub Total} predict adequately the performance of the desiccant wheel. In addition, the coupled operation of the desiccant wheel and heat wheel, contributed to the reduction of the external thermal energy requirement for the regeneration of the desiccant wheel. This study can be applied in other researches seeking evaluation of the desiccant wheel, heat wheel, and their combined operation. Moreover, the data presented here are significant for the desiccant wheel benchmarking and for evaluation of the desiccant wheel models. (author)

  6. New steering mechanism for wheeled mobile robots

    Institute of Scientific and Technical Information of China (English)

    Sidibe Marie Bernard; FU Yi-li; XU He; MA Yu-lin

    2007-01-01

    A new castor wheel mechanism for omni-directional mobile platform is presented. A motion of translation is transformed into a rotation to steer the wheel with the help of a helical path fits into a translation joint and three rollers whose axes are connected to the driving shaft of the wheel. When the path moves in translation it acts on the rollers for steering. The path-roller friction transmission, the wheel kinematics and the maneuverability have been analyzed.

  7. 49 CFR 230.112 - Wheels and tires.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Wheels and tires. 230.112 Section 230.112... Tenders Wheels and Tires § 230.112 Wheels and tires. (a) Mounting. Wheels shall be securely mounted on... wheels mounted on the same axle shall not vary more than 1/4 inch. (d) Tire thickness. Wheels may...

  8. Motion Control of Wheeled Mobile Robots

    Directory of Open Access Journals (Sweden)

    Birol Kocaturk

    2015-01-01

    Full Text Available This article presents strategy for navigation of a wheeled mobile robot in unstructured environments with obstacles. The vehicle has two wheels independently to control the angular velocity. This work deals with mobile robots modelling then control strategies and simulation results. Simulation results recommends fuzzy logic controller for the wheeled mobile robot motion in unstructured environments.

  9. Supplementary magnetic tests for railway wheel sets

    Directory of Open Access Journals (Sweden)

    Zbigniew Hilary ŻUREK

    2008-01-01

    Full Text Available During manufacturing process the wheel set is subjected to many different flaw detection methods; however, these methods are not sufficient while the wheel set is in service. The paper presents an example of monitoring of magnetic parameters changes of wheel set rolling surface (changes result from material degradation due to materialfatigue.

  10. Before the Outline--The Writing Wheel.

    Science.gov (United States)

    Rae, Colleen

    1990-01-01

    Illustrates the use of the writing wheel, a prewriting technique for writing from thesis statements that requires students to create a picture of a wheel. Shows how the wheel can be used in writing paragraphs and how it can be combined with summary writing to produce an integrated term paper. (DB)

  11. Roughness on Dutch railway wheels and rails

    NARCIS (Netherlands)

    Dings, P.C.; Dittrich, M.G.

    1996-01-01

    Surface roughness on 150 railway wheels and on the rails of 30 sites in the Netherlands have been measured. Block braked wheels were found to show higher roughnesses than the rail at any site. The smoothest rail is 8 dB smoother than the smoothest wheel. It was concluded that in reducing railway

  12. Getting Off the Hamster Wheel

    Science.gov (United States)

    Sammon, Grace

    2005-01-01

    Even with all the external elements of school reform in place, educators can end up spinning their wheels. To make progress, schools must identify the nonnegotiable key elements of their reform plans and use the habits of highly effective schools to turn them into school practice. These habits are: (1) demonstrate high expectations and a vision…

  13. Some peculiarities of corrosion of wheel steel

    Directory of Open Access Journals (Sweden)

    Alexander SHRAMKO

    2009-01-01

    Full Text Available Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosion nucleation and their influence on corrosion depends on type of inclusion. Mechanism of corrosion of wheel steel corrosion was discussed.

  14. Wheel of concert hall acoustics

    OpenAIRE

    Kuusinen, A.; Lokki, T.

    2017-01-01

    More than a hundred years of research on concert hall acoustics has provided an extensive list of attributes to describe and evaluate the perceptual aspects of sound in concert halls. This brief overview discusses the current knowledge, and presents a "wheel of concert hall acoustics" in which the main aspects are gathered together with the descriptive attributes that are commonly encountered in the research literature. Peer reviewed

  15. Rover's Wheel Churns Up Bright Martian Soil

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel. The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life. Spirit acquired this mosaic with the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. The view presented here is an approximately true-color rendering.

  16. Reaction wheels for kinetic energy storage

    Science.gov (United States)

    Studer, P. A.

    1984-01-01

    In contrast to all existing reaction wheel implementations, an order of magnitude increase in speed can be obtained efficiently if power to the actuators can be recovered. This allows a combined attitude control-energy storage system to be developed with structure mounted reaction wheels. The feasibility of combining reaction wheels with energy storage wwheels is demonstrated. The power required for control torques is a function of wheel speed but this energy is not dissipated; it is stored in the wheel. The I(2)R loss resulting from a given torque is shown to be constant, independent of the design speed of the motor. What remains, in order to efficiently use high speed wheels (essential for energy storage) for control purposes, is to reduce rotational losses to acceptable levels. Progress was made in permanent magnet motor design for high speed operation. Variable field motors offer more control flexibility and efficiency over a broader speed range.

  17. Preliminary Design and Investigation of Integrated Compressor with Composite Material Wheel

    Science.gov (United States)

    Wang, Jifeng; Müller, Norbert

    2012-06-01

    An integrated water vapor compressor with composite material wheel is developed and strength analysis using FEM is presented. The design of wound composite material allows for integrating all rotating parts of the drive that may simply reduce to only the rotor of the electrical motor, since no drive shaft is required anymore. This design can reduce the number of parts and mass, which is convenient for engineers to maintain the compressor. The electrical motors are brushless DC motors operating through a frequency drive and apply a torque on the wheels through the materials bonded in the wheel shrouds. This system allows a large amount of compression to be produced in a multi-stage compression setup. To determine the stress and vibration characteristics of this integrated compressor, numerical analysis is carried out using FEM. The simulation result shows that the integrated compressor with composite material wheel can be used in a chiller system where water as a refrigerant.

  18. A novel instrumented multipeg running wheel system, Step-Wheel, for monitoring and controlling complex sequential stepping in mice.

    Science.gov (United States)

    Kitsukawa, Takashi; Nagata, Masatoshi; Yanagihara, Dai; Tomioka, Ryohei; Utsumi, Hideko; Kubota, Yasuo; Yagi, Takeshi; Graybiel, Ann M; Yamamori, Tetsuo

    2011-07-01

    Motor control is critical in daily life as well as in artistic and athletic performance and thus is the subject of intense interest in neuroscience. Mouse models of movement disorders have proven valuable for many aspects of investigation, but adequate methods for analyzing complex motor control in mouse models have not been fully established. Here, we report the development of a novel running-wheel system that can be used to evoke simple and complex stepping patterns in mice. The stepping patterns are controlled by spatially organized pegs, which serve as footholds that can be arranged in adjustable, ladder-like configurations. The mice run as they drink water from a spout, providing reward, while the wheel turns at a constant speed. The stepping patterns of the mice can thus be controlled not only spatially, but also temporally. A voltage sensor to detect paw touches is attached to each peg, allowing precise registration of footfalls. We show that this device can be used to analyze patterns of complex motor coordination in mice. We further demonstrate that it is possible to measure patterns of neural activity with chronically implanted tetrodes as the mice engage in vigorous running bouts. We suggest that this instrumented multipeg running wheel (which we name the Step-Wheel System) can serve as an important tool in analyzing motor control and motor learning in mice.

  19. ATLAS- lowering the muon small wheel

    CERN Multimedia

    CERN Audiovisual Service

    2008-01-01

    ATLAS - the two muon small wheels lowered into the cavern Like briefly separated twin sisters, ATLAS’s small wheels were once again united at the experiment’s surface building at Point 1 on St Valentine’s Day. The lowering of the small wheels into the tunnel will mark the end of the installation of detector components for the experiment. At around 15.40 on Friday 29th February the ATLAS collaboration cracked open the champagne as the second of the small wheels was lowered into the cavern.

  20. ATLAS- lowering the muon small wheel

    CERN Multimedia

    2008-01-01

    ATLAS - the two muon small wheels lowered into the cavern Like briefly separated twin sisters, ATLAS’s small wheels were once again united at the experiment’s surface building at Point 1 on St Valentine’s Day. The lowering of the small wheels into the tunnel will mark the end of the installation of detector components for the experiment. At around 15.40 on Friday 29th February the ATLAS collaboration cracked open the champagne as the second of the small wheels was lowered into the cavern.

  1. Electronic 4-wheel drive control device

    Science.gov (United States)

    Hayato, S.; Takanori, S.; Shigeru, H.; Tatsunori, S.

    1984-01-01

    The internal rotation torque generated during operation of a 4-wheel drive vehicle is reduced using a control device whose clutch is attached to one part of the rear-wheel drive shaft. One torque sensor senses the drive torque associated with the rear wheel drive shaft. A second sensor senses the drive torque associated with the front wheel drive shaft. Revolution count sensors sense the revolutions of each drive shaft. By means of a microcomputer, the engagement of the clutch is changed to insure that the ratio of the torque sensors remains constant.

  2. Finite element simulation of wheel impact test

    Directory of Open Access Journals (Sweden)

    S.H. Yang

    2008-06-01

    Full Text Available Purpose: In order to achieve better performance and quality, the wheel design and manufacturing use a number of wheel tests (rotating bending test, radial fatigue test, and impact test to insure that the wheel meets the safety requirements. The test is very time consuming and expensive. Computer simulation of these tests can significantly reduce the time and cost required to perform a wheel design. In this study, nonlinear dynamic finite element is used to simulate the SAE wheel impact test.Design/methodology/approach: The test fixture used for the impact test consists of a striker with specified weight. The test is intended to simulate actual vehicle impact conditions. The tire-wheel assembly is mounted at 13° angle to the vertical plane with the edge of the weight in line with outer radius of the rim. The striker is dropped from a specified height above the highest point of the tire-wheel assembly and contacts the outboard flange of the wheel.Because of the irregular geometry of the wheel, the finite element model of an aluminium wheel is constructed by tetrahedral element. A mesh convergence study is carried out to ensure the convergence of the mesh model. The striker is assumed to be rigid elements. Initially, the striker contacts the highest area of the wheel, and the initial velocity of the striker is calculated from the impact height. The simulated strains at two locations on the disc are verified by experimental measurements by strain gages. The damage parameter of a wheel during the impact test is a strain energy density from the calculated result.Findings: The prediction of a wheel failure at impact is based on the condition that fracture will occur if the maximum strain energy density of the wheel during the impact test exceeds the total plastic work of the wheel material from tensile test. The simulated results in this work show that the total plastic work can be effectively employed as a fracture criterion to predict a wheel

  3. Control Electronics For Reaction Wheel

    Science.gov (United States)

    Chamberlin, Keith

    1995-01-01

    Bidirectional operation achieved with single-polarity main power supply. Control circuitry generates pulse-width-modulated 800-Hz waveforms to drive two-phase ac motor and reaction wheel. Operates partly in response to digital magnitude-and-direction torque command generated by external control subsystem and partly in response to tachometric feedback in form of two once-per-revolution sinusoids with amplitudes proportional to speed. Operation in either of two modes called "normal" and "safehold." In normal mode, drive pulses timed so that, on average over one or few cycles, motor applies commanded torque. In safehold mode, pulses timed to keep motor running at set speed in one direction.

  4. The energy wheel in operation

    Science.gov (United States)

    Barthelemy, J. P.

    An energy wheel was implemented as an uninterruptible power supply unit for a rural telephone exchange. A high speed rotor, magnetically suspended, inside a vacuum container, is activated by a brushless motor. Being reversible, this motor acts as an electrical energy generator in case of failure or microcuts from the mains. No failure, no maintenance, no detrimental effect of cold winter environment, and satisfactory level of available back up energy are reported. Improvements such as mass reduction, easy implementation, vacuum tightness, and ac supply are identified.

  5. Omni rotational driving and steering wheel

    DEFF Research Database (Denmark)

    2008-01-01

    omni rotational part (105) with a suspension (116) such that wheel part (108) can move relatively to the upper omni rotational part (105) in a suspension direction (118), and a reduction gear (120) for gearing the drive torque is provided in the wheel part (108) in order e.g. to assure traction...

  6. 16 CFR 1507.8 - Wheel devices.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Wheel devices. 1507.8 Section 1507.8... FIREWORKS DEVICES § 1507.8 Wheel devices. Drivers in fireworks devices commonly known as “wheels” shall be securely attached to the device so that they will not come loose in transportation, handling, and...

  7. 49 CFR 215.103 - Defective wheel.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange on the car is worn to a thickness of 7/8 of an inch, or less, at a point 3/8 of an inch above...

  8. A Full Disturbance Model for Reaction Wheels

    NARCIS (Netherlands)

    Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

    2014-01-01

    Reaction wheels are rotating devices used for the attitude control of spacecraft. However, reaction wheels also generate undesired disturbances in the form of vibrations, which may have an adverse effect on the pointing accuracy and stability of spacecraft (optical) payloads. A disturbance model for

  9. Development of the FASTER Wheeled Bevameter

    Science.gov (United States)

    Richter, L.; Eder, V.; Hoheneder, W.; Imhof, B.; Lewinger, W.; Ransom, S.; Saaj, C.; Weclewski, P.; Waclavicek, R.,

    2014-04-01

    This paper describes the development of a Wheeled Bevameter (WB) within the FASTER project (Forward Acquisition of Soil and Terrain Data for Exploration Rovers), funded by the European Union's FP7 programme. In FASTER, novel and innovative concepts for in situ forward sensing of soil properties and terrain conditions in the planned path of a planetary rover are developed. Terrain strength measurements for assessment of the mobility of crosscountry vehicles have decades of heritage on Earth, but typically trafficability of terrains is only gauged by human operators ahead of vehicle operations rather than in-line by probes deployed from the vehicle itself, as is intended for FASTER. For FASTER, a Wheeled Bevameter (WB) has been selected as the terrain sensing instrument for the vehicle. Wheeled Bevameters are suitable for terrain measurements while driving but traditionally have mostly been employed on terrestrial vehicles to evaluate particular wheel designs. The WB as conceived in FASTER uses a dedicated, passive-rolling test wheel (‚test wheel') placed on the terrain as the loading device to enable to determine bearing strength, compressive strength and shear strength of the terrain immediately ahead of the vehicle, as well as rover-terrain interaction parameters used in semi-empirical vehicle-terrain traction models. The WB includes a placement mechanism for the test wheel. The test wheel would remain lowered onto the ground during nominal rover motion, including when climbing and descending slopes. During normal operations, the placement mechanism assumes the function of a passive suspension of the wheel, allowing it to follow the terrain contour. Quantities measured with the WB are: test wheel sinkage (through a laser sensor), test wheel vertical load, test wheel horizontal reaction force, and test wheel rotation rate. Measurements are performed while the rover is in motion. Measured test wheel rotation rate (with appropriate corrections for slight skid) can

  10. Omni rotational driving and steering wheel

    DEFF Research Database (Denmark)

    2008-01-01

    Abstract of WO 2008138346  (A1) There is disclosed a driving and steering wheel (112) module (102) with an omni rotational part (106), the module comprising a flange part (104) fixable on a robot, and the omni rotational part (106) comprises an upper omni rotational part (105) and a driving...... and steering wheel part (108), where the omni rotational part (106) is provided for infinite rotation relative to the flange part (104) by both a drive motor (110) and a steering motor (114) being positionable on the flange part (104), and the driving and steering wheel part (108) is suspended from the upper...... omni rotational part (105) with a suspension (116) such that wheel part (108) can move relatively to the upper omni rotational part (105) in a suspension direction (118), and a reduction gear (120) for gearing the drive torque is provided in the wheel part (108) in order e.g. to assure traction...

  11. Biaxial wheel/hub test facility. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, G.; Grubisic, V. [eds.

    2000-07-01

    The 4{sup th} meeting aims to exchange the experience and knowledge of engineers during several presentations and discussions about new developments required for a reliable, time and cost reducing validation of the wheel/hub assembly. Tremendous development of the wheel performance, described by the ratio of the rated load (kg) versus the wheel weight (kg) had taken place during the last 5000 years. Starting from the ratio of 3 for wooden 2-piece-disc-wheels in Mesopotamia it needed nearly 1000 years to increase the ratio to approx 5 at light-weight spoke wheels for fighting carriages, found in the grave of king Tutenchamon in Egypt. Modern light alloy wheels of commercial vehicles reach values up to 160 kg/kg. Additionally the comlex design of the modern systems for cars and commercial vehicles comprising wheel, brake, hub, bearing, spindle and hub carrier, including different materials and their treatment, fasteners, press-fits, require an appropriate testing procedure. The variable loading conditions, caused by operational wheel forces, brake and torque moments including heating, may result in changing tolerances and press-fits during operation and consequently in different damage mechanisms. This can be simulated in the Biaxial Wheel Test Machine, whereby corresponding load programs are necessary. An overview about all biaxial test machines in usage at the end of 1999 is shown in the introduction. The total number is 17 for cars, 7 for commercial vehicles and 1 for trains. The six presentations of this meeting were consequently concentrated on: (a) recommendations for a standardization of load programs of the German Wheel Committee, (b) the simulation of brake and torque events and (c) the possibility for a numerical stress analyses and fatigue life assessment. (orig./AKF)

  12. The response of a high-speed train wheel to a harmonic wheel-rail force

    Science.gov (United States)

    Sheng, Xiaozhen; Liu, Yuxia; Zhou, Xin

    2016-09-01

    The maximum speed of China's high-speed trains currently is 300km/h and expected to increase to 350-400km/h. As a wheel travels along the rail at such a high speed, it is subject to a force rotating at the same speed along its periphery. This fast moving force contains not only the axle load component, but also many components of high frequencies generated from wheel-rail interactions. Rotation of the wheel also introduces centrifugal and gyroscopic effects. How the wheel responds is fundamental to many issues, including wheel-rail contact, traction, wear and noise. In this paper, by making use of its axial symmetry, a special finite element scheme is developed for responses of a train wheel subject to a vertical and harmonic wheel-rail force. This FE scheme only requires a 2D mesh over a cross-section containing the wheel axis but includes all the effects induced by wheel rotation. Nodal displacements, as a periodic function of the cross-section angle 6, can be decomposed, using Fourier series, into a number of components at different circumferential orders. The derived FE equation is solved for each circumferential order. The sum of responses at all circumferential orders gives the actual response of the wheel.

  13. Minisatellite Attitude Guidance Using Reaction Wheels

    Directory of Open Access Journals (Sweden)

    Ion STROE

    2015-06-01

    Full Text Available In a previous paper [2], the active torques needed for the minisatellite attitude guidance from one fixed attitude posture to another fixed attitude posture were determined using an inverse dynamics method. But when considering reaction/momentum wheels, instead of this active torques computation, the purpose is to compute the angular velocities of the three reaction wheels which ensure the minisatellite to rotate from the initial to the final attitude. This paper presents this computation of reaction wheels angular velocities using a similar inverse dynamics method based on inverting Euler’s equations of motion for a rigid body with one fixed point, written in the framework of the x-y-z sequence of rotations parameterization. For the particular case A=B not equal C of an axisymmetric minisatellite, the two computations are compared: the active torques computation versus the computation of reaction wheels angular velocities ̇x , ̇y and ̇z. An interesting observation comes out from this numerical study: if the three reaction wheels are identical (with Iw the moment of inertia of one reaction wheel with respect to its central axis, then the evolutions in time of the products between Iw and the derivatives of the reaction wheels angular velocities, i.e. ̇ , ̇ and ̇ remain the same and do not depend on the moment of inertia Iw.

  14. Medicine Wheels of the Great Plains

    Science.gov (United States)

    Vogt, David

    Medicine Wheels are unexplained aboriginal boulder configurations found primarily on hilltops and river valley vistas across the northwest Great Plains of North America. Their varied, complex designs have inspired diverse hypotheses concerning their meaning and purpose, including astronomical ones. While initial "observatory" speculations were unfounded, and quests to "decode" these structures remain unfulfilled and possibly misguided, the Medicine Wheels nevertheless represent a uniquely worthwhile case study in archaeoastronomical theory and method. In addition, emerging technologies for data acquisition and analysis pertinent to Medicine Wheels offer prospectively important new sight lines for the future of archaeoastronomy.

  15. Dynamics and wheel's slip ratio of a wheel-legged robot in wheeled motion considering the change of height

    Science.gov (United States)

    Ding, Xilun; Li, Kejia; Xu, Kun

    2012-09-01

    The existing research on dynamics and slip ratio of wheeled mobile robot (WMR) are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS-II. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS-II in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified. Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height.

  16. The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels

    Directory of Open Access Journals (Sweden)

    Paul Molyneux-Berry

    2014-01-01

    Full Text Available The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing. The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets.

  17. The influence of wheel/rail contact conditions on the microstructure and hardness of railway wheels.

    Science.gov (United States)

    Molyneux-Berry, Paul; Davis, Claire; Bevan, Adam

    2014-01-01

    The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an "in-service" wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets.

  18. The Influence of Wheel/Rail Contact Conditions on the Microstructure and Hardness of Railway Wheels

    Science.gov (United States)

    Davis, Claire

    2014-01-01

    The susceptibility of railway wheels to wear and rolling contact fatigue damage is influenced by the properties of the wheel material. These are influenced by the steel composition, wheel manufacturing process, and thermal and mechanical loading during operation. The in-service properties therefore vary with depth below the surface and with position across the wheel tread. This paper discusses the stress history at the wheel/rail contact (derived from dynamic simulations) and observed variations in hardness and microstructure. It is shown that the hardness of an “in-service” wheel rim varies significantly, with three distinct effects. The underlying hardness trend with depth can be related to microstructural changes during manufacturing (proeutectoid ferrite fraction and pearlite lamellae spacing). The near-surface layer exhibits plastic flow and microstructural shear, especially in regions which experience high tangential forces when curving, with consequentially higher hardness values. Between 1 mm and 7 mm depth, the wheel/rail contacts cause stresses exceeding the material yield stress, leading to work hardening, without a macroscopic change in microstructure. These changes in material properties through the depth of the wheel rim would tend to increase the likelihood of crack initiation on wheels toward the end of their life. This correlates with observations from several train fleets. PMID:24526883

  19. UT Biomedical Informatics Lab (BMIL probability wheel

    Directory of Open Access Journals (Sweden)

    Sheng-Cheng Huang

    2016-01-01

    Full Text Available A probability wheel app is intended to facilitate communication between two people, an “investigator” and a “participant”, about uncertainties inherent in decision-making. Traditionally, a probability wheel is a mechanical prop with two colored slices. A user adjusts the sizes of the slices to indicate the relative value of the probabilities assigned to them. A probability wheel can improve the adjustment process and attenuate the effect of anchoring bias when it is used to estimate or communicate probabilities of outcomes. The goal of this work was to develop a mobile application of the probability wheel that is portable, easily available, and more versatile. We provide a motivating example from medical decision-making, but the tool is widely applicable for researchers in the decision sciences.

  20. Magnetic Levitation Experiments with the Electrodynamic Wheel

    Science.gov (United States)

    Cordrey, Vincent; Gutarra-Leon, Angel; Gaul, Nathan; Majewski, Walerian

    Our experiments explored inductive magnetic levitation using circular Halbach arrays with the strong variable magnetic field on the outer rim of the ring. Such a system is usually called an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We constructed two Electrodynamic Wheels with different diameters and demonstrated that the magnetic interactions produce both lift and drag forces on the EDW which can be used for levitation and propulsion of the EDW. The focus of our experiments is the direct measurement of lift and drag forces to compare with theoretical models using wheels of two different radii. Supported by Grants from the Virginia Academy of Science, Society of Physics Students, Virginia Community College System, and the NVCC Educational Foundation.

  1. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel mechanical noise is one of the largest sources of disturbance forcing on space-based observatories. Such noise arises from mass imbalance, bearing...

  2. Reaction Wheel with Embedded MEMS IMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheels are used to stabilize satellites and to slew their orientation from object to object with precision and accuracy by varying the rotational speed of...

  3. Users prod FERC to encourage electricity wheeling

    Energy Technology Data Exchange (ETDEWEB)

    Hume, M.

    1985-08-19

    Some users urging the Federal Energy Regulatory Commission (FERC) to encourage or require utilities to transmit user-owned power draw parallels with the natural gas industry. Utilities contend that wheeling in this way does not necessarily improve system-wide efficiency, and can threaten reliability, although all agree that excess capacity should be moved to areas of less efficient generation or capacity need. Legislation giving FERC authority to order wheeling for customers could increase rates to remaining customers who cannot shop around.

  4. Aerodynamic analysis of an isolated vehicle wheel

    Science.gov (United States)

    Leśniewicz, P.; Kulak, M.; Karczewski, M.

    2014-08-01

    Increasing fuel prices force the manufacturers to look into all aspects of car aerodynamics including wheels, tyres and rims in order to minimize their drag. By diminishing the aerodynamic drag of vehicle the fuel consumption will decrease, while driving safety and comfort will improve. In order to properly illustrate the impact of a rotating wheel aerodynamics on the car body, precise analysis of an isolated wheel should be performed beforehand. In order to represent wheel rotation in contact with the ground, presented CFD simulations included Moving Wall boundary as well as Multiple Reference Frame should be performed. Sliding mesh approach is favoured but too costly at the moment. Global and local flow quantities obtained during simulations were compared to an experiment in order to assess the validity of the numerical model. Results of investigation illustrates dependency between type of simulation and coefficients (drag and lift). MRF approach proved to be a better solution giving result closer to experiment. Investigation of the model with contact area between the wheel and the ground helps to illustrate the impact of rotating wheel aerodynamics on the car body.

  5. High frequency vibration characteristics of electric wheel system under in-wheel motor torque ripple

    Science.gov (United States)

    Mao, Yu; Zuo, Shuguang; Wu, Xudong; Duan, Xianglei

    2017-07-01

    With the introduction of in-wheel motor, the electric wheel system encounters new vibration problems brought by motor torque ripple excitation. In order to analyze new vibration characteristics of electric wheel system, torque ripple of in-wheel motor based on motor module and vector control system is primarily analyzed, and frequency/order features of the torque ripple are discussed. Then quarter vehicle-electric wheel system (QV-EWS) dynamics model based on the rigid ring tire assumption is established and the main parameters of the model are identified according to tire free modal test. Modal characteristics of the model are further analyzed. The analysis indicates that torque excitation of in-wheel motor is prone to arouse horizontal vibration, in which in-phase rotational, anti-phase rotational and horizontal translational modes of electric wheel system mainly participate. Based on the model, vibration responses of the QV-EWS under torque ripple are simulated. The results show that unlike vertical low frequency (lower than 20 Hz) vibration excited by road roughness, broadband torque ripple will arouse horizontal high frequency (50-100 Hz) vibration of electric wheel system due to participation of the three aforementioned modes. To verify the theoretical analysis, the bench experiment of electric wheel system is conducted and vibration responses are acquired. The experiment demonstrates the high frequency vibration phenomenon of electric wheel system and the measured order features as well as main resonant frequencies agree with simulation results. Through theoretical modeling, analysis and experiments this paper reveals and explains the high frequency vibration characteristics of electric wheel system, providing references for the dynamic analysis, optimal design of QV-EWS.

  6. The Goal Wheel: Adapting Navajo Philosophy and the Medicine Wheel to Work with Adolescents

    Science.gov (United States)

    Garner, Holly; Bruce, Mary Alice; Stellern, John

    2011-01-01

    The purpose of this article is to describe a group counseling model that is based on the indigenous medicine wheel as well as Navajo philosophy by which to help troubled adolescents restore harmony and balance in their lives, through establishing goals and sequential steps to accomplish these goals. The authors call this model the Goal Wheel. A…

  7. Model Predictive Control considering Reachable Range of Wheels for Leg / Wheel Mobile Robots

    Science.gov (United States)

    Suzuki, Naito; Nonaka, Kenichiro; Sekiguchi, Kazuma

    2016-09-01

    Obstacle avoidance is one of the important tasks for mobile robots. In this paper, we study obstacle avoidance control for mobile robots equipped with four legs comprised of three DoF SCARA leg/wheel mechanism, which enables the robot to change its shape adapting to environments. Our previous method achieves obstacle avoidance by model predictive control (MPC) considering obstacle size and lateral wheel positions. However, this method does not ensure existence of joint angles which achieves reference wheel positions calculated by MPC. In this study, we propose a model predictive control considering reachable mobile ranges of wheels positions by combining multiple linear constraints, where each reachable mobile range is approximated as a convex trapezoid. Thus, we achieve to formulate a MPC as a quadratic problem with linear constraints for nonlinear problem of longitudinal and lateral wheel position control. By optimization of MPC, the reference wheel positions are calculated, while each joint angle is determined by inverse kinematics. Considering reachable mobile ranges explicitly, the optimal joint angles are calculated, which enables wheels to reach the reference wheel positions. We verify its advantages by comparing the proposed method with the previous method through numerical simulations.

  8. Time-frequency analysis of wheel-rail shock in the presence of wheel flat

    Directory of Open Access Journals (Sweden)

    Jianming Ding

    2014-12-01

    Full Text Available Against the deficiencies of traditional time domain and frequency domain analysis in detecting wheel-rail (W-R system hidden risks which wheel flats generate, the time-frequency characteristics of W-R shock caused by wheel flat are analyzed and the vehicle-rail dynamic model with wheel flat is investigated. The 10 degrees of freedom (DOF vehicle model is built up. 90-DOF rail model is constructed. The wheel flat excitation model is built up. The vehicle-track coupling dynamic model including wheel flat excitation is set up through nonlinear Hertzian contact theory. The vertical accelerations of axle box are calculated at different speeds and flat sizes based on the vehicle-track coupling dynamic model with wheel flat. Frequency slice wavelet transform (FSWT is employed to analyze time-frequency characteristics of axle box accelerations to detect the W-R noncontact risks s which the traditional time domain or frequency domain method does not analyze. The results show that the small flat size and high running speed lead to high frequency W-R impact. Large flat size and high running speed result in momentary loss of W-R contact, and there exist security risks between wheel and rail. The conclusion that the phase of axle box accelerations is same to W-R forces lays a theoretical foundation of monitoring W-R contact safety from axle box acceleration instead of traditional W-R force detection.

  9. Project considerations and design of systems for wheeling cogenerated power

    Energy Technology Data Exchange (ETDEWEB)

    Tessmer, R.G. Jr.; Boyle, J.R.; Fish, J.H. III; Martin, W.A.

    1994-08-01

    Wheeling electric power, the transmission of electricity not owned by an electric utility over its transmission lines, is a term not generally recognized outside the electric utility industry. Investigation of the term`s origin is intriguing. For centuries, wheel has been used to describe an entire machine, not just individual wheels within a machine. Thus we have waterwheel, spinning wheel, potter`s wheel and, for an automobile, wheels. Wheel as a verb connotes transmission or modification of forces and motion in machinery. With the advent of an understanding of electricity, use of the word wheel was extended to be transmission of electric power as well as mechanical power. Today, use of the term wheeling electric power is restricted to utility transmission of power that it doesn`t own. Cogeneration refers to simultaneous production of electric and thermal power from an energy source. This is more efficient than separate production of electricity and thermal power and, in many instances, less expensive.

  10. Effects of soil moisture content and tractor wheeling intensity on traffic-induced soil compaction

    Directory of Open Access Journals (Sweden)

    Iman AHMADI

    2015-12-01

    Full Text Available Soil compaction causes deleterious effects on physical and mechanical proprieties of agricultural soils. In order to investigate the effect of soil moisture content and tractor wheeling intensity on traffic-induced soil compaction, this study was carried out on a field with clay loam soil. Soil dry bulk density and hydraulic conductivity as well as emergence percentage of corn seedlings and dry mass of the sampled mature plants were considered the dependent variables of the experiment. Independent variables consisted of soil moisture content with five levels (12, 15, 17, 19, and 21%, traffic intensity with three levels (four, two, and zero passes of tractor wheel (tractor model: John Deere 3350 from the entire area of the plot, and soil sampling depth with three levels (0-10, 10-20, and 20-30 cm. According to the results of this study, gradual increase in soil water content generally resulted in an increase in soil bulk density; moreover, increasing the tractor wheeling intensity from 0 to 4 passes increased bulk density by 13%. Furthermore, the driest soil water content had the highest and the wettest soil water content had the lowest emergence percentage of corn seedlings among the treatments; moreover, traffic intensity treatment inversely affected the emergence percentage of corn seedlings and the dry mass of mature plants. To sum up, these results indicate that, for improving water permeability and reducing dry bulk density of the examined clay loam soil, as well as better emergence of corn seedlings and ultimately increasing crop yield, it is recommended to avoid wheeling when soil moisture content is high, reduce the number of machinery wheel passes from the farm as low as possible, and restrict the wheel passes to fixed strips along the field, whenever possible.

  11. Design of Wheeled Mobile Robot with Tri-Star Wheel as Rescue Robot

    Directory of Open Access Journals (Sweden)

    Rafiuddin Syam

    2016-05-01

    Full Text Available This study aims to design, and analyze a mobilerobot that can handle some of the obstacles, they are unevensurfaces, slopes, can also climb stairs. WMR in this study is Tristarwheel that is containing three wheels for each set. Onaverage surface only two wheels in contact with the surface, ifthere is an uneven surface or obstacle then the third wheel willrotate with the rotation center of the wheel in contact with theleading obstacle then only one wheel in contact with the surface.This study uses the C language program. Furthermore, theminimum thrust to be generated torque of the motor andtransmission is 9.56 kg. The results obtained by calculation andanalysis of DC motors used must have a torque greater than14.67 kg.cm. Minimum thrust to be generated motor torque andthe transmission is 9.56 kg. The experimental results give goodresults for robot to moving forward, backward, turn left, turnright and climbing the stairs

  12. Reaction Wheel Disturbance Model Extraction Software - RWDMES

    Science.gov (United States)

    Blaurock, Carl

    2009-01-01

    The RWDMES is a tool for modeling the disturbances imparted on spacecraft by spinning reaction wheels. Reaction wheels are usually the largest disturbance source on a precision pointing spacecraft, and can be the dominating source of pointing error. Accurate knowledge of the disturbance environment is critical to accurate prediction of the pointing performance. In the past, it has been difficult to extract an accurate wheel disturbance model since the forcing mechanisms are difficult to model physically, and the forcing amplitudes are filtered by the dynamics of the reaction wheel. RWDMES captures the wheel-induced disturbances using a hybrid physical/empirical model that is extracted directly from measured forcing data. The empirical models capture the tonal forces that occur at harmonics of the spin rate, and the broadband forces that arise from random effects. The empirical forcing functions are filtered by a physical model of the wheel structure that includes spin-rate-dependent moments (gyroscopic terms). The resulting hybrid model creates a highly accurate prediction of wheel-induced forces. It accounts for variation in disturbance frequency, as well as the shifts in structural amplification by the whirl modes, as the spin rate changes. This software provides a point-and-click environment for producing accurate models with minimal user effort. Where conventional approaches may take weeks to produce a model of variable quality, RWDMES can create a demonstrably high accuracy model in two hours. The software consists of a graphical user interface (GUI) that enables the user to specify all analysis parameters, to evaluate analysis results and to iteratively refine the model. Underlying algorithms automatically extract disturbance harmonics, initialize and tune harmonic models, and initialize and tune broadband noise models. The component steps are described in the RWDMES user s guide and include: converting time domain data to waterfall PSDs (power spectral

  13. Steady state modeling of desiccant wheels

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Kærn, Martin Ryhl

    2014-01-01

    Desiccant wheels are rotary desiccant dehumidifiers used in air conditioning and drying applications. The modeling of simultaneous heat and mass transfer in these components is crucial for estimating their performances, as well as for simulating and optimizing their implementation in complete sys...... be taken into account in a future version of the model. More experimental data have to be gathered to implement eventual missing phenomena and validate the model for all input parameters....... systems. A steady state two-dimensional model is formulated and implemented aiming to obtain good accuracy and short computational times. Comparison with experimental data from the literature shows that the model reproduces the physical behavior of desiccant wheels. Mass diffusion in the desiccant should......Desiccant wheels are rotary desiccant dehumidifiers used in air conditioning and drying applications. The modeling of simultaneous heat and mass transfer in these components is crucial for estimating their performances, as well as for simulating and optimizing their implementation in complete...

  14. Reviews Equipment: Vibration detector Equipment: SPARK Science Learning System PS-2008 Equipment: Pelton wheel water turbine Book: Atomic: The First War of Physics and the Secret History of the Atom Bomb 1939-49 Book: Outliers: The Story of Success Book: T-Minus: The Race to the Moon Equipment: Fridge Rover Equipment: Red Tide School Spectrophotometer Web Watch

    Science.gov (United States)

    2010-03-01

    WE RECOMMEND Vibration detector SEP equipment measures minor tremors in the classroom SPARK Science Learning System PS-2008 Datalogger is easy to use and has lots of added possibilities Atomic: The First War of Physics and the Secret History of the Atom Bomb 1939-49 Book is crammed with the latest on the atom bomb T-Minus: The Race to the Moon Graphic novel depicts the politics as well as the science Fridge Rover Toy car can teach magnetics and energy, and is great fun Red Tide School Spectrophotometer Professional standard equipment for the classroom WORTH A LOOK Pelton wheel water turbine Classroom-sized version of the classic has advantages Outliers: The Story of Success Study of why maths is unpopular is relevant to physics teaching WEB WATCH IOP webcasts are improving but are still not as impressive as Jodrell Bank's Chromoscope website

  15. High-spin Mn wheels.

    Science.gov (United States)

    Manoli, Maria; Prescimone, Alessandro; Bagai, Rashmi; Mishra, Abhudaya; Murugesu, Muralee; Parsons, Simon; Wernsdorfer, Wolfgang; Christou, George; Brechin, Euan K

    2007-08-20

    The syntheses, structures, and magnetic properties of the complexes [MnIV4MnIII10MnII2O2(OCH3)12(tmp)8(O2CCH3)10].3Et2O (1.3Et2O), [MnIV2MnIII18MnII2O6(OCH3)14(O2CCH3)16(tmp)8(HIm)2].2CH3OH (2.2CH3OH), and [MnIV2MnIII18MnII2O6(OCH3)14(O2CCH3)16(Br-mp)8(HIm)2].2C6H14.5CH3OH (3.2C6H14.5CH3OH) are reported. The unusual wheel-like complexes were prepared by the treatment of [Mn3O(O2CCH3)6(HIm)3](O2CCH3) (HIm = imidazole) with 1,1,1-tris-(hydroxymethyl)propane (H3tmp) (1 and 2) or 2-(bromomethyl)-2-(hydroxymethyl)-1,3-propanediol (Br-mpH3) (3) in the presence of sodium methoxide (NaOCH3, 2, and 3) in CH3OH. Complex 1.3Et2O crystallizes in the triclinic space group P, while complexes 2.2CH3OH and 3.2C6H14.5CH3OH crystallize in the orthorhombic space group Pbca. Direct current magnetic susceptibility data, collected for 1-3 in the respective 1.8-300 K and 0.1-7 T temperature and magnetic-field ranges, afford spin ground-state values of S = 14 +/- 1 for complex 1 and S = 9 +/- 1 for complexes 2 and 3. Alternating current susceptibility measurements performed on all three complexes in the 1.8-10 K temperature range in a 3.5 G oscillating field at frequencies between 50 and 1000 Hz reveal out-of-phase chi"M signals below approximately 3 K. Single-crystal hysteresis loop and relaxation measurements confirm single-molecule magnetism behavior.

  16. Optically trapped and driven paddle-wheel

    Science.gov (United States)

    Asavei, Theodor; Nieminen, Timo A.; Loke, Vincent L. Y.; Stilgoe, Alexander B.; Bowman, Richard; Preece, Daryl; Padgett, Miles J.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2013-06-01

    We demonstrate the control and rotation of an optically trapped object, an optical paddle-wheel, with the rotation direction normal to the beam axis. This is in contrast to the usual situation where the rotation is about the beam axis. The paddle-wheel can be optically driven and moved to any position in the field of view of the microscope, which can be of interest for various biological applications where controlled application of a fluid flow is needed in a particular location and in a specific direction. This is of particular interest in signal transduction studies in cells, especially when a cell is flat and spread out on a surface.

  17. Wheeled foot quadruped robot HITAN-I

    Institute of Scientific and Technical Information of China (English)

    Wang Pengfei; Sun Lining

    2006-01-01

    In view of the robot running environment, the structure of wheeled foot and quadruped are adopted in this robot system, which combines the priorities of both wheeled robot and legged robot. Based on CAN bus, the two-class robot control system using multiple controllers and drivers is constructed. At the same time, serial inverse kinematics of swaying leg and parallel inverse kinematics of supporting legs are analyzed independently. The forward gait and turning gait are planned and experiment image is given at last.

  18. GEAR WHEELS THE PROCESSED BY ELECTRICAL EROSION

    Directory of Open Access Journals (Sweden)

    MARCEL S.POPA

    2015-12-01

    Full Text Available For low tooth loads and low peripheral speeds between 0.3 and 2 m / s are chosen based alloys and steels, gray cast iron. In industry are preferable ferrous alloys: bronze, brass and aluminum alloys, and where speeds and demands are low gears are made of sheet steel or alloys. Wheel group required less include some hand-operated mechanisms, such as jacks, some trolls. These wheels are larger and they are made of alloy steel, semi-hard and sometimes gray cast iron FC250, FC300.

  19. [Fracture of the diaphyseal radius during Cyr wheel practice - an uncommon injury of wheel gymnastics].

    Science.gov (United States)

    Kauther, M D; Rummel, S; Hussmann, B; Lendemans, S; Nast-Kolb, D; Wedemeyer, C

    2011-12-01

    The cyr wheel is a modified gymnastic wheel with only one ring that can lead to extreme forces on the gymnast. We report on a distal radius shaft fracture (AO 22 A 2.1) and a fracture of the styloid process of the ulna that occurred after holding on to a slipping Cyr wheel and exposition to high pressure on the lower arm. The fracture was fixed by screws and a plate. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Measuring wheel/rail contact stresses using ultrasound

    OpenAIRE

    Marhsall, M.B.; Lewis, R.; Dwyer-Joyce, R.S.; Olofsson, O.; Bjorklund, S

    2004-01-01

    The investigation of contact area and pressure distribution in a wheel/rail contact is essential information required in fatigue and wear calculations to determine design life, regrinding requirements, and maintenance schedules. The aim of this work was to use ultrasound to non-destructively determine wheel/rail contact pressures. Three different contacts were investigated those resulting from; un-used, sand damaged, and worn wheel/rail specimens. \\ud \\ud A wheel/rail interface behaves like a...

  1. On a New Method for Evaluation of Wheel Climb Derailment

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the paper, a new derailment index λ for evaluation of wheel climb derailment is proposed which is based on primary suspension forces. It is easy to apply because of its minimum criterion characteristic and can also be applied to explain the reason why wheel climb derailments are almost always accompanied by some wheel unloadings.

  2. Rolling Friction on a Wheeled Laboratory Cart

    Science.gov (United States)

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  3. Investigating Functions with a Ferris Wheel

    Science.gov (United States)

    Johnson, Heather Lynn; Hornbein, Peter; Azeem, Sumbal

    2016-01-01

    The authors provide a dynamic Ferris wheel computer activity that teachers can use as an instructional tool to help students investigate functions. They use a student's work to illustrate how students can use relationships between quantities to further their thinking about functions.

  4. Steerable wheel structure for ground vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Frye, N.V.

    1988-09-27

    This patent describes a ground vehicle having a fore-and-aft body including transversely spaced apart, right and left, fore-and-aft supports: steerable wheel structure comprising transverse axle means disposed between the supports and having right and left end portions respectively adjacent to the right and left supports, a wheel journaled on the axle means intermediate the supports on a transverse horizontal axis, right and left carriers respectively on the right and left supports, each including a fixed element mounted fixedly on the associated support and a movable member arranged for selective fore-and-aft movement relative to the support and relative to each other, right and left connecting means connecting the right and left movable members respectively to the right and left end portions of the axle means for effecting steering of the wheel as one carrier moves forward and the other moves simultaneously rearwardly, and vice versa, at least one of the members at each side of the body being constructed to accommodate fore-and-aft swinging of the axle means during steering of the wheel, and means for moving the movable members simultaneously, one forwardly and the other rearwardly.

  5. Examination of a failed fifth wheel coupling

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1998-03-01

    Full Text Available Examination of a fifth wheel coupling which had failed in service showed that it had been modified and that the operating handle had been moved from its original design position. This modification completely eliminated the safety device designed...

  6. Some Armchair Worries about Wheeled Behavior

    NARCIS (Netherlands)

    Keijzer, F.A.

    1998-01-01

    Autonomous agents research aims to understand adaptive behavior by building models that exhibit such behavior. In this paper, I describe some theoretical worries about the tendency to simplify the sensory-motor control of these behaving models as much as possible. Wheeled robots provide a good examp

  7. Some Armchair Worries about Wheeled Behavior

    NARCIS (Netherlands)

    Keijzer, F.A.

    1998-01-01

    Autonomous agents research aims to understand adaptive behavior by building models that exhibit such behavior. In this paper, I describe some theoretical worries about the tendency to simplify the sensory-motor control of these behaving models as much as possible. Wheeled robots provide a good examp

  8. Experiments on a Tail-wheel Shimmy

    Science.gov (United States)

    Harling, R; Dietz, O

    1954-01-01

    Model tests on the "running belt" and tests with a full-scale tail wheel were made on a rotating drum as well as on a runway in order to investigate the causes of the undesirable shimmy phenomena frequently occurring on airplane tail wheels, and the means of avoiding them. The small model (scale 1:10) permitted simulation of the mass, moments of inertia, and fuselage stiffness of the airplane and determination of their influence on the shimmy, whereas by means of the larger model with pneumatic tires (scale 1:2) more accurate investigations were made on the tail wheel itself. The results of drum and road tests show good agreement with one another and with model values. Detailed investigations were made regarding the dependence of the shimmy tendency on trail, rolling speed, load, size of tires, ground friction,and inclination of the swivel axis; furthermore, regarding the influence of devices with restoring effect on the tail wheel, and the friction damping required for prevention of shimmy. Finally observations from slow-motion pictures are reported and conclusions drawn concerning the influence of tire deformation.

  9. 77 FR 67400 - RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as Wheeling Corrugating...

    Science.gov (United States)

    2012-11-09

    ... Employment and Training Administration RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as..., 2012, applicable to workers of RG Steel Wheeling, LLC, a division of RG Steel, LLC, doing business as... RG Steel, LLC, doing business as Wheeling Corrugating Company, Beech Bottom, West Virginia,...

  10. A dynamic wheel-rail impact analysis of railway track under wheel flat by finite element analysis

    Science.gov (United States)

    Bian, Jian; Gu, Yuantong; Murray, Martin Howard

    2013-06-01

    Wheel-rail interaction is one of the most important research topics in railway engineering. It involves track impact response, track vibration and track safety. Track structure failures caused by wheel-rail impact forces can lead to significant economic loss for track owners through damage to rails and to the sleepers beneath. Wheel-rail impact forces occur because of imperfections in the wheels or rails such as wheel flats, irregular wheel profiles, rail corrugations and differences in the heights of rails connected at a welded joint. A wheel flat can cause a large dynamic impact force as well as a forced vibration with a high frequency, which can cause damage to the track structure. In the present work, a three-dimensional finite element (FE) model for the impact analysis induced by the wheel flat is developed by the use of the FE analysis (FEA) software package ANSYS and validated by another validated simulation. The effect of wheel flats on impact forces is thoroughly investigated. It is found that the presence of a wheel flat will significantly increase the dynamic impact force on both rail and sleeper. The impact force will monotonically increase with the size of wheel flats. The relationships between the impact force and the wheel flat size are explored from this FEA and they are important for track engineers to improve their understanding of the design and maintenance of the track system.

  11. Wheel traffic effect on air-filled porosity and air permeability in a soil catena across the wheel rut

    DEFF Research Database (Denmark)

    Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

    The impact of wheel traffic on soil physical properties is usually quantified by randomly collecting soil cores at specific depths below the wheeled surface. However, modeling studies as well as few measurements indicated a non-uniform stress distribution in a catena across the wheel rut, which m...

  12. Design of Wheeled Mobile Robot with Tri-Star Wheel as Rescue Robot

    Directory of Open Access Journals (Sweden)

    Rafiuddin Syam

    2014-10-01

    Full Text Available This study aims to design, and analyze a mobile robot that can handle some of the obstacles, they are uneven surfaces, slopes, can also climb stairs. WMR in this study is Tristar wheel that is containing three wheels for each set. On average surface only two wheels in contact with the surface, if there is an uneven surface or obstacle then the third wheel will rotate with the rotation center of the wheel in contact with the leading obstacle then only one wheel in contact with the surface. This study uses the C language program. Furthermore, the minimum thrust to be generated torque of the motor and transmission is 9.56 kg. The results obtained by calculation and analysis of DC motors used must have a torque greater than 14.67 kg.cm. Minimum thrust to be generated motor torque and the transmission is 9.56 kg. The experimental results give good results for robot to moving forward, backward, turn left, turn right and climbing the stairs.

  13. Designing a Miniature Wheel Arrangement for Mobile Robot Platforms

    CERN Document Server

    Kayani, Saheeb Ahmed

    2011-01-01

    In this research report details of design of a miniature wheel arrangement are presented. This miniature wheel arrangement is essentially a direction control mechanism intended for use on a mobile robot platform or base. The design is a specific one employing a stepper motor as actuator and as described can only be used on a certain type of wheeled robots. However as a basic steering control element, more than one of these miniature wheel arrangements can be grouped together to implement more elaborate and intelligent direction control schemes on varying configurations of wheeled mobile robot platforms.

  14. Kinematics and dynamics modelling of a mecanum wheeled mobile platform

    CSIR Research Space (South Africa)

    Tlale, NS

    2008-12-01

    Full Text Available velocity of the mecanum wheel is determined as: _ = n _ m sin (1) where _ m is the rotational velocity of the DC motor that is driving the mecanum wheel and n is the gear ratio of the DC motor driving the mecanum wheel. The rotational velocity of each... wheels and the gear ratio of the DC motors used, m is the change in the number of encoder pulses for wheel and T is the time interval of sampling encoder pulses. The effectiveness of the motor, e, in converting the driving motor?s rotational...

  15. Effect of sucrose availability on wheel-running as an operant and as a reinforcing consequence on a multiple schedule: Additive effects of extrinsic and automatic reinforcement.

    Science.gov (United States)

    Belke, Terry W; Pierce, W David

    2015-07-01

    As a follow up to Belke and Pierce's (2014) study, we assessed the effects of repeated presentation and removal of sucrose solution on the behavior of rats responding on a two-component multiple schedule. Rats completed 15 wheel turns (FR 15) for either 15% or 0% sucrose solution in the manipulated component and lever pressed 10 times on average (VR 10) for an opportunity to complete 15 wheel turns (FR 15) in the other component. In contrast to our earlier study, the components advanced based on time (every 8min) rather than completed responses. Results showed that in the manipulated component wheel-running rates were higher and the latency to initiate running longer when sucrose was present (15%) compared to absent (0% or water); the number of obtained outcomes (sucrose/water), however, did not differ with the presentation and withdrawal of sucrose. For the wheel-running as reinforcement component, rates of wheel turns, overall lever-pressing rates, and obtained wheel-running reinforcements were higher, and postreinforcement pauses shorter, when sucrose was present (15%) than absent (0%) in manipulated component. Overall, our findings suggest that wheel-running rate regardless of its function (operant or reinforcement) is maintained by automatically generated consequences (automatic reinforcement) and is increased as an operant by adding experimentally arranged sucrose reinforcement (extrinsic reinforcement). This additive effect on operant wheel-running generalizes through induction or arousal to the wheel-running as reinforcement component, increasing the rate of responding for opportunities to run and the rate of wheel-running per opportunity.

  16. High-power rotating wheel targets at RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Atsushi E-mail: ayoshida@rarfaxp.riken.go.jp; Morita, Kousuke; Morimoto, Kouji; Kaji, Daiya; Kubo, Toshiyuki; Takahashi, Yutaka; Ozawa, Akira; Tanihata, Isao

    2004-03-21

    Two kinds of rotating wheel targets for high-power heavy ion reaction have been developed. One is a thick disk target with water-cooling being developed for the in-flight RI beam separator (BigRIPS). An in-beam test was performed using {sup 40}Ar beam at 24 AMeV, 1.9 particle {mu}A, with the beam spot size 3 mm in diameter, resulting 0.25 GW/m{sup 2} beam power stopped at the surface of carbon disk 2 mm in thickness and 260 mm in diameter. It performed stably without melting. A simulation study has been developed and its possibility for the use of BigRIPS is discussed. The second is a thin target foil mounted on a wheel disk which rotates in He cooling gas of 13.32-133.2 Pa. Its main use is in fusion reactions to search for super-heavy elements by using the gas-filled recoil separator (GARIS). A typical foil is Pb or Bi of 200-300 {mu}g/cm{sup 2} in thickness evaporated onto a carbon backing foil of 30 {mu}g/cm{sup 2} thickness, and covered by evaporated carbon of 10 {mu}g/cm{sup 2} thickness. It can withstand long use under high-intensity {sup 64}Ni beam at 311 MeV, and 0.5 particle {mu}A.

  17. Wheel pose measurement based on cross structure light

    Science.gov (United States)

    Zhao, Qiancheng; Ding, Xun; Wang, Xian; Zhao, Yafeng

    2016-01-01

    It's necessary for automobile to detect and adjust four-wheel alignment parameters regularly, due to the significant effect on improving stability, enhancing security and reducing tire wear of automobiles. In order to measure the parameters that determined by relative position and posture of four wheels to the automobile cab, this paper proposes a method which applies monocular vision of linear structure light to wheel pose measurement. Firstly, space coordinates of feature point cloud are calculated out from the principle of structured light. Then, an algorithm is designed to determine the normal vector of wheel tangent plane and measure the wheel pose. Finally, actual experiments that by evaluation of adjusted wheel angle measurement are carried out to verify the system accuracy. The corresponding studies can be applied in designing and developing 3D four-wheel alignment system that based on structured light.

  18. A computational study of tandem dual wheel aerodynamics and the effect of fenders and fairings on spray dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Paschkewitz, J S

    2006-01-13

    With the goal of understanding how to mitigate the safety hazard of splash and spray around heavy vehicles, a computational study of the aerodynamics and spray dispersion about a simplified trailer wheel assembly has been completed. A tandem dual slick (TDS) wheel model that neglects complex geometric features such as brakes, wheel bolts and wheel cutouts but with the same dimensions as an actual trailer wheel assembly was used . A detailed simulation of the wheels alone demonstrated that the flow field is both unsteady and complex, containing a number of vortical structures that interact strongly with spray. Preliminary simulations with fenders and fairings demonstrated that these devices prevent the ballistic transport of drops larger than approximately 0.1 mm, but the fine mist speculated to be responsible for visibility reduction is unaffected. This work suggests that to use computational fluid dynamics (CFD) to design and evaluate spray mitigation strategies the jet or sheet breakup processes can be modeled using an array of injectors of small (< 0.01 mm) water droplets; however the choice of size distribution, injection locations, directions and velocities is largely unknown and requires further study. Possible containment strategies would include using flow structures to 'focus' particles into regions away from passing cars or surface treatments to capture small drops.

  19. Analysing a Relationship Between Wheel Wear and Cutting Forces During Diamond Grinding

    Directory of Open Access Journals (Sweden)

    M. A. Shavva

    2014-01-01

    carbide (Т15К6 work pieces was experimentally made. Experiments were carried out on the universal flat-grinding machine 3G71M using a diamond grinding wheel 6А2 250х20х4х29х76 АС6 160/125 А1 100% М1-01 according to GOST 16170-91. When using this equipment, cutting operation conditions, namely grinding speed and longitudinal table feed were 35 m/s and 3 - 12 m/min, respectively.The work piece was clamped in a vise. Vise was set on the universal attachment. Device was installed on a three-component dynamometer brands Kistler 9257B to measure cutting forces.Grinding was carried out under the following operation conditions: traverse Strav= 3 m/min, depth of cutting t = 20 μm. Grinding used a water-based cooling emulsion. Wheel speed was 35m/s. The dynamometer was tuned to the frequency of signal equal to 250 Hz.After processing the experimental and calculated data were compared using the theoretical formulas. The maximum difference between them was 17%.Owing to the presented model it is possible to obtain data on the diamond tool wear during cutting through a change of the tangential component of the cutting force. With the definite maximum wear of diamond wheel it is possible to calculate a threshold value of the tangential component of the cutting force. When the threshold value of the tangential component of the cutting force is reached, a diamond wheel must be subjected to dressing. On-time wheel dressing allows us to avoid reducing quality of the machined surface.Control of forces in the cutting zone is difficult to organize; the procedure can be performed by power control of the grinding spindle through the current control.

  20. Improved Squeaky Wheel Optimisation for Driver Scheduling

    CERN Document Server

    Aickelin, Uwe; Li, Jingpeng

    2008-01-01

    This paper presents a technique called Improved Squeaky Wheel Optimisation for driver scheduling problems. It improves the original Squeaky Wheel Optimisations effectiveness and execution speed by incorporating two additional steps of Selection and Mutation which implement evolution within a single solution. In the ISWO, a cycle of Analysis-Selection-Mutation-Prioritization-Construction continues until stopping conditions are reached. The Analysis step first computes the fitness of a current solution to identify troublesome components. The Selection step then discards these troublesome components probabilistically by using the fitness measure, and the Mutation step follows to further discard a small number of components at random. After the above steps, an input solution becomes partial and thus the resulting partial solution needs to be repaired. The repair is carried out by using the Prioritization step to first produce priorities that determine an order by which the following Construction step then schedul...

  1. Phenomena of Foamed Concrete under Rolling of Aircraft Wheels

    Science.gov (United States)

    Jiang, Chun-shui; Yao, Hong-yu; Xiao, Xian-bo; Kong, Xiang-jun; Shi, Ya-jie

    2014-04-01

    Engineered Material Arresting System (EMAS) is an effective technique to reduce hazards associated with aircraft overrunning runway. In order to ascertain phenomena of the foamed concrete used for EMAS under rolling of aircraft wheel, a specially designed experimental setup was built which employed Boeing 737 aircraft wheels bearing actual vertical loads to roll through the foamed concrete. A number of experiments were conducted upon this setup. It is discovered that the wheel rolls the concrete in a pure rolling manner and crushes the concrete downwards, instead of crushing it forward, as long as the concrete is not higher than the wheel axle. The concrete is compressed into powder in-situ by the wheel and then is brought to bottom of the wheel. The powder under the wheel is loose and thus is not able to sustain wheel braking. It is also found that after being rolled by the wheel the concrete exhibits either of two states, i.e. either 'crushed through' whole thickness of the concrete or 'crushed halfway', depending on combination of strength of the concrete, thickness of the concrete, vertical load the wheel carries, tire dimension and tire pressure. A new EMAS design concept is developed that if an EMAS design results in the 'crushed through' state for the main gears while the 'crushed halfway' state for the nose gear, the arresting bed would be optimal to accommodate the large difference in strength between the nose gear and the main gear of an aircraft.

  2. Braking, Wheeled Vehicles. Test Operations Procedure (TOP)

    Science.gov (United States)

    2008-05-20

    shields removed, inspect the internal brake components, perform a camshaft rotation test and record the measurement obtained. c. If with non-removable...preceding 24 months, perform a camshaft rotation test and record the measurement. (2) When proof of wheel removal is not provided, remove brake drum(s...adjustment. Reject the vehicle if: • The adjustment is not within the manufacturer’s specifications. 15. Brake Camshafts Procedure: With

  3. A magneto-electric quantum wheel

    CERN Document Server

    Feigel, Alexander

    2009-01-01

    Here we show that self-propulsion in quantum vacuum may be achieved by rotating or aggregating magneto-electric nano-particles. The back-action follows from changes in momentum of electro-magnetic zero-point fluctuations, generated in magneto-electric materials. This effect may provide new tools for investigation of the quantum nature of our world. It might also serve in the future as a "quantum wheel" to correct satellite orientation in space.

  4. Coatings for gear wheels; Beschichtungen fuer Zahnraeder

    Energy Technology Data Exchange (ETDEWEB)

    Petrik, M.; Wittorf, R.; Thomsen, H. [Fraunhofer-Institut fuer Schicht- und Oberflaechentechnik, IST, Braunschweig (Germany). Transferzentrum Tribologie; Kaestner, P. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik; Kropp, J.P. [Technische Univ. Braunschweig (Germany). Inst. fuer Konstruktionstechnik

    2008-08-15

    In order to optimize the goal, steel gear wheels regarding load-carrying capacity and wear, thin film coatings were tested. Different coating systems were examined numerically with the software ELASTICA {sup registered} for their suitability. The characteristics of the coating systems were determined dependent on the material, its surface treatment as well as the diameters of relevant rolling partners. Differences were made between macroscopic rolling contacts between the teeth profiles and microscopic contacts with surface roughness and abrasion particles. First the four best suitable coating systems were deposited on simplified rollers and examined under different conditions. Two coating systems were determined, which show special suitability for the coating of the gear wheels. The first system is an a:C-H coating with an CrN interlayer. The second system is an a:C-H coating with an CrN interlayer on a plasma-nitrided substrat (Duplex-process). In order to protect the coatings on the teeth, their involute profile was provided with a tip relief. As gear wheel materials 16MnCr5, 42CrMo4 as well as the special steel ETG {sup registered} 88 were used. Two kinds of flow fats were used as lubricants and additional the unlubricated operation was examined. The gear wheels were tested at three different speeds on a test machine especially built for it. The testing routine was carried out in so-called power-stages. Each stage means a defined number of contacts and a certain Hertzian stress on the teeth profiles. With each stage the Hertzian stress was increased. The end of operation time is the beginning of cavitation pitting. The test results showed that in particular with the steel 16MnCr5 and 42CrMo4 the used Duplex-systems leads to considerable increases of the load-carrying capacity of the tooth flanks and the wear resistance. (orig.)

  5. Rotating target wheel for the FMA

    Energy Technology Data Exchange (ETDEWEB)

    Back, B.B.; Davids, C.N.; Falout, J. [and others

    1995-08-01

    In anticipation of high intensity beams that will be available from the PII-ECR source injector to ATLAS, a new rotating target wheel was developed for the sliding seal chamber at the FMA. The wheel is 9 inch in diameter and contains up to ten targets. The rotation of the wheel is achieved by a DC motor, a ferrofluidic feedthrough, and a gear mechanism that allows both target rotation and changing the target angle relative to the beam. The nominal rotation speed is 1000 RPM, although higher speeds can be achieved if necessary. The assembly is equipped with an absolute encoder which is read out via a newly developed CAMAC module. This module provides the following main functions: (1) a TTL signal to be used for sweeping the beam when a target frame is about to pass through the beam, (2) a read-out of the target position that can be included in the data event structure, (3) programmable set points for the beam-off signal. The system is presently being tested and will be used in experiments scheduled for March 1995.

  6. Numerical simulation of low pressure die-casting aluminum wheel

    Institute of Scientific and Technical Information of China (English)

    Mi Guofa; Liu Xiangyu; Wang Kuangfei; Fu Hengzhi

    2009-01-01

    The FDM numerical simulation software, ViewCast system, was employed to simulate the low pressure die casting (LPDC) of an aluminum wheel. By analyzing the mold-filling and solidification stage of the LPDC process, the distribution of liquid fraction, temperature field and solidification pattern of castings were studied. The potential shrinkage defects were predicted to be formed at the rim/spoke junctions, which is in consistence with the X-ray detection result. The distribution pattern of the defects has also been studied. A solution towards reducing such defects has been presented. The cooling capacity of the mold was improved by installing water pipes both in the side mold and the top mold. Analysis on the shrinkage defects under forced cooling mode proved that adding the cooling system in the mold is an effective method for reduction of shrinkage defects.

  7. Private Finance 2 (PF2): Re-inventing the Wheel?

    Science.gov (United States)

    Zawawi, N. A. W. A.; Abdul-Aziz, A. R.; Khamidi, M. F.; Othman, I.; Idrus, A.; Umar, A. A.

    2013-06-01

    The Procurement policy of any government is the most influential factor in determining the efficiency of infrastructure and service provision like roads, water supply and energy. The UK's HM Treasury released its new guidelines on private involvement in infrastructures provision and services towards reforming the popular Private Finance Initiatives (PFI) policy. This new approach, it now refers to as the Private Finance 2 (PF2) is meant to correct the imperfections which have bedeviled the older version-PFI. However, the 'new guidelines' contained nothing really new in the area of private financing and operation of public infrastructures, at best it is akin to 're-inventing the wheel' rather than being 'new'. While dwelling extensively on issues relating to cheaper financing sources, risks transfer, counterpart funding by government and improving public sector procurement skills, this paper argues that some countries in the developing world have long recognised these issues and taken practical steps to correct them.

  8. Rover's Wheel Churns Up Bright Martian Soil (False Color)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel. The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life. The image is presented here in false color that is used to bring out subtle differences in color.

  9. Rover's Wheel Churns Up Bright Martian Soil (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel. The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life. The image is presented here as a vertical projection, as if looking straight down, and in false color, which brings out subtle color differences.

  10. Rover's Wheel Churns Up Bright Martian Soil (Stereo)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel. The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life. Multiple images taken with Spirit's panoramic camera are combined here into a stereo view that appears three-dimensional when seen through red-blue glasses, with the red lens on the left.

  11. Problems of locomotive wheel wear in fleet replacement

    Directory of Open Access Journals (Sweden)

    L.P. Lingaytis

    2013-08-01

    Full Text Available Purpose. To conduct a research and find out the causes of defects appearing on the wheel thread of freight locomotives 2М62 and SIEMENS ER20CF. Methodology. To find the ways to solve this problem comparing the locomotive designs and their operating conditions. Findings. After examining the nature of the wheel wear the main difference was found: in locomotives of the 2M62 line wears the wheel flange, and in the locomotives SIEMENS ER20CF – the tread surface. After installation on the 2M62 locomotive the lubrication system of flanges their wear rate significantly decreased. On the new freight locomotives SIEMENS ER20CF the flange lubrication systems of the wheel set have been already installed at the factory, however the wheel thread is wearing. As for locomotives 2M62, and on locomotives SIEMENS ER20CF most wear profile skating wheels of the first wheel set. On both locomotive lines the 2М62 and the SIEMENS ER20CF the tread profile of the first wheel set most of all is subject to the wear. After reaching the 170 000 km run, the tread surface of some wheels begins to crumble. There was a suspicion that the reason for crumb formation of the wheel surface may be insufficient or excessive wheel hardness or its chemical composition. In order to confirm or deny this suspicion the following studies were conducted: the examination of the rim surface, the study of the wheel metal hardness and the document analysis of the wheel production and their comparison with the results of wheel hardness measurement. Practical value. The technical condition of locomotives is one of the bases of safety and reliability of the rolling stock. The reduction of the wheel wear significantly reduces the operating costs of railway transport. After study completion it was found that there was no evidence to suggest that the ratio of the wheel-rail hardness could be the cause of the wheel surface crumbling.

  12. Evaluation of power consumption of paddle wheel in an open raceway pond.

    Science.gov (United States)

    Li, Yanxi; Zhang, Qinghua; Wang, Zhihui; Wu, Xia; Cong, Wei

    2014-07-01

    Open raceway ponds are widely adopted in microalgae cultivation. Paddle wheels consume the most part of power during the process of cultivation in open raceway ponds. The configuration of blades directly determines power consumption for paddle wheels. In this work, power consumption of four blades configurations was determined in a bench-scale open raceway pond of 2.2 m(2). The effect of blades configuration, the influence of filling levels from 5 to 15 cm and influence of rotational speeds from 7 to 15 r min(-1) on shaft power consumption (P(S)), fluid velocity (U(c)) and paddle wheel efficiency (η) was investigated. Results demonstrated that flat blades were the most efficient configuration. Higher culture depth led to larger U(c), more P(s) and larger η, especially when blades were not totally immerged in water. Under the same filling level and rotational speed, the value of P(S) decreases in the order: zigzagged, flat, forward-curved and back-curved, respectively. The zigzagged blades led to a larger U(c) at the culture depth of 5 cm, while flat and forward-curved blades drove a larger U(c) when culture depth was higher than 5 cm. The maximum value of η was 0.50 with flat blades at 11 r min(-1) and 15 cm of culture depth. Empirical correlations of non-dimensional numbers related to operation parameters and blades geometry for four paddle wheel blades were also proposed.

  13. Graftpolyrotaxane: Graft polymer possessing movable graft chains on cyclodextrins as the polyrotaxane wheels

    Energy Technology Data Exchange (ETDEWEB)

    Takashima, T; Hinoue, K; Kihara, N; Hayashi, M; Koyama, Y; Takata, T, E-mail: ttakata@polymer.titech.ac.j [Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8552 (Japan)

    2009-08-01

    Graftpolyrotaxanes having graft chains on the wheel components were prepared from main chain-type polyrotaxane having monofunctional cyclodextrin wheels and terminal end-reactive poly(ethylene glycol) (PEG). The well-defined polyrotaxane having mono(6-hydroxyl) permethyl-{alpha}-CD (monoOH-{alpha}-CD) as the wheel components and a polytetrahydrofuran (PTHF) axle with bulky end-capping groups was synthesized by the two pathways; (i) synthesis by solid-state end-capping of pseudopolyrotaxane consisting of monoOAc-{alpha}-CD and hydroxy-terminated PTHF and (ii) one-pot synthesis using monoOH-{alpha}-CD and amine-terminated PTHF in water. The grafting reaction on the wheel moieties of the resulting polyrotaxane was carried out by acylation reaction with PEG-mono-carboxylic acid derivatives in high conversion yields. To estimate the relative rotary movement of CDs and the axle polymer in the polyrotaxane and graftpolyrotaxane, the rotational correlation time ({tau}{sub c}) of polyrotaxanes was estimated from the longitudinal relaxation time (T{sub 1}) of {sup 13}C NMR. The results clearly indicate that the graftpolyrotaxane described here is a new type of graft polymer in terms of the special circumrotation behavior such as the independent rotary movement of CDs with the graft chain and the axle polymer.

  14. Detection of wheel rim by immersion scan of phased array ultrasonic flaw testing

    Science.gov (United States)

    Cai, Yi-He; Guo, Jian-qiang; Wang, Ze-yong; Gao, Xiao-rong; Jiang, Xiang-dong; Li, Xi

    2015-02-01

    In order to achieve the in-service detection to high speed train wheel rims, this article analyzed the effects of the number of array elements to image focusing and image quality using water immersion ultrasonic phased array technology. Also, the effects of the depth of water to detecting technique had been researched. According to the results of the experiments, the number of optimal array elements, the corresponding thickness of immersion layer, and the optimal range of water's depth had been obtained. Thus, appropriate references had been provided to water immersion ultrasonic phased array testing.

  15. The colour wheels of art, perception, science and physiology

    Science.gov (United States)

    Harkness, Nick

    2006-06-01

    Colour is not the domain of any one discipline be it art, philosophy, psychology or science. Each discipline has its own colour wheel and this presentation examines the origins and philosophies behind the colour circles of Art, Perception, Science and Physiology (after image) with reference to Aristotle, Robert Boyle, Leonardo da Vinci, Goethe, Ewald Hering and Albert Munsell. The paper analyses and discusses the differences between the four colour wheels using the Natural Colour System® notation as the reference for hue (the position of colours within each of the colour wheels). Examination of the colour wheels shows the dominance of blue in the wheels of art, science and physiology particularly at the expense of green. This paper does not consider the three-dimensionality of colour space its goal was to review the hue of a colour with regard to its position on the respective colour wheels.

  16. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Sona Benesova

    2013-05-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  17. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Soňa Benešová

    2013-09-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  18. CAF, a generalised conicity criteria for the wheel rail contact

    OpenAIRE

    AYASSE, JB; Chollet, H; FLEURET, JS; Leveque, E.

    2002-01-01

    With several examples, this paper will show why the most significant parameter to be considered at the wheel rail contact is the angle of the tangent plane, function of the transversal relative displacement between wheel and rail (contact angle function, CAF). This parameter is the key point of INRETS methodology for static and dynamic studies of the wheel rail contact in non linear conditions. A practical example is given with switch blades.

  19. Experimental characterization of wheel-rail contact patch evolution

    OpenAIRE

    Marshall, M.B.; Lewis, R.; Dwyer-Joyce, R.S.; Olofsson, U.; Björklund, S.

    2006-01-01

    The contact area and pressure distribution in a wheel/rail contact is essential information required in any fatigue or wear calculations to determine design life, re-grinding, and maintenance schedules. As wheel or rail wear or surface damage takes place the contact patch size and shape will change. This leads to a redistribution of the contact stresses. The aim of this work was to use ultrasound to nondestructively quantify the stress distribution in new, worn, and damaged wheel-rail contact...

  20. Neutron Scattering Collimation Wheel Instrument for Imaging Research

    Science.gov (United States)

    Van Every, E.; Deyhim, A.

    2016-09-01

    The design of a state-of-the-art selector wheel instrument to support the area of neutron imaging research (neutron radiography/ tomography) is discussed. The selector wheel is installed on the DINGO Radiography instrument at the Bragg Institute HB2 beamline at ANSTO in Sidney Aus. The selector wheel consists of a single axis drum filled with a wax/steel shielding mixture and six square cutouts for neutron optics and a larger solid shielding sector to act as a shutter. This paper focuses on the details of design and shielding of the selector wheel.

  1. Frictional Heat-Induced Phase Transformation on Train Wheel Surface

    Institute of Scientific and Technical Information of China (English)

    SU Hang; PAN Tao; LI Li; YANG Cai-fu; CUI Yin-hui; JI Huai-zhong

    2008-01-01

    By combining thermomechanical coupling finite element analysis with the characteristics of phase transformation [continuous cooling transformation (CCT) curve],the thermal fatigue behavior of train wheel steel under high speed and heavy load conditions was analyzed.The influence of different materials on the formation of the phase transformation zone of the wheel tread was discussed.The result showed that the peak temperature of wheel/track friction zone could be higher than the austenitizing temperature for braking.The depth of the austenitized region could reach a point of 0.9 mm beneath the wheel tread surface.The supercooled austenite is transformed to a hard and brittle martensite layer during the following rapid cooling process,which may lead to cracking and then spalling on the wheel tread surface.The decrease in carbon contents of the train wheel steel helps inhibit the formation of martensite by increasing the austenitizing temperature of the train wheel steel.When the carbon contents decrease from 0.7% to 0.4%,the Ac3 of the wheel steel is increased by 45 ℃,and the thickness of the martensite layer is decreased by 30%,which is helpful in reducing the thermal cycling fatigue of the train wheel tread such as spalling.

  2. Influence of wheel configuration on wheelchair basketball performance : Wheel stiffness, tyre type and tyre orientation

    NARCIS (Netherlands)

    Mason, B. S.; Lemstra, M.; van der Woude, L. H. V.; Vegter, R.; Goosey-Tolfrey, V. L.

    The aim of the current investigation was to explore the lateral stiffness of different sports wheelchair wheels available to athletes in 'new' and 'used' conditions and to determine the effect of (a) stiffness, (b) tyre type (clincher vs. tubular) and (c) tyre orientation on the physiological and

  3. Wheel-slip Control Method for Seeking Maximum Value of Tangential Force between Wheel and Rail

    Science.gov (United States)

    Kondo, Keiichiro; Yasuoka, Ikuo; Yamazaki, Osamu; Toda, Shinichi; Nakazawa, Yosuke

    A method for reducing motor torque in proportion to wheel slip is applied to an inverter-driven electric locomotive. The motor torque at wheel-slip speed is less than the torque at the maximum tangential force or the adhesion force. A novel anti-slip control method for seeking the maximum value of the tangential force between the wheel and rail is proposed in this paper. The characteristics of the proposed method are analyzed theoretically to design the torque reduction ratio and the rate of change of the pattern between the wheel-slip speed and motor current. In addition, experimental tests are also carried out to verify that the use of the proposed method increases the traction force of an electric locomotive driven by induction motors and inverters. The experimental test results obtained by using the proposed control method are compared with the experimental results obtained by using a conventional control method. The averaged operational current when using the proposed control method is 10% more than that when using the conventional control method.

  4. Influence of wheel configuration on wheelchair basketball performance : Wheel stiffness, tyre type and tyre orientation

    NARCIS (Netherlands)

    Mason, B. S.; Lemstra, M.; van der Woude, L. H. V.; Vegter, R.; Goosey-Tolfrey, V. L.

    2015-01-01

    The aim of the current investigation was to explore the lateral stiffness of different sports wheelchair wheels available to athletes in 'new' and 'used' conditions and to determine the effect of (a) stiffness, (b) tyre type (clincher vs. tubular) and (c) tyre orientation on the physiological and bi

  5. Wheel Torque Distribution of Four-Wheel-Drive Electric Vehicles Based on Multi-Objective Optimization

    Directory of Open Access Journals (Sweden)

    Cheng Lin

    2015-04-01

    Full Text Available The wheel driving torque on four-wheel-drive electric vehicles (4WDEVs can be modulated precisely and continuously, therefore maneuverability and energy-saving control can be carried out at the same time. In this paper, a wheel torque distribution strategy is developed based on multi-objective optimization to improve vehicle maneuverability and reduce energy consumption. In the high-layer of the presented method, sliding mode control is used to calculate the desired yaw moment due to the model inaccuracy and parameter error. In the low-layer, mathematical programming with the penalty function consisting of the yaw moment control offset, the drive system energy loss and the slip ratio constraint is used for wheel torque control allocation. The programming is solved with the combination of off-line and on-line optimization to reduce the calculation cost, and the optimization results are sent to motor controllers as torque commands. Co-simulation based on MATLAB® and Carsim® proves that the developed strategy can both improve the vehicle maneuverability and reduce energy consumption.

  6. 解决检修轮对车轮探伤难题的思考%Reflection on the Solution of Problems in Using Overhaul Wheels to Detect Flaws of Wheel

    Institute of Scientific and Technical Information of China (English)

    陈艳伶

    2014-01-01

    This article analyzed the status of flaw -detecting of spoke boards of car wheels ,put forward the difficulties of flaw-detecting in repair process:one lies in wheel rust ,and the other lies in the magnetic field of detecting machines ,and proposed to correspond innovate rust -removing water wheel washing equipment and detecting equipment to solve the two problems ,so as to the quality of wheel flaw-detecting ,ensure wheel flaws to be found timely ,and prevent accidents .%本文对车轮辐板探伤的现状进行了分析,提出了目前检修过程中车轮探伤的难点,一个是车轮除锈问题,一个是探伤机磁场问题,并提出了应对水轮冲洗除锈设备和探伤设备进行相应改造解决这两项难题,以确保车轮探伤质量,确保车轮裂纹能够及时发现,防止行车事故的发生。

  7. Strangulation--Suicide at the wheel.

    Science.gov (United States)

    Madea, Burkhard; Schmidt, Peter; Kernbach-Wighton, Gerhard; Doberentz, Elke

    2015-11-01

    In cases of suicide at the wheel mostly velocity is used to cause death by a single occupant vehicle crash against a fixed roadside object or collision with other vehicles. A further well known mode of death is e.g. carbon monoxide poisoning. In the recent years several cases of vehicle assisted ligature strangulation resulting even in decapitation have been reported. However, cars are also used in rare cases just as places for a suicide by hanging or ligature strangulation. Not only forensic pathologists but also police officers have to be aware of this rare type of suicide to avoid unnecessary investigations.

  8. First Wheel of the Hadronic EndCap Calorimeter Completed

    CERN Document Server

    Oram, C.J.

    2002-01-01

    With the LAr calorimeters well advanced in module production, the attention is turning to Batiment 180 where the calorimeter modules are formed into complete detectors and inserted into their respective cryostats. For the Hadronic End Cap (HEC) Group the task in B180 is to assemble the wheels, rotate them into their final orientation, and put them onto the cradle in front of the End Cap Cryostat. These tasks have been completed for the first HEC wheel in the B180 End Cap Clean Room. Given that this wheel weighs 70 tons the group is very relieved to have established that these gymnastics with the wheel proceed in a routine fashion. To assemble a wheel we take modules that have already been cold tested, do the final electrical testing and locate them onto the HEC wheel assembly table. Four wheels are required in total, each consisting of 32 modules. Wheel assembly is done in the horizontal position, creating a doughnut-like object sitting on the HEC table. The first picture shows the last module being added ...

  9. Experiments on the resistance of airplane wheels and radiators

    Science.gov (United States)

    1924-01-01

    Experiments were made on the resistance of four airplane wheels of different sizes and coverings and two Lamblin radiators. The results show the important influence of the wheel coverings. The closing of a shutter, which was fitted to one of the radiators, considerably lessened the resistance.

  10. Considering the Influence of Prerequisite Performance on Wheel Spinning

    Science.gov (United States)

    Wan, Hao; Beck, Joseph Barbosa

    2015-01-01

    The phenomenon of wheel spinning refers to students attempting to solve problems on a particular skill, but becoming stuck due to an inability to learn the skill. Past research has found that students who do not master a skill quickly tend not to master it at all. One question is why do students wheel spin? A plausible hypothesis is that students…

  11. Model-based analysis and simulation of regenerative heat wheel

    DEFF Research Database (Denmark)

    Wu, Zhuang; Melnik, Roderick V. N.; Borup, F.

    2006-01-01

    of mathematical models for the thermal analysis of the fluid and wheel matrix. The effect of heat conduction in the direction of the fluid flow is taken into account and the influence of variations in rotating speed of the wheel as well as other characteristics (ambient temperature, airflow and geometric size...

  12. 76 FR 29265 - Certain Steel Wheels From China

    Science.gov (United States)

    2011-05-20

    ... Register of April 5, 2011 (76 FR 18781). The conference was held in Washington, DC, on April 20, 2011, and... COMMISSION Certain Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the... threatened with material injury by reason of imports from China of certain steel wheels, provided for...

  13. 77 FR 27249 - Certain Steel Wheels From China

    Science.gov (United States)

    2012-05-09

    ..., and by publishing the notice in the Federal Register on November 23, 2011 (76 FR 72441). The hearing... COMMISSION Certain Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the... of imports of certain steel wheels from China, provided for in subheading 8708.70 of the...

  14. Procedure and applications of combined wheel/rail roughness measurement

    NARCIS (Netherlands)

    Dittrich, M.G.

    2009-01-01

    Wheel-rail roughness is known to be the main excitation source of railway rolling noise. Besides the already standardised method for direct roughness measurement, it is also possible to measure combined wheel-rail roughness from vertical railhead vibration during a train pass-by. This is a different

  15. The Development of Wheels for the Lunar Roving Vehicle

    Science.gov (United States)

    Asnani, Vivake; Delap, Damon; Creager, Colin

    2009-01-01

    The Lunar Roving Vehicle (LRV) was developed for NASA s Apollo program so astronauts could cover a greater range on the lunar surface, carry more science instruments, and return more soil and rock samples than by foot. Because of the unique lunar environment, the creation of flexible wheels was the most challenging and time consuming aspect of the LRV development. Wheels developed for previous lunar systems were not sufficient for use with this manned vehicle; therefore, several new designs were created and tested. Based on criteria set by NASA, the choices were narrowed down to two: the wire mesh wheel developed by General Motors (GM), and the hoop spring wheel developed by the Bendix Corporation. Each of these underwent intensive mechanical, material, and terramechanical analyses, and in the end, the wire mesh wheel was chosen for the LRV. Though the wire mesh wheel was determined to be the best choice for its particular application, it may be insufficient towards achieving the objectives of future lunar missions that could require higher tractive capability, increased weight capacity, or extended life. Therefore lessons learned from the original LRV wheel development and suggestions for future Moon wheel projects are offered.

  16. Prediction of aspects of soil-wheel systems.

    NARCIS (Netherlands)

    Koolen, A.J.; Lerink, P.; Kurstjens, D.A.G.; Akker, van den J.J.H.; Arts, W.B.M.

    1992-01-01

    A simple formula is given which predicts maximum stress-depth relationships under wheels from vertical wheel load and the tyre inflation pressure. Predictions were compared with stress measurements at a depth of 30 cm under a wide range of vehicles. Stress measurements at a depth of 15 cm showed tha

  17. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory tracking...

  18. Simulation of Intelligent Single Wheel Mobile Robot

    Directory of Open Access Journals (Sweden)

    Maki K. Rashid

    2008-11-01

    Full Text Available Stabilization of a single wheel mobile robot attracted researcher attentions in robotic area. However, the budget requirements for building experimental setups capable in investigating isolated parameters and implementing others encouraged the development of new simulation methods and techniques that beat such limitations. In this work we have developed a simulation platform for testing different control tactics to stabilize a single wheel mobile robot. The graphic representation of the robot, the dynamic solution, and, the control scheme are all integrated on common computer platform using Visual Basic. Simulation indicates that we can control such robot without knowing the detail of it's internal structure or dynamics behaviour just by looking at it and using manual operation tactics. Twenty five rules are extracted and implemented using Takagi-Sugeno's fuzzy controller with significant achievement in controlling robot motion during the dynamic simulation. The resulted data from the successful implementation of the fuzzy model are used to utilize and train a neurofuzzy controller using ANFIS scheme to produce further improvement in robot performance

  19. New Small Wheel Technical Design Report

    CERN Document Server

    Kawamoto, T; Pontecorvo, L; Dubbert, J; Mikenberg, G; Iengo, P; Dallapiccola, C; Amelung, C; Levinson, L; Richter, R; Lellouch, D; CERN. Geneva. The LHC experiments Committee; LHCC

    2013-01-01

    In order to benefit from the expected high luminosity performance that will be provided by the Phase-I upgraded LHC, the first station of the ATLAS muon end-cap system (Small Wheel,SW) will need to be replaced. The New Small Wheel (NSW) will have to operate in a high background radiation region (up to 15 kHz=cm2) while reconstructing muon tracks with high precision, as well as furnishing information for the Level-1 trigger. These performance criteria are demanding. In particular, the precision reconstruction of tracks for offline analysis requires a spatial resolution of about 100microns, and the Level-1 trigger track segments have to be reconstructed online with an angular resolution of approximately 1mrad. The NSW will have two chamber technologies, one primarily devoted to the Level-1 trigger function (small-strip Thin Gap Chambers, sTGC) and one dedicated to precision tracking (Micromegas detectors, MM). The sTGC are primarily deployed for triggering given their single bunch crossing identification capabi...

  20. Camber Angle Inspection for Vehicle Wheel Alignments

    Science.gov (United States)

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-01-01

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ±0.015∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi. PMID:28165365

  1. Camber Angle Inspection for Vehicle Wheel Alignments

    Directory of Open Access Journals (Sweden)

    Jieh-Shian Young

    2017-02-01

    Full Text Available This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  2. Design and Fem Analysis of Car Alloy Wheel

    Directory of Open Access Journals (Sweden)

    Venkatesh. K

    2016-12-01

    Full Text Available The requirements for improved stiffness, reliability, fatigue life and increased efficiency involves challenges of developing innovative design solutions. The present work mainly focus on the design of car alloy wheel, where the analytical and FEM analysis approach was implemented to analyze baseline design. Initially static analysis was performed to obtain total deformation, strain and the stress of car alloy wheel. Three Dimensional model was created using CATIA and FE software ANSYS was used for discretization and analysis to obtain expected solution. The results were obtained through linear static analysis in terms of Total deformation while Minimum principal stress, Max Principal stress were found to be nearly equal for both 6 arms wheel and 4 arms wheel and 22.16 % of reduction in weight was observed and hence overall weight of the car alloy wheel was optimized.

  3. ONLINE GRINDING WHEEL WEAR COMPENSATION BY IMAGE BASED MEASURING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    WAN Daping; HU Dejin; WU Qi; ZHANG Yonghong

    2006-01-01

    Automatic compensation of grinding wheel wear in dry grinding is accomplished by an image based online measurement method. A kind of PC-based charge-coupled device image recognition system is schemed out, which detects the topography changes of the grinding wheel surface. Profile data, which corresponds to the wear and the topography, is measured by using a digital image processing method. The grinding wheel wear is evaluated by analyzing the position deviation of the grinding wheel edge. The online wear compensation is achieved according to the measure results. The precise detection and automatic compensation system is integrated into an open structure CNC curve grinding machine. A practical application is carried out to fulfil the precision curve grinding. The experimental results confirm the benefits of the proposed techniques, and the online detection accuracy is less than 5 μm. The grinding machine provides higher precision according to the in-process grinding wheel error compensation.

  4. Wheel traffic effect on air-filled porosity and air permeability in a soil catena across the wheel rut

    DEFF Research Database (Denmark)

    Berisso, Feto Esimo; Schjønning, Per; Lamandé, Mathieu

    experiment was conducted on a clay loam soil at Suberg, Switzerland, in 2010. Four repeated wheeling were performed by driving a forage harvester (wheel load of 6100 kg and a tyre width of 0.8 m) forward and rearward in the same track. We sampled 100 cm3 intact cores at 10, 30 and 50 cm depth in a soil...

  5. Installation of the first of the big wheels of the ATLAS muon spectrometer, a thin gap chamber (TGC) wheel

    CERN Multimedia

    Claudia Marcelloni

    2006-01-01

    The muon spectrometer will include four big moving wheels at each end, each measuring 25 metres in diameter. Of the eight wheels in total, six will be composed of thin gap chambers for the muon trigger system and the other two will consist of monitored drift tubes (MDTs) to measure the position of the muons

  6. Rancang Bangun Pompa Sistem Wheel Spiral untuk Skala Kecil

    Directory of Open Access Journals (Sweden)

    Feri Arlius

    2017-04-01

    Full Text Available Abstrak. Kebutuhan air semakin meningkat, maka air dari sisi ketersediaan perlu dikelola serta diatur sesuai dengan kebutuhan, sehingga air dapat dimanfaatkan dan didistribusikan jika diperlukan. Salah satu permasalahan yang mendasar di Indonesia pada sektor pertanian adalah ketersediaan air. Air terbatas dalam jumlah dan waktu juga ruang serta letak sumber air yang lebih rendah dari lahan pertanian. Terkait tingginya kebutuhan air tersebut, pemanfaatan teknologi yang mampu mengangkat dan mengalirkan air dari sumbernya ke lahan-lahan pertanian serta hunian penduduk sangat dibutuhkan, salah satu teknologinya adalah pompa. Penelitian ini bertujuan untuk melakukan rancang bangun pompa sistem wheel spiral sebagai inovasi untuk irigasi.Pengujian dilakukan 3 kali ulangan dengan lama waktu 1 jam dengan RPM 6,917 ± 7,83, kecepatan sudut 0,72 ± 0,77, daya poros 0,25 ± 0,27 Watt, debit air tertampung 0,0001533 ±0,0001732 m3/s, energi kinetik 0,36 ± 0,42 Watt, dan rata-rata efisiensi pompa 67,85 %. Tinggi maksimum pengeluaran yang dapat dicapai oleh pompa adalah 1,52 m. Pompa ini bisa menaikkan air lebih tinggi dari sudu-sudu tertinggi pada kincir serta efisiensi yang dihasilkan cukup besar sehingga dapat digunakan untuk mengairi lahan yang berada diatas sumber air.   Design Of Pump With Spiral Wheel System For Small Scale Abstract. The needs of water is always increase, the available water have to manage and control by human as a needed. Water can be used and distributed if it needs. One of the basic water’s problem in agriculture sector is the field capacity of water. Water is limited in quantity, naut and the water position is lower than the land. Thinking about the high need of water, it is important to use technology to rise and distribute the water from the reservoir to lands and also to living live. One of the technology is pump. This research was conducted to design a pump without machine as a new invention for irrigation. This research is

  7. Direct and Inverse Kinematic Analysis of a Leg-wheeled Passive Wheel Mobile Robot--Ice-skater Robot

    Institute of Scientific and Technical Information of China (English)

    宋立博; 张家梁; 吕恬生; 陆顺寿

    2003-01-01

    A new passive wheel type of leg-wheeled mobile robot based on rolling principle was introduced. To enhance the stability and maintain vertical to the ground of wheels, four passive wheels were installed at the end of four legs respectively and parallel mechanisms were used as legs. And an inertia coordinate system and a robot coordinate system were established, the related kinematic equation of the robot was gotten according to some assumptions after the configuration or the posture of wheels and legs was analyzed. At the same time, the turning conditions of the robot were also obtained. Based on the motion principle, the VSS-based logic control system was designed and the skating straight experiments and the turning experiments were conducted. And some conclusions were drawn.

  8. Photos taken during the assembly of the first 4-plane wheel prototype, built in 1998.

    CERN Multimedia

    Dixon, N.

    1998-01-01

    Photo 1 - End Cap. 4 -plane wheel prototype - One plane complete. Photo 2 - End Cap. 4 -plane wheel prototype - Radiator Foil. Photo 3 - End Cap. 4-plane wheel prototype - Glueing technique. Photo 4 - End Cap. 4-plane wheel prototype - Glueing ring. Photo 5 - End Cap. 4-plane wheel prototype - Glueing ring. Photo 6 - End Cap. 4-plane wheel prototype - Completed straw plane. Photo 7 - End Cap. 4-plane wheel prototype - Webs on assembly table. Photo 8 - End Cap. 4-plane wheel prototype - Operations on inner ring. Photo 9 - End Cap. 4-plane wheel prototype - Glueing operations. Photo 10 - End Cap. 4-plane wheel prototype - Glueing equipment. Photo 11 - End Cap. 4-plane wheel prototype - Assembly of 4-plane wheel. Photo 12 - End Cap. 4-plane wheel prototype - Positioning tool. Photo 13 - End Cap. 4-plane wheel prototype - Testing. Photo 14 - End Cap. 4-plane wheel prototype - Glued to web ring 2. Photo 15 - End Cap. 4-plane wheel prototype - Positioning tool. Photo 16 - End Cap. 4-plane wheel prototype - Detail o...

  9. Dynamic motion stabilization for front-wheel drive in-wheel motor electric vehicles

    Directory of Open Access Journals (Sweden)

    Jia-Sheng Hu

    2015-12-01

    Full Text Available This article presents a new dynamic motion stabilization approach to front-wheel drive in-wheel motor electric vehicles. The approach includes functions such as traction control system, electronic differential system, and electronic stability control. The presented electric vehicle was endowed with anti-skid performance in longitudinal accelerated start; smooth turning with less tire scrubbing; and safe driving experience in two-dimensional steering. The analysis of the presented system is given in numerical derivations. For practical verifications, this article employed a hands-on electric vehicle named Corsa-electric vehicle to carry out the tests. The presented approach contains an integrated scheme which can achieve the mentioned functions in a single microprocessor. The experimental results demonstrated the effectiveness and feasibility of the presented methodology.

  10. Infinity properads and infinity wheeled properads

    CERN Document Server

    Hackney, Philip; Yau, Donald

    2015-01-01

    The topic of this book sits at the interface of the theory of higher categories (in the guise of (∞,1)-categories) and the theory of properads. Properads are devices more general than operads, and enable one to encode bialgebraic, rather than just (co)algebraic, structures.   The text extends both the Joyal-Lurie approach to higher categories and the Cisinski-Moerdijk-Weiss approach to higher operads, and provides a foundation for a broad study of the homotopy theory of properads. This work also serves as a complete guide to the generalised graphs which are pervasive in the study of operads and properads. A preliminary list of potential applications and extensions comprises the final chapter.   Infinity Properads and Infinity Wheeled Properads is written for mathematicians in the fields of topology, algebra, category theory, and related areas. It is written roughly at the second year graduate level, and assumes a basic knowledge of category theory.

  11. Optimization of Resilient Wheels for Rolling Noise Control

    Science.gov (United States)

    BOUVET, PASCAL; VINCENT, NICOLAS; COBLENTZ, ARNAUD; DEMILLY, FRANÇOIS

    2000-03-01

    Resilient wheels are currently used on light rail systems such as tramways to prevent squealing noise and to reduce impact noise. On the other hand, they are rarely found on main lines (passenger rolling stock and freight rolling stock). Although manufacturers often claim that resilient wheels are favourable for rolling noise control, no extensive theoretical investigation confirming this statement has been published to date. In this paper, it is shown how resilient wheels can be effectively optimised in order to reduce rolling noise emission, compared to a conventional monobloc wheel. A preliminary analysis of the physical phenomena accounting for rolling noise generation emphasizes the key design parameters affecting both wheel and radiation. These parameters are the radial dynamic stiffness and damping loss factor of the rubber layer. The tread mass is also relevant. The influence of these design parameters is then qualified by a parametric study performed with the TWINS software. An optimum radial dynamic stiffness of the resilient layer is found which depends on operating conditions. Reductions in overall rolling noise up to 3 dB(A) are calculated for the configurations investigated. However, poor selection of the design parameters can lead to a noise increase compared to a standard monobloc wheel. It is also shown that a proper design for rolling noise control will not affect wheel efficiency with regard to squeal noise.

  12. Diagnostics of the wheel thread of railway rolling stock

    Directory of Open Access Journals (Sweden)

    S. Yu. Buryak

    2013-02-01

    Full Text Available Purpose. At present, the devastating impact of faulty wheels on rails on the move is a major problem of railway transport. This factor is one of the most important, which causes the shift from traditional manual methods of verification and external examination to the automated diagnostic system of rolling stock in operation. Methodology. To achieve this goal the main types of wheel damages and the way they appear are analyzed. The methods for defects and abnormalities of the wheel thread determining as well as their advantages and disadvantages were presented. Nowadays these methods are under usage in both the international practice and in the one of the CIS countries. Findings. The faulty wheel sound on the move was researched and analyzed. The necessity of using the automated system, enabling one to reduce significantly the human factor is substantiated. Originality. The method to determine the wheel thread damage on the basis of a sound diagnostic is proposed. Practical value. Automatic tracking system of the wheels condition allows performing their more qualitative diagnostics, detecting a fault at the early stage and forecasting the rate of its extension. Besides detecting the location of the faulty wheel in the rolling stock, it is also possible to trace the dynamics of the fault extension and to give the recommendations on how to eliminate it.

  13. Low-cost real-time automatic wheel classification system

    Science.gov (United States)

    Shabestari, Behrouz N.; Miller, John W. V.; Wedding, Victoria

    1992-11-01

    This paper describes the design and implementation of a low-cost machine vision system for identifying various types of automotive wheels which are manufactured in several styles and sizes. In this application, a variety of wheels travel on a conveyor in random order through a number of processing steps. One of these processes requires the identification of the wheel type which was performed manually by an operator. A vision system was designed to provide the required identification. The system consisted of an annular illumination source, a CCD TV camera, frame grabber, and 386-compatible computer. Statistical pattern recognition techniques were used to provide robust classification as well as a simple means for adding new wheel designs to the system. Maintenance of the system can be performed by plant personnel with minimal training. The basic steps for identification include image acquisition, segmentation of the regions of interest, extraction of selected features, and classification. The vision system has been installed in a plant and has proven to be extremely effective. The system properly identifies the wheels correctly up to 30 wheels per minute regardless of rotational orientation in the camera's field of view. Correct classification can even be achieved if a portion of the wheel is blocked off from the camera. Significant cost savings have been achieved by a reduction in scrap associated with incorrect manual classification as well as a reduction of labor in a tedious task.

  14. Wheel-Based Ice Sensors for Road Vehicles

    Science.gov (United States)

    Arndt, G. Dickey; Fink, Patrick W.; Ngo, Phong H.; Carl, James R.

    2011-01-01

    Wheel-based sensors for detection of ice on roads and approximate measurement of the thickness of the ice are under development. These sensors could be used to alert drivers to hazardous local icing conditions in real time. In addition, local ice-thickness measurements by these sensors could serve as guidance for the minimum amount of sand and salt required to be dispensed locally onto road surfaces to ensure safety, thereby helping road crews to utilize their total supplies of sand and salt more efficiently. Like some aircraft wing-surface ice sensors described in a number of previous NASA Tech Briefs articles, the wheelbased ice sensors are based, variously, on measurements of changes in capacitance and/or in radio-frequency impedance as affected by ice on surfaces. In the case of ice on road surfaces, the measurable changes in capacitance and/or impedance are attributable to differences among the electric permittivities of air, ice, water, concrete, and soil. In addition, a related phenomenon that can be useful for distinguishing between ice and water is a specific transition in the permittivity of ice at a temperature- dependent frequency. This feature also provides a continuous calibration of the sensor to allow for changing road conditions. Several configurations of wheel-based ice sensors are under consideration. For example, in a simple two-electrode capacitor configuration, one of the electrodes would be a circumferential electrode within a tire, and the ground would be used as the second electrode. Optionally, the steel belts that are already standard parts of many tires could be used as the circumferential electrodes. In another example (see figure), multiple electrodes would be embedded in rubber between the steel belt and the outer tire surface. These electrodes would be excited in alternating polarities at one or more suitable audio or radio frequencies to provide nearly continuous monitoring of the road surface under the tire. In still another

  15. TO SUBSTANTIATION OF COMBINE WHEELED CHASSIS FOR BEET HARVESTING EQUIPMENT

    Directory of Open Access Journals (Sweden)

    G. A. Tajanowskij

    2016-01-01

    Full Text Available The paper considers a current scientific and technical problem pertaining to creation of multi-bridge wheeled chassis for highly efficient modular sugar beet harvesters of large cargo capacity and, in particular, to selection of main parameters of chassis and wheeled drive. Such machines are designed for operation under complicated soil and climatic conditions during sugar beet harvesting. Methodological rules and regulations have been developed for solution of problems pertaining to scientifically sunstantiated selection of a manufactured or developed wheeled chassis model, building-block parameters of a working device and a chassis, rational control algorithm of the unit running system while using a specified (domestic or foreign semi-mounted equipment for beet harvesting. While solving the problem theoretical provisions for wheeled vehicles regarding specific features of a wheeled chassis for modular sugar beet harvesters with extensive mechanical or hydrostatic wheel drive of a multi-bridge propulsion system have been developed in the paper. Calculated and theoretical expressions for determination of main parameters for a wheeled chassis have been obtained and they include physical quantities of operational conditions that explicitly determine its working process. Such approach has made it possible to realize the obtained expressions as a software application which is suitable for analysis of main parameters in respect of the investigated harvester chassis and rational parameters of a branch wheel drive and also for a complete set of tires in the case when a sugar beet harvester is designed on the basis of wheeled chassis according to the selected scheme. Investigations have theoretical significance and represent practical interest for development spesialists of new modular multi-bridge sugar beet harvesters.

  16. The Matsu Wheel: A Cloud-Based Framework for Efficient Analysis and Reanalysis of Earth Satellite Imagery

    Science.gov (United States)

    Patterson, Maria T.; Anderson, Nicholas; Bennett, Collin; Bruggemann, Jacob; Grossman, Robert L.; Handy, Matthew; Ly, Vuong; Mandl, Daniel J.; Pederson, Shane; Pivarski, James; hide

    2016-01-01

    Project Matsu is a collaboration between the Open Commons Consortium and NASA focused on developing open source technology for cloud-based processing of Earth satellite imagery with practical applications to aid in natural disaster detection and relief. Project Matsu has developed an open source cloud-based infrastructure to process, analyze, and reanalyze large collections of hyperspectral satellite image data using OpenStack, Hadoop, MapReduce and related technologies. We describe a framework for efficient analysis of large amounts of data called the Matsu "Wheel." The Matsu Wheel is currently used to process incoming hyperspectral satellite data produced daily by NASA's Earth Observing-1 (EO-1) satellite. The framework allows batches of analytics, scanning for new data, to be applied to data as it flows in. In the Matsu Wheel, the data only need to be accessed and preprocessed once, regardless of the number or types of analytics, which can easily be slotted into the existing framework. The Matsu Wheel system provides a significantly more efficient use of computational resources over alternative methods when the data are large, have high-volume throughput, may require heavy preprocessing, and are typically used for many types of analysis. We also describe our preliminary Wheel analytics, including an anomaly detector for rare spectral signatures or thermal anomalies in hyperspectral data and a land cover classifier that can be used for water and flood detection. Each of these analytics can generate visual reports accessible via the web for the public and interested decision makers. The result products of the analytics are also made accessible through an Open Geospatial Compliant (OGC)-compliant Web Map Service (WMS) for further distribution. The Matsu Wheel allows many shared data services to be performed together to efficiently use resources for processing hyperspectral satellite image data and other, e.g., large environmental datasets that may be analyzed for

  17. Impulsive dynamics and stabilization of a single wheel robot

    Institute of Scientific and Technical Information of China (English)

    Ou Yongsheng; Wu Xinyu; Xu Yangsheng

    2011-01-01

    The impulsive motion of a dynamically stabilized robot-Gyrover, which is a single-wheel gyroscopically stabilized robot is studied. A method based on the D' Alembert-Lagrange principle is proposed to develop the impulsive dynamic model of the single wheel robot. This method that can be used to find ways to investigate a single wheel mobile robot rolling on a rough terrain is tested using the experimental platform Gyrover. The conditions of falling over without actuators are addressed. Simulations that validate the analysis are provided as well.

  18. Life Assessment and Life Extension of an Aircraft Wheel

    Directory of Open Access Journals (Sweden)

    M. Aghaie-Khafri

    2012-01-01

    Full Text Available The effect of heat treatment and shot peening on the fatigue life of an aluminum aircraft wheel was studied. The effect of residual stress and heat treatment on the fatigue of specimens was studied by means of fatigue testing, residual stress measurement, and fractography. Finite element simulation was used for life assessment and evaluation of the effect of surface treatments on the life extension of the aircraft wheel. The results obtained show that the operational life of the aircraft wheel extended by imposed compressive residual stress and aging treatment.

  19. Light wheel confined in a purely dielectric composite waveguide.

    Science.gov (United States)

    Ye, Yu Qian; Jin, Yi; He, Sailing

    2009-03-16

    A properly designed composite waveguide consisting of a one-dimensional photonic crystal waveguide and a conventional dielectric waveguide is proposed for the realization of a localized "light wheel". Light confinedly rotating between the two waveguides is numerically demonstrated and explained physically in detail. A delocalized "light wheel" is found at the band gap edge caused by contra-directional coupling between the two waveguides. Because of this delocalized "light wheel" , the composite waveguide can be used to trap light as a cavity, and a quality factor of 9 x 10(3) is achieved as an example. The present structure is completely dielectric and thus easy to realize with a low loss.

  20. Supramolecular architecture of metal-organic frameworks involving dinuclear copper paddle-wheel complexes.

    Science.gov (United States)

    Gomathi, Sundaramoorthy; Muthiah, Packianathan Thomas

    2013-12-15

    The two centrosymmetric dinuclear copper paddle-wheel complexes tetrakis(μ-4-hydroxybenzoato-κ(2)O:O')bis[aquacopper(II)] dimethylformamide disolvate dihydrate, [Cu2(C7H5O3)4(H2O)2]·2C3H7NO·2H2O, (I), and tetrakis(μ-4-methoxybenzoato-κ(2)O:O')bis[(dimethylformamide-κO)copper(II)], [Cu2(C8H7O3)4(C3H7NO)2], (II), crystallize with half of the dinuclear paddle-wheel cage unit in the asymmetric unit and, in addition, complex (I) has one dimethylformamide (DMF) and one water solvent molecule in the asymmetric unit. In both (I) and (II), two Cu(II) ions are bridged by four syn,syn-η(1):η(1):μ carboxylate groups, showing a paddle-wheel cage-type structure with a square-pyramidal coordination geometry. The equatorial positions of (I) and (II) are occupied by the carboxylate groups of 4-hydroxy- and 4-methoxybenzoate ligands, and the axial positions are occupied by aqua and DMF ligands, respectively. The three-dimensional supramolecular metal-organic framework of (I) consists of three different R2(2)(20) and an R4(4)(36) ring motif formed via O-H···O and OW-HW···O hydrogen bonds. Complex (II) simply packs as molecular species.

  1. Implementations of newly developed wheel and rail profile design methods

    Directory of Open Access Journals (Sweden)

    Gang Shen

    2014-06-01

    Full Text Available The developments of a series of wheel profile computer aided methods based on the RRDF or CADF contact functions are briefly described. Since 2001 the implementations of these methods are carried out according to different requirements for tramway vehicles, metro vehicles, and main line EMU vehicles etc. It is found that the main advantage of these new methods in wheel profile design is obtaining the proper wheel profiles to efficiently reduce the wears of wheel and rail and to improve the performances of both stability and curving performances. Moreover, post process of transfering a profile with discrete points to a profile with arc and line combinations is studied with a high precision.

  2. Laser-assisted Grinding Wheel Dressing (Ⅱ)-Experimental Researches

    Institute of Scientific and Technical Information of China (English)

    Ming CHEN; Fanghong SUN; Youngmoon LEE; Seunghan YANG; Jongchan LEE

    2003-01-01

    Most of the mechanical dressing technologies for resin bonded superabrasive grinding wheels are time consumingand costly. Based on the outcomes of the simulations in the previous study, this paper demonstrates the comprehensive researches on the laser-ass

  3. Forces on wheels and fuel consumption in cars

    CERN Document Server

    Güémez, J

    2014-01-01

    Motivated by real classroom discussions, we analyse the forces acting on moving vehicles, specifically friction forces on the wheels. In usual cars, with front-wheel drive, when the car accelerates these forces are in the forward direction in the front wheels, but they are in the opposite direction in the rear wheels. The situation may be intriguing for students, but it may also be helpful and stimulating to clarify the role of friction forces on rolling objects. In this article we also study thermodynamical aspects of an accelerating car, relating the distance traveled with the amount of fuel consumed. The fuel consumption is explicitly shown to be Galilean invariant and we identify the Gibbs free energy as the relevant quantity that enters in the thermodynamical description of the accelerating car. The more realistic case of the car's motion taking into account the dragging forces is also discussed.

  4. Development of Diamond-like Carbon Fibre Wheel

    Institute of Scientific and Technical Information of China (English)

    魏源迁; 山口勝美; 洞口巌; 竹内雅之

    2004-01-01

    A unique diamond-like carbon (DLC) grinding wheel was developed, in which the DLC fibres were made by rolling Al sheets coated with DLC films and aligned normally to the grinding wheel surface by laminating Al sheets together with DLC fibres. In this paper, the formation process of DLC fibres and the fabrication process of a DLC fibre wheel were investigated. Many grinding experiments were also carried out on a precision NC plane milling machine using a newly developed DLC wheel. Grinding of specimens of silicon wafers, optical glasses, quartz, granites and hardened die steel SKD11 demonstrated the capabilities of nanometer surface finish. A smooth surface with a roughness value of Ra2.5nm (Ry26nm) was achieved.

  5. Wheel slip dump valve for railway braking system

    Science.gov (United States)

    Zhang, Xuan; Zhang, LiHao; Li, QingXuan; Shi, YanTao

    2017-09-01

    As we all know, pneumatic braking system plays an important role in the safety of the whole vehicle. In the anti slip braking system, the pressure of braking cylinder can be adjusted by the quick power response of wheel slip dump valve, so that the lock situation won’t occur during vehicle service. During the braking of railway vehicles, the braking force provided by braking disc reduces vehicle’s speed. But the locking slip will happen due to the oversize of braking force or the reduction of sticking coefficient between wheel and rail. It will cause not only the decline of braking performance but also the increase of braking distance. In the meanwhile, it will scratch the wheel and influence the stable running of vehicles. Now, the speed of passenger vehicle has been increased. In order to shorten the braking distance as far as possible, sticking stickiness must be fully applied. So the occurrence probability of wheel slip is increased.

  6. Modeling of Railway Wheels Made of Austempered Ductile Iron

    Directory of Open Access Journals (Sweden)

    Giętka T.

    2016-12-01

    Full Text Available A person is forced to travel constantly throughout its entire life. The more modern the society, the greater the pace of life, and the greater the need to be present in many places that are distant from each other. Rail transport occupies second place in this regard, after air transport. This means of transportation has many advantages, however the time of travel requires continuous improvement, in particular, to match the competition. One factor limiting the speed of travel is inter-operation between the wheels – rail kinematic pair. When rolling on a rail, a wheel is subject to wear, which unavoidably leads to its degradation. Frequent damage to both the wheel and the rail necessitates consideration of this problem. Because any changes to the rail are very expensive and time-consuming, this paper focuses on possible changes to the wheel.

  7. Research on CNC Turning System of Aspheric Machining Grinding Wheel

    Institute of Scientific and Technical Information of China (English)

    ZOU Qin; GUO Yin-biao

    2005-01-01

    The technology of machining aspheric surface with high precision is the premise for the application of aspheric surface. The grinding machining with error compensation is a commonly used method to machine aspheric surface, which will directly influence the quality of aspheric workpiece surface. Multifunctional CNC grinding wheel truing system is a four-axis CNC truing system which can be applied to grinding wheel truing. In this system,DSP-based multi-axes motion control card is adopted as the controller, and visual C++ is used as development tool.When the design of hardware and software is completed, the system can implement truing of various grinding wheel with high precision aspheric machining such as plane grinding wheel, arc grinding one, and sphere grinding one.

  8. Miniature Reaction Wheel for Small Satellite Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of this project is to design, develop, demonstrate, and deliver a miniature, high torque, low-vibration reaction wheel for use on small satellites....

  9. Scaling Relations for Wheeled Locomotion in Granular Media

    Science.gov (United States)

    Slonaker, James; Kamrin, Ken

    Vehicular wheel design for use on granular material has not currently been perfected. Resistive Force Theory (RFT) is a reduced-order empirical model for granular drag, which shows promise to help simulate and understand locomotion processes to design more efficient wheels. Here we explore the fundamental scaling relations derived from RFT and their experimental validation. Similar to the non-dimensional scaling relations in fluid mechanics, the relative simplicity of RFT asserts that only one material parameter, the ''grain-structure coefficient'', is required, which reduces the complexity of the non-dimensional groups implied by the system. Therefore, wheels with differing input design parameters like size, mass, shape and even gravity, can be tested and their performance related to each other in predictable ways. We experimentally confirmed these relations by testing with 3D printed wheel geometries in a controlled sand bed.

  10. Finite Element Analysis of Wheel Rim Using Abaqus Software

    Directory of Open Access Journals (Sweden)

    Bimal Bastin

    2017-02-01

    Full Text Available The rim is the "outer edge of a wheel, holding the tire". It makes up the outer circular design of the wheel on which the inside edge of the tire is mounted on vehicles such as automobiles. A standard automotive steel wheel rim is made from a rectangular sheet metal. Design is an important industrial activity which influences the quality of the product being produced. The wheel rim is modeled by using modeling software SOLIDWORKS . Later this modal is imported to ABAQUS for analysis. Static load analysis has been done by applying a pressure of 5N/mm2 . The materials taken for analysis are steel alloy, Aluminium, Magnesium, and Forged Steel. The displacement occurred to the rim is noted after applying the static load to different materials and maximum principal stresses were also noted

  11. TECHNOLOGICAL FEATURES OF MANUFACTURE OF REINFORCED RAIL WHEEL

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2008-01-01

    Full Text Available The results of research of influence of parameters of thermomechanical hardening on the structure, complex of physico-mechanical and service properties of hardened railway wheels are presented.

  12. BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL PAINTING

    Science.gov (United States)

    This evaluation addressed product quality, waste reduction/pollution prevention and economics in replacing chemical solvent strippers with a bicarbonate of soda blasting technology for removal of paint from aircraft wheels. The evaluation was conducted in the Paint Stripping Sho...

  13. Obstacle performance of cobalt-enriching crust wheeled mining vehicle

    Institute of Scientific and Technical Information of China (English)

    HUANG Zhong-hua; LIU Shao-jun; XIE Ya

    2006-01-01

    A cobalt-enriching crust mining vehicle with four independent driven wheels was proposed. The influence of center-of-gravity position of mining vehicle on obstacle performance was studied. The results show that the mining vehicle has optimal obstacle performance with center-of-gravity position in the middle of suspension. A virtual prototype based on ADAMS software was built and its obstacle performance was simulated. Simulation results show that the mining vehicle with four independent driven wheels has excellent obstacle performance, the maximum climbing capacity is no less than 30°, the maximal ditch width and shoulder height are no less than wheel radius ofmining vehicle. Thus wheeled mining vehicle is feasible for cobalt-enriching crust commercial mining.

  14. Numerical simulation of wheel wear evolution for heavy haul railway

    Institute of Scientific and Technical Information of China (English)

    王璞; 高亮

    2015-01-01

    The prediction of the wheel wear is a fundamental problem in heavy haul railway. A numerical methodology is introduced to simulate the wheel wear evolution of heavy haul freight car. The methodology includes the spatial coupling dynamics of vehicle and track, the three-dimensional rolling contact analysis of wheel-rail, the Specht’s material wear model, and the strategy for reproducing the actual operation conditions of railway. The freight vehicle is treated as a full 3D rigid multi-body model. Every component is built detailedly and various contact interactions between parts are accurately simulated, taking into account the real clearances. The wheel−rail rolling contact calculation is carried out based on Hertz’s theory and Kalker’s FASTSIM algorithm. The track model is built based on field measurements. The material loss due to wear is evaluated according to the Specht’s model in which the wear coefficient varies with the wear intensity. In order to exactly reproduce the actual operating conditions of railway, dynamic simulations are performed separately for all possible track conditions and running velocities in each iterative step. Dimensionless weight coefficients are introduced that determine the ratios of different cases and are obtained through site survey. For the wheel profile updating, an adaptive step strategy based on the wear depth is introduced, which can effectively improve the reliability and stability of numerical calculation. At last, the wear evolution laws are studied by the numerical model for different wheels of heavy haul freight vehicle running in curves. The results show that the wear of the front wheelset is more serious than that of the rear wheelset for one bogie, and the difference is more obvious for the outer wheels. The wear of the outer wheels is severer than that of the inner wheels. The wear of outer wheels mainly distributes near the flange and the root;while the wear of inner wheels mainly distributes around the

  15. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.

    1996-06-01

    It is widely accepted that dead-reckoning based on the rolling with no-slip condition on the wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The authors establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  16. High Speed, Low Weight Momentum/Reaction Wheels

    OpenAIRE

    1999-01-01

    Advancements in several critical areas have made possible lightweight, strong and highly reliable momentum / reaction wheels. The development of reliable bearings with design features that allow high speed operation for space flight applications has significantly altered the weight / speed / wheel design considerations. Current designs typically operate at speeds at or below 6,000 RPM The new retainerless can achieve speeds 10 times that and meet or improve all other significant bearing opera...

  17. Voluntary wheel running: a review and novel interpretation.

    Science.gov (United States)

    Sherwin

    1998-07-01

    Voluntary wheel running by animals is an activity that has been observed and recorded in great detail for almost a century. This review shows that it is performed, often with startling intensity and coordination, by a wide variety of wild, laboratory and domestic species with diverse evolutionary histories. However, despite the plethora of published studies on wheel running, there is considerable disagreement between many findings, thus leading to a lack of consensus on explanations of the causality and function. In the initial part of this review, I discuss the internal and external factors that may be involved in the causality of this behaviour, with an emphasis on disparities in both the factual and theoretical development of the subject. I then address the various proposed functions of wheel running, again highlighting evidence to the contrary. This leads to the conclusion that any single theory on the basis of wheel running is likely to be simplistic with little generality. I then present a novel, behaviour-based interpretation in which it is argued that wheel running has no directly analogous naturally occurring behaviour, it is (sometimes) performed for its own sake per se rather than as a redirected or substitute activity, and studies on motivation show that wheel running is self-reinforcing and perceived by animals as 'important'. This review proposes that wheel running may be an artefact of captive environments or of the running-wheel itself, possibly resulting from feedback dysfunction. I also discuss the ubiquity and intensity of its performance, along with its great plasticity and maladaptiveness, all indicating that if it is an artefact, it is nevertheless one of great interest to behavioural science. Copyright 1998 The Association for the Study of Animal Behaviour.

  18. Analysis of fault conditions in permanentmagnet in-wheel motors

    OpenAIRE

    Liao, Yonghui

    2011-01-01

    The use of light in-wheel motors is an attractive alternative for smaller passenger vehicles in urban areas. An in-wheel motor design has already been developed in a previous master thesis project. In this project, the proposed design is further analysed during electrical faults using a FEM software package (JMAG). A failure modes and effects analysis (FMEA) is carried out to identify the important faults. The faults simulated in this project are: phase short circuit, phase open circuit, high...

  19. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    2003-01-01

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory trackin....... The stability of the hybrid control scheme is finally analyzed using Lyapunov-like arguments....

  20. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. We establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  1. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The author establishes that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  2. Modelling of Dynamics of a Wheeled Mobile Robot with Mecanum Wheels with the use of Lagrange Equations of the Second Kind

    Science.gov (United States)

    Hendzel, Z.; Rykała, Ł.

    2017-02-01

    The work presents the dynamic equations of motion of a wheeled mobile robot with mecanum wheels derived with the use of Lagrange equations of the second kind. Mecanum wheels are a new type of wheels used in wheeled mobile robots and they consist of freely rotating rollers attached to the circumference of the wheels. In order to derive dynamic equations of motion of a wheeled mobile robot, the kinetic energy of the system is determined, as well as the generalised forces affecting the system. The resulting mathematical model of a wheeled mobile robot was generated with the use of Maple V software. The results of a solution of inverse and forward problems of dynamics of the discussed object are also published.

  3. Adhesion-creepage characteristics of wheel/rail system under dry and contaminated rail surfaces

    Science.gov (United States)

    Alzoubi, Mohammed F.

    1998-11-01

    This thesis presents an experimental and theoretical study of adhesion and creepage characteristics of wheel and rail under both dry and contaminated rail surfaces. The experimental work was conducted largely on the IIT 1/4.5 Scale Wheel/Rail Simulation Facility. Based on the experimental data in the laboratory, a theoretical model of adhesion and creepage relationship with different degrees of contamination was developed. Non-dimensional analysis of parameters yielded four important non-dimensional groups, which include the adhesion, creepage coefficients, the elastic properties of the materials, the load on the wheel surface roughness of wheel and rail, train speed and the contaminant density, viscosity and minimum film thickness. Rail contaminants were gathered from several U.S. passenger rail systems and tested on the laboratory facility. It was found that presence of moisture reduce the adhesion levels with these contaminants. Under hot air jet applications, normal adhesion could be achieved. A series of tests were conducted with water contamination on clean rail. Maximum adhesion for different tests was nearly constant and approximately 0.2. Maximum adhesion produced under water contamination is significantly affected by the average roughness of the wheel and the rail. As the roughness decreases, maximum adhesion drops sharply. Maximum adhesion also decreases with speed in the presence of moisture even at relatively low speeds (4--8 mph). An empirical relation of maximum adhesion with axle load, speed and roughness has been derived. An analytical expression for the adhesion-creepage curves under (TOR) lubrication has been derived. The maximum adhesion coefficient achieved for different (TOR) lubricant formulations was found to be approximately proportional to kinematic viscosity. A theoretical approach for estimating potential energy savings with the (TOR) lubricant was developed using the laboratory data of the 1/12.5 scale simulator and 1/4.5 scale test

  4. Designing Omni-Directional Mobile Robot with Mecanum Wheel

    Directory of Open Access Journals (Sweden)

    Jefri E.M. Salih

    2006-01-01

    Full Text Available This study presents the processes undertaken in the design and development of an intelligent omni-directional mobile robot using four custom-made mecanum wheels. The mecanum wheel developed consists of nine rollers made from delrin. All mecanum wheels are independently powered using four units of precisian gear DC motors and the wheel/motor assemblies were mounted directly to the robot chassis made using an aluminum frame. A four channel high power H-bridge using 2 units of LMD 18200 motor drivers IC circuit was design, built and interfaced to a BasicStamp (BS2 microcontroller board. Basic mobility algorithm using BasicStamp software was developed to test the basic mobility capabilities and test the qualitative view of the system's mobility performance. An experiment was set-up to analyze the motion characteristic of the mobile robot motion in Y-axis, X-axis and rotary motion. Data from the experiment will be used for mathematically model for mobile robot platform and speed controller modeling and design. Mecanum wheel mobile robot provides a convenient platform for further development in the mobile platform. The combination of mechanical design on the wheel and chassis, motion control and multiple input/output sensors allow the exploration of large number of control algorithm and software to be implemented to the robot for practical applications.

  5. Milestone reached for the Big Wheels of the Muon Spectrometer

    CERN Multimedia

    Sandro Palestini

    The assembly and integration of the Big Wheels sectors of the Muon Spectrometer is reaching its conclusion, with only a few sectors of Wheel TGC-A-3 remaining on the assembly stations in building 180. The six trigger chambers (TGCs) wheels and two precision chambers wheels (MDTs) contain in total 104 sectors, which were assembled, equipped with detectors and fully tested over a period of two years. The few remaining Big Wheel sectors still stored in building 180 Most of the sectors left building 180 over the last twelve months, and form the six Wheels currently installed in the ATLAS detector. The remaining two will be installed before the end of the summer. The commitment of the personnel from the many teams who contributed to different parts of the project was essential to its success. In particular, teams coming from countries of different traditions and languages, such as China, Israel, Japan, Pakistan, Russia and USA contributed and collaborated very effectively to the timely completion of the p...

  6. On fractional control method for four-wheel-steering vehicle

    Institute of Scientific and Technical Information of China (English)

    CHEN Ning; CHEN Nan; CHEN YanDong

    2009-01-01

    Four-wheel-steering (4WS) system can enhance vehicle cornering ability by steering the rear wheels in accordance with the front wheels steering and vehicle status. With such steering control system, it becomes possible to improve the lateral stability and handling performance, in this paper, a new control method for 4WS vehicle is proposed, its rear wheels steering angle is in accordance with the angle of front wheels steering and vehicle yaw rate, and the effects of front wheels steering angle velocity are considered by adopting the fractional derivative theory. Some design specifications for control law are also given. The effects of the control method are verified by a kind of numerical scheme presented in this paper. The dynamic characteristics such as the side-slip angle and the yaw angle velocity of the vehicle gravity center are compared among three kinds of vehicles with different control methods. And the kinematics characteristics such as turning radius between 4WS and 2WS are also discussed. Nu-merical simulation shows that the control method presented can improve the transient response and reduce the turning radius of 4WS vehicle.

  7. On fractional control method for four-wheel-steering vehicle

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Four-wheel-steering (4WS) system can enhance vehicle cornering ability by steering the rear wheels in accordance with the front wheels steering and vehicle status. With such steering control system, it becomes possible to improve the lateral stability and handling performance. In this paper, a new control method for 4WS vehicle is proposed, its rear wheels steering angle is in accordance with the angle of front wheels steering and vehicle yaw rate, and the effects of front wheels steering angle velocity are considered by adopting the fractional derivative theory. Some design specifications for control law are also given. The effects of the control method are verified by a kind of numerical scheme presented in this paper. The dynamic characteristics such as the side-slip angle and the yaw angle velocity of the vehicle gravity center are compared among three kinds of vehicles with different control methods. And the kinematics characteristics such as turning radius between 4WS and 2WS are also discussed. Nu- merical simulation shows that the control method presented can improve the transient response and reduce the turning radius of 4WS vehicle.

  8. Paper recycling framework, the "Wheel of Fiber".

    Science.gov (United States)

    Ervasti, Ilpo; Miranda, Ruben; Kauranen, Ilkka

    2016-06-01

    At present, there is no reliable method in use that unequivocally describes paper industry material flows and makes it possible to compare geographical regions with each other. A functioning paper industry Material Flow Account (MFA) that uses uniform terminology and standard definitions for terms and structures is necessary. Many of the presently used general level MFAs, which are called frameworks in this article, stress the importance of input and output flows but do not provide a uniform picture of material recycling. Paper industry is an example of a field in which recycling plays a key role. Additionally, terms related to paper industry recycling, such as collection rate, recycling rate, and utilization rate, are not defined uniformly across regions and time. Thus, reliably comparing material recycling activity between geographical regions or calculating any regional summaries is difficult or even impossible. The objective of this study is to give a partial solution to the problem of not having a reliable method in use that unequivocally describes paper industry material flows. This is done by introducing a new material flow framework for paper industry in which the flow and stage structure supports the use of uniform definitions for terms related to paper recycling. This new framework is termed the Detailed Wheel of Fiber.

  9. Control of two Wheeled Welding Mobile Manipulator

    Directory of Open Access Journals (Sweden)

    M. D. Ngo

    2008-11-01

    Full Text Available A three-linked manipulator mounted on a two-wheeled mobile platform is used to weld a long curved welding path. A welding torch mounted at the end of a manipulator of the welding mobile manipulator (WMM must be controlled for tracking a welding path with constant velocity and constant welding angle of torch. In this paper, a decentralized control method is applied to control the WMM considered as two separate subsystems such as a mobile platform and a manipulator. Two decentralized motion controllers are designed to control two subsystems of WMM, respectively. Firstly, based on a tracking error vector of the manipulator and a feedback motion of the mobile platform, a kinematic controller is designed for manipulator. Secondly, based on an another tracking error vector of the mobile platform and a feedback angular velocities of revolution joints of three-link, a sliding mode controller is designed for the mobile platform. These controllers are obtained based on the Lyapunov's function and its stability condition to ensure for the tracking error vectors to be asymptotically stable. Furthermore, simulation and experimental results are presented to illustrate the effectiveness of the proposed algorithm.

  10. Torque blending and wheel slip control in EVs with in-wheel motors

    Science.gov (United States)

    de Castro, Ricardo; Araújo, Rui E.; Tanelli, Mara; Savaresi, Sergio M.; Freitas, Diamantino

    2012-01-01

    Among the many opportunities offered by electric vehicles (EVs), the design of power trains based on in-wheel electric motors represents, from the vehicle dynamics point of view, a very attractive prospect, mainly due to the torque-vectoring capabilities. However, this distributed propulsion also poses some practical challenges, owing to the constraints arising from motor installation in a confined space, to the increased unsprung mass weight and to the integration of the electric motor with the friction brakes. This last issue is the main theme of this work, which, in particular, focuses on the design of the anti-lock braking system (ABS). The proposed structure for the ABS is composed of a tyre slip controller, a wheel torque allocator and a braking supervisor. To address the slip regulation problem, an adaptive controller is devised, offering robustness to uncertainties in the tyre-road friction and featuring a gain-scheduling mechanism based on the vehicle velocity. Further, an optimisation framework is employed in the torque allocator to determine the optimal split between electric and friction brake torque based on energy performance metrics, actuator constraints and different actuators bandwidth. Finally, based on the EV working condition, the priorities of this allocation scheme are adapted by the braking supervisor unit. Simulation results obtained with the CarSim vehicle model, demonstrate the effectiveness of the overall approach.

  11. Measurement of the air boundary layer on the periphery of a rotating grinding wheel using LDA

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H [AMTReL, GERI, Liverpool John Moores University, Liverpool (United Kingdom); Lin, B [School of Mechanical Engineering, Tianjin University, Tianjin (China); Cai, R [AMTReL, GERI, Liverpool John Moores University, Liverpool (United Kingdom); Morgan, M N [AMTReL, GERI, Liverpool John Moores University, Liverpool (United Kingdom)

    2007-07-15

    In this paper, the velocity profile of the air boundary layer around a rotating grinding wheel was measured using the Laser Doppler Anemometry technique. Experimental results show that the tangential velocity of the air decreases greatly with increasing distance from the wheel surface. The distribution of the tangential velocity is also found to be almost uniform near to the centre of the wheel width, and decreases greatly as the wheel edge is approached. Generally, the radial velocity of air in the area close to the wheel surface is small, and then increases with the increasing distance from wheel surface.

  12. General motors front wheel drive 2-mode hybrid transmission

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, James [General Motors Corp., Pontiac, MI (United States). New Transmission Products Group.; Holmes, Alan G. [General Motors Corp., Pontiac, MI (United States). Powertrain Hybrid Architecture

    2009-07-01

    General Motors now expands the application of two-mode hybrid technology to front wheel drive vehicles with the development of a hybrid electric transmission packaged into essentially the same space as a conventional automatic transmission for front wheel drive. This was accomplished using a space-efficient arrangement based on two planetary gear sets and electric motor-generators with large internal diameters. A combination of damper and hydraulically-controlled clutch allow comfortable shutdown and restarting of large-displacement engines in front wheel drive vehicles. The hybrid system delivers electric low-speed urban driving, two continuously variable ranges of transmission speed ratios, four fixed transmission speed ratios, electric acceleration boosting, and regenerative braking. In the first vehicle application, the two-mode hybrid helps to reduce vehicle fuel consumption by approximately one-third. (orig.)

  13. Modeling and Analysis of Linearized Wheel-Rail Contact Dynamics

    Directory of Open Access Journals (Sweden)

    Zulfiqar Ali Soomro

    2014-07-01

    Full Text Available The dynamics of the railway vehicles are nonlinear and depend upon several factors including vehicle speed, normal load and adhesion level. The presence of contaminants on the railway track makes them unpredictable too. Therefore in order to develop an effective control strategy it is important to analyze the effect of each factor on dynamic response thoroughly. In this paper a linearized model of a railway wheel-set is developed and is later analyzed by varying the speed and adhesion level by keeping the normal load constant. A wheel-set is the wheel-axle assembly of a railroad car. Patch contact is the study of the deformation of solids that touch each other at one or more points

  14. Railway Wheel Flat Detection Based on Improved Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Yifan Li

    2016-01-01

    Full Text Available This study explores the capacity of the improved empirical mode decomposition (EMD in railway wheel flat detection. Aiming at the mode mixing problem of EMD, an EMD energy conservation theory and an intrinsic mode function (IMF superposition theory are presented and derived, respectively. Based on the above two theories, an improved EMD method is further proposed. The advantage of the improved EMD is evaluated by a simulated vibration signal. Then this method is applied to study the axle box vibration response caused by wheel flats, considering the influence of both track irregularity and vehicle running speed on diagnosis results. Finally, the effectiveness of the proposed method is verified by a test rig experiment. Research results demonstrate that the improved EMD can inhibit mode mixing phenomenon and extract the wheel fault characteristic effectively.

  15. Calibration procedure of measuring system for vehicle wheel load estimation

    Science.gov (United States)

    Kluziewicz, M.; Maniowski, M.

    2016-09-01

    The calibration procedure of wheel load measuring system is presented. Designed method allows estimation of selected wheel load components while the vehicle is in motion. Mentioned system is developed to determine friction forces between tire and road surface, basing on measured internal reaction forces in wheel suspension mechanism. Three strain gauge bridges and three-component piezoelectric load cell are responsible for internal force measurement in suspension components, two wire sensors are measuring displacements. External load is calculated via kinematic model of suspension mechanism implemented in Matlab environment. In the described calibration procedure, internal reactions are measured on a test stand while the system is loaded by a force of known direction and value.

  16. Design And Development Of Three Wheeled Campus Vehicle

    Directory of Open Access Journals (Sweden)

    Sharad Patel

    2015-08-01

    Full Text Available In todays world infrastructure of College and Industries are becoming large so if one has to travel or visit from one place to another he has to walk long distance and sometimes it becomes very hasty and inconvenient. Sometimes after too many traveling in campus it causes strain and pain in body. So to travel these distances two-wheeled or three wheeled electric scooter like Segway PT Irrway were introduced. But these scooters are very costly such as they starts from amp8377 50000. Another problem with those vehicle is that they are difficult to handle when we drive first time. So in alternate to this product we developed whole newly designed product and this is Reliable Ecofriendly Compact vehicle for campus. Its utilities are college campus Airports Industries Recreational Parks Sanctuaries Museums Palaces Villas etc. So Our research is on design and development of three-wheel campus vehicle and also its multipurpose utility among the society.

  17. Engineering report. Part 1: NASA wheel air seal development for space shuttle type environmental requirements

    Science.gov (United States)

    1973-01-01

    The sealing techniques are studied for existing aircraft wheel-tire designs to meet the hard vacuum .00001 torr and cold temperature -65 F requirements of space travel. The investigation covers the use of existing wheel seal designs.

  18. IN SITU TRUING/DRESSING OF DIAMOND WHEEL FOR PRECISION GRINDING

    Institute of Scientific and Technical Information of China (English)

    WAN Daping; WANG Yan; HU Dejin

    2008-01-01

    An application for achieving on-machine truing/dressing and monitoring of diamond wheel is dealt with in dry grinding. A dry electrical discharge (ED) assisted truing and dressing method is adopted in preparation of diamond grinding wheels. Effective and precise truing/dressing of a diamond wheel is carried out on a CNC curve grinding machine by utilizing an ED assisted diamond dresser. The dressed wheel is monitored online by a CCD vision system. It detects the topography changes of a wheel surface. The wear condition is evaluated by analyzing the edge deviation of a wheel image. The benefits of the proposed methods are confirmed by the grinding experiments. The designed truing/dressing device has high material removal rate, low dresser wear, and hence guarantees a desired wheel surface. Real-time monitoring of the wheel profile facilitates determining the optimum dressing amount, dressing interval, and the compensation error.

  19. Development and application of resilient wheels in urban rail transit vehicle

    Directory of Open Access Journals (Sweden)

    Juan WEN

    Full Text Available Urban rail transit vehicles have been more and more attractive to people as a kind of fast, comfortable, energy-saving, environmental protection and safe transportation. But because of the vehicle noise and vibration, urban rail vehicles also face severe challenges. The research of resilient wheels has been continuously developed and improved. Based on the review of development background and structure sorts of resilient wheels, the advantages of resilient wheels are described, and the research status of noise and vibration reducing, infinite element strength analysis, vehicle dynamic analysis and the wheel-rail wear of resilient wheels are discussed. Taking the low-floor LRVs (light rail vehicles in domestic and overseas as example, the development and application of the resilient wheels in city rail transit is described, and the application prospects of the resilient wheels in LRVs in domestic and the future research direction of elastic wheel are discussed.

  20. INFLUENCE OF WHEEL STRUCTURAL PARAMETERS ON MACHINING ACCURACY OF ULTRA-PRECISION PLANE HONING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new idea for designing wheel patterns is presented so as to solve the problems about machining accuracy ofworkpiece and wear of honing wheel in ultra-precision plane honing. The influence factors on motion principle and pat-tern structures are analyzed and optimization machining parameters are obtained. By calculating effective cutting lengthon the surface of workpiece cut by wheel's abrasive and the orbit of one point on the surface of workpiece contactingwith wheel, the wear coefficient of different kinds of wheels and accuracy coefficient of workpiece machined by corre-sponding wheels are obtained. Furthermore, the simulation results show that the optimal pattern structure of wheel turnsout to have lower wheel wear and higher machining accuracy.

  1. ANALYSIS OF POSSIBLE BLOCK SCHEMATIC DIAGRAMS OF ELECTROMECHANICAL TRANSMISSIONS FOR WHEEL TRACTORS

    Directory of Open Access Journals (Sweden)

    A. Kliuchnikov

    2012-01-01

    Full Text Available The paper considers advantages of stepless electromechanical transmissions. Possible diagrams of their development for application at wheel tractors have been presented in the paper. schemes for wheel tractors applications Presented and analyzed. 

  2. PARAMETER MATCHING OF INTERNAL COMBUSTION ENGINE AND ELECTROMECHANICAL POWER TRAIN OF WHEEL TRACTOR

    Directory of Open Access Journals (Sweden)

    A. Kliuchnikov

    2012-01-01

    Full Text Available The paper considers stepless electromechanical power train of a wheel tractor. Methodology for parameter matching of electromechanical transmission and internal combustion engine for their optimum performance as part of a power wheel tractor unit. 

  3. Simulation of the ATLAS New Small Wheel Trigger Sysmtem

    CERN Document Server

    Saito, Tomoyuki; The ATLAS collaboration

    2017-01-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the original design value to explore higher energy scale. In order to benefit from the expected high luminosity performance, the first station of the ATLAS muon end-cap Small Wheel system will be replaced by a New Small Wheel (NSW) detector. The NSW provide precise track segment information to the muon Level-1 trigger to reduce fake triggers. This contribution will summarize a detail of the NSW trigger decision system, track reconstruction algorithm implemented into the trigger processor and results of performance studies on the trigger system.

  4. Hybrid Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bak, Thomas; Bendtsen, Jan Dimon; Ravn, Anders Peter

    2003-01-01

    We present a hybrid systems solution to the problem of trajectory tracking for a four-wheel steered four-wheel driven mobile robot. The robot is modelled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. Under normal driving conditions, a nonlinear trajectory tracking...... feedback control law based on dynamic feedback linearization is sufficient to stabilize the system and ensure asymptotically stable tracking. Transitions to other modes are derived systematically from this model, whenever the configuration space of the controlled system has some fundamental singular points....... The stability of the hybrid control scheme is finally analyzed using Lyapunov-like arguments....

  5. A Feasability Study of the Wheel Electrostatic Spectrometer

    Science.gov (United States)

    Johansen, Michael Ryan; Phillips, James Ralph; Kelley, Joshua David; Mackey, Paul J.; Holbert, Eirik; Clements, Gregory R.; Calle, Carlos I.

    2014-01-01

    Mars rover missions rely on time-consuming, power-exhausting processes to analyze the Martian regolith. A low power electrostatic sensor in the wheels of a future Mars rover could be used to quickly determine when the rover is driving over a different type of regolith. The Electrostatics and Surface Physics Laboratory at NASA's Kennedy Space Center developed the Wheel Electrostatic Spectrometer as a feasibility study to investigate this option. In this paper, we discuss recent advances in this technology to increase the repeatability of the tribocharging experiments, along with supporting data. In addition, we discuss the development of a static elimination tool optimized for Martian conditions.

  6. Mono- and multilayers of molecular spoked carbazole wheels on graphite

    Directory of Open Access Journals (Sweden)

    Stefan-S. Jester

    2014-11-01

    Full Text Available Self-assembled monolayers of a molecular spoked wheel (a shape-persistent macrocycle with an intraannular spoke/hub system and its synthetic precursor are investigated by scanning tunneling microscopy (STM at the liquid/solid interface of 1-octanoic acid and highly oriented pyrolytic graphite. The submolecularly resolved STM images reveal that the molecules indeed behave as more or less rigid objects of certain sizes and shapes – depending on their chemical structures. In addition, the images provide insight into the multilayer growth of the molecular spoked wheels (MSWs, where the first adlayer acts as a template for the commensurate adsorption of molecules in the second layer.

  7. Fabrication of micro gear wheels by micropowder injection molding

    Institute of Scientific and Technical Information of China (English)

    Haiqing Yin; Xuanhui Qu; Chengchang Jia

    2008-01-01

    The micropowder injection molding technology was investigated to fabricate the microsized gear wheels on a conventional injection molding machine. The feedstock comprised of carbonyl ferrum powder and a wax-based thermoplastic binder. Microinjection molding was fulfilled at about 423 K under 100 MPa. The heating system was applied to the die to improve the fluidity of the feedstock and subsequently the cooling system was used to enhance the strength of the green compacts after injection by decreasing the temperature of the die. The gear wheels were realized successfully with their addendum circle diameter ranging from 800 to 200 m and with the center hole as small as 60 μtm.

  8. A Star-Wheel Stair-Climbing Wheelchair

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; WU Bo; JIN Ai-min; JIANG Shi-hong; ZHENG Yu-fei; ZHANG Shuai

    2014-01-01

    In order to achieve a wheelchair climb stairs function, this paper designs a star-wheel stair-climbing mechanism. Through the effect of the lock coupling, the star-wheel stair-climbing mechanism is formed to be fixed axis gear train or planetary gear train achieving flat-walking and stair-climbing functions. Crossing obstacle analysis obtains the maximum height and minimum width of obstacle which the wheelchair can cross. Stress-strain analysis in Solidworks simulation is performed to verify material strength.

  9. Metering Wheel-Wire Track Wire Boom Deployment Mechanism

    Science.gov (United States)

    Granoff, Mark S.

    2014-01-01

    The NASA MMS Spin Plane Double Probe (SDP) Deployer utilizes a helical path, rotating Metering Wheel and a spring loaded Wire "Holding" Track to pay out a "fixed end" 57 meter x 1.5 mm diameter Wire Boom stored between concentric storage cylinders. Unlike rotating spool type storage devices, the storage cylinders remain stationary, and the boom wire is uncoiled along the length of the cylinder via the rotation of the Metering Wheel. This uncoiling action avoids the need for slip-ring contacts since the ends of the wire can remain stationary. Conventional fixed electrical connectors (Micro-D type) are used to terminate to operational electronics.

  10. Steering Control of Wheeled Armored Vehicle with Brushless DC Motor

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Considering the steering characters of one type of wheeled armored vehicle, a brushless direct current (DC) motor is adapted as the actuator for steering control. After investigating the known algorithms, one kind of algorithm, which combines the fuzzy logic control with the self-adapting PID control and the startup and pre-brake control, is put forward. Then a test-bed is constructed, and an experiment is conducted. The result of experiment confirms the validity of this algorithm in steering control of wheeled armored vehicle with brushless DC motor.

  11. Steered wheel for the support and/or steering of a vehicle, particularly hovercraft

    Energy Technology Data Exchange (ETDEWEB)

    Duell, H.J.; Kirchner, G.

    1977-04-07

    The invention concerns a steered wheel for the support or steering of a hovercraft, whose wheel suspension is provided with an eccentric journal for automatic setting in the direction of travel. So that the vehicle will not leave its track during changes of direction when the wheel is turned around the eccentric axis, according to the invention the wheel is supported on movable bearings at the journal in the direction of the driving axle.

  12. Motion Control of a Four-wheel-drive Omnidirectional Wheelchair with High Step Climbing Capability

    OpenAIRE

    WADA, Masayoshi

    2010-01-01

    Mechanism and omnidirectional control of a 4WD mechanism for wheelchairs are presented in this chapter. The omnidirectional wheelchair system is proposed for improving maneuverability of standard wheelchairs The 4WD mechanism has high mobility which equips four wheels, two omni-wheels in the front and two normal tires in the rear, and all wheels provide traction even with two motors to drive these wheels. To realize holonomic and omnidirectional motion of a chair by utilizing the 4WD mechanis...

  13. 14 CFR Appendix D to Part 23 - Wheel Spin-Up and Spring-Back Loads

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wheel Spin-Up and Spring-Back Loads D.... D Appendix D to Part 23—Wheel Spin-Up and Spring-Back Loads D23.1 Wheel spin-up loads. (a) The... spring-back of the landing gear and adjacent structure at the instant just after the wheels come up...

  14. Design Optimization of a Mecanum Wheel to Reduce Vertical Vibrations by the Consideration of Equivalent Stiffness

    OpenAIRE

    Jong-Jin Bae; Namcheol Kang

    2016-01-01

    Mecanum wheels are capable of moving a vehicle to any direction instantaneously by the combination of independent wheel rotations. Because the mecanum wheel is composed of a hub and rollers, however, it has unavoidable drawbacks such as vertical and horizontal vibrations due to the sequential contacts between rollers and ground. In order to investigate the dynamic characteristics of a mecanum wheel, we made a prototype and performed experiments to measure the vertical vibrations. Interestingl...

  15. Design of a robot for in-pipe inspection using omnidirectional wheels and active stabilization

    NARCIS (Netherlands)

    Dertien, Edwin; Mozaffari Foumashi, Mohammad; Pulles, Kees; Stramigioli, Stefano

    2014-01-01

    This paper discusses the design of a vehicle for in-pipe inspection using omnidirectional wheels and active stabilizing control. A novel propulsion mechanism is discussed using omnidirectional wheels (or omni-wheels) is presented which allows direct control of the orientation in the pipe. This paper

  16. Investigation of wear mechanism of tread during operation of railway wheels

    Directory of Open Access Journals (Sweden)

    Svetlana GUBENKO

    2012-01-01

    Full Text Available Causes of wear particles formation on railway wheels tread were investigated. Structural factors connecting with plastic deformation, formation of “white layer”, and also with non-metallic inclusions and corrosive products of wheel steel, defining wear of railway wheels tread during operation were fixed.

  17. Microstructure and mechanical properties of railway wheels manufactured with low-medium carbon Si-Mn-Mo-V steel

    Institute of Scientific and Technical Information of China (English)

    Mingru Zhang; Haicheng Gu

    2008-01-01

    The suitability of carbide-free bainite steel as railway wheel materials was investigated. The low-medium carbon Si-Mn-Mo-V steel was designed to make railway wheels by forging and rolling. The slack quenching with water was conducted on the tread of rim section by programmed control to simulate isothermal heat treatment after being austenitized. Microstructures and mechanical properties have been studied. The results indicate that the microstructure of the rim is mainly carbide-free bainite, and the mixed mi- crostructure of bainitic ferrite and granular bainite is observed in web and hub. The mechanical properties are superior to both the standard requirements and the commercial production, such as CL60 plain carbon. The Charpy impact energy is relatively high at room and/or subzero temperatures. The force-displacement curves and fractographies reveal the excellent ability of resistance to crack initiation and propagation.

  18. STABILITY OF WHEELED VEHICLES AS COMPLEX OPERATIONAL PROPERTIES

    Directory of Open Access Journals (Sweden)

    N. Artemov

    2011-01-01

    Full Text Available Different views on the definition of «stability of wheeled vehicles» are considered and the author’s own definition is offered. A version of the structure of stability properties as a complex op-erational property is offered.

  19. A Switching Controller System for a Wheeled Mobile Robot

    Institute of Scientific and Technical Information of China (English)

    Masanori Sato; Atushi Kanda; Kazuo Ishii

    2007-01-01

    A wheeled mobile mechanism with a passive and/or active linkage mechanism for rough terrain environment is developed and evaluated. The wheeled mobile mechanism which has high mobility in rough terrain needs sophisticated system to adapt various environments.We focus on the development of a switching controller system for wheeled mobile robots in rough terrain. This system consists of two sub-systems: an environment recognition system using link angles and an adaptive control system. In the environment recognition system, we introduce a Self-Organizing Map (SOM) for clustering link angles. In the adaptive controllers, we introduce neural networks to calculate the inverse model of the wheeled mobile robot.The environment recognition system can recognize the environment in which the robot travels, and the adjustable controllers are tuned by experimental results for each environment. The dual sub-system switching controller system is experimentally evaluated. The system recognizes its environment and adapts by switching the adjustable controllers. This system demonstrates superior performance to a well-tuned single PID controller.

  20. The TASC Wheel Supports a Honey Bee Challenge

    Science.gov (United States)

    Seeley, Claire

    2011-01-01

    The concept of TASC (Thinking Actively in a Social Context) was created by Belle Wallace (Wallace et al., 1993) as a model that can be used to nurture and develop thinking skills. As children work through the TASC wheel, the teacher has a very good opportunity to facilitate explicit conversations about thinking. This allows the children to grow in…

  1. Development of a Large Scale, High Speed Wheel Test Facility

    Science.gov (United States)

    Kondoleon, Anthony; Seltzer, Donald; Thornton, Richard; Thompson, Marc

    1996-01-01

    Draper Laboratory, with its internal research and development budget, has for the past two years been funding a joint effort with the Massachusetts Institute of Technology (MIT) for the development of a large scale, high speed wheel test facility. This facility was developed to perform experiments and carry out evaluations on levitation and propulsion designs for MagLev systems currently under consideration. The facility was developed to rotate a large (2 meter) wheel which could operate with peripheral speeds of greater than 100 meters/second. The rim of the wheel was constructed of a non-magnetic, non-conductive composite material to avoid the generation of errors from spurious forces. A sensor package containing a multi-axis force and torque sensor mounted to the base of the station, provides a signal of the lift and drag forces on the package being tested. Position tables mounted on the station allow for the introduction of errors in real time. A computer controlled data acquisition system was developed around a Macintosh IIfx to record the test data and control the speed of the wheel. This paper describes the development of this test facility. A detailed description of the major components is presented. Recently completed tests carried out on a novel Electrodynamic (EDS) suspension system, developed by MIT as part of this joint effort are described and presented. Adaptation of this facility for linear motor and other propulsion and levitation testing is described.

  2. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    CERN Document Server

    Guemez, Julio

    2016-01-01

    We describe the kinematics, dynamics and also some energetic issues related to the Marta mouse motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-to-go round, as presented recently by Paul Hewitt in the Figuring Physics section of this magazine.

  3. "Walking" Along a Free Rotating Bicycle Wheel (Round and Round)

    Science.gov (United States)

    Güémez, J.; Fiolhais, M.

    2015-01-01

    We describe the kinematics, dynamics, and also some energy issues related to Marta mouse's motion when she walks on top of a horizontal bicycle wheel, which is free to rotate like a merry-go-round, as presented recently by Paul Hewitt in the "Figuring Physics" section of this journal. The situation is represented in Fig. 1, which was…

  4. Design of wheel-type walking-assist device

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Ho; Kim, Seung Ho; Kim, Chang Hoi; Seo, Yong Chil; Jung, Kyung Min; Lee, Sung Uk

    2006-03-15

    In this research, a outdoor wheel-type walking-assist device is developed to help an elder having a poor muscular strength at legs for walking, sitting and standing up easily at outdoors, and also for going and downing stairs. In conceptually designing, the environments of an elder's activity, the size of an elder's body and a necessary function of helping an elder are considered. This device has 4 wheels for stability. When an elder walks in incline plane with the proposed device, a rear-wing is rotated to keep the supporting device horizontal, regardless of an angle of inclination. A height-controlling device, which can control the height of the supporting device for adjusting an elder's height, is varied vertically to help an elder to sit and stand-up easily. Moreover, a outdoor wheel-type walking-assist device is conceptually designed and is made. In order to design it, the preview research is investigated firstly. On the basis of the proposed walking-assist device, the outdoor walking-assist device is designed and made. The outdoor wheel-type walking-assist device can go and down stairs automatically. This device go up and down the stair of having maximum 20cm height and an angle of 25 degrees with maximum 4 sec/stairs speed, and move at flatland with 60cm/sec speed.

  5. Soft Legged Wheel-Based Robot with Terrestrial Locomotion Abilities

    Directory of Open Access Journals (Sweden)

    Ali Sadeghi

    2016-12-01

    Full Text Available In recent years robotics has been influenced by a new approach, soft-robotics, bringing the idea that safe interaction with user and more adaptation to the environment can be achieved by exploiting easily deformable materials and flexible components in the structure of robots. In 2016, the soft-robotics community has promoted a new robotics challenge, named RoboSoft Grand Challenge, with the aim of bringing together different opinions on the usefulness and applicability of softness and compliancy in robotics. In this paper we describe the design and implementation of a terrestrial robot based on two soft legged wheels. The tasks predefined by the challenge were set as targets in the robot design, which finally succeeded to accomplish all the tasks. The wheels of the robot can passively climb over stairs and adapt to slippery grounds using two soft legs embedded in their structure. The soft legs, fabricated by integration of soft and rigid materials and mounted on the circumference of a conventional wheel, succeed to enhance its functionality and easily adapt to unknown grounds. The robot has a semi stiff tail that helps in the stabilization and climbing of stairs. An active wheel is embedded at the extremity of the tail in order to increase the robot maneuverability in narrow environments. Moreover two parallelogram linkages let the robot to reconfigure and shrink its size allowing entering inside gates smaller than its initial dimensions.

  6. 76 FR 18781 - Certain Steel Wheels From China

    Science.gov (United States)

    2011-04-05

    ....8 of the Commission's rules, as amended, 67 FR 68036 (November 8, 2002). Even where electronic... (C) of the Commission's Handbook on Electronic Filing Procedures, 67 FR 68168, 68173 (November 8... COMMISSION Certain Steel Wheels From China AGENCY: United States International Trade Commission....

  7. Characterizing the Performance of the Wheel Electrostatic Spectrometer

    Science.gov (United States)

    Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Calle, C. I.; Clements, J. S.

    2013-01-01

    Insulators need to be discharged after each wheel revolution. Sensor responses repeatable within one standard deviation in the noise of the signal. Insulators may not need to be cleaned after each revolution. Parent Technology- Mars Environmental Compatibility Assessment/Electrometer Electrostatic sensors with dissimilar cover insulators Protruding insulators tribocharge against regolith simulant Developed for use on the scoop for the 2001 Mars Odyssey lander Wheel Electrostatic Spectrometer Embedded electrostatic sensors in prototype Martian rover wheel If successful, this technology will enable constant electrostatic testing on Mars Air ionizing fan used to neutralize the surface charge on cover insulators . WES rolled on JSClA lunar simulant Control experiment -Static elimination not conducted between trials -Capacitor discharged after each experiment Charge neutralization experiment -Static elimination conducted between trials -Capacitor discharged after each experiment. Air ionizing fan used on insulators after each wheel revolution Capacitor discharged after each trial Care was taken to roll WES with same speed/pressure Error bars represent one standard deviation in the noise of e ach sensor

  8. Our Wheels Project: Finding the Extraordinary within the Ordinary

    Science.gov (United States)

    Cowan, Jane

    2015-01-01

    The Wheels Project took place from January to March, 2012 in a junior kindergarten/kindergarten classroom at the St. Nicholas location of Owl Child Care Services of Ontario in Waterloo. Owl Child Care Services, a nonprofit registered charity, operates seven centers in Kitchener, Waterloo, and Cambridge, Ontario. Owl is one of the largest…

  9. Single wheel testers, single track testers, and instrumented tractors

    Science.gov (United States)

    Single wheel testers and single track testers are used for determining tractive performance characteristics of tires and tracks. Instrumented tractors are useful in determining the tractive performance of tractors. These machines are also used for determining soil-tire and soil-track interactions,...

  10. A new solution method for wheel/rail rolling contact.

    Science.gov (United States)

    Yang, Jian; Song, Hua; Fu, Lihua; Wang, Meng; Li, Wei

    2016-01-01

    To solve the problem of wheel/rail rolling contact of nonlinear steady-state curving, a three-dimensional transient finite element (FE) model is developed by the explicit software ANSYS/LS-DYNA. To improve the solving speed and efficiency, an explicit-explicit order solution method is put forward based on analysis of the features of implicit and explicit algorithm. The solution method was first applied to calculate the pre-loading of wheel/rail rolling contact with explicit algorithm, and then the results became the initial conditions in solving the dynamic process of wheel/rail rolling contact with explicit algorithm as well. Simultaneously, the common implicit-explicit order solution method is used to solve the FE model. Results show that the explicit-explicit order solution method has faster operation speed and higher efficiency than the implicit-explicit order solution method while the solution accuracy is almost the same. Hence, the explicit-explicit order solution method is more suitable for the wheel/rail rolling contact model with large scale and high nonlinearity.

  11. 29 CFR 1926.303 - Abrasive wheels and tools.

    Science.gov (United States)

    2010-07-01

    ... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels and tools. (a) Power. All grinding machines shall be supplied with sufficient power to maintain...

  12. Outer Wheel Uniformity of the ElectroMagnetic Endcap Calorimeter

    CERN Document Server

    Oliver, C

    2005-01-01

    An analysis of the test beam data for the uniformity of three ECC modules is presented. A non-uniformity of less than 0.6 per cent is obtained for the outer wheel of the three modules. The results are found to be independent of the signal reconstruction method used as long as the residuals are kept below 4 per cent.

  13. Theoretical design study of the MSFC wind-wheel turbine

    Science.gov (United States)

    Frost, W.; Kessel, P. A.

    1982-01-01

    A wind wheel turbine (WWT) is studied. Evaluation of the probable performance, possible practical applications, and economic viability as compared to other conventional wind energy systems is discussed. The WWT apparatus is essentially a bladed wheel which is directly exposed to the wind on the upper half and exposed to wind through multiple ducting on the lower half. The multiple ducts consist of a forward duct (front concentrator) and two side ducts (side concentrators). The forced rotation of the wheel is then converted to power through appropriate subsystems. Test results on two simple models, a paper model and a stainless steel model, are reported. Measured values of power coefficients over wind speeds ranging from 4 to 16 m/s are given. An analytical model of a four bladed wheel is also developed. Overall design features of the wind turbine are evaluated and discussed. Turbine sizing is specified for a 5 and 25 kW machine. Suggested improvements to the original design to increase performance and performance predictions for an improved WWT design are given.

  14. Dynamics of micromachined vibrating gimbal and wheel gyroscope

    Institute of Scientific and Technical Information of China (English)

    TijingCAI

    2000-01-01

    We deduce dynamic equations of micromachined vibrating gimbal and wheel gyroscope and give an approximate solution of enough accuracy. The comparison between the approximate solution and the solution used often in the literature is given. According to property of the approximate solution a decoupled two-axes gyroscope will be composed of two single-axes gyroscopes.

  15. Wheel-rail interaction at short-wave irregularities

    NARCIS (Netherlands)

    Steenbergen, M.J.M.M.

    2008-01-01

    Short-wave irregularities in the wheel-rail interface are at the basis of track and vehicle damage and deterioration. On the short term, they result into high dynamic train-track interaction forces and a high energy input into the system that must be dissipated in the different system components or

  16. Using the Pottery Wheel to Explore Topics in Calculus

    Science.gov (United States)

    Farnell, Elin; Snipes, Marie A.

    2015-01-01

    Students sometimes struggle with visualizing the three-dimensional solids encountered in certain integral problems in a calculus class. We present a project in which students create solids of revolution with clay on a pottery wheel and estimate the volumes of these objects using Riemann sums. In addition to giving students an opportunity for…

  17. Stochastic Wheel-Slip Compensation Based Robot Localization and Mapping

    Directory of Open Access Journals (Sweden)

    SIDHARTHAN, R. K.

    2016-05-01

    Full Text Available Wheel slip compensation is vital for building accurate and reliable dead reckoning based robot localization and mapping algorithms. This investigation presents stochastic slip compensation scheme for robot localization and mapping. Main idea of the slip compensation technique is to use wheel-slip data obtained from experiments to model the variations in slip velocity as Gaussian distributions. This leads to a family of models that are switched depending on the input command. To obtain the wheel-slip measurements, experiments are conducted on a wheeled mobile robot and the measurements thus obtained are used to build the Gaussian models. Then the localization and mapping algorithm is tested on an experimental terrain and a new metric called the map spread factor is used to evaluate the ability of the slip compensation technique. Our results clearly indicate that the proposed methodology improves the accuracy by 72.55% for rotation and 66.67% for translation motion as against an uncompensated mapping system. The proposed compensation technique eliminates the need for extro receptive sensors for slip compensation, complex feature extraction and association algorithms. As a result, we obtain a simple slip compensation scheme for localization and mapping.

  18. Operational methods for minimising soil compaction and diffuse pollution risk from wheelings in winter cereals

    Science.gov (United States)

    Jackson, Bob; Silgram, Martyn; Quinton, John

    2010-05-01

    Recent UK government-funded research has shown that compacted, unvegetated tramlines wheelings can represent an important source and transport pathway, which can account for 80% of surface runoff, sediment and phosphorus losses to edge-of-field from cereals on moderate slopes. For example, recent research found 5.5-15.8% of rainfall lost as runoff, and losses of 0.8-2.9 kg TP/ha and 0.3-4.8 T/ha sediment from tramline wheelings. When compaction was released by shallow cultivation, runoff was reduced to 0.2-1.7% of rainfall with losses of 0.0-0.2 kg TP/ha and 0.003-0.3 T/ha sediment respectively i.e. close to reference losses from control areas without tramlines. Recent independent assessments using novel tracer techniques have also shown that tramline wheelings can represent important sediment sources at river catchment scale. In response to these latest findings, a new project is now underway investigating the most cost-effective and practical ways of operationalising methods for managing tramline wheelings in autumn-sown cereal systems to reduce the risk of soil compaction from the autumn spray operation and the associated risk of surface runoff and diffuse pollution loss of sediment, phosphorus and nitrogen to edge of field. Research is focusing on the over-winter period when soils are close to field capacity and the physical protection of the soil surface granted by growing crop is limited. This paper outlines this new multi-disciplinary project and associated methodologies, which include hillslope-scale event-based evaluations of the effectiveness of novel mitigation methods on surface runoff and diffuse pollution losses to edge of field, assessments of the economic and practical viability of mitigation methods, and modelling the impact on water quality of implementation of the most promising techniques at both farm and catchment scale. The study involves a large consortium with 20 partners, including many industrial organisations representing tractor, crop

  19. Wheeled mobility (wheelchair) service delivery: scope of the evidence.

    Science.gov (United States)

    Greer, Nancy; Brasure, Michelle; Wilt, Timothy J

    2012-01-17

    Identifying the appropriate wheelchair for a person who needs one has implications for both disabled persons and society. For someone with severe locomotive problems, the right wheelchair can affect mobility and quality of life. However, policymakers are concerned about the increasing demand for unnecessarily elaborate chairs. The Office of Inspector General, U.S. Department of Health and Human Services, issued 4 reports between 2009 and 2011 detailing fraud and misapplication of Medicare funds for powered wheelchairs, more than a decade after similar concerns were first raised by 4 contractors who process claims for durable medical equipment. Subsequent concerns have arisen about whether some impaired persons who need wheeled mobility devices may now be inappropriately denied coverage. A transparent, evidence-based approach to wheeled mobility service delivery (the matching of mobility-impaired persons to appropriate devices and supporting services) might lessen these concerns. This review describes the process of wheeled mobility service delivery for long-term wheelchair users with complex rehabilitation needs and presents findings from a survey of the literature (published and gray) and interviews with key informants. Recommended steps in the delivery process were identified in textbooks, guidelines, and published literature. Delivery processes shared many commonalities; however, no research supports the recommended approaches. A search of bibliographic databases through March 2011 identified 24 studies that evaluated aspects of wheeled mobility service delivery. Most were observational, exploratory studies designed to determine consumer use of and satisfaction with the process. The evidence base for the effectiveness of approaches to wheeled mobility service delivery is insufficient, and additional research is needed to develop standards and guidelines.

  20. The new forging process of a wheel hub drop forging

    Directory of Open Access Journals (Sweden)

    A. Gontarz

    2006-08-01

    Full Text Available Purpose: The main purpose of the research was working out a new flashless forming process of wheel hubforging in three-slide forging press (TSFP. It was assumed that the new process would be more effective thanthe forging processes applied in typical forging machines.Design/methodology/approach: The designing of the new process was based on the simulation by finiteelement method with the assumption of 3D state of strain. Calculations were made mainly for the analysis of thematerial flow kinematics and the process loads parameters. Experimental research were also made determiningthe dependency of clamping load in the function of forming load. On the basis of the analysis, the formingprocess of a wheel hub drop forging on the TSFP was worked out.Findings: The results of research confirmed the possibility of flashless forming process of wheel hub forgingin TSFP with axial cavities. The main parameters limiting the forming processes of wheel hub forgings are:permissible upsetting ratio and reciprocal relation of forming and clamping forces.Research limitations/implications: The further research within the range of determining force parameters fordifferent types of material and schemata of forming in TSFP were considered as purposeful. The works dealingwith analysis of forming processes of different types of products in order to classify drop forgings possible toform in this press will be examined.Practical implications: The comparison of the new forming process with the forging process on hammershowed majority of advantages which include: decrease of time and energy, decrease of drop forging weight andmachining, decrease of material consumption.Originality/value: The new process of wheel hub forging forming with axial cavities was worked out. Theparameters important during designing of forming processes in TSFP were provided. The relations betweenforces of forming tools were also determined.

  1. Cryogenic filter wheel design for an infrared instrument

    Science.gov (United States)

    Azcue, Joaquín.; Villanueva, Carlos; Sánchez, Antonio; Polo, Cristina; Reina, Manuel; Carretero, Angel; Torres, Josefina; Ramos, Gonzalo; Gonzalez, Luis M.; Sabau, Maria D.; Najarro, Francisco; Pintado, Jesús M.

    2014-09-01

    In the last two decades, Spain has built up a strong IR community which has successfully contributed to space instruments, reaching Co-PI level in the SPICA mission (Space Infrared Telescope for Cosmology and Astrophysics). Under the SPICA mission, INTA, focused on the SAFARI instrument requirements but highly adaptable to other missions has designed a cryogenic low dissipation filter wheel with six positions, taking as starting point the past experience of the team with the OSIRIS instrument (ROSETTA mission) filter wheels and adapting the design to work at cryogenic temperatures. One of the main goals of the mechanism is to use as much as possible commercial components and test them at cryogenic temperature. This paper is focused on the design of the filter wheel, including the material selection for each of the main components of the mechanism, the design of elastic mount for the filter assembly, a positioner device designed to provide positional accuracy and repeatability to the filter, allowing the locking of the position without dissipation. In order to know the position of the wheel on every moment a position sensor based on a Hall sensor was developed. A series of cryogenic tests have been performed in order to validate the material configuration selected, the ball bearing lubrication and the selection of the motor. A stepper motor characterization campaign was performed including heat dissipation measurements. The result is a six position filter wheel highly adaptable to different configurations and motors using commercial components. The mechanism was successfully tested at INTA facilities at 20K at breadboard level.

  2. Simulation modeling of wheeled vehicle dynamics on the stand "Roller"

    Directory of Open Access Journals (Sweden)

    G. O. Kotiev

    2014-01-01

    Full Text Available The tests are an integral part of the wheeled vehicle design, manufacturing, and operation. The need for their conducting arises from the research and experimental activities to assess the qualitative and quantitative characteristics of the vehicles in general, as well as the individual components and assemblies. It is obvious that a variety of design features of wheeled vehicles request a development of methods both for experimental studies and for creating the original bench equipment for these purposes.The main positive feature of bench tests of automotive engineering is a broad capability to control the combinations of traction loads, speed rates, and external input conditions. Here, the steady state conditions can be used for a long time, allowing all the necessary measurements to be made, including those with video and photo recording experiment.It is known that the benefits of test "M" type (using a roller dynamometer include a wide range of test modes, which do not depend on the climatic conditions, as well as a capability to use a computer-aided testing programs. At the same time, it is known that the main drawback of bench tests of full-size vehicle is that the tire rolling conditions on the drum mismatch to the real road pavements, which are difficult to simulate on the drum surface. This problem can be solved owing to wheeled vehicle tests at the benches "Roller" to be, in efficiency, the most preferable research method. The article gives a detailed presentation of developed at BMSTU approach to its solving.Problem of simulation mathematical modeling has been solved for the vehicle with the wheel formula 8 × 8, and individual wheel-drive.The simulation results have led to the conclusion that the proposed principle to simulate a vehicle rolling on a smooth non-deformable support base using a bench " Roller " by simulation modeling is efficient.

  3. Innovative grinding wheel design for cost-effective machining of advanced ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Kuo, P.; Liu, S.; Murphy, D.; Picone, J.W.; Ramanath, S.

    2000-05-01

    This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

  4. 77 FR 70478 - RG Steel Wheeling, LLC, Wheeling Office, A Division Of RG Steel, LLC, Including On-Site Leased...

    Science.gov (United States)

    2012-11-26

    ..., Including On-Site Leased Workers From Pro Unlimited and Green Energy Initiatives LLC, Including Workers...-site leased workers from Pro Unlimited and Green Energy Initiatives, LLC, Wheeling, West Virginia (TA-W... their wages reported through a separate unemployment insurance (UI) tax account under the name...

  5. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  6. A method for improved accuracy in three dimensions for determining wheel/rail contact points

    Science.gov (United States)

    Yang, Xinwen; Gu, Shaojie; Zhou, Shunhua; Zhou, Yu; Lian, Songliang

    2015-11-01

    Searching for the contact points between wheels and rails is important because these points represent the points of exerted contact forces. In order to obtain an accurate contact point and an in-depth description of the wheel/rail contact behaviours on a curved track or in a turnout, a method with improved accuracy in three dimensions is proposed to determine the contact points and the contact patches between the wheel and the rail when considering the effect of the yaw angle and the roll angle on the motion of the wheel set. The proposed method, with no need of the curve fitting of the wheel and rail profiles, can accurately, directly, and comprehensively determine the contact interface distances between the wheel and the rail. The range iteration algorithm is used to improve the computation efficiency and reduce the calculation required. The present computation method is applied for the analysis of the contact of rails of CHINA (CHN) 75 kg/m and wheel sets of wearing type tread of China's freight cars. In addition, it can be proved that the results of the proposed method are consistent with that of Kalker's program CONTACT, and the maximum deviation from the wheel/rail contact patch area of this two methods is approximately 5%. The proposed method, can also be used to investigate static wheel/rail contact. Some wheel/rail contact points and contact patch distributions are discussed and assessed, wheel and rail non-worn and worn profiles included.

  7. NUMERICAL SIMULATION OF TWO-POINT CONTACT BETWEEN WHEEL AND RAIL

    Institute of Scientific and Technical Information of China (English)

    Jun Zhang; Shouguang Sun; Xuesong Jin

    2009-01-01

    The elastic-plastic contact problem with rolling friction of wheel-rail is solved using the FE parametric quadratic programming method. Thus, the complex elastic-plastic contact problem can be calculated with high accuracy and efficiency, while the Hertz's hypothesis and the elastic semi-space assumption are avoided. Based on the 'one-point' contact calculation of wheel-rail, the computational model of 'two-point' contact are established and calculated when the wheel flange is close to the rail. In the case of 'two-point' contact, the changing laws of wheelrail contact are introduced and contact forces in various load cases are carefully analyzed. The main reason of wheel flange wear and rail side wear is found. Lubrication computational model of the wheel flange is constructed. Comparing with the result without lubrication, the contact force between wheel flange and rail decreases, which is beneficial for reducing the wear of wheel-rail.

  8. Indirect method for wheel-rail force measurement and derailment evaluation

    Science.gov (United States)

    Wei, Lai; Zeng, Jing; Wu, Pingbo; Gao, Hao

    2014-12-01

    Wheel set flange derailment criteria for railway vehicles are derived and the influence of wheel-rail contact parameters is studied. An indirect method for wheel-rail force measurement based on these derailment evaluation criteria is proposed. Laboratory tests for the calibration of strain-force devices on the bearing box are carried out to determine the relationship between the applied force and the measured strain. The simulation package, SIMPACK, is used to develop a passenger car model to generate wheel-rail forces and vibration signals. Different cases are considered in this model to provide an accurate validation of the identified wheel-rail forces. A feasibility test is conducted in the Beijing Loop test line using a passenger car equipped with a set of strain gauges on the wheel set. The comparison of the force time history applied to the instrumented wheel set and that obtained using the indirect method is presented.

  9. Method for the multi-criteria optimization of car wheel suspension mechanisms

    Directory of Open Access Journals (Sweden)

    Catalin Alexandru

    2016-08-01

    Full Text Available The paper deals with a general method for the multi-criteria optimization of the rear wheels suspension mechanisms in terms of kinematic behavior. The suspension mechanism is decomposed in basic binary links, and the kinematic synthesis is separately performed for each of them. The design variables are the global coordinates of the joint locations on the car body (chassis. The disposing of the joints on the wheel carrier were exclusively established by constructive criteria. The design objectives relate to kinematic position parameters of the wheel (displacements of the wheel centre along longitudinal and transversal directions, and modifications of the wheel axis direction, the optimization goal being to minimize these variations during the wheel travel. A computer program for the kinematic study was developed in C++. The application was performed for the wheel suspension mechanism of a race car.

  10. To the question of modeling of wheels and rails wear processes

    Directory of Open Access Journals (Sweden)

    S.V. Myamlin

    2013-06-01

    Full Text Available Purpose. There is a need of wear process modeling in the wheel-rail system. This is related to the fact that the wear processes in this system are absolutely different in the initial and final stages. The profile change of rail and, especially, of the wheels caused by the wear significantly affects the rolling stock dynamics, traffic safety and the resource of the wheels and rails. Wear modeling and the traffic safety evaluation requires the accounting of the low frequency component forces (including the modeling of transitional areas affecting the wheel on the side of the rail and carriage in motion of rolling stock, so the statistical analysis is not possible. Methodology. The method of mathematical modeling of the wheel set and the rail interaction was used during the research conducting. Findings. As a result of the modeling of the wheel set motion on the rail track, the mathematic model with 19 freedom degrees was obtained. This model takes into account the axle torque and studies wheels constructions as the components of the mechanical systems, consisting of a hub and tire. Originality. The mathematic model allows evaluating the wear degree of the wheels and rails when using on the rolling stock not only all-metal wheel sets, but also compound ones with the use of spring wheels and independent rotation of semi-axes with the wheels. Practical value. The development of the improved mathematical model of freight car wheel set motion with differential rotation of the wheels and compound axles allows studying the wear processes of wheels and rails.

  11. Innovative grinding wheel design for cost-effective machining of advanced ceramics. Phase I, final report

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Ramanath, S.; Simpson, M.; Lilley, E.

    1996-02-01

    Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics. This program was a cooperative effort involving three Norton groups representing a superabrasive grinding wheel manufacturer, a diamond film manufacturing division and a ceramic research center. The program was divided into two technical tasks, Task 1, Analysis of Required Grinding Wheel Characteristics, and Task 2, Design and Prototype Development. In Task 1 we performed a parallel path approach with Superabrasive metal-bond development and the higher technical risk, CVD diamond wheel development. For the Superabrasive approach, Task 1 included bond wear and strength tests to engineer bond-wear characteristics. This task culminated in a small-wheel screening test plunge grinding sialon disks. In Task 2, an improved Superabrasive metal-bond specification for low-cost machining of ceramics in external cylindrical grinding mode was identified. The experimental wheel successfully ground three types of advanced ceramics without the need for wheel dressing. The spindle power consumed by this wheel during test grinding of NC-520 sialon is as much as to 30% lower compared to a standard resin bonded wheel with 100 diamond concentration. The wheel wear with this improved metal bond was an order of magnitude lower than the resin-bonded wheel, which would significantly reduce ceramic grinding costs through fewer wheel changes for retruing and replacements. Evaluation of ceramic specimens from both Tasks 1 and 2 tests for all three ceramic materials did not show evidence of unusual grinding damage. The novel CVD-diamond-wheel approach was incorporated in this program as part of Task 1. The important factors affecting the grinding performance of diamond wheels made by CVD coating preforms were determined.

  12. Vorticity amplification near the stagnation point of landing gear wheels

    Science.gov (United States)

    Feltham, G.; Ekmekci, A.

    2014-04-01

    The vicinity near the forward stagnation point of landing-gear wheels has been found to support a mechanism for oncoming streams of weak vorticity to collect, grow, and amplify into discrete large-scale vortical structures that then shed with a distinct periodicity. To the authors' knowledge, such a flow phenomenon has never been reported before for landing gear wheels, which are in essence finite (three-dimensional) cylinders. To gain further insight into this phenomenon, a detailed experimental study has been undertaken employing the hydrogen bubble visualization and Particle Image Velocimetry techniques. A very thin platinum wire, similar to those used in hydrogen bubble visualization applications, was placed upstream of the wheel model to produce two streams of weak vorticity (with opposite sign) that convected toward the model. As the vorticity streams enter the stagnation region of the wheels, significant flow deceleration and vorticity stretching act to collect, grow, and amplify the incoming vorticity streams into large-scale vortical structures. Experiments were performed at a fixed Reynolds number, with a value of 32 500 when defined based on the diameter of the wheel and a value of 21 based on the diameter of the vorticity-generating upstream wire. First, to establish a baseline, the natural flow field (without the presence of an upstream wire) was characterized, where experimentally determined values for the stagnation boundary-layer thickness and the velocity profile along the stagnation streamline were both found to agree with the values provided in the literature for two-dimensional cylinders. Subsequently, the dynamics of vorticity collection, growth, amplification, and shedding were studied. The size, stand-off distance and the shedding frequency of the vortical structures forming near the stagnation region were all found to strongly depend on the impingement location of the inbound vorticity on the wheel. A simple relationship between the non

  13. Rutting Resistance of Asphalt Overlay with Multilayer Wheel Tracking Test

    Institute of Scientific and Technical Information of China (English)

    LIAO Weidong; CHEN Zheng; WU Shaopeng; MO Liantong; LIU Gang

    2006-01-01

    The rutting resistance of multilayer asphalt overlay was researched by using laboratory wheel tracking test. The effects of loading level and test temperature on rutting resistance of asphalt overlay structure were evaluated by means of multilayer specimens .In comparison with multilayer tests, standard specimens of various layers were also conducted to evaluate the rutting resistance. Experimental results indicated that the test temperature and applied load have a significant effect on rutting resistance of asphalt concrete. Higher test temperature and heavier applied load resulted in higher rut depths. In addition, the mutilayer wheel tracking test has been demonstrated to be a more reasonable solution in evaluation on rutting resistance of asphatt pavement structure beasuse it reflects the cumulative permanent deformation in all of asphalt layers.

  14. Mathematical Modeling of the Braking System of Wheeled Mainline Aircraft

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2016-01-01

    Full Text Available The braking system of the landing gear wheels of a mainline aircraft has to meet mandatory requirements laid out in the Aviation Regulations AP-25 (Para 25.735. «Brakes and brake systems". These requirements are essential when creating the landing gear wheel brake control system (WBCS and are used as main initial data in its mathematical modeling. The WBCS is one of the most important systems to ensure the safe completion of the flight. It is a complex of devices, i.e. units (hydraulic, electrical, and mechanical, connected through piping, wiring, mechanical constraints. This complex should allow optimizing the braking process when a large number of parameters change. The most important of them are the following: runway friction coefficient (RFC, lifting force, weight and of the aircraft, etc. The main structural elements involved in braking the aircraft are: aircraft wheels with pneumatics (air tires and brake discs, WBCS, and cooling system of gear wheels when braking.To consider the aircraft deceleration on the landing run is of essence at the stage of design, development, and improvement of brakes and braking systems. Based on analysis of equation of the aircraft motion and energy balance can be determined energy loading and its basic design parameters, braking distances and braking time.As practice and analysis of energy loading show, they (brake + wheel absorb the aircraftpossessed kinetic energy at the start of braking as much as 60-70%, 70-80%, and 80-90%, respectively, under normal increased, and emergency operating conditions. The paper presents a procedure for the rapid calculation of energy loading of the brake wheel.Currently, the mainline aircrafts use mainly electrohydraulic brake systems in which there are the main, backup, and emergency-parking brake systems. All channels are equipped with automatic anti-skid systems. Their presence in the emergency (the third reserve channel significantly improves the reliability and safety of

  15. Continuous Wheel Momentum Dumping Using Magnetic Torquers and Thrusters

    Science.gov (United States)

    Oh, Hwa-Suk; Choi, Wan-Sik; Eun, Jong-Won

    1996-12-01

    Two momentum management schemes using magnetic torquers and thrusters are sug-gested. The stability of the momentum dumping logic is proved at a general attitude equilibrium. Both momentum dumping control laws are implemented with Pulse-Width- Pulse-Frequency Modulated on-off control, and shown working equally well with the original continuous and variable strength control law. Thrusters are assummed to be asymmetrically configured as a contingency case. Each thruster is fired following separated control laws rather than paired thrusting. Null torque thrusting control is added on the thrust control calculated from the momentum control law for the gener-ation of positive thrusting force. Both magnetic and thrusting control laws guarantee the momentum dumping, however, the wheel inner loop control is needed for the "wheel speed" dumping, The control laws are simulated on the KOrea Multi-Purpose SATellite (KOMPSAT) model.

  16. Effect of machinery wheel load on grass yield

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Kristensen, Kristian

    2010-01-01

    Effect of machinery wheel load on grass   Ole Green1, Rasmus N. Jørgensen2, Kristian Kristensen3, René Gislum3, Dionysis Bochtis1, & Claus G. Sørensen1   1University of Aarhus, Dept. of Agricultural Engineering 2University of Southern Denmark, Inst. of Chemical Eng., Biotechnology and Environmental...... 3University of Aarhus, Dept. of Genetics and Biotechnology   Corresponding author: Ole Green Address & e-mail: Research Centre Foulum, Blichers Allé 20, 8830 Tjele. Ole.Green@agrsci.dk     Abstract   Different traffic intensities have been shown to have a negative influence on the yield of grass...... and clover. A full scale grass-clover field trial was established to estimate the effect on clover-grass yields as a function of different wheel loads and tire pressures. The trial comprised 16 different traffic intensities with 35 replicates and 1 traffic free treatment with 245 replicates, totalling 17...

  17. Demographic Profile of Older Adults Using Wheeled Mobility Devices

    Directory of Open Access Journals (Sweden)

    Amol M. Karmarkar

    2011-01-01

    Full Text Available The purpose of this study was to determine whether the use of wheeled mobility devices differed with respect to age, gender, residential setting, and health-related factors among older adults. A total of 723 adults ageing 60 and older are representing three cohorts, from nursing homes, the Center for Assistive Technology, and the wheelchair registry from the Human Engineering Research Laboratories. Wheeled mobility devices were classified into three main groups: manual wheelchairs, power wheelchairs, and scooters. Our results found factors including age, gender, diagnosis, and living settings to be associated with differences in use of manual versus powered mobility devices. Differences in use were also noted for subtypes of manual (depot, standard, and customized and powered (scooter, standard, and customized mobility devices, on demographic, living arrangements, and health-related factors. Consideration of demographic, health-related, and environmental factors during the prescription process may help clinicians identify the most appropriate mobility device for the user.

  18. Characterizing the Perfonnance of the Wheel Electrostatic Spectrometer

    Science.gov (United States)

    Johansen, Michael R.; Mackey, P. J.; Holbert, E.; Clements, J. S.; Calle, C. I.

    2013-01-01

    A Wheel Electrostatic Spectrometer has been developed as a surveying tool to be incorporated into a planetary rover design. Electrostatic sensors with various protruding cover insulators are embedded into a prototype rover wheel. When these insulators come into contact with a surface, a charge develops on the cover insulator through tribocharging. A charge spectrum is created by analyzing the accumulated charge on each of the dissimilar cover insulators. We eventually intend to prove charge spectra can be used o determine differences in planetary regolith properties. We tested the effects of residual surface charge on the cover insulators and discovered a need to discharge the sensor cover insulators after each revolution. We proved the repeatability of the measurements for this sensor package and found that the sensor repeatability lies within one standard deviation of the noise in the signal.

  19. Monitoring Grinding Wheel Redress-life Using Support Vector Machines

    Institute of Scientific and Technical Information of China (English)

    Xun Chen; Thitikorn Limchimchol

    2006-01-01

    Condition monitoring is a very important aspect in automated manufacturing processes. Any malfunction of a machining process will deteriorate production quality and efficiency. This paper presents an application of support vector machines in grinding process monitoring. The paper starts with an overview of grinding behaviour. Grinding force is analysed through a Short Time Fourier Transform (STFT) to identify features for condition monitoring. The Support Vector Machine (SVM) methodology is introduced as a powerful tool for the classification of different wheel wear situations.After training with available signal data, the SVM is able to identify the state of a grinding process. The requirement and strategy for using SVM for grinding process monitoring is discussed, while the result of the example illustrates how effective SVMs can be in determining wheel redress-life.

  20. Soil compaction and structural morphology under tractor wheelings

    Science.gov (United States)

    Shanahan, Peter; Quinton, John; Binley, Andrew; Silgram, Martyn

    2010-05-01

    Compaction of cultivated soils is a major problem for agriculture in terms of yield decline and sustainable soil resource management. Tramline wheelings exacerbate runoff and increase erosion from arable land. The UK Department for Environment, Food and Rural Affairs (Defra) LINK Project - a joint venture between agri-business, land managers and research groups - is currently evaluating a number of methods for alleviating compaction in tractor wheelings across a range of soil types in England. Using innovative applications of agri-geophysics (e.g. ground penetrating radar, electrical resistivity, acoustics and x-ray tomography), this current project aims to determine relationships between properties derived from geophysical methods (e.g. soil moisture, porosity), soil compaction and structural morphology. Such relationships are important for a clearer understanding of hydrological and biogeochemical processes in compacted soils, to address land management practices and develop cost-effective mitigation measures. Our poster will present some early results of this study.

  1. Design and Optimization of Composite Gyroscope Momentum Wheel Rings

    Science.gov (United States)

    Bednarcyk, Brett A.; Arnold, Steven M.

    2007-01-01

    Stress analysis and preliminary design/optimization procedures are presented for gyroscope momentum wheel rings composed of metallic, metal matrix composite, and polymer matrix composite materials. The design of these components involves simultaneously minimizing both true part volume and mass, while maximizing angular momentum. The stress analysis results are combined with an anisotropic failure criterion to formulate a new sizing procedure that provides considerable insight into the design of gyroscope momentum wheel ring components. Results compare the performance of two optimized metallic designs, an optimized SiC/Ti composite design, and an optimized graphite/epoxy composite design. The graphite/epoxy design appears to be far superior to the competitors considered unless a much greater premium is placed on volume efficiency compared to mass efficiency.

  2. Utilization of wheel dop based on ergonomic aspects

    Science.gov (United States)

    Widiasih, Wiwin; Murnawan, Hery; Setiawan, Danny

    2017-06-01

    Time is an important thing in life. People need a tool or equipment to measure time which is divided into two types, namely clock and watch. Everyone needs those kinds of tool. It becomes an opportunity for manufacturer to build a business. However, establishing a business by depending on the demand is not enough, it is necessary to take a consideration of making innovation. Innovation is a difficult thing to find out, but it is not impossible to do it. By creating an innovative product, it can be a strategy to win the competitive market. This study aimed to create an innovative product based on the ergonomic aspects, which was by utilizing wheel dop. This methodology consisted of pre-study, planning and product development, and product analysis. This product utilized wheel dop and was made based on the ergonomic aspects.

  3. Dynamics based modeling of wheeled platform for humanoid robot torso

    Directory of Open Access Journals (Sweden)

    Petrović Vladimir M.

    2016-01-01

    Full Text Available From the ancient mythology till the modern times, people were trying to build an artificial mechanical replica of themselves. Inspired by this long tradition of various engineering projects, we will hereby describe a partly humanoid robotic structure. Our robotic configuration is composed out of an anthropomimetic upper body, but instead of legs it uses a wheeled cart for the motion. In our research, this so-called semi-anthropomimetic structure has a four-wheeled cart. This work is aiming to analyze the behaviour of the robot that is exposed to different kind of external disturbances. Disturbances coming from the outside in the form of external forces (impulse and long term simulate the interactions of the robot and its ambience. Necessary simulations were thoroughly executed (in that way analyzing robotic balance and proper size of the cart is evaluated following the ZMP theoretical background. [Projekat Ministarstva nauke Republike Srbije, br. TR-35003 i br. III-44008

  4. Process capability improvement through DMAIC for aluminum alloy wheel machining

    Science.gov (United States)

    Sharma, G. V. S. S.; Rao, P. Srinivasa; Babu, B. Surendra

    2017-07-01

    This paper first enlists the generic problems of alloy wheel machining and subsequently details on the process improvement of the identified critical-to-quality machining characteristic of A356 aluminum alloy wheel machining process. The causal factors are traced using the Ishikawa diagram and prioritization of corrective actions is done through process failure modes and effects analysis. Process monitoring charts are employed for improving the process capability index of the process, at the industrial benchmark of four sigma level, which is equal to the value of 1.33. The procedure adopted for improving the process capability levels is the define-measure-analyze-improve-control (DMAIC) approach. By following the DMAIC approach, the C p, C pk and C pm showed signs of improvement from an initial value of 0.66, -0.24 and 0.27, to a final value of 4.19, 3.24 and 1.41, respectively.

  5. Experimental analysis and regression prediction of desiccant wheel behavior in high temperature heat pump and desiccant wheel air-conditioning system

    DEFF Research Database (Denmark)

    Sheng, Ying; Zhang, Yufeng; Sun, Yuexia

    2014-01-01

    The objectives of this study are to evaluate the performance of desiccant wheel (DW) in the running system and obtain the useful data for practical application. The combined influences of multiple variables on the performance of desiccant wheel are investigated based on evaluating the indexes of ...

  6. In-Flight Position Calibration of the Cassini Articulated Reaction Wheel Assembly

    Science.gov (United States)

    Brown, Todd S.

    2012-01-01

    NASA's long-lived Cassini-Huygens spacecraft is currently in its 14th year of flight and in the midst of its second, and final, extended mission. Cassini is a massive interplanetary spacecraft that is three axis stabilized and can maintain attitude control using either its reaction control system thrusters or using reaction wheel control. Cassini has four identical reaction wheels, of which three are mutually orthogonal and have a fixed orientation. The fourth reaction wheel has an articulation motor that allows this reaction wheel to be aligned with the momentum direction of any of the other three fixed reaction wheels. The articulation motor allows this reaction wheel to be used as a replacement for any of the other three wheels without any performance degradation. However, due to limitations in the design of this backup system, there are few telemetric indications of the orientation of this reaction wheel following an articulation. This investigation serves to outline the procedures that have been developed by the Cassini Attitude and Articulation Control Subsystem to calibrate the position of the articulated reaction wheel assembly in the event that the momentum direction of this reaction wheel must be reoriented.

  7. A mechanical model for deformable and mesh pattern wheel of lunar roving vehicle

    Science.gov (United States)

    Liang, Zhongchao; Wang, Yongfu; Chen, Gang (Sheng); Gao, Haibo

    2015-12-01

    As an indispensable tool for astronauts on lunar surface, the lunar roving vehicle (LRV) is of great significance for manned lunar exploration. An LRV moves on loose and soft lunar soil, so the mechanical property of its wheels directly affects the mobility performance. The wheels used for LRV have deformable and mesh pattern, therefore, the existing mechanical theory of vehicle wheel cannot be used directly for analyzing the property of LRV wheels. In this paper, a new mechanical model for LRV wheel is proposed. At first, a mechanical model for a rigid normal wheel is presented, which involves in multiple conventional parameters such as vertical load, tangential traction force, lateral force, and slip ratio. Secondly, six equivalent coefficients are introduced to amend the rigid normal wheel model to fit for the wheels with deformable and mesh-pattern in LRV application. Thirdly, the values of the six equivalent coefficients are identified by using experimental data obtained in an LRV's single wheel testing. Finally, the identified mechanical model for LRV's wheel with deformable and mesh pattern are further verified and validated by using additional experimental results.

  8. A Multiple Data Fusion Approach to Wheel Slip Control for Decentralized Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Dejun Yin

    2017-04-01

    Full Text Available Currently, active safety control methods for cars, i.e., the antilock braking system (ABS, the traction control system (TCS, and electronic stability control (ESC, govern the wheel slip control based on the wheel slip ratio, which relies on the information from non-driven wheels. However, these methods are not applicable in the cases without non-driven wheels, e.g., a four-wheel decentralized electric vehicle. Therefore, this paper proposes a new wheel slip control approach based on a novel data fusion method to ensure good traction performance in any driving condition. Firstly, with the proposed data fusion algorithm, the acceleration estimator makes use of the data measured by the sensor installed near the vehicle center of mass (CM to calculate the reference acceleration of each wheel center. Then, the wheel slip is constrained by controlling the acceleration deviation between the actual wheel and the reference wheel center. By comparison with non-control and model following control (MFC cases in double lane change tests, the simulation results demonstrate that the proposed control method has significant anti-slip effectiveness and stabilizing control performance.

  9. The new forging process of a wheel hub drop forging

    OpenAIRE

    A. Gontarz

    2006-01-01

    Purpose: The main purpose of the research was working out a new flashless forming process of wheel hubforging in three-slide forging press (TSFP). It was assumed that the new process would be more effective thanthe forging processes applied in typical forging machines.Design/methodology/approach: The designing of the new process was based on the simulation by finiteelement method with the assumption of 3D state of strain. Calculations were made mainly for the analysis of thematerial flow kine...

  10. Delayed Bilateral Teleoperation of Wheeled Robots including a Command Metric

    OpenAIRE

    2015-01-01

    This paper proposes a control scheme applied to the delayed bilateral teleoperation of wheeled robots with force feedback, considering the performance of the operator`s command execution. In addition, the stability of the system is analyzed taking into account the dynamic model of the master as well as the remote mobile robot under asymmetric and time-varying delays of the communication channel. Besides, the performance of the teleoperation system, where a human operator drives a 3D simulator...

  11. A Bibliographic Survey of Automobile and Aircraft Wheel Shimmy

    Science.gov (United States)

    1951-12-01

    advantage. Many tire mechanics questions continue to require clarificationand work of this character should lead to the establishment, of superior anti-shimmy...Italian) (1945-1946) American Aviation Annali di Matematica (Italian) (1930-1948) Arts et Metiers Association Technique Maritime et Aeronautiquep...tudinal direction of the airplane. Thus, the pendulum-suspended dual-wheel offers a favorable arrangement which may be superior with respect to weight in

  12. Teens Take the Wheel (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2015-10-22

    One of most noteworthy moments in a teenager’s life is earning a driver’s license. While it provides a newfound freedom, it also presents serious risks. In this podcast, Amy Jewett discusses ways to keep young drivers safe behind the wheel.  Created: 10/22/2015 by MMWR.   Date Released: 10/22/2015.

  13. Kinematic Control of Wheeled Snake-Like Mobile Robot

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    From a bionics viewpoint , this paper proposes a mechanical model of a wheeled snake-like mobile mechanism. On the hypothesis of the existing non-holonomic constraints on the robot kinematics, we set up the relationship among the kinetic control parameters in the snake-like movement using Lie group and Lie algebra of the principle fiber bundle and provide some theoretical control methods to realize the snake-like locomotion.

  14. Models of diagnostic relations in a wheeled tractor

    Directory of Open Access Journals (Sweden)

    Ryszard Michalski

    2014-03-01

    Full Text Available Modern wheeled tractors are equipped with new-generation electric and electronic systemswhich control the operation of actuator systems. Such solutions require an on-board computer foronline monitoring of functional performance, exhaust gas emissions, safety and operating parameters.Mechatronic diagnostic systems identify the machine’s actual operating load in different operatingmodes and under specific circumstances.Knowledge engineering methods have not yet been developed in the process of diagnosing a tractor’sdefects, but they seem to offer almost endless possibilities. A defect is defined as every event whichhas an adverse effect on tractor performance and which should be detected in the diagnostic processwith an indication of the type and place of damage as well as the magnitude and variability of damageover time. Diagnostic knowledge is a symbolic representation of empirical relations based on whichdiagnostic procedures are developed.The identification of diagnostic relations based on different methods and information sources willfoster the growth of reliable declarative knowledge comprising facts and state-symptom diagnosticrelations, as well as procedural knowledge which underlies diagnostic inference.The determination of symptom-damage relations requires a knowledge base of potential defects in theassemblies and subassemblies of a wheeled tractor. A diagnostic knowledge base can be created based on the identified diagnostic relations, including data acquired during damage simulations.The identification of diagnostic relations between specific defects and the corresponding parameterswas one of the key steps in the process of developing a mechatronic diagnostic system in a wheeledtractor. To facilitate the detection of specific defects at a given moment, a single set of diagnosticsymptoms was allocated to every defect in a wheeled tractor. Diagnostic symptoms are identified bysensors when threshold values are exceeded

  15. Three results on cycle-wheel Ramsey numbers

    NARCIS (Netherlands)

    Zhang, Yanbo; Broersma, Haitze J.; Chen, Yaojun

    Given two graphs G1 and G2, the Ramsey number R(G1,G2) is the smallest integer N such that, for any graph G of order N, either G1 is a subgraph of G, or G2 is a subgraph of the complement of G. We consider the case that G1 is a cycle and G2 is a (generalized) wheel. We expand the knowledge on exact

  16. Localization of Wheeled Mobile Robot Based on Extended Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Li Guangxu

    2015-01-01

    Full Text Available A mobile robot localization method which combines relative positioning with absolute orientation is presented. The code salver and gyroscope are used for relative positioning, and the laser radar is used to detect absolute orientation. In this paper, we established environmental map, multi-sensor information fusion model, sensors and robot motion model. The Extended Kalman Filtering (EKF is adopted as multi-sensor data fusion technology to realize the precise localization of wheeled mobile robot.

  17. EXPERIMENTAL EVALUATION OF ARTICULATED WHEELED VEHICLES POSITION STABILITY

    Directory of Open Access Journals (Sweden)

    Ye. Dubinin

    2015-07-01

    Full Text Available With introducing a mobile measurement system with linear acceleration sensors there was experimentally determined the parameter of position stability of the articulated wheeled vehicle on the example of HTA-200 «Slobozhanets». It was determined that the position stability was provided within the entire range of operating speeds and accelerations. The obtained results can be used to enhance the traffic safety of articulated vehicles.

  18. Wear Property of Cast Steel Wheel Material in Rail Truck

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; LIU Yan-lei; ZHANG Bin; FU Xiu-qin; ZHANG Hong; SONG Guo-xiang

    2009-01-01

    Wear property of material plays a key role in the service time of workpiece.A major objective in the development of new wheel materials is to improve the wear performance.The wear property of B and B+ grade cast steel materials was reported.The results showed that B+ grade cast steel material exhibited better wear property than the B grade material.Carbon content related to the hardness match was the principal factor affecting the wear properties.

  19. Study of the Correlation between the Performances of Lunar Vehicle Wheels Predicted by the Nepean Wheeled Vehicle Performance Model and Test Data

    Science.gov (United States)

    Wong, J. Y.; Asnani, V. M.

    2008-01-01

    This paper describes the results of a study of the correlation between the performances of wheels for lunar vehicles predicted using the Nepean wheeled vehicle performance model (NWVPM), developed under the auspices of Vehicle Systems Development Corporation, Ottawa, Canada, and the corresponding test data presented in Performance evaluation of wheels for lunar vehicles , Technical Report M-70-2, prepared for George C. Marshall Space Flight Center, National Aeronautics and Space Administration (NASA), USA, by the US Army Engineer Waterways Experiment Station (WES). The NWVPM was originally developed for design and performance evaluation of terrestrial off-road wheeled vehicles. The purpose of this study is to assess the potential of the NWVPM for evaluating wheel candidates for the new generation of extra-terrestrial vehicles. Two versions of a wire-mesh wheel and a hoop-spring wheel, which were considered as candidates for lunar roving vehicles for the NASA Apollo program in the late 1960s, together with a pneumatic wheel were examined in this study. The tractive performances of these wheels and of a 464 test vehicle with the pneumatic wheels on air-dry sand were predicted using the NWVPM and compared with the corresponding test data obtained under Earth s gravity and previously documented in the above-named report. While test data on wheel or vehicle performances obtained under Earth s gravity may not necessarily be representative of those on extra-terrestrial bodies, because of the differences in gravity and in environmental conditions, such as atmospheric pressure, it is still a valid approach to use test data obtained under Earth s gravity to evaluate the predictive capability of the NWVPM and its potential applications to predicting wheel or wheeled rover performances on extra-terrestrial bodies. Results of this study show that, using the ratio (P20/W) of the drawbar pull to normal load at 20 per cent slip as a performance indicator, there is a reasonable

  20. Commissioning a Rotating Target Wheel Assembly for Heavy Element Studies

    Science.gov (United States)

    Fields, L. D.; Bennett, M. E.; Mayorov, D. A.; Folden, C. M.

    2013-10-01

    The heaviest elements are produced artificially by fusing nuclei of light elements within an accelerator to form heavier nuclei. The most direct method to increase the production rate of nuclei is to increase the beam intensity, necessitating the use of a rotating target to minimize damage to the target by deposited heat. Such a target wheel was constructed for heavy element research at Texas A&M University, Cyclotron Institute, consisting of a wheel with three banana-shaped target cutouts. The target is designed to rotate at 1700 rpm, and a fiber optic cable provides a signal to trigger beam pulsing in order to avoid irradiating the spokes between target segments. Following minor mechanical modifications and construction of a dedicated electrical panel, the rotating target assembly was commissioned for a beam experiment. A 15 MeV/u beam of 20Ne was delivered from the K500 cyclotron and detected by a ruggedized silicon detector. The beam pulsing response time was characterized as a function of the rational frequency of the target wheel. Preliminary analysis suggests that the K500 is capable of pulsing at rates of up to 250 Hz, which is sufficient for planned future experiments. Funded by DOE and NSF-REU Program.

  1. Stability Simulation of a Vehicle with Wheel Active Steering

    Directory of Open Access Journals (Sweden)

    Brabec Pavel

    2016-01-01

    Full Text Available This paper deals with the possibility of increasing the vehicle driving stability at a higher speed. One of the ways how to achieve higher stability is using the 4WS system. Mathematical description of vehicle general movement is a very complex task. For simulation, models which are aptly simplified are used. For the first approach, so-called single-truck vehicle model (often linear is usually used. For the simulation, we have chosen to extend the model into a two-truck one, which includes the possibility to input more vehicle parameters. Considering the 4WS system, it is possible to use a number of potential regulations. In our simulation model, the regulation system with compound coupling was used. This type of regulation turns the rear wheels depending on the input parameters of the system (steering angle of the front wheels and depending on the output moving quantities of the vehicle, most frequently the yaw rate. Criterion for compensation of lateral deflection centre of gravity angle is its zero value, or more precisely the zero value of its first-order derivative. Parameters and set-up of the simulation model were done in conjunction with the dSAPACE software. Reference performances of the vehicle simulation model were made through the defined manoeuvres. But the simulation results indicate that the rear-wheels steering can have a positive effect on the vehicle movement stability, especially when changing the driving direction at high speed.

  2. MATHEMATICAL MODEL OF ATTITUDE CONTROL BUCKET‐WHEEL EXCAVATOR

    Directory of Open Access Journals (Sweden)

    Ivana ONDERKOVÁ

    2013-07-01

    Full Text Available This lecture deals with the application problems of convertibility GPS system at paddle excavator K 800. The claims of the modern operating surface mining of the excavators requires a lot of information for monitoring of mining process, capacity mining, selective extraction etc. The utilization of monitoring the excavator setting by GPS system proved to be the only one proper because the receivers are resistant to the vibration, dust, temperature divergence and weather changeable. Only the direct contact with communications satellite is required. It means that they can´t be located in a metal construction space (shadow caused by construction elements, influence of electrical high voltage cables even they can´t be located close to the paddle wheel on the paddle boom (shadow possibility caused by cuttinng edge created during lower gangplanks mining. This is the reason that GPS receivers are set uppermost on the metal construction excavator and the mathematical formulation is required for determination of paddle wheel petting. The relations for calculation of the paddle wheel coordinate were defined mathematically and after that the mathematical model was composed.

  3. The Read Out Controller for the ATLAS New Small Wheel

    CERN Document Server

    AUTHOR|(SzGeCERN)781403; The ATLAS collaboration; Popa, Stefan; Tulbure, Traian Tiberiu; Ivanovici, Mihail; Martoiu, Victor Sorin; Levinson, Lorne; Vermeulen, Jos

    2016-01-01

    In the upgrade process of the ATLAS detector, the innermost stations of the endcaps (Small Wheels, SW) will be replaced. The New Small Wheel (NSW) will have two chamber technologies, one for the Level-1 trigger function (small-strip Thin Gap Chambers, sTGC) and one primarily dedicated to precision tracking (Micromegas detectors, MM). Custom front-end Application Specific Integrated Circuits (ASICs) will be used to read and filter information from both the sTGC and MM detectors. In the context of the New Small Wheel data path, we designed the Read Out Controller (ROC) ASIC for handling, preprocessing and formatting the data generated by the NSW VMM upstream chips. The ROC will concentrate the data streams from 8 VMMs, filter data based on the BCID and transmit the data to FELIX via the L1DDC. ROC is composed of 8 VMM Capture modules, a cross-bar and 4 SubROC modules. The output data is sent via 4 high-speed e-links.

  4. New Record Five-Wheel Drive, Spirit's Sol 1856

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, 180-degree view of the rover's surroundings during the 1,856th Martian day, or sol, of Spirit's surface mission (March 23, 2009). The center of the view is toward the west-southwest. The rover had driven 25.82 meters (84.7 feet) west-northwestward earlier on Sol 1856. This is the longest drive on Mars so far by a rover using only five wheels. Spirit lost the use of its right-front wheel in March 2006. Before Sol 1856, the farthest Spirit had covered in a single sol's five-wheel drive was 24.83 meters (81.5 feet), on Sol 1363 (Nov. 3, 2007). The Sol 1856 drive made progress on a route planned for taking Spirit around the western side of the low plateau called 'Home Plate.' A portion of the northwestern edge of Home Plate is prominent in the left quarter of this image, toward the south. This view is presented as a cylindrical projection with geometric seam correction.

  5. Structure Analysis of a Turbocharger Compressor Wheel Using FEA

    Directory of Open Access Journals (Sweden)

    Shaik Mohammad Rafi

    2014-10-01

    Full Text Available When people talk about race cars or high-performance sports cars, the topic of turbochargers usually comes up. Turbochargers also appear on large diesel engines. A turbo can significantly boost an engine's horsepower without significantly increasing its weight, which is the huge benefit that makes turbos so popular. Turbochargers are a type of forced induction system. They compress the air flowing into the engine. The advantage of compressing the air is that it lets the engine squeeze more air into a cylinder, and more air means that more fuel can be added. Therefore, you get more power from each explosion in each cylinder. Here in this project we are designing the compressor wheel by using Pro-E and doing analysis by using FEA package. The main aim of the project is to increase the performance of the compressor wheel for this we are changing the material and also we are changing the existing design. By comparing the results we will get the best model from this data we suggests the design modifications to the company to improve the performance of the compressor wheel.

  6. GMT azimuth bogie wheel-rail interface wear study

    Science.gov (United States)

    Teran, Jose; Lindh, Cory; Morgan, Chris; Manuel, Eric; Bigelow, Bruce C.; Burgett, William S.

    2016-07-01

    Performance of the GMT azimuth drive system is vital for the operation of the telescope and, as such, all components subject to wear at the drive interface merit a high level of scrutiny for achieving a proper balance between capital costs, maintenance costs, and the risk for downtime during planned and unplanned maintenance or replacement procedures. Of particular importance is the interface between the azimuth wheels and rail, as usage frequency is high, the full weight of the enclosure must be transferred through small patches of contact, and replacement of the rail would pose a greater logistical challenge than the replacement of smaller components such as bearings and gearmotors. This study investigates tradeoffs between various wheel-rail and roller-track interfaces, including performance, complexity, and anticipated wear considerations. First, a survey of railway and overhead crane industry literature is performed and general detailing recommendations are made to minimize wear and the risk of rolling contact fatigue. Second, Adams/VI-Rail is used to simulate lifetime wear of four specific configurations under consideration for the GMT azimuth wheel-rail interface; all studied configurations are shown to be viable, and their relative merits are discussed.

  7. The Coastal Hazard Wheel system for coastal multi-hazard assessment & management in a changing climate

    DEFF Research Database (Denmark)

    Appelquist, Lars Rosendahl; Halsnæs, Kirsten

    2015-01-01

    screening and management. The system is developed to assess the main coastal hazards in a single process and covers the hazards of ecosystem disruption, gradual inundation, salt water intrusion, erosion and flooding. The system was initially presented in 2012 and based on a range of test......This paper presents the complete Coastal Hazard Wheel (CHW) system, developed for multi-hazard-assessment and multi-hazard-management of coastal areas worldwide under a changing climate. The system is designed as a low-tech tool that can be used in areas with limited data availability......-applications and feedback from coastal experts, the system has been further refined and developed into a complete hazard management tool. This paper therefore covers the coastal classification system used by the CHW, a standardized assessment procedure for implementation of multi-hazard-assessments, technical guidance...

  8. Analysis of limit forces on the vehicle wheels using an algorithm of Dynamic Square Method

    Science.gov (United States)

    Brukalski, M.

    2016-09-01

    This article presents a method named as Dynamic Square Method (DSM) used for dynamic analysis of a vehicle equipped with a four wheel drive system. This method allows determination of maximum (limit) forces acting on the wheels. Here, the maximum longitudinal forces acting on the wheels are assumed and then used to predict whether they can be achieved by a specific dynamic motion or whether the actual friction forces under a given wheel is large enough to transfer lateral forces. For the analysis of DSM a four wheel vehicle model is used. On the basis of this characteristic it is possible to determine the maximum longitudinal force acting on the wheels of the given axle depending on the lateral acceleration of the vehicle. The results of this analysis may be useful in the development of a control algorithm used for example in active differentials.

  9. Theoretical prediction of the damping of a railway wheel with sandwich-type dampers

    Science.gov (United States)

    Merideno, Inaki; Nieto, Javier; Gil-Negrete, Nere; Giménez Ortiz, José Germán; Landaberea, Aitor; Iartza, Jon

    2014-09-01

    This paper presents a procedure for predicting the damping added to a railway wheel when sandwich-type dampers are installed. Although there are different ways to reduce the noise generated by a railway wheel, most devices are based on the mechanism of increasing wheel damping. This is why modal damping ratios are a clear indicator of the efficiency of the damping device and essential when a vibro-acoustic study of a railway wheel is carried out. Based on a number of output variables extracted from the wheel and damper models, the strategy explained herein provides the final damping ratios of the damped wheel. Several different configurations are designed and experimentally tested. Theoretical and experimental results agree adequately, and it is demonstrated that this procedure is a good tool for qualitative comparison between different solutions in the design stages.

  10. Design and Trafficability Study of Flexible Wheel for Planetary Exploration Rover

    Institute of Scientific and Technical Information of China (English)

    LI Wen; GAO Feng; XU Guo-yan

    2007-01-01

    To reduce sending costs, a flexible wheel configuration is proposed. The wheel is made of titanium alloy (Ti-6Al-4V) in consideration of the planetary environment factors (i.e. strong radiation, big temperature differences, high vacuum), and mass constraint of launch vehicle. The advantages of the proposed wheel involves the potential for: ① small sending volume and mass, ② large deployed area and volume to reduce wheel loading, ③ a damping effect to smooth motion on rough terrain. To study the trafficability and tractive performance of the wheel concept, the drawbar pull and driven torque were calculated based on simplified model of terramechanics formulations. The results show that the wheel possesses sufficient drawbar pull to negotiate all types of soil stratums listed in this contribution.

  11. Green's functions for analysis of dynamic response of wheel/rail to vertical excitation

    Science.gov (United States)

    Mazilu, Traian

    2007-09-01

    An analytical model to simulate wheel/rail interaction using the Green's functions method is proposed in this paper. The model consists of a moving wheel on a discretely supported rail. Particularly for this model of rail, the bending and the longitudinal displacement are coupled due to the rail pad and a complex model of the rail pad is adopted. An efficient method for solving a time-domain analysis for wheel/rail interaction is presented. The method is based on the properties of the rail's Green functions and starting to these functions, a track's Green matrix is assembled for the numerical simulations of wheel/rail response due to three kinds of vertical excitations: the steady-state interaction, the rail corrugation and the wheel flat. The study points to influence of the worn rail—rigid contact—on variation in the wheel/rail contact force. The concept of pinned-pinned inhibitive rail pad is also presented.

  12. Design optimization on the front wheel orientation parameters of a vehicle

    Institute of Scientific and Technical Information of China (English)

    CHU Zhigang; DENG Zhaoxiang; HU Yumei; ZHU Ming

    2003-01-01

    A uniform optimization object function for front wheel orientation parameters of a vehicle is reported, which includes the tolerances of practical values and set values of front wheel orientation parameters under full load, and the changing value of each parameter with front wheel fluctuation to build a front suspension model for optimization analysis based on the multi-body dynamic (MD) theory. The original suspension is optimized with this model, and the variation law of each parameter with front wheel fluctuation is obtained. The results of a case study demonstrate that the front wheel orientation parameters of the optimized vehicle are reasonable under typical conditions and the variation of each parameter is in an ideal range with the wheel fluctuating within ±40 mm. In addition, the driving performance is improved greatly in the road test and practical use.

  13. Multispectral Imager With Improved Filter Wheel and Optics

    Science.gov (United States)

    Bremer, James C.

    2007-01-01

    Figure 1 schematically depicts an improved multispectral imaging system of the type that utilizes a filter wheel that contains multiple discrete narrow-band-pass filters and that is rotated at a constant high speed to acquire images in rapid succession in the corresponding spectral bands. The improvement, relative to prior systems of this type, consists of the measures taken to prevent the exposure of a focal-plane array (FPA) of photodetectors to light in more than one spectral band at any given time and to prevent exposure of the array to any light during readout. In prior systems, these measures have included, variously the use of mechanical shutters or the incorporation of wide opaque sectors (equivalent to mechanical shutters) into filter wheels. These measures introduce substantial dead times into each operating cycle intervals during which image information cannot be collected and thus incoming light is wasted. In contrast, the present improved design does not involve shutters or wide opaque sectors, and it reduces dead times substantially. The improved multispectral imaging system is preceded by an afocal telescope and includes a filter wheel positioned so that its rotation brings each filter, in its turn, into the exit pupil of the telescope. The filter wheel contains an even number of narrow-band-pass filters separated by narrow, spoke-like opaque sectors. The geometric width of each filter exceeds the cross-sectional width of the light beam coming out of the telescope. The light transmitted by the sequence of narrow-band filters is incident on a dichroic beam splitter that reflects in a broad shorter-wavelength spectral band that contains half of the narrow bands and transmits in a broad longer-wavelength spectral band that contains the other half of the narrow spectral bands. The filters are arranged on the wheel so that if the pass band of a given filter is in the reflection band of the dichroic beam splitter, then the pass band of the adjacent filter

  14. Analysis of wheel motion on corrugated rail; Corrugation ga hasseishita rail wo sokosuru sharin no undo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Horie, A. [Tokyo Gas Co. Ltd., Tokyo (Japan); Ikuta, S.; Suda, Y. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science] Terumichi, Y. [Sophia University, Tokyo (Japan). Faculty of Science and Technology; Ono, S. [The University of Tokyo, Tokyo (Japan)

    1998-09-01

    An analysis is conducted into the compound vibration of a wheel/rail system which is a two-axle truck travelling on rails with corrugation type wear generated thereon. Each wheel is analyzed using an analysis model in which the travelling mass, contact spring (concentrated mass system of one degree of freedom), and rails provide a system of distributed constants. Calculation is then made about the variation in the contact force that occurs between the wheels and rails when the truck travels at a prescribed speed in a sector with corrugation (assumed to be sinusoidal) generated on the rails therein. It is then found that there is interaction between the front wheels and rear wheels, that the lateral vibration generated by the excitation of rails due to the traveling of the front wheels is transmitted through the rails to reach the rear wheels for their excitation for an increase in the variation in the contact force between the rear wheels and rails and that, vice versa, the travel of the rear wheels increases the variation in the contact force between the front wheels and rails. It is also found, concerning both front wheels and rear wheels, that there are periodic fluctuations, dependent on the wheelbase, in the amplitude of the contact force variation at the steady state and that the period, as compared with the wavelength of corrugation, is shorter in the front wheels and longer in the rear wheels. 4 refs., 5 figs.

  15. Experimental Setup for Diamond Grinding Using Electrochemical InProcess Controlled Dressing (ECD) of Grinding Wheel

    OpenAIRE

    M. A. Shavva; E. M. Zaharevich

    2014-01-01

    The most effective method for finish machining of hard-metals and alloys is to use the diamond grinding wheels for grinding. An application of diamond wheels significantly increases the employee output, reduces costs, and raises manufacturing efficiency with achieving the high performance properties of treated surfaces.During grinding a working surface of diamond wheel wears out. It adversely affects the cutting capability of the diamond grains, and depending on the grinding conditions can oc...

  16. ANALYSIS OF LATERAL VIBRATION OF THE WHEEL RELATIVE TO THE RAIL WITH VIDEO

    Directory of Open Access Journals (Sweden)

    V. O. Melnychuk

    2010-03-01

    Full Text Available In the article the videotape recordings of wheel motion on rail track, done during the dynamic tests of carriages, are analyzed. The treatment includes fixing of wheel rim positions in relation to a rail, construction of the spline function of displacement and its frequency description. The purpose of analysis is to determine the presence of harmonic components in the transversal wheel displacements.

  17. Necessity and effects of dynamic systems for railway wheel defect detection

    Directory of Open Access Journals (Sweden)

    S. Vesković

    2012-07-01

    Full Text Available State of railway vehicles highly influences transport safety due to vehicle derailments and in the same time worsens the quality of freight and passenger transportation. One of important elements that influence the state of railway vehicles is the wheel state. Wheel defects are common in railway transport. Therefore, timely defect detection is very important. This paper presents ways and effects of timely detection of wheel defects.

  18. Influence of axle-wheel interface on ultrasonic testing of fatigue cracks in wheelset.

    OpenAIRE

    Makino, Kazunari; Biwa, Shiro

    2013-01-01

    For the ultrasonic testing at the wheel seat of railway axles, quantitative investigation of the reflection and transmission phenomena at the axle-wheel interface is important. This paper describes the influence of the axle-wheel interface on the ultrasonic testing of a fatigue crack in a wheelset by applying the spring interface model. The normal and tangential stiffnesses were identified experimentally for an as-manufactured wheelset at the normal incidence, and the reflection coefficient f...

  19. APPLIED PROBLEMS OF CURVILINEAR MOTION DYNAMICS OF ALL-WHEEL DRIVE TRACTION MEANS

    Directory of Open Access Journals (Sweden)

    G. S. Gorin

    2014-01-01

    Full Text Available Fundamental principles for hybrid theory on turning of an all-wheel drive system are given in the paper. The paper shows expediency of accounting longitudinal additional tangential reactions (parasitic forces in contacts of central and lateral wheels with foundation. Algorithms for calculating additional tangential reactions have been proposed in the paper. The paper presents calculation kinematics model for turning of steered and rigid bogie with inter-wheel differential at various axial drive.

  20. Optimization of Honing Wheel Structure Parameters in Ultra-precision Plane Honing

    Institute of Scientific and Technical Information of China (English)

    SYOJI; Katsuo

    2002-01-01

    Free abrasive particle machining in simple machine such as: honing, polishing can get higher surface finish mirror, but surface error, and working procedure is hard to control. Therefore, the vertical disposed ultra-precision plane honing method by ultra-particle diamond honing wheel is put forward to. The results of experiments indicate: plane-honing wheel has higher machining accuracy and machining efficiency. But at the same time the structure parameters of honing wheel effects on machining accuracy. B...

  1. Dynamic Research of the Flexible Wheel of a Double Harmonic Gear Transmission

    Directory of Open Access Journals (Sweden)

    Draghita Ianici

    2015-07-01

    Full Text Available The paper presents the results of a dynamic research of the flexible wheel of the double harmonic gear transmission, by determining the state of strain and stress of its wall, in cases the wheel is deformed by a mechanical waves generator with: two rolls, two eccentric discs and cam. The dynamic research involves modelling and the numerical simulation of flexible wheel, by using the finite element method, with the help of SolidWorks Simulation program in elastic range.

  2. Caffeine stimulates voluntary wheel running in mice without increasing aerobic capacity.

    Science.gov (United States)

    Claghorn, Gerald C; Thompson, Zoe; Wi, Kristianna; Van, Lindsay; Garland, Theodore

    2017-03-01

    The "energy drink" Red Bull and the "sports drink" Gatorade are often marketed to athletes, with claims that they cause performance gains. However, both are high in sugars, and also consumed by non-athletes. Few studies have addressed the effects of these drinks or their biologically active components in rodent exercise models. We used three experiments to test effects on both voluntary exercise behavior and maximal aerobic capacity in lines of mice known to differ in "athletic" traits. Mice from four replicate High Runner (HR) lines have been selectively bred for voluntary running on wheels, and run approximately three times as many revolutions per day as do mice from four non-selected Control (C) lines. HR mice also have higher endurance and maximal oxygen consumption (VO2max) during forced treadmill exercise. In Experiment 1, we tested the hypothesis that Gatorade or Red Bull might cause or allow mice to increase their voluntary wheel running. On days 5 and 6 of 6days of wheel access, as is used to select breeders, HR mice ran 3.3-fold more than C, and females ran 1.2-fold more than males, with no linetype by sex interaction. On day 7, mice were administered Gatorade, Red Bull or tap water. During the subsequent 19-hour period, Gatorade had no statistical effect on running, but Red Bull significantly increased distance run by both sexes and in both HR and C lines. The increase in distance run caused by Red Bull was attributable to time spent running, not an increase in mean (or maximum) speed. As previous studies have found that sucrose alone does not generally increase wheel running, we tested two other active ingredients in Red Bull, caffeine and taurine, in Experiment 2. With a similar testing protocol, caffeine alone and caffeine+taurine increased running by about half the magnitude of Red Bull. In Experiment 3, we tested the hypothesis that Red Bull or caffeine alone can increase physiological performance ability during aerobic exercise, measured as VO2max

  3. Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels

    Science.gov (United States)

    Reilly, C.; Duan, J.; Yao, L.; Maijer, D. M.; Cockcroft, S. L.

    2013-09-01

    Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels are in a select group of cast components that have strict specifications for both mechanical and aesthetic characteristics due to their important structural requirements and their visibility on a vehicle. The modern aluminum alloy automotive wheel continues to experience tightened tolerances relating to defects to improve mechanical performance and/or the physical appearance. Automotive aluminum alloy wheels are assessed against three main criteria: wheel cosmetics, mechanical performance, and air tightness. Failure to achieve the required standards in any one of these categories will lead to the wheel either requiring costly repair or being rejected and remelted. Manufacturers are becoming more reliant on computational process modeling as a design tool for the wheel casting process. This article discusses and details examples of the use of computational process modeling as a predictive tool to optimize the casting process from the standpoint of defect minimization with the emphasis on those defects that lead to failure of aluminum automotive wheels, namely, macroporosity, microporosity, and oxide films. The current state of applied computational process modeling and its limitations with regard to wheel casting are discussed.

  4. A comparing design of satellite attitude control system based on reaction wheel

    Institute of Scientific and Technical Information of China (English)

    CHENG Hao; GE Sheng-min; SHEN Yi

    2008-01-01

    The disturbance caused by the reaction wheel with a current controller greatly influences the accuracy and stability of the satellite attitude control system.To solve this problem,the idea of speed feedback compensation control reaction wheel is put forward.This paper introduces the comparison on design and performance of two satellite attitude control systems,which are separately based on the current control reaction wheel and the speed feedback compensation control reaction wheel.Analysis shows that the speed feedback compensation control flywheel system may effectively suppress the torque fluctuation.Simulation results indicate that the satellite attitude control system with the speed feedback compensation control flywheel has improved performance.

  5. Position and force control of a vehicle with two or more steerable drive wheels

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Unseren, M.A.

    1992-01-01

    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-M robot and have measured a dramatic reduction in error (more than a factor of 20) compared to rations without force control.

  6. Position and force control of a vehicle with two or more steerable drive wheels

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Unseren, M.A.

    1992-11-01

    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-M robot and have measured a dramatic reduction in error (more than a factor of 20) compared to rations without force control.

  7. Experimental and numerical investigation of coupled microvibration dynamics for satellite reaction wheels

    Science.gov (United States)

    Addari, D.; Aglietti, G. S.; Remedia, M.

    2017-01-01

    Microvibrations of a satellite reaction wheel assembly are commonly analysed in either hard-mounted or coupled boundary conditions, though coupled wheel-to-structure disturbance models are more representative of the real environment in which the wheel operates. This article investigates the coupled microvibration dynamics of a cantilever configured reaction wheel assembly mounted on either a stiff or flexible platform. Here a method is presented to cope with modern project necessities: (i) need of a model which gives accurate estimates covering a wide frequency range; (ii) reduce the personnel and time costs derived from the test campaign, (iii) reduce the computational effort without affecting the quality of the results. The method involves measurements of the disturbances induced by the reaction wheel assembly in a hard-mounted configuration and of the frequency and speed dependent dynamic mass of the reaction wheel. In addition, it corrects the approximation due to missing speed dependent dynamic mass in conventional reaction wheel assembly microvibration analysis. The former was evaluated experimentally using a previously designed and validated platform. The latter, on the other hand, was estimated analytically using a finite element model of the wheel assembly. Finally, the validation of the coupled wheel-structure disturbance model is presented, giving indication of the level of accuracy that can be achieved with this type of analyses.

  8. Research on the Variable Steering Ratio of Four-Wheel-Steering Vehicle

    Institute of Scientific and Technical Information of China (English)

    林程; 陈思忠; 任良成

    2004-01-01

    The steering characteristic of a four-wheel-steering vehicle is numerically simulated for in-depth research of the handling stability of four-wheel steering. The research results show that the deteriorating tendency of the steering stability due to the increase of the vehicle speed is improved obviously in the case of four-wheel steering. The approach of variable steering ratio is discussed. The use of the variable steering ratio can not only raise the steering stability of vechicles at high vehicle speed, but also reduce the dicomfort and steering burden of drivers; and hence is helpful for the subjective evaluation of four-wheel steering vehicles.

  9. Position and force control of a vehicle with two or more steerable drive wheels

    Energy Technology Data Exchange (ETDEWEB)

    Reister, D.B.; Unseren, M.A.

    1992-10-01

    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach to the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input. We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-III robot and have measured a dramatic reduction in error (more than a factor of 20) compared to motions without force control.

  10. STUDY ON A NEW TYPE OF THROWAWAY SOFT GRINDING WHEELS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In accordance with the difficult problems of belt cross vibrations and effects of belt tension on machine spindle precision in abrasive belt grinding, a new soft grinding wheel is put forward, which is provided with the advantages of belt grinding and can be installed directly on the grinding machine spindle substituting for common grinding wheels. The new soft grinding wheel does not need any ancillary facilities and dressing devices in grinding. With analyzing error of wheel and grinding experiment, the highefficiency grinding characteristics grinding hardbrittle materials has been obtained.

  11. Improvement of the lunar rover with two parallel wheels

    Science.gov (United States)

    Bi, Z. F.; Deng, Z. Q.; Tao, J. G.

    With raising the new upsurge for lunar exploration the lunar rover with two parallel wheels is proposed for lunar exploration The lunar rover is driven by the offset of the driving weight and it is selected as the subsystem of the lunar rover group system The communication among the lunar rover group is simulated with blue-tooth technology In the group system the characteristic and the stability are the key problems for application The lunar rover has simple structure and it is controlled easily and also it has more performance such as motion flexibility antidumping combinability The lunar rover is composed of two wheels and a case platform Each wheel is controlled independently On the top of the case platform CCD is used for navigation In the front and the back of the case platform there are docking mechanism for combination The precise speed and position of the lunar rover is controlled by PMAC With PC 104 the actual load such as the information of sensors and real-time communication via blue-tooth is processed The good stability of the lunar rover is favorable for vision navigation and combination of several rovers Focused on the stability the lunar rover with changeable radius is proposed Screw pair is used in the lunar rover system for adjusting the driving radius Through adjusting the driving radius the tilt angle of the case platform can be variant value under the same driving moment and also the tilt angle can keep equal under the variant driving moment For testing the feasibility of the scheme based on the

  12. System Analysis of Flat Grinding Process with Wheel Face

    Directory of Open Access Journals (Sweden)

    T. N. Ivanova

    2014-01-01

    Full Text Available The paper presents a conducted system analysis of the flat grinding wheel face, considers the state parameters, input and output variables of subsystems, namely: machine tool, workpiece, grinding wheel, cutting fluids, and the contact area. It reveals the factors influencing the temperature and power conditions for the grinding process.Aim: conducting the system analysis of the flat grinding process with wheel face expects to enable a development of the system of grinding process parameters as a technical system, which will make it possible to evaluate each parameter individually and implement optimization of the entire system.One of the most important criteria in defining the optimal process conditions is the grinding temperature, which, to avoid defects appearance of on the surface of component, should not exceed the critical temperature values to be experimentally determined. The temperature criterion can be useful for choosing the conditions for the maximum defect-free performance of the mechanical face grinding. To define the maximum performance of defect-free grinding can also use other criteria such as a critical power density, indirectly reflecting the allowable thermal stress grinding process; the structure of the ground surface, which reflects the presence or absence of a defect layer, which is determined after the large number of experiments; flow range of the diamond layer.Optimal conditions should not exceed those of defect-free grinding. It is found that a maximum performance depends on the characteristics of circles and grade of processed material, as well as on the contact area and grinding conditions. Optimal performance depends on the diamond value (cost and specific consumption of diamonds in a circle.Above criteria require formalization as a function of the variable parameters of the grinding process. There is an option for the compromise of inter-criteria optimality, thereby providing a set of acceptable solutions, from

  13. New Record Five-Wheel Drive, Spirit's Sol 1856 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11962 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11962 NASA's Mars Exploration Rover Spirit used its navigation camera to take the images that have been combined into this stereo, 180-degree view of the rover's surroundings during the 1,856th Martian day, or sol, of Spirit's surface mission (March 23, 2009). The center of the view is toward the west-southwest. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 25.82 meters (84.7 feet) west-northwestward earlier on Sol 1856. This is the longest drive on Mars so far by a rover using only five wheels. Spirit lost the use of its right-front wheel in March 2006. Before Sol 1856, the farthest Spirit had covered in a single sol's five-wheel drive was 24.83 meters (81.5 feet), on Sol 1363 (Nov. 3, 2007). The Sol 1856 drive made progress on a route planned for taking Spirit around the western side of the low plateau called 'Home Plate.' A portion of the northwestern edge of Home Plate is prominent in the left quarter of this image, toward the south. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  14. A five-wheel wheelchair with an active-caster drive system.

    Science.gov (United States)

    Munakata, Yu; Tanaka, Aki; Wada, Masayoshi

    2013-06-01

    A novel wheelchair system with an active-caster drive mechanism is presented in this paper. A manual (hand propelled) wheelchair with an external single-wheel drive system forms a five-wheel configuration. The active-caster mechanism is applied to a drive system to motorize a manual wheelchair. Two electric motors which drive a wheel axis and a steering axis of a drive wheel independently are equipped on the active-caster. A coordinated control of the two motors enables the velocity vector on the steering shaft to direct in an arbitrary direction with an arbitrary magnitude. The generated velocity vector allows a wheelchair to go straight and/or rotate completely in a same way as a standard electric wheelchair. Namely 2DOF of the wheelchair can be controlled independently by a single drive wheel without any constraint, such as the orientation of the drive wheel which is well known as a non-holonomic constraint. In addition to the 2DOF mobility, the proposed system enables wheelchair users to change drive modes, a rear drive and a front drive. The drive wheel on the back side of the wheelchair is vertically actuated by a linear motor to change the height of the drive wheel that can vary load distribution and the number of wheels contacting to the ground. The five-wheel-contact makes the wheelchair to move as the normal mode in which the center of rotation is located at the midpoint of the main wheels. Depressing the drive wheel results in lost contacts of the main wheels from the ground in which the center of rotation is jumped at the midpoint of the front wheels, namely it performs as a front drive wheelchair. In this paper, kinematic models of the wheelchair and that with an active-caster drive system are analyzed and a control method by using a 2DOF joystick is derived. Based on the kinematic model, a prototype mechanism of the active-caster is designed and mounted on a manual wheelchair to realize the five-wheel wheelchair. In the experiments, the independent 2

  15. Three-wheeled scooter taxi: A safety analysis

    Indian Academy of Sciences (India)

    S Mukherjee; D Mohan; T R Gawade

    2007-08-01

    The rollover propensity of a three-wheeled scooter taxi used extensively on SE Asian roads is analysed in this report. A rigid body mathematical model was used to simulate increasing steer, NHTSA -turn, and Road Edge Recovery maneuvers. The anomaly between public perception of the rollover susceptibility and available crash data has been resolved through finite element (FE) simulation. The optimum configuration of the vehicle and seating arrangement for varying numbers of passengers was determined. The safety of occupants and pedestrians in impact events was analysed through simulation in MADYMOTM, and cost effective solutions to improve safety were identified.

  16. Verification hybrid control of a wheeled mobile robot and manipulator

    Science.gov (United States)

    Muszynska, Magdalena; Burghardt, Andrzej; Kurc, Krzysztof; Szybicki, Dariusz

    2016-04-01

    In this article, innovative approaches to realization of the wheeled mobile robots and manipulator tracking are presented. Conceptions include application of the neural-fuzzy systems to compensation of the controlled system's nonlinearities in the tracking control task. Proposed control algorithms work on-line, contain structure, that adapt to the changeable work conditions of the controlled systems, and do not require the preliminary learning. The algorithm was verification on the real object which was a Scorbot - ER 4pc robotic manipulator and a Pioneer - 2DX mobile robot.

  17. MOBILITY EVALUATION AND INNOVATION OF WHEELED SPACE ROVER

    Institute of Scientific and Technical Information of China (English)

    SHANG Jianzhong; LUO Zirong; LI Shengyi; TANG Li

    2006-01-01

    The mission and function requirements of lunar rover are analyzed, based on virtual prototype technology, the mobility evaluation theory and method for wheeled space rover are proposed,which provide a new way to study the innovative design of lunar rover. Based on the above theoretical system, an innovative lunar rover suspension system, which adopts a two-crank-slider mechanism, is proposed, and its dynamics model is created. Adopting virtual prototype technology, the ground adaptability, over-obstacle ability and driving placidity of the rover are evaluated in the virtual prototype software ADAMS. The analysis results show that the rover provides a high degree of mobility.

  18. A Localisation and Navigation System for an Autonomous Wheel Loader

    OpenAIRE

    Lilja, Robin

    2011-01-01

    Autonomous vehicles are an emerging trend in robotics, seen in a vast range of applications and environments. Consequently, Volvo Construction Equipment endeavour to apply the concept of autonomous vehicles onto one of their main products. In the company’s Autonomous Machine project an autonomous wheel loader is being developed. As an ob jective given by the company; a demonstration proving the possibility of conducting a fully autonomous load and haul cycle should be performed. Conducting su...

  19. STRAD Wheel: Web-Based Library for Visualizing Temporal Data.

    Science.gov (United States)

    Fernondez-Prieto, Diana; Naranjo-Valero, Carol; Hernandez, Jose Tiberio; Hagen, Hans

    2017-01-01

    Recent advances in web development, including the introduction of HTML5, have opened a door for visualization researchers and developers to quickly access larger audiences worldwide. Open source libraries for the creation of interactive visualizations are becoming more specialized but also modular, which makes them easy to incorporate in domain-specific applications. In this context, the authors developed STRAD (Spatio-Temporal-Radar) Wheel, a web-based library that focuses on the visualization and interactive query of temporal data in a compact view with multiple temporal granularities. This article includes two application examples in urban planning to help illustrate the proposed visualization's use in practice.

  20. EFFECT OF DRIVING WHEEL TYPE ON DRAWBAR PULL OF TRACTOR

    Directory of Open Access Journals (Sweden)

    Rudolf Abrahám

    2013-12-01

    Full Text Available This paper is focused on the possibility of increasing the drawbar pull of agricultural tractor on the soil and grass-covered surface. From our perspective, we have chosen one available and the cheapest way, i.e. steel boots for tyres of small tractors, and this was compared with a newly developed system of auto-extensible blades next to the wheel. The tractor with steel boots and auto-extensible blades reached a higher drawbar pull on average by 70 % in comparison with tyres.

  1. The Read Out Controller for the ATLAS New Small Wheel

    CERN Document Server

    Coliban, Radu Mihai; The ATLAS collaboration; Tulbure, Traian Tiberiu; Martoiu, Victor Sorin; Levinson, Lorne; Vermeulen, Jos

    2016-01-01

    In the context of the New Small Wheel data path, we designed the Read Out Controller (ROC) ASIC for handling, preprocessing and formatting the data generated by the NSW VMM upstream chips. The ROC will concentrate the data streams from 8VMMs, filter data based on the BCID and transmit the data to FELIX via the L1DDC. ROC is composed of 8 VMM Capture modules, a cross-bar and 4 SubROC modules. The output data is sent via 4 high-speed e-links.

  2. Wheels and Suspension on Mars Science Laboratory Rover

    Science.gov (United States)

    2008-01-01

    This image from August 2008 shows NASA's Mars Science Laboratory rover in the course of its assembly, before additions of its arm, mast, laboratory instruments and other equipment. The six wheels are half a meter (20 inches) in diameter. The deck is 1.1 meter (3.6 feet) above the ground. The Mars Science Laboratory spacecraft is being assembled and tested for launch in 2011. This image was taken at NASA's Jet Propulsion Laboratory, Pasadena, Calif., which manages the Mars Science Laboratory Mission for NASA's Science Mission Directorate, Washington. JPL is a division of the California Institute of Technology.

  3. Care for the case manager: balancing your wheel of life.

    Science.gov (United States)

    Crowell, D M

    1998-01-01

    The case manager's role in our complex health care system is demanding and draining without some self-reflective attention. The Wheel of Life is a key tool for individuals to assess how well they are leading a fully balanced life. The eight aspects of a balanced life--values, self-care, work, relationships, leisure, relaxation, exercise, and centering--are explained and discussed. A self-reflective activity is presented that encourages readers to assess their current life balance. This focused clarification of personal and professional life will facilitate a more fully balanced life with rewards for case managers as individuals, and for their family, clients, and the health care organization.

  4. Effect of machinery wheel load on grass yield

    DEFF Research Database (Denmark)

    Green, Ole; Jørgensen, Rasmus Nyholm; Kristensen, Kristian

    2010-01-01

    Effect of machinery wheel load on grass   Ole Green1, Rasmus N. Jørgensen2, Kristian Kristensen3, René Gislum3, Dionysis Bochtis1, & Claus G. Sørensen1   1University of Aarhus, Dept. of Agricultural Engineering 2University of Southern Denmark, Inst. of Chemical Eng., Biotechnology and Environmental...... 3University of Aarhus, Dept. of Genetics and Biotechnology   Corresponding author: Ole Green Address & e-mail: Research Centre Foulum, Blichers Allé 20, 8830 Tjele. Ole.Green@agrsci.dk     Abstract   Different traffic intensities have been shown to have a negative influence on the yield of grass...

  5. Generic trajectory representation and trajectory following for wheeled robots

    DEFF Research Database (Denmark)

    Kjærgaard, Morten; Andersen, Nils Axel; Ravn, Ole

    2014-01-01

    This article presents the work towards a purely generic navigation solution for wheeled mobile robots motivated by the following goals: Generic: Works for different types of robots. Configurable: Parameters maps to geometric properties of the robot. Predictable: Well defined where the robot...... will drive. Safe: Avoid fatal collisions. Based on a survey of existing methods and algorithms the article presents a generic way to represent constraints for different types of robots, a generic way to represent trajectories using Bëzier curves, a method to convert the trajectory so it can be driven...

  6. Finish machining of hardened gears wheels using cubic boron nitride (CBN inserts

    Directory of Open Access Journals (Sweden)

    R. Talar

    2012-04-01

    Full Text Available The paper presents some results of investigation of finish machining of hardened bearing surfaces of cylindrical gear wheels. Finish machining has been performed with wedges of defined geometry made of CBN. The presented investigation results are related mainly to the wear processes of the cutting wedges. Additional results of quality examination of finish machined gear wheels have been presented, too.

  7. Reinforcement Value and Substitutability of Sucrose and Wheel Running: Implications for Activity Anorexia

    Science.gov (United States)

    Belke, Terry W.; Duncan, Ian D.; Pierce, W. David

    2006-01-01

    Choice between sucrose and wheel-running reinforcement was assessed in two experiments. In the first experiment, ten male Wistar rats were exposed to concurrent VI 30 s VI 30 s schedules of wheel-running and sucrose reinforcement. Sucrose concentration varied across concentrations of 2.5, 7.5, and 12.5%. As concentration increased, more behavior…

  8. Wheeled Vehicle Steering Systems. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle steering systems. It provides the basic theory, and also includes…

  9. Wheeled Vehicle Clutches, Transmissions, and Transfers. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle clutches, transmissions, and transfer cases. It provides the basic…

  10. Wheeled Vehicle Electrical Systems. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle electrical systems. It provides the basic theory, and also includes…

  11. Magnetic power conversion with machines containing full or porous wheel heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Egolf, Peter W. [Institute of Thermal Sciences IGT-SIT, University of Applied Sciences of Western Switzerland, Hesso, Route de Cheseaux 1, CH 1401 Yverdon-les-Bains (Switzerland)], E-mail: Peter.egolf@heig-vd.ch; Kitanovski, Andrej; Diebold, Marc; Gonin, Cyrill; Vuarnoz, Didier [Institute of Thermal Sciences IGT-SIT, University of Applied Sciences of Western Switzerland, Hesso, Route de Cheseaux 1, CH 1401 Yverdon-les-Bains (Switzerland)

    2009-04-15

    A first part of the article contains a thermodynamic theory describing the temperature distribution in a Curie wheel. The occurring nonlinear ordinary differential equation has an analytical solution. If a Curie wheel is stabilized by levitation, it is named Palmy wheel. These wheels show a full structure, and because of this reason, their uptake of heat from a flame (Curie wheel) or by (solar) light absorption (Palmy wheel) only on the periphery of a cylinder is very limited. To improve the method, a modification of the principle by introducing a convective heat transport into a porous wheel is discussed. By this the power conversion rate from a heat flux to mechanical and electric power is very much increased. The second part of the article presents results of a theoretical/numerical study on the efficiencies of magnetic power conversion plants operating with porous wheels. Furthermore, these efficiencies-which are promising-are compared with those of existing power conversion plants, as e.g. geothermal binary cycle power plants.

  12. Effective pathfinding for four-wheeled robot based on combining Theta* and hybrid A* algorithms

    Directory of Open Access Journals (Sweden)

    Віталій Геннадійович Михалько

    2016-07-01

    Full Text Available Effective pathfinding algorithm based on Theta* and Hybrid A* algorithms was developed for four-wheeled robot. Pseudocode for algorithm was showed and explained. Algorithm and simulator for four-wheeled robot were implemented using Java programming language. Algorithm was tested on U-obstacles, complex maps and for parking problem

  13. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion... HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Fig. 8 Figure 8 to Part 1512—Reflectorized Bicycle Wheel Rim Abrasion Test Device EC03OC91.074...

  14. The earliest evidence of wheeled vehicles in Europe and the Near East

    NARCIS (Netherlands)

    Bakker, JA; Kruk, J; Lanting, AE; Milisauskas, S

    1999-01-01

    The earliest evidence of wheeled vehicles dates to the Funnel Beaker (TRB) culture in Europe and the Late Uruk period in the Near East. Results of excavations and C14 determinations from Poland, Germany, Iraq, Syria and Turkey suggest that the appearance of wheeled vehicles was contemporary in Europ

  15. Design and Development of Labview Based Steering Wheel Angle Sensor System

    Directory of Open Access Journals (Sweden)

    Tony George

    2015-04-01

    Full Text Available Conventional angle sensors can measure only 360°,but passenger car steering wheel turns through +/-720o (a total of 4 complete turns. In this paper we describe iGMR based steering wheel angle sensor implementation which can be used as a rotation sensor to measure +/- 720°.

  16. Motion design of a hybrid wheeled/legged robot for lunar exploration

    Institute of Scientific and Technical Information of China (English)

    陈学东; 田文罡; 李小清; 渡边桂吾

    2003-01-01

    The robot consists of a quadruped mechanism and two active dual-wheel casters possesses the advan-tages of wheeled and legged mechanism, and can quickly move on the relatively plane ground with the wheeledmechanism, and can walk on the extremely uneven terrain with the legged mechanism. The effectiveness of themotion design of the hybrid robot is illustrated by simulation results.

  17. Wheeled Vehicle Drive Lines, Axles, and Suspension Systems. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle drive lines, axles, and suspension systems. It provides the basic…

  18. State Spending on Higher Education: Testing the Balance Wheel over Time

    Science.gov (United States)

    Delaney, Jennifer A.; Doyle, William R.

    2011-01-01

    This article considers the role of higher education in state budgets. It empirically models and tests the balance wheel hypothesis in a robust framework. The balance wheel model posits that in good economic times, higher education is an attractive area for states to fund and tends to be funded at a higher rate than other state budget categories.…

  19. The Medicine Wheel: A Versatile Tool for Promoting Positive Change in Diverse Contexts

    Science.gov (United States)

    Kemppainen, David; Kopera-Frye, Karen; Woodard, Julie

    2008-01-01

    This essay describes the utility of employing the medicine wheel with university students in both counselling and instructional contexts. A brief description of the medicine wheel, its history, symbolic significance, and use in diverse contexts is discussed. The preliminary data suggest this to be a valuable tool in addressing both the academic…

  20. 49 CFR 238.119 - Rim-stamped straight-plate wheels.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Safety Planning and General... than a private car, that is equipped with a rim-stamped straight-plate wheel if a brake shoe acts on... replacement wheel on a private car that operates in a passenger train if a brake shoe acts on the tread of...

  1. Design of the Dual Offset Active Caster Wheel for Holonomic Omni-directional Mobile Robots

    Directory of Open Access Journals (Sweden)

    Woojin Chung

    2011-01-01

    Full Text Available It is shown how a holonomic and omni-directional mobile robot is designed towards indoor public services. Dual offset steerable wheels with orthogonal velocity components are proposed. The proposed wheel provides precise positioning and reliable navigation performance as well as durability. A fabricated prototype is introduced, then, an experiment is carried out.

  2. Design of the Dual Offset Active Caster Wheel for Holonomic Omni-Directional Mobile Robots

    Directory of Open Access Journals (Sweden)

    Woojin Chung

    2010-12-01

    Full Text Available It is shown how a holonomic and omni-directional mobile robot is designed towards indoor public services. Dual offset steerable wheels with orthogonal velocity components are proposed. The proposed wheel provides precise positioning and reliable navigation performance as well as durability. A fabricated prototype is introduced, then, an experiment is carried out.

  3. Improved infrared-sensing running wheel systems with an effective exercise activity indicator.

    Science.gov (United States)

    Chen, Chi-Chun; Chang, Ming-Wen; Chang, Ching-Ping; Chang, Wen-Ying; Chang, Shin-Chieh; Lin, Mao-Tsun; Yang, Chin-Lung

    2015-01-01

    This paper describes an infrared-sensing running wheel (ISRW) system for the quantitative measurement of effective exercise activity in rats. The ISRW system provides superior exercise training compared with commercially available traditional animal running platforms. Four infrared (IR) light-emitting diode/detector pairs embedded around the rim of the wheel detect the rat's real-time position; the acrylic wheel has a diameter of 55 cm and a thickness of 15 cm, that is, it is larger and thicker than traditional exercise wheels, and it is equipped with a rubber track. The acrylic wheel hangs virtually frictionless, and a DC motor with an axially mounted rubber wheel, which has a diameter of 10 cm, drives the acrylic wheel from the outer edge. The system can automatically train rats to run persistently. The proposed system can determine effective exercise activity (EEA), with the IR sensors (which are connected to a conventional PC) recording the rat exercise behavior. A prototype of the system was verified by a hospital research group performing ischemic stroke experiments on rats by considering middle cerebral artery occlusion. The experimental data demonstrated that the proposed system provides greater neuroprotection in an animal stroke model compared with a conventional treadmill and a motorized running wheel for a given exercise intensity. The quantitative exercise effectiveness indicator showed a 92% correlation between an increase in the EEA and a decrease in the infarct volume. This indicator can be used as a noninvasive and objective reference in clinical animal exercise experiments.

  4. Biologically Inspired Modular Neural Control for a Leg-Wheel Hybrid Robot

    DEFF Research Database (Denmark)

    Manoonpong, Poramate; Wörgötter, Florentin; Laksanacharoen, Pudit

    2014-01-01

    processing and state memorization. Its outputs drive two front wheels while the rear wheel is controlled through a velocity regulating network (VRN) module. In parallel, a neural oscillator network module serves as a central pattern generator (CPG) controls leg movements for sidestepping. Stepping directions...

  5. Indices and Computational Strategy for Unmanned Ground Wheeled Vehicle Mobility Estimation and Enhancement

    Science.gov (United States)

    2013-08-01

    proper tire to terrain interactions. The current work applies this strategic approach to both multi-wheel UGVs with mechanical/ mechatronic driveline...Coefficient”, IEEE/ASME Transactions of Mechatronics , Vol. 9, N 2, pp. 454-458. [37] Larin, V.V., 2010, “Theory of Motion of All-Wheel Drive

  6. Construction of a Special Mobile Robot that Uses a Special Travelling Wheel

    Directory of Open Access Journals (Sweden)

    Brabec Pavel

    2016-01-01

    Full Text Available This paper deals with the engineering design of a solution of a mobile robot that uses a special travelling wheel for transmission of motive power onto a surface. It further explains the principle of a vehicle travelling wheel that – according to an actual situation of the surface – changes the way of the wheel movement on the surface. The work content in our workplace is the engineering design of the solution of a mobile robot frame which uses a special travelling wheel pursuant to our patent to transfer the driving force onto the surface. This travelling wheel is able to transform and adapt to the driving conditions. Since it is an unmanned ground robot, not so common technical solutions can be used. Because it is also meant to be used in a rough terrain, the concept of four-wheel drive has been chosen and a four-wheel chassis has been designed to make it more simple. In terms of need of excellent handling and movement fluency, all four wheels will be directionally steered (4WS and will be placed as much in the frame corners as possible in order to have a space for 90° steer angle.

  7. IntellWheels: Modular development platform for intelligent wheelchairs

    Directory of Open Access Journals (Sweden)

    Rodrigo Antonio Marques Braga, PhD

    2011-11-01

    Full Text Available Intelligent wheelchairs (IWs can become an important solution to the challenge of assisting individuals who have disabilities and are thus unable to perform their daily activities using classic powered wheelchairs. This article describes the concept and design of IntellWheels, a modular platform to facilitate the development of IWs through a multiagent system paradigm. In fact, modularity is achieved not only in the software perspective, but also through a generic hardware framework that was designed to fit, in a straightforward manner, almost any commercial powered wheelchair. Experimental results demonstrate the successful integration of all modules in the platform, providing safe motion to the IW. Furthermore, the results achieved with a prototype running in autonomous mode in simulated and mixed-reality environments also demonstrate the potential of our approach. Although some future research is still necessary to fully accomplish our objectives, preliminary tests have shown that IntellWheels will effectively reduce users' limitations, offering them a much more independent life.

  8. Simulation of the ATLAS New Small Wheel (NSW) System

    CERN Document Server

    Maekawa, Koki; The ATLAS collaboration

    2017-01-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the present design value by undergoing an extensive upgrade program over the coming decade. In order to benefit from the expected high luminosity performance that will be provided by the Phase-1 upgraded LHC, the first station of the ATLAS muon end-cap Small Wheel system will need to be replaced by a New Small Wheel (NSW) detector. The NSW is going to be installed in the ATLAS detector in the forward region of 1.3 < |η| < 2.7 during the second long LHC shutdown. The NSW will have to operate in a high background radiation region, while reconstructing muon tracks with high precision as well as furnishing information for the Level-1 trigger. A detailed study of the final design and validation of the readout electronics for a set of precision tracking (Micromegas) and trigger chambers (small-strip Thin Gap Chambers or sTGC) that are able to work at high rates with excellent real-...

  9. Simulation of the ATLAS New Small Wheel (NSW) System

    CERN Document Server

    Maekawa, Koki; The ATLAS collaboration

    2017-01-01

    The instantaneous luminosity of the Large Hadron Collider (LHC) at CERN will be increased up to a factor of five with respect to the present design value by undergoing an extensive upgrade program over the coming decade. In order to benefit from the expected high luminosity performance, the first station of the ATLAS muon end-cap Small Wheel system will need to be replaced by a New Small Wheel (NSW) detector during the second long LHC shutdown. The NSW will have to operate in a high background radiation region, while reconstructing muon tracks with high precision as well as furnishing information for the Level-1 trigger. The NSW simulation has been developed to model the actual response of the detector and its fast electronics. The simulation has been used to get a deep understanding of the trigger logic timing, the tracking-segment finding efficiency, track rate and track-pointing resolutions at the high background hit rate expected during the next phases of ATLAS at LHC. The results of these performance stu...

  10. Numerical Analysis of Asphalt Pavements under Moving Wheel Loads

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The responses of the pavement in service are the basis for the design of the semi-rigid base course asphalt pavement.Due to the dynamic characteristics of wheel loads and the temperature loads,the dynamic response analysis is very significant.In this article, the dynamic analysis of asphalt pavement under moving wheel loads is carried out using finite element method coupled with non-reflective boundary method.The influences of the base modulus, thickness, the vehicle velocity, the tire pressure, and the contact condition at the interface are studied using parametric analysis.The results of numerical analysis show that it is not appropriate to simply increase the base modulus or thickness in the design.It would be beneficial if the base design is optimized synthetically.The increase of damping is also beneficial to the pavements because of the surface deflection and the stresses declination.Furthermore, the good contact condition at the interface results in good performance because it combines every layer of the pavement to work together.As overload aggravates the working condition of the pavement, it is not allowed.

  11. Vibration Characteristics of Roundabout Swing of HAWT Wind Wheel

    Directory of Open Access Journals (Sweden)

    Jian-long Ma

    2016-01-01

    Full Text Available Modal testing was used to show that the roundabout swing was a natural vibration mode of the wind wheel of a horizontal-axis wind turbine (HAWT. During the vibration, the blade root was simultaneously subjected to bending and rotary shear stresses. A method for indirect testing and determination of the dynamic frequencies of the typical vibrations of the wind wheel was developed, based on the frequency-holding characteristic of each subsignal during the transmission of the multiple mixed-vibration signals. The developed method enabled simple and accurate acquisition of the dynamic frequencies without destruction of the flow and structural fields. The dynamic vibration stress of the roundabout swing was found to be significantly stronger than those of the first- and second-order flexural vibrations of the blades. By a combination of numerical simulations and tests, it was determined that the pneumatic circumferential force was the primary determinant of the roundabout swing vibration frequencies, the relationship being quadratic. The roundabout swing vibration potentially offers new explanations and analytical pathways regarding the behavior of horizontal-axis wind turbines, which have been found to be frequently involved in fatigue-damage accidents within periods shorter than their design lives.

  12. Aging Analysis of Micromegas Detectors for ATLAS New Small Wheel

    CERN Document Server

    Quinnan, Melissa

    2015-01-01

    In preparation for the coming High Luminosity Large Hadron Collider (HL-LHC) upgrade, the New Small Wheel (NSW) will replace the Small Wheel of the ATLAS Muon Spectrometer as part of the 2018 ATLAS Phase-I upgrade. Micromegas (MM) detectors will serve as one component of the NSW. These gaseous micro-mesh detectors will accommodate the higher luminosity and trigger rate of the future HL-LHC.In order to predict performance of MM after several years in the HL-LHC, radiation aging tests were conducted in the Gamma Irradiation Facility (GIF++) using a Cs 137 source. Two small MM prototype "T" chambers were irradiated and studied over the course of several months to accelerate the aging process and characterize chamber behavior. This report outlines a record of the aging process thus far and demonstrates techniques used to describe aging effects, namely measurements of average current, integrated charge, and gain. These will be used in the ongoing aging analysis of the T chambers and in future aging studies of the ...

  13. The continuous Wagon Wheel Illusion is object-based.

    Science.gov (United States)

    VanRullen, Rufin

    2006-11-01

    The occurrence of perceived reversed motion while observers view a periodic, continuously moving stimulus (the "continuous Wagon Wheel Illusion") has been taken as evidence that some aspects of motion perception rely on discrete sampling of visual information. The spatial extent of this sampling is currently under debate. When two separate motion stimuli are viewed simultaneously, the illusion of reversed motion rarely occurs for both objects together: this rules out global sampling of the visual field. The same result holds when the objects are superimposed by transparency: this argues against location-based sampling. Here we show that the sampling is in fact object-based: we use a rotating ring stimulus split in two halves. When the two halves move in opposite directions, appearing to belong to separate objects, perceptual reversals occur in either half at a time, but rarely in both. When the two halves physically move in compatible directions, they generally appear to reverse simultaneously: the illusion keeps the perceptual object united. Rather than the local low-level properties of the motion stimulus (which are comparable in both cases), it is thus the high-level organization of the scene that determines the extent of perceived motion reversals. These results imply that the continuous Wagon Wheel Illusion, and any discrete perceptual sampling that may cause it, is restricted to the object of our attention.

  14. Mechatronic modeling of real-time wheel-rail contact

    CERN Document Server

    Bosso, Nicola; Gugliotta, Antonio; Somà, Aurelio

    2013-01-01

    Real-time simulations of the behaviour of a rail vehicle require realistic solutions of the wheel-rail contact problem which can work in a real-time mode. Examples of such solutions for the online mode have been well known and are implemented within standard and commercial tools for the simulation codes for rail vehicle dynamics. This book is the result of the research activities carried out by the Railway Technology Lab of the Department of Mechanical and Aerospace Engineering at Politecnico di Torino. This book presents work on the project for the development of a real-time wheel-rail contact model and provides the simulation results obtained with dSpace real-time hardware. Besides this, the implementation of the contact model for the development of a real-time model for the complex mechatronic system of a scaled test rig is presented in this book and may be useful for the further validation of the real-time contact model with experiments on a full scale test rig.

  15. Dynamic model for the wheel-rail contact friction

    Science.gov (United States)

    Lee, HyunWook; Sandu, Corina; Holton, Carvel

    2012-02-01

    Accurately estimating the coefficient of friction (CoF) is essential in modelling railroad dynamics, reducing maintenance costs, and increasing safety in rail operations. The typical assumption of a constant CoF is widely used in theoretical studies; however, it has been noticed that the CoF is not constant, but rather depends on various dynamic parameters and instantaneous conditions. In this paper, we present a newly developed three-dimensional nonlinear CoF model for the dry rail condition and test the CoF variation using this model with estimated dynamic parameters. The wheel-rail is modelled as a mass-spring-damper system to simulate the basic wheel-rail dynamics. Although relatively simple, this model is considered sufficient for the purpose of this study. Simulations are performed at a train speed of 20 m/s using rail roughness as an excitation source. The model captures the CoF extremes and illustrates its nonlinear behaviour and instantaneous dependence on several structural and dynamic parameters.

  16. Research of Influence Electric Conditions Combined ElectroDiamond Processing by on Specific Consumption of Wheel*

    Science.gov (United States)

    Lobanov, D. V.; Arkhipov, P. V.; Yanyushkin, A. S.; Skeeba, V. Yu

    2016-08-01

    The paper presents results of stability research of cutting properties of diamond abrasive tools in metal binder for grinding high-strength composite materials, as well as the need to reduce the specific consumption of wheel, as one of the most important economic indicators of processing. Shows a comparative analysis of the results of preliminary researches of various methods diamond processing, in which determined that the minimum specific consumption of wheel reached by combined electro-diamond grinding, combining electrochemical grinding with simultaneous continuous electrochemical correction surface wheel. Were conducted more research directed at identifying the specific consumption the diamond wheel on metallic binder depending from electric conditions combined electrodiamond processing. Researches have established the advantages of combined electro-diamond of hard alloys processing and define rational modes to ensure a satisfactory consumption of the diamond wheel, as well as significantly increasing quality and performance.

  17. Differential wheel speed sensor integration with GPS/INS for land vehicle navigation

    Science.gov (United States)

    Hazlett, Andrew C.

    This paper develops an approach for the integration of GPS, inertial measurements from accelerometers and gyros, and differential wheel speed sensors for land vehicle navigation. Incorporating differential wheel speed sensor information into land vehicle navigation provides a solution for eliminating large errors caused by vehicle roll and pitch while also reducing errors from sideslip. Extended Kalman and Unscented Filtering algorithms are designed with a six degree-of-freedom model. In order to incorporate differential wheel speed information properly, the effective wheel radius must also be estimated as part of the overall estimation approach. Simulation results show the performance of the filters for cases of GPS/INS with and without the differential wheel speed sensor.

  18. The Inlet Engine Valves Grinding Using Different Types of Cutting Fluids and Grinding Wheels

    Directory of Open Access Journals (Sweden)

    Eraldo Jannone da Silva

    2002-06-01

    Full Text Available In this paper an experimental research is presented in which different types of cutting fluids (a cutting oil and three different types of soluble oils and grinding wheels (alumina and vitrified CBN were tested in the inlet engine valves grinding. As evaluation parameters the workpiece residual stress and the grinding wheel wear were analyzed. The cutting fluid and the grinding wheel types adopted resulted in changes in all the parameters, due to the different lubricant abilities among the fluids and due to the differences in the mechanical and thermal properties among the abrasives tested. For grinding this steel, the CBN wheel is the best choice, mainly due to compressive residual stress results obtained for all cutting fluids tested. The cutting oil is the most adequate cutting fluid to be used, due to its higher lubricity and ability in keeping the wheel sharp for longer periods of time, reducing the overall grinding energy and the thermal damage.

  19. Attitude stabilization of a pico-satellite by momentum wheel and magnetic coils

    Institute of Scientific and Technical Information of China (English)

    Tao MENG; Hao WANG; Zhong-he JIN; Ke HAN

    2009-01-01

    The three-axis active attitude control method with a momentum wheel and magnetic coils for a pico-satellite is considered. The designed satellite is a 2.5 kg class satellite stabilized to nadir pointing. The momentum wheel performs a pitch-axis momentum bias, nominally spinning at a particular rate. Three magnetic coils are mounted perpendicularly along the body axis for precise attitude control through the switch control mechanism. Momentum wheel start up control, damping control and attitude acquisition control are considered. Simulation results show that the proposed combined control laws for the pico-satellite is reliable and has an appropriate accuracy under different separation conditions. The proposed strategy to start up the wheel after separation from the launch vehicle shows that its pitch momentum wheel can start up successfully to its nominal speed from rest,and the attitude convergence can be completed within several orbits, depending on separation conditions.

  20. Design and optimisation of wheel-rail profiles for adhesion improvement

    Science.gov (United States)

    Liu, B.; Mei, T. X.; Bruni, S.

    2016-03-01

    This paper describes a study for the optimisation of the wheel profile in the wheel-rail system to increase the overall level of adhesion available at the contact interface, in particular to investigate how the wheel and rail profile combination may be designed to ensure the improved delivery of tractive/braking forces even in poor contact conditions. The research focuses on the geometric combination of both wheel and rail profiles to establish how the contact interface may be optimised to increase the adhesion level, but also to investigate how the change in the property of the contact mechanics at the wheel-rail interface may also lead to changes in the vehicle dynamic behaviour.

  1. Study on general theory of kinematics and dynamics of wheeled mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Tsukishima, T. (Hitachi, Ltd., Tokyo (Japan)); Sakai, K.; Takano, M.; Inouse, K. (The University of Tokyo, Tokyo (Japan). Faculty of Engineering)

    1992-03-30

    The general theory of kinematics and dynamics of wheeled mobile robots (WMR) was proposed. Various configurations of WMRs were modeled as planar linkage mechanism (tree-structure-link) which is composed of branching multiple links and whose end corresponds to wheels on a floor. The difference of the mechanism from robotic manipulators was clarified which are modeled as 3-D serial link mechanism. In dynamics of WMRs, the equation of motion of WMRs was derived for joint input torques, and forces and moments acting on wheels were determined as a function of a slip velocity, assuming the slippage of wheels was essential in dynamics of WMRs. The kinematics of WMRs was obtained as a special case of dynamics where wheel motion is assumed to have no slippage. In addition, since most of industrial motors are velocity-controlled, the equation of motion was rewritten in velocity input form, and the proposed theory was verified by numerical simulation. 11 refs., 15 figs.

  2. Wheel-running reinforcement in free-feeding and food-deprived rats.

    Science.gov (United States)

    Belke, Terry W; Pierce, W David

    2016-03-01

    Rats experiencing sessions of 30min free access to wheel running were assigned to ad-lib and food-deprived groups, and given additional sessions of free wheel activity. Subsequently, both ad-lib and deprived rats lever pressed for 60s of wheel running on fixed ratio (FR) 1, variable ratio (VR) 3, VR 5, and VR 10 schedules, and on a response-initiated variable interval (VI) 30s schedule. Finally, the ad-lib rats were switched to food deprivation and the food-deprived rats were switched to free food, as rats continued responding on the response-initiated VI 30-s schedule. Wheel running functioned as reinforcement for both ad-lib and food-deprived rats. Food-deprived rats, however, ran faster and had higher overall lever-pressing rates than free-feeding rats. On the VR schedules, wheel-running rates positively correlated with local and overall lever pressing rates for deprived, but not ad-lib rats. On the response-initiated VI 30s schedule, wheel-running rates and lever-pressing rates changed for ad-lib rats switched to food deprivation, but not for food-deprived rats switched to free-feeding. The overall pattern of results suggested different sources of control for wheel running: intrinsic motivation, contingencies of automatic reinforcement, and food-restricted wheel running. An implication is that generalizations about operant responding for wheel running in food-deprived rats may not extend to wheel running and operant responding of free-feeding animals.

  3. Water

    Science.gov (United States)

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  4. Morphological Analyses and Simulated Flood Elevations in a Watershed with Dredged and Leveed Stream Channels, Wheeling Creek, Eastern Ohio

    Science.gov (United States)

    Sherwood, James M.; Huitger, Carrie A.; Ebner, Andrew D.; Koltun, G.F.

    2008-01-01

    -sectional area, the mean percentage differences between the measured and estimated values were -16.0 and -11.2, respectively. The predominantly negative bias in differences between the measured and estimated values indicates that bankfull mean depths and cross-sectional areas in studied reaches generally are smaller than the regional trend. This may be an indication of channel filling and over widening or it may reflect insufficient representation in the regional dataset of basins with characteristics like that of Wheeling Creek. Step-backwater models were constructed for four previously dredged reaches to determine the height of levees required to contain floods with recurrence intervals of 2, 10, 50, and 100 years. Existing levees (all of which are uncertified) were found to contain the 100-year flood at only 20 percent of the surveyed cross sections. At the other 80 percent of the surveyed cross sections, levee heights would have to be raised an average of 2.5 feet and as much as 6.3 feet to contain the 100-year flood. Step-backwater models also were constructed for three undredged reaches to assess the impacts of selected dredging and streambed aggradation scenarios on water-surface elevations corresponding to the 2-, 10-, 50-, and 100-year floods. Those models demonstrated that changes in water-surface elevations associated with a given depth of dredging were proportionately smaller for larger floods due to the fact that more of the flood waters are outside of the main channel. For example, 2.0 feet of dredging in the three study reaches would lower the water-surface elevation an average of 1.30 feet for the 2-year flood and 0.64 feet for the 100-year flood.

  5. TECHNO-ECONOMIC ASSESSMENT OF THE USE OF WHEELS OF PERSPECTIVE STRUCTURAL SCHEME FOR RAILWAY VEHICLES

    Directory of Open Access Journals (Sweden)

    S. A. Semenov

    2016-12-01

    Full Text Available Purpose. The article is aimed to the definition of technical and economic efficiency from the use of wheels of perspective structural scheme in the undercarriage of the rail vehicles (wagon. Methodology. The use efficiency of wheels of promising design scheme by reducing the motion resistance and wear of the wheel flanges is estimated by calculated values of estimated annual economic effect of implementation and payback period of the costs required for the development and implementation of the proposed wheel. Non-recurring costs include the cost associated with conducting research and development work, as well as the additional costs required for the manufacture of wheels of promising design scheme. Findings. In the course of computation and analysis of the economic efficiency from introductions of wheels of promising design concept, carried out on the basis of the initial data for the South-West railway, it was determined the profit which can be obtained by reducing the following operating costs: cost of returning the wheel flange on wheel sets; cost of fuel and energy resources for train traction; the value of the idle of cars in the current uncoupling repair; cost of repairs and current maintenance of rail track. In addition, it can be additionally released a number of cars by reducing their downtime. The calculation of net discounted income is carried out with the following assumptions: calculation period; estimated increase in the cost of wheel sets with wheels of promising constructive scheme compared to the model, the values of net profit for the accounting period, which was calculated by calculating the average value minus the cost of research, development and manufacturing of wheelset park with wheels of new design scheme. For a given billing period, the calculated value of the net discounted income was obtained and the payback period of the project was determined. Originality. The approaches to the perfection of design scheme of wheels

  6. Forming the Calculated Dynamic Transmission Systems of Wheeled Vehicles

    Directory of Open Access Journals (Sweden)

    A. B. Fominykh

    2017-01-01

    Full Text Available To calculate dynamic loading of transmission parts of wheeled vehicles, it is necessary to build up the appropriate calculated dynamic systems and determine their inertial, elastic, and damping parameters.The initial point of this process is to form an initial dynamic system. Hereafter, to cut the time of computations there is a need to reduce the number of masses of this system, and sometimes simplify its structure. The main requirement to be fulfilled in this case is that the calculated dynamical system is to be equivalent to the initial one (in terms of similarity of the vibrational process characteristics in these systems, i.e., the frequencies and modes of oscillations of both systems, their amplitude-frequency characteristics. This is possible when the energy characteristics of the corresponding systems are equal, i.e. their kinetic and potential energies, dissipative functions, and external force energies.Usually, when forming the initial and calculated dynamic systems, all types of friction are reduced to a linearly viscous one. However, it disables us to investigate the motion of these systems if there is an arbitrary, in particular, poly-harmonic action (for example, on the side of the internal combustion engine, since in this case the linear friction coefficients given will depend on the frequency and amplitude of the oscillations.The paper is aimed at determining the equivalent parameters of calculated dynamic systems of wheeled vehicles, including the dissipative parameters for the general case of friction.On the basis of energy principles, the expressions are obtained to determine the equivalent inertial, elastic, and damping parameters of the calculated dynamical systems of wheeled vehicles when the structure is changed and the number of masses of the system is decreased. The presented technique enables us to investigate the motion of these systems under arbitrary, including poly-harmonic, action on the system, using the

  7. Analysis and control of high-speed wheeled vehicles

    Science.gov (United States)

    Velenis, Efstathios

    In this work we reproduce driving techniques to mimic expert race drivers and obtain the open-loop control signals that may be used by auto-pilot agents driving autonomous ground wheeled vehicles. Race drivers operate their vehicles at the limits of the acceleration envelope. An accurate characterization of the acceleration capacity of the vehicle is required. Understanding and reproduction of such complex maneuvers also require a physics-based mathematical description of the vehicle dynamics. While most of the modeling issues of ground-vehicles/automobiles are already well established in the literature, lack of understanding of the physics associated with friction generation results in ad-hoc approaches to tire friction modeling. In this work we revisit this aspect of the overall vehicle modeling and develop a tire friction model that provides physical interpretation of the tire forces. The new model is free of those singularities at low vehicle speed and wheel angular rate that are inherent in the widely used empirical static models. In addition, the dynamic nature of the tire model proposed herein allows the study of dynamic effects such as transients and hysteresis. The trajectory-planning problem for an autonomous ground wheeled vehicle is formulated in an optimal control framework aiming to minimize the time of travel and maximize the use of the available acceleration capacity. The first approach to solve the optimal control problem is using numerical techniques. Numerical optimization allows incorporation of a vehicle model of high fidelity and generates realistic solutions. Such an optimization scheme provides an ideal platform to study the limit operation of the vehicle, which would not be possible via straightforward simulation. In this work we emphasize the importance of online applicability of the proposed methodologies. This underlines the need for optimal solutions that require little computational cost and are able to incorporate real, unpredictable

  8. Water

    Science.gov (United States)

    ... Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks Water Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir For information about lead in water in Flint, MI, please visit http://www.phe. ...

  9. 不同工况下轮轨材料间的摩擦磨损行为%Friction and Wear Behavior of Wheel/Rail Materials under Different Working Conditions

    Institute of Scientific and Technical Information of China (English)

    郭静; 王文健; 刘启跃; 周仲荣

    2013-01-01

    The rolling friction and wear behavior of wheel/rail materials was studied using a MMS-2A testing apparatus under dry, water and sanding conditions. Furthermore, the damage of wheel/rail samples was analyzed. The results show that the water would decrease rolling friction coefficient and wear volume of wheel/rail materials. Sanding could increase rolling friction coefficient and wear quantity of wheel/rail materials under water condition, and worsen the damage of the wheel/rail surface. The dry friction after sanding could make rolling friction coefficient come to the normal level in dry conditioa With the conditions changes from water to dry and water sanding, the surface damage of wheel material transformed from concave-convex roughness with slight delamination to serious spalling damage, and the delamination damage was dominant for the rail material. However, the spalling damage of rail material was slighter than that of wheel specimen.%在MMS-2A型滚动摩擦试验机上研究了干态、水态和水砂态三种工况下轮轨材料间的摩擦磨损行为,分析了轮轨试样表面的损伤情况.结果表明:相比于干态,水会使轮轨材料间的摩擦因数、磨损量明显下降;水介质中撒砂可增加轮轨材料间的滚动摩擦因数和磨损量,且加重了轮轨表面的损伤,水砂态试验中的干摩擦会使摩擦因数恢复到干态下的正常水平;随水态、干态到水砂态工况的变化,车轮试样表面从粗糙凸起并伴有轻微剥落向严重剥落损伤转变,钢轨材料的表面损伤主要表现为片层状剥离并伴有剥落现象,但较车轮材料的剥落损伤程度轻.

  10. Hybrid isolation of micro vibrations induced by reaction wheels

    Science.gov (United States)

    Lee, Dae-Oen; Park, Geeyong; Han, Jae-Hung

    2016-02-01

    As the technology for precision satellite payloads continues to advance, the requirements for the pointing stability of the satellites are becoming extremely high. In many situations, even small amplitude disturbances generated by the onboard components may cause serious degradation in the performance of high precision payloads. In such situations, vibration isolators can be installed to reduce the vibration transmission. In this work, a hybrid vibration isolator comprising passive and active components is proposed to provide an effective solution to the vibration problems caused by the reaction wheel disturbances. Firstly, mathematical modeling and experimental study of a single axis vibration isolator having high damping and high roll-off rate for the high frequency region and active components that enhance isolation performance for narrow frequency bands are presented. This concept is then extended to multi-axis by forming Stewart platform and the performance is experimentally verified. The tests on a flexible testbed show effective vibration isolation by the proposed vibration isolator.

  11. An approach for ergonomic design of mouse wheel

    Institute of Scientific and Technical Information of China (English)

    Gao Sande; Nakana Keijiro; and Huang Loulin

    2012-01-01

    A new method for ergonomic design of a computer mouse is proposed in this paper. In the method, the movements of joints and tip of the forefinger during operating a mouse was captured by a high-speed video camera. The captured videos were ana- lyzed and an algorithm was developed to decide the size and location of the mouse wheel according to ergonomic principles. The al- gorithm was then coded in a software package with Visual C++ and OpenGL languages. Results of the calculation and simulation agreed well with those of the experiments. The software can also be used for shape design of mouse body, buttons and their layouts.

  12. From wheels to wings with evolutionary spiking circuits.

    Science.gov (United States)

    Floreano, Dario; Zufferey, Jean-Christophe; Nicoud, Jean-Daniel

    2005-01-01

    We give an overview of the EPFL indoor flying project, whose goal is to evolve neural controllers for autonomous, adaptive, indoor micro-flyers. Indoor flight is still a challenge because it requires miniaturization, energy efficiency, and control of nonlinear flight dynamics. This ongoing project consists of developing a flying, vision-based micro-robot, a bio-inspired controller composed of adaptive spiking neurons directly mapped into digital microcontrollers, and a method to evolve such a neural controller without human intervention. This article describes the motivation and methodology used to reach our goal as well as the results of a number of preliminary experiments on vision-based wheeled and flying robots.

  13. Developments towards a filter wheel hyperspectral camera for planetary exploration

    Science.gov (United States)

    Gunn, M.; Langstaff, D. P.; Barnes, D.

    2011-10-01

    The benefits of hyperspectral imaging in remote sensing applications are well established and it is now routinely exploited in terrestrial applications. However the restrictions imposed on mass and power consumption and the extreme operating conditions encountered in extra-terrestrial environments have limited its widespread use for planetary exploration. Instead multispectral camera systems with typically 10-12 discrete filters are employed, providing only coarse spectral information. By exploiting the properties of interference filters off axis it is possible to obtain additional spectral information. Recent advances in filter technology have made it possible to develop a simple and lightweight wide angle hyperspectral camera employing a filter wheel. The theory of operation and early test results from a prototype camera system are presented.

  14. An autonomous miniature wheeled robot based on visual feedback control

    Institute of Scientific and Technical Information of China (English)

    CHEN Haichu

    2007-01-01

    Using two micro-motors,a novel omni-direction miniature wheeled robot is designed on the basis of the bi-corner driving principle.The robot takes advantage of the Bluetooth technology to wirelessly transmit data at a short distance.Its position and omni-direction motion are precise.A Charge Coupled Device(CCD)camera is used for measuring and for visual navigation.A control system is developed.The precision of the position is 0.5 mm,the resolution is about 0.05 mm,and the maximum velocity is about 52 mm/s.The visual navigation and control system allow the robot to navigate and track the target and to accomplish autonomous locomotion.

  15. Precision forging technologies for magnesium alloy bracket and wheel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Fundamental investigations on precision forging technology of magnesium alloys were studied. As-cast billet prestraining and a new concept of hollow billet were proposed in order to reduce the maximum forming load. A scheme of isothermal forming and the use of combined female dies were adopted, which can improve the die filling capacity and ensure the manufacture of high quality forgings. By means of the developed technique, AZ80 alloy wheel and AZ31 alloy bracket were produced successfully at suitable process parameters and applied in the automotive industries. The results show that the hot compression of AZ80 magnesium alloy has the peak flow stresses of pre-strained alloy with finer grain, which are lower by 20% than those of as-cast alloy under the same deformation conditions. The forming load is related to contact area and average positive stress on interface during forging process.

  16. An NSF rotator's perspective: view from inside the hamster wheel

    Science.gov (United States)

    White, Gary

    2015-03-01

    Duncan McBride served as my unofficial mentor during my time at NSF as a ``rotator'' (or, in NSF-speak, an IPA, short for an Intergovernmental Personnel Act assignee), from fall 2012 through summer of 2013. A rotator's main job is to help keep the wheels of the grant submission process turning, shepherding individual proposal jackets through the submission cycle. While most proposals are eventually ``Declined'' it is the few that are funded that evoke the most vivid memories of my time there. I hope to relay a little bit about what that was like on a daily basis, to give one hamster's take on the machinations of the NSF machine, and testify to Duncan McBride's critical role in establishing physics as the leader in disciplinary based educational research (DBER). It was a heady experience in many ways, despite the sheer girth of proposal jackets to be processed and the uncertain footing upon which federal employees tread these days.

  17. Analysis of the attenuation of railway squeal noise by preloaded rings inserted in wheels.

    Science.gov (United States)

    Brunel, J F; Dufrénoy, P; Charley, J; Demilly, F

    2010-03-01

    Squeal from railway wheels occurring in short radius curves produces a very intense and highly annoying noise in the range 400-8000 Hz. When the excitation, due to lateral forces acting on the wheel, cannot be avoided, additional systems can be added on the wheel to limit acoustic emission. A very economical approach is the use of metal rings inserted into grooves machined in the wheels. Unfortunately the effectiveness of these so called damping rings varies from one wheel to another and for different rings. Because the mechanisms of attenuation are not well understood, these variations have not to date been explained. The aim of this paper is to clarify the attenuation mechanisms for damping rings especially for the first three axial wheel modes, which are the predominant sound radiated ones in curve passage and for which the effectiveness of the treatment is lower. It has been generally assumed that friction between the ring and the groove has been the mechanism for squeal noise attenuation. Here it is shown that the vibration attenuation is due to modal coupling between the wheel and the ring. The validity of this proposed mechanism is investigated using experimental measurements and theoretical and numerical models. The results presented here will provide an avenue for optimization of the damping ring noise control treatment to obtain significant levels of squeal noise attenuation notably for the first three axial modes.

  18. The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion

    Directory of Open Access Journals (Sweden)

    Tsai Chung-Ying

    2012-11-01

    Full Text Available Abstract Background The rear-wheel camber, defined as the inclination of the rear wheels, is usually used in wheelchair sports, but it is becoming increasingly employed in daily propulsion. Although the rear-wheel camber can increase stability, it alters physiological performance during propulsion. The purpose of the study is to investigate the effects of rear-wheel cambers on temporal-spatial parameters, joint angles, and propulsion patterns. Methods Twelve inexperienced subjects (22.3±1.6 yr participated in the study. None had musculoskeletal disorders in their upper extremities. An eight-camera motion capture system was used to collect the three-dimensional trajectory data of markers attached to the wheelchair-user system during propulsion. All participants propelled the same wheelchair, which had an instrumented wheel with cambers of 0°, 9°, and 15°, respectively, at an average velocity of 1 m/s. Results The results show that the rear-wheel camber significantly affects the average acceleration, maximum end angle, trunk movement, elbow joint movement, wrist joint movement, and propulsion pattern. The effects are especially significant between 0° and 15°. For a 15° camber, the average acceleration and joint peak angles significantly increased (p Conclusions The rear-wheel camber affects propulsion patterns and joint range of motion. When choosing a wheelchair with camber adjustment, the increase of joint movements and the base of support should be taken into consideration.

  19. Synthesis and single-molecule imaging of highly mobile adamantane-wheeled nanocars.

    Science.gov (United States)

    Chu, Pin-Lei E; Wang, Lin-Yung; Khatua, Saumyakanti; Kolomeisky, Anatoly B; Link, Stephan; Tour, James M

    2013-01-22

    The synthesis and single-molecule imaging of two inherently fluorescent nanocars equipped with adamantane wheels is reported. The nanocars were imaged using 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) as the chromophore, which was rigidly incorporated into the nanocar chassis via Sonogashira cross-coupling chemistry that permitted the synthesis of nanocars having different geometries. In particular, studied here were four- and three-wheeled nanocars with adamantane wheels. It was found that, for the four-wheeled nanocar, the percentage of moving nanocars and the diffusion constant show a significant improvement over p-carborane-wheeled nanocars with the same chassis. The three-wheeled nanocar showed only limited mobility due to its geometry. These results are consistent with a requisite wheel-like rolling motion. We furthermore developed a model that relates the percentage of moving nanocars in single-molecule experiments with the diffusion constant. The excellent agreement between the model and the new results presented here as well as previous single-molecule studies of fluorescent nanocars yields an improved understanding of motion in these molecular machines.

  20. Fault detection method for railway wheel flat using an adaptive multiscale morphological filter

    Science.gov (United States)

    Li, Yifan; Zuo, Ming J.; Lin, Jianhui; Liu, Jianxin

    2017-02-01

    This study explores the capacity of the morphology analysis for railway wheel flat fault detection. A dynamic model of vehicle systems with 56 degrees of freedom was set up along with a wheel flat model to calculate the dynamic responses of axle box. The vehicle axle box vibration signal is complicated because it not only contains the information of wheel defect, but also includes track condition information. Thus, how to extract the influential features of wheels from strong background noise effectively is a typical key issue for railway wheel fault detection. In this paper, an algorithm for adaptive multiscale morphological filtering (AMMF) was proposed, and its effect was evaluated by a simulated signal. And then this algorithm was employed to study the axle box vibration caused by wheel flats, as well as the influence of track irregularity and vehicle running speed on diagnosis results. Finally, the effectiveness of the proposed method was verified by bench testing. Research results demonstrate that the AMMF extracts the influential characteristic of axle box vibration signals effectively and can diagnose wheel flat faults in real time.

  1. Design Optimization of a Mecanum Wheel to Reduce Vertical Vibrations by the Consideration of Equivalent Stiffness

    Directory of Open Access Journals (Sweden)

    Jong-Jin Bae

    2016-01-01

    Full Text Available Mecanum wheels are capable of moving a vehicle to any direction instantaneously by the combination of independent wheel rotations. Because the mecanum wheel is composed of a hub and rollers, however, it has unavoidable drawbacks such as vertical and horizontal vibrations due to the sequential contacts between rollers and ground. In order to investigate the dynamic characteristics of a mecanum wheel, we made a prototype and performed experiments to measure the vertical vibrations. Interestingly, it was observed that the vertical accelerations were asymmetric with respect to the average value of signals; the vibration signals of upward and downward directions show quite different shape. This asymmetric phenomenon was confirmed through the dynamic simulations performed by RecurDyn. In addition, the peak-to-peak and RMS values of the displacements and accelerations were calculated to investigate the effects of the curvature of rollers on the vertical vibrations of the vehicle. Furthermore, we proposed a mecanum wheel having a spring to attenuate the vibrations. It was also noted that the significant reduction of the vertical accelerations was observed due to the absence of the spring. Finally, considering the equivalent stiffness of the mecanum wheel for several different fillet radii, we found the optimal geometric design which minimizes the vertical vibration of a mecanum wheel.

  2. Design and Stability Analysis of a 3D Rimless Wheel with Flat Feet and Ankle Springs

    Science.gov (United States)

    Narukawa, Terumasa; Takahashi, Masaki; Yoshida, Kazuo

    A two-dimensional rimless wheel provides a simple model of bipedal walking. The motion of the rimless wheel is stable, and this particular property has clarified the fundamental role of a swing leg in planar bipedal walking that addresses the problem of falling forward. In this paper, a three-dimensional rimless wheel is investigated as a simple model of three-dimensional bipedal walking. The 3D rimless wheel model is useful in understanding the essential dynamics of 3D bipedal locomotion. The model consists of two rimless wheels connected by a link at the center of the wheels, and flat feet connected to the spokes with springs. The first numerical stability studies indicated that the motion of the 3D rimless wheel could be unstable; however, numerical simulations and experimental results showed that for a given slope and physical parameters, including the spring constant at the ankles, a stable motion is obtained. This indicates the usefulness of ankle springs in providing stable bipedal locomotion in three-dimensions.

  3. Design and experimental research of the on-line detection system for diamond arc grinding wheel

    Science.gov (United States)

    Zhang, Feihu; Li, Chen; Liu, Zhongde; Ren, Lele; Xie, Haisheng

    2016-10-01

    The principle of measuring displacement by eddy current sensor was derived. The calibration experiment was carried out for 5 kinds of different materials, which showed that the linearity of eddy current sensor was better, and the sensitivity of eddy current sensor varied with different materials. Based on the principle of measuring displacement by eddy current sensor, the on-line detection system for diamond circular wheel was designed, and the data acquisition was realized by using LABVIEW software. By moving the eddy current sensor in the vertical direction with the grinding wheel fixed, the coordinate of arc in the grinding wheel was obtained. The radius of the grinding wheel was fitted by using the genetic algorithm, which showed that the fitting results were accurate. The data acquisition of the grinding wheel was carried out in a cycle by fixing the electric eddy current sensor and the circulars of the grinding wheel in different processes, namely before dressing, after dressing and after shaping. The results showed that the circular of the grinding wheel after dressing and after shaping were significantly improved compared with that before dressing.

  4. Wear characteristics and prediction of wheel profiles in high-speed trains

    Institute of Scientific and Technical Information of China (English)

    韩鹏; 张卫华; 李艳

    2015-01-01

    Wheel/rail relationship is a fundamental problem of railway system. Wear of wheel profiles has great effect on vehicle performance. Thus, it is important not just for the analysis of wear characteristics but for its prediction. Actual wheel profiles of the high-speed trains on service were measured in the high-speed line and the wear characteristics were analyzed which came to the following results. The wear location was centralized from−15 mm to 25 mm. The maximum wear value appeared at the area of 5 mm from tread center far from wheel flange and it was less than 1.5 mm. Then, wheel wear was fitted to get the polynomial functions on different locations and operation mileages. A binary numerical prediction model was raised to predict wheel wear. The prediction model was proved by vehicle system dynamics and wheel/rail contact geometry. The results show that the prediction model can reflect wear characteristics of measured profiles and vehicle performances.

  5. A Study of Torque Vectoring and Traction Control for an All-Wheel Drive Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Maharun Mui’nuddin

    2014-07-01

    Full Text Available Common vehicle always experience energy loss during cornering manoeuver. Thus, to ensure it did not happened especially at high speed, a study of torque vectoring and traction control need to be made since it can increase the traction control of tyres during cornering at high speed. The study of torque vectoring and traction control for an all-wheel drive electric vehicle was conducted by modelling an all-wheel drive electric vehicle (EV in ADAMS/Car software. In addition, an optimal control algorithm will be developed for best performance to minimize energy losses using MATLAB/Simulink software. Furthermore, to prove the effectiveness of the all-wheel drive electric, the torque and traction control simulation of the all-wheel drive electric vehicle will be compared with uncontrolled electric vehicle model. According to the result, torque vectoring and traction control of in-wheel motor in all wheel drive EV can help to increase the performance of the electric vehicle during cornering manoeuver. In conclusion, this study of torque vectoring and traction control for an all-wheel drive electric vehicle will help researchers to improve the design of the future electric vehicle in term of the vehicle performance during cornering manoeuvre.

  6. Narrow-track wheeled agricultural tractor parameter variation.

    Science.gov (United States)

    Guzzomi, A; Rondelli, V

    2013-10-01

    Despite a general consensus among farmers, manufacturers, and researchers that wheeled agricultural tractor design has changed over time, there is little published evidence. There is debate as to whether the standardized rollover protective structure (ROPS) energy and force requirements, based on a tractor reference mass and pertaining to studies conducted more than 40 years ago, are appropriate for modern tractors. This article investigated the physical parameters of 326 modern narrow-track tractors, measured according to OECD Code 6 over 16 years (1993 to 2008 inclusive): 252 (-77%) were fixed-chassis tractors and 74 (-23%) were articulated. To understand the significance of design changes, the data were analyzed with respect to time and as a function of tractor mass. Articulated and fixed-chassis data were treated separately. The time data allowed qualitative analysis, while the mass data allowed quantitative analysis. The parameters show some changes over time and clearly indicate differences between articulated and fixed-chassis types. The parameter changes, along with the differences between types, may have important safety ramifications for ROPS energy absorption requirements, and these aspects are discussed. Regression lines with R2 values were fitted to the mass-related data for fixed-chassis and articulated tractors to determine the suitability of fit. The mass relations also displayed differences between fixed-chassis and articulated tractors. Thus, the most significant recommendation from this study is that the standardized testing procedure for narrow-track wheeled agricultural tractor category should be split into two groups: fixed-chassis and articulated.

  7. Science on Wheels: A Coherent Link Between Educational Perspectives

    Science.gov (United States)

    López-Garriga, Juan; Muñoz-Sola, Yldefonso; Echevarría, Yolanda; Nazario, William

    1997-11-01

    We have developed a Science on Wheels Program focusing on precollege students and teachers. This Program, the only one of its kind in Puerto Rico, is unique in the Nation since it is geared towards the almost 100% Hispanic population on the Island. Science on Wheels, as a coherent link between rural grades 7 through 12 education and the university, consists of science demonstration shows, teacher training workshops and the incorporation of demonstrations and hands-on activities by grades 7 through 12 teachers into their precollege chemistry and science courses. In a three year period, over 5,000 students and 300 teachers, as well as general public and administrators, have been exposed to scientific phenomena. An important feature of our initiative is that it incorporates undergraduate students in this teaching process. The undergraduate students have been trained by their professors to assist in workshops and to present the science shows. Science shows were evaluated by a sample of around 450 students. Results indicate that about 90% of these students would like to see more activities of this kind included as part of their science courses. Evaluation of the training workshops by precollege teachers showed that 96% were interested in attending additional workshops, 82% agreed that these topics could be incorporated in their science classes, and 71% felt confident performing demonstrations in their science classes. In spite of this relatively low percentage of self confidence, students showed an overwhelming acceptance, with about 80% of the students giving the maximum rating to the demonstrations presented by their teachers in their science classes. Our results seem to indicate that science shows can help to increase scientific literacy even in those students who will not pursue careers in science. This, together with an effective workshop program for teachers, can improve precollege students' motivation and performance in science classes.

  8. Estimators of wheel slip for electric vehicles using torque and encoder measurements

    Science.gov (United States)

    Boisvert, M.; Micheau, P.

    2016-08-01

    For the purpose of regenerative braking control in hybrid and electrical vehicles, recent studies have suggested controlling the slip ratio of the electric-powered wheel. A slip tracking controller requires an accurate slip estimation in the overall range of the slip ratio (from 0 to 1), contrary to the conventional slip limiter (ABS) which calls for an accurate slip estimation in the critical slip area, estimated at around 0.15 in several applications. Considering that it is not possible to directly measure the slip ratio of a wheel, the problem is to estimate the latter from available online data. To estimate the slip of a wheel, both wheel speed and vehicle speed must be known. Several studies provide algorithms that allow obtaining a good estimation of vehicle speed. On the other hand, there is no proposed algorithm for the conditioning of the wheel speed measurement. Indeed, the noise included in the wheel speed measurement reduces the accuracy of the slip estimation, a disturbance increasingly significant at low speed and low torque. Herein, two different extended Kalman observers of slip ratio were developed. The first calculates the slip ratio with data provided by an observer of vehicle speed and of propeller wheel speed. The second observer uses an original nonlinear model of the slip ratio as a function of the electric motor. A sinus tracking algorithm is included in the two observers, in order to reject harmonic disturbances of wheel speed measurement. Moreover, mass and road uncertainties can be compensated with a coefficient adapted online by an RLS. The algorithms were implemented and tested with a three-wheel recreational hybrid vehicle. Experimental results show the efficiency of both methods.

  9. Inflight Performance of Cassini Reaction Wheel Bearing Drag in 1997-2013

    Science.gov (United States)

    Lee, Allan Y.; Wang, Eric K.

    2013-01-01

    As the first spacecraft to achieve orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for a first and second extended missions through September 2017. Cassini is a three-axis stabilized spacecraft. It uses reaction wheels to achieve high level of spacecraft pointing stability that is needed during imaging operations of several science instruments. The Cassini flight software makes in-flight estimates of reaction wheel bearing drag torque and made them available to the mission operations team. These telemetry data are being trended for the purpose of monitoring the long-term health of the reaction wheel bearings. Anomalous drag torque signatures observed over the past 15 years are described in this paper. One of these anomalous drag conditions is bearing cage instability that appeared (and disappeared) spontaneously and unpredictably. Cage instability is an uncontrolled vibratory motion of the bearing cage that can produce high-impact forces internal to the bearing that will cause intermittent and erratic torque transients. Characteristics of the observed cage instabilities and other drag torque "spikes" are described in this paper. In day-to-day operations, the reaction wheels' rates must be neither too high nor too low. To protect against operating the wheels in any undesirable conditions (such as prolonged low spin rate operations), a ground software tool named Reaction Wheel Bias Optimization Tool (RBOT) was developed for the management of the wheels. Disciplined and long-term use of this ground software has led to significant reduction in the daily consumption rate of the wheels' low spin rate dwell time. Flight experience on the use of this ground software tool as well as other lessons learned on the management of Cassini reaction wheels is given in this paper.

  10. INVESTIGATION OF PROCESS PERTAINING TO INTERACTION OF TRACTOR DRIVING WHEELS WITH GROUND SURFACE

    Directory of Open Access Journals (Sweden)

    V. V. Guskov

    2017-01-01

    Full Text Available The paper presents results of investigations on the process pertaining to interaction of a driving wheel with ground surface and describes methodology for optimization of backbone parameters. The mentioned process has some specific differences in comparison with the process of wheel rolling along hard surface. Ground surface is represented by mixture of sandy and clay particles with plant residues and it has a number of physical and mechanical properties. The main of these properties is resistance of soil against compression and displacement. Compression process determines a track depth and resistance to motion and displacement process determines wheel gripping property and its tangential traction force. While executing the investigations laws of compression and displacement proposed by Prof.V. V. Katsygin as the most adequate reflection of actual processes have been used in the paper. Motion of the driving wheel along ground surface is accompanied by its slipping. It has been determined that the maximum wheel traction force is formed not with 100% slipping as it was supposed until present but the value has been obtained at 45–60 % slipping according to soil category. The developed integral equations with due account of the aspect make it possible to calculate road hold characteristics of driving wheels of the designed wheel tractor and evaluate its traction, speed and economic characteristics. Methodology has been developed for optimization of backbone parameters of wheeled running gear in the designed tractor such as design mass and adhesion weight, width, diameter and air pressure in a tire. The proposed methodology has been introduced in designing practice of wheeled tractors at OJSC “Minsk Tractor Works”.

  11. Application of watersheds algorithms to train wheel tread check and measure systems

    Science.gov (United States)

    Shen, Bangxing; Zhang, Haibo; Wang, Wei

    2006-11-01

    A image system and a new kind of image processing algorithm (watersheds algorithm) are introduced; First, we get the prime wheel tread data by a Charge Coupled Device (CCD), after the pretreatment of the data, we use the watersheds algorithm to get the trail wheel abrasion and peel off strips, than we will get the numerical value of the damage. The result of the experiment shows that the system can obtain the edge of the trail wheel abrasion and peel off strips; the algorithm is fast, stable and anti-jamming; the recognition system can satisfy the manufactory requirements.

  12. Experimental and Numerical Assessment of Vibro-Acoustic Behavior of Rubber-Damped Railway Wheels

    Science.gov (United States)

    Pešek, Luděk; Půst, Ladislav

    The reduction of noise and vibrations is very important task in many industrial and transport applications. The sources of intensive noise and vibrations are also tram and railway wheels at high speeds. Therefore the modern types of steel railway wheels contain the visco-elastic paddings. The first problem treated in this contribution is concerned with the theoretical and experimental investigation of the thermo-mechanical properties of rubber-like damping elements loaded with prestress by harmonic force. The dynamic modal and spectral properties of the whole railway wheel with damping elements will be investigated by the 3-D FEM model as the second problem.

  13. Robust Feedback Linearization-based Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Andersen, Palle; Pedersen, Tom Søndergaard

    This paper considers the trajectory tracking problem for a four-wheel driven, four-wheel steered mobile robot moving in outdoor terrain. The robot is modeled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. A nonlinear trajectory tracking feedback control law based...... on dynamic feedback linearization is designed for this model. Since several parameters in the model, in particular the ground-wheel contact friction, are not well known a priori, a robustness analysis is carried out for bounded uncertainties. It is demonstrated that uncertainties can render the closed...

  14. Robust Feedback Linearization-based Control Design for a Wheeled Mobile Robot

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Andersen, Palle; Pedersen, Tom Søndergaard

    2002-01-01

    This paper considers the trajectory tracking problem for a four-wheel driven, four-wheel steered mobile robot moving in outdoor terrain. The robot is modeled as a non-holonomic dynamic system subject to pure rolling, no-slip constraints. A nonlinear trajectory tracking feedback control law based...... on dynamic feedback linearization is designed for this model. Since several parameters in the model, in particular the ground-wheel contact friction, are not well known a priori, a robustness analysis is carried out for bounded uncertainties. It is demonstrated that uncertainties can render the closed...

  15. Kinematics Modeling of an Omnidirectional Autonomous Mobile Robot with Castor Wheels

    Institute of Scientific and Technical Information of China (English)

    Peng Yiqiang

    2006-01-01

    The kinematics model of an omnidirectional wheeled mobile robot (WMR) platform with 3 castor wheels was built, which includes the actuated inverse solution and the sensed forward solution. Motion simulations verify the consistency between the actuated inverse solution and the sensed forward solution. Analysis results show that the WMR possesses 3 degrees of freedom, and its motion trajectory is a straight line. The "pushing" and "pulling" motion patterns of the WMR can be generated by using different wheel orientations. It can be used in the places where the space is limited.

  16. The Research on Selecting the Optimum Coefficient of Inharmonious Motion for the Front Wheel Assist Tractor

    Institute of Scientific and Technical Information of China (English)

    HuangXinghua; LinWumin

    1995-01-01

    Based on dynamic analysis for the Front Wheel Assist(FWA) tractor,a calculating and analysing method on selecting the optimum coefficient of inharmonious motion for the FWA tractor is described in this paper and the mathematical odels are also established.The article first time dlefines the ratio of thrust of front wheels to that of rear wheels.Which is an important parameter affeeting the tractive performance of the FWA tractor and establishes the conditon of no power circulation of the FWA tractor.The optimum coefficient of inharmonious motion for a FWA tractor (UTB-445)is also given.

  17. Analysis on the crossing obstacle of wheel-track hybrid mobile robot

    Institute of Scientific and Technical Information of China (English)

    帅立国

    2016-01-01

    A novel wheel-track hybrid mobile robot with many movement patterns is designed.According to different environments,it can switch between the pure wheel pattern and the pure track one.Ac-cording to a homogeneous coordinate transformation matrix, gravity stability and its obstacle perform-ance are analyzed.Its gravity equation and climbing obstacle conditions are established.Experimen-tal results show that this hybrid mobile robot could fully possess the advantages of both the wheel and the track mechanisms and achieve a good obstacle climbing capability.

  18. Adaptive trajectory tracking control of two-wheeled self-balance robot

    Institute of Scientific and Technical Information of China (English)

    Qin Yong; Zang Xizhe; Wang Xiaoyu; Li Tian; Zhao Jie

    2009-01-01

    Wheeled mobile robot is one of the well-known nonholonomic systems. A two-wheeled self-balance robot is taken as the research objective. This paper carried out a detailed force analysis of the robot and established a non-linear dynamics model. An adaptive tracking controller for the kinematic model of a nonholonomic mobile robot with unknown parameters is also proposed. Using control Lyapunov function (CLF), the controller's global asymptotic stability has been proven. The adaptive trajectory tracking controller decreases the disturbance in the course of tracking control and enhances the real-time control characteristics. The simulation result indicated that the wheeled mobile robot tracking can be effectively controlled.

  19. Grain Refiner Effect on the Microstructure and Mechanical Properties of the A356 Automotive Wheels

    Science.gov (United States)

    Aguirre-De la Torre, E.; Afeltra, U.; Gómez-Esparza, C. D.; Camarillo-Cisneros, J.; Pérez-Bustamante, R.; Martínez-Sánchez, R.

    2013-12-01

    A356 aluminum alloy automotive wheels, 17 inch in diameter, were produced by low-pressure die casting. Contents of Al-5Ti-B (ATB) master alloy were added from 0 to 0.79 wt.%. Microstructural and mechanical properties were evaluated under industrial casting process conditions. The obtained results from mechanical testing provide evidence that additions of 0.13 and 0.27 wt.% of ATB have an improvement on the mechanical performance of the automotive wheels. This can be compared with the use of a grain refiner's higher concentrations, leading to a significant reduction in the cost-benefit ratio for the manufacturing of A356 automotive wheels.

  20. DEVELOPMENT AND MOTION ANALYSIS OF MINIATURE WHEEL-TRACK-LEGGED MOBILE ROBOT

    Institute of Scientific and Technical Information of China (English)

    DUAN Xingguang; HUANG Qiang; XU Yan; RAHMAN N; ZHENG Change

    2007-01-01

    A miniature wheel-track-legged mobile robot to carry out military and civilian missions in both indoor and outdoor environments is presented. Firstly, the mechanical design is discussed, which consists of four wheeled and four independently controlled tracked arms, embedded control system and teleoperation. Then the locomotion modes of the mobile robot and motion analysis are analyzed.The mobile robot can move using wheeled, tracked and legged modes, and it has the characteristics of posture-recovering, high mobility, small size and light weight. Finally, the effectiveness of the developed mobile robot is confirmed by experiments such as posture recovering when tipped over, climbing stairs and traversing the high step.

  1. Characterizing Wheel-Soil Interaction Loads Using Meshfree Finite Element Methods: A Sensitivity Analysis for Design Trade Studies

    Science.gov (United States)

    Contreras, Michael T.; Trease, Brian P.; Bojanowski, Cezary; Kulakx, Ronald F.

    2013-01-01

    A wheel experiencing sinkage and slippage events poses a high risk to planetary rover missions as evidenced by the mobility challenges endured by the Mars Exploration Rover (MER) project. Current wheel design practice utilizes loads derived from a series of events in the life cycle of the rover which do not include (1) failure metrics related to wheel sinkage and slippage and (2) performance trade-offs based on grouser placement/orientation. Wheel designs are rigorously tested experimentally through a variety of drive scenarios and simulated soil environments; however, a robust simulation capability is still in development due to myriad of complex interaction phenomena that contribute to wheel sinkage and slippage conditions such as soil composition, large deformation soil behavior, wheel geometry, nonlinear contact forces, terrain irregularity, etc. For the purposes of modeling wheel sinkage and slippage at an engineering scale, meshfree nite element approaches enable simulations that capture su cient detail of wheel-soil interaction while remaining computationally feasible. This study implements the JPL wheel-soil benchmark problem in the commercial code environment utilizing the large deformation modeling capability of Smooth Particle Hydrodynamics (SPH) meshfree methods. The nominal, benchmark wheel-soil interaction model that produces numerically stable and physically realistic results is presented and simulations are shown for both wheel traverse and wheel sinkage cases. A sensitivity analysis developing the capability and framework for future ight applications is conducted to illustrate the importance of perturbations to critical material properties and parameters. Implementation of the proposed soil-wheel interaction simulation capability and associated sensitivity framework has the potential to reduce experimentation cost and improve the early stage wheel design proce

  2. Water

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available Water scarcity is without a doubt on of the greatest threats to the human species and has all the potential to destabilise world peace. Falling water tables are a new phenomenon. Up until the development of steam and electric motors, deep groudwater...

  3. Development of a Mechanism for Measuring Forces and Aligning Moment Acting on the Steering Wheels of a Four-Wheel Vehicle

    Directory of Open Access Journals (Sweden)

    A Hajiahmad

    2014-09-01

    Full Text Available In this paper, a low-cost dynamometer for rolling, steered wheels is described. The dynamometer was constructed to determine whether such an instrumented mechanism was practical. Four S-beam load cells, an Opto-counter and a potentiometer were used to obtain all moments, and forces using dynamic and kinematic analysis. Minimal simplifying assumptions considered for the required calculations. Overturning, aligning and rolling resistance moments besides vertical force are directly measured by the load cells. The Opto-counter detects wheel angular velocity and the potentiometer was used to measure the steering angle. The results showed that the mechanism was very well calibrated with a coefficient of determination of over 0.99 and can be used to define wheel dynamic behavior.

  4. WHEEL-I : development of a wheelchair propulsion laboratory for rehabilitation

    NARCIS (Netherlands)

    de Groot, Sonja; Vegter, Riemer J. K.; Vuijk, Coen; van Dijk, Frank; Plaggenmarsch, Corien; Sloots, Maurits; Stolwijk-Swuste, Janneke; Woldring, Ferry; Tepper, Marga; van der Woude, Lucas H. V.

    2014-01-01

    Objective: To describe the enabling factors and barriers experienced in the Wheelchair Expert Evaluation Laboratory implementation (WHEEL-i) project, in which scientific knowledge, tools and associated systematic analyses of hand-rim wheelchair propulsion technique, user's wheelchair propulsion capa

  5. The early stage wheel fatigue crack detection using eddy current pulsed thermography

    Science.gov (United States)

    Peng, Jianping; Zhang, Kang; Yang, Kai; He, Zhu; Zhang, Yu; Peng, Chaoyong; Gao, Xiaorong

    2017-02-01

    The in-service wheel-set quality is one of critical challenges for railway safety, especially for the high-speed train. The defect in wheel tread, initiated by rolling contact fatigue (RCF) damage, is one of the most significant phenomena and has serious influence on rail industry. Eddy current pulsed thermography is studied to compensate the UT method for detection these early stage of fatigue cracks in wheel tread surface. This paper proposes approximately uniform magnetic field, excited by Helmholtz coils, based pulsed eddy current thermography to achieve open-view image and meet the irregular surface in wheel tread through numerical way. Some features are extracted and studied also to quantify the fatigue crack in term of eddy current pulsed thermography. The proposed method enhances the capability for cracks detection and quantitative evaluation compared with previous NDT method in railway.

  6. Coordinated control of slip ratio for wheeled mobile robots climbing loose sloped terrain.

    Science.gov (United States)

    Li, Zhengcai; Wang, Yang

    2014-01-01

    A challenging problem faced by wheeled mobile robots (WMRs) such as planetary rovers traversing loose sloped terrain is the inevitable longitudinal slip suffered by the wheels, which often leads to their deviation from the predetermined trajectory, reduced drive efficiency, and possible failures. This study investigates this problem using terramechanics analysis of the wheel-soil interaction. First, a slope-based wheel-soil interaction terramechanics model is built, and an online slip coordinated algorithm is designed based on the goal of optimal drive efficiency. An equation of state is established using the coordinated slip as the desired input and the actual slip as a state variable. To improve the robustness and adaptability of the control system, an adaptive neural network is designed. Analytical results and those of a simulation using Vortex demonstrate the significantly improved mobile performance of the WMR using the proposed control system.

  7. Using Single Free Sorting and Multivariate Exploratory Methods to Design a New Coffee Taster's Flavor Wheel.

    Science.gov (United States)

    Spencer, Molly; Sage, Emma; Velez, Martin; Guinard, Jean-Xavier

    2016-12-01

    The original Coffee Taster's Flavor Wheel was developed by the Specialty Coffee Assn. of America over 20 y ago, and needed an innovative revision. This study used a novel application of traditional sensory and statistical methods in order to reorganize the new coffee Sensory Lexicon developed by World Coffee Research and Kansas State Univ. into scientifically valid clusters and levels to prepare a new, updated flavor wheel. Seventy-two experts participated in a modified online rapid free sorting activity (no tasting) to sort flavor attributes of the lexicon. The data from all participants were compiled and agglomeration hierarchical clustering was used to determine the clusters and levels of the flavor attributes, while multidimensional scaling was used to determine the positioning of the clusters around the Coffee Taster's Flavor Wheel. This resulted in a new flavor wheel for the coffee industry. © 2016 The Authors. Journal of Food Science published by Wiley Periodicals, Inc. on behalf of Institute of Food Technologists.

  8. Method of Assessment of Hard Rock Workability using Bucket Wheel Excavators

    Science.gov (United States)

    Machniak, Łukasz; Kozioł, Wiesław

    2017-03-01

    A new hypothesis concerning a process of the mining solid rocks using bucket wheel excavators (BWE). Destroying of the rock mass structure is a result of breaking and not, as so far accepted, of cutting. This approach excludes, for the description of solid rock workability using bucket wheel excavators, used classifications based on individual linear or surface resistances of cutting. The possibility of a replacement mechanism for determining of the workability by bucket wheel excavators using rippers was assumed. On this basis, an innovative method for assessing the workability of solid rocks was developed, which is a combination of an derived empirical energy relationship LSE of breaking by tractor rippers from a compressive strength, a seismic wave velocity, a density of solid rock, and the modified classification of workability by bucket wheel excavators according to Bulukbasi (1991). The proposed method allows for multi-parameter assessment of the workability class based on the parameters that are independent variables in the specified dependencies.

  9. A rough terrain traction control technique for all-wheel-drive mobile robots

    National Research Council Canada - National Science Library

    Silva, Alexandre F. Barral; Santos, Auderi Vicente; Meggiolaro, Marco Antonio; Speranza Neto, Mauro

    2010-01-01

    ... - and guaranteeing an adequate trajectory and speed control while reducing the power requirements. Traction control of all-wheel-drive robots in rough terrain was originally motivated by space exploration, such as in the case of the Mars Exploration Rovers...

  10. The Wheel of Competency Assessment: Presenting Quality Criteria for Competency Assessment Programs

    NARCIS (Netherlands)

    Baartman, Liesbeth; Bastiaens, Theo; Kirschner, Paul A.; Van der Vleuten, Cees

    2009-01-01

    Baartman, L. K. J., Bastiaens, T. J., Kirschner, P. A., & Van der Vleuten, C. P. M. (2006). The wheel of competency assessment: Presenting quality criteria for Competency Assessment Programmes. Studies in Educational Evaluation, 32, 153-170.

  11. Wheeling and Banking Strategies for Optimal Renewable Energy Deployment. International Experiences

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, Jenny [National Renewable Energy Lab. (NREL), Golden, CO (United States); Vora, Ravi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mathur, Shivani [National Renewable Energy Lab. (NREL), Golden, CO (United States); Madrigal, Paola [Energy Regulatory Commission (Mexico); Chatterjee, Sushanta K. [Central Electricity Regulatory Commission (India); Shah, Rakesh [SunEdison, Mumbai (India)

    2016-03-01

    This paper defines the principles of wheeling (i.e., transmission) tariffs and renewable energy (RE) banking provisions and their role in RE deployment in countries with plans for large-scale RE. It reviews experiences to date in the United States, Mexico, and India and discusses key policy and regulatory considerations for devising more effective wheeling and/or banking provisions for countries with ambitious RE deployment targets. The paper addresses the challenges of competing needs of stakeholders, especially those of RE generators, distribution utilities, and transmission network owners and operators. The importance of wheeling and banking and their effectiveness for financial viability of RE deployment is also explored. This paper aims to benefit policymakers and regulators as well as key renewable energy stakeholders. Key lessons for regulators include: creating long-term wheeling and banking policy certainty, considering incentivizing RE through discounted transmission access, and assessing the cost implications of such discounts, as well as expanding access to renewable energy customers.

  12. Enhanced voluntary wheel running in GPRC6A receptor knockout mice

    DEFF Research Database (Denmark)

    Clemmensen, Christoffer; Pehmøller, Christian; Klein, Anders B

    2013-01-01

    to voluntary wheel running and forced treadmill exercise. Moreover, we assessed energy expenditure in the basal state, and evaluated the effects of wheel running on food intake, body composition, and a range of exercise-induced central and peripheral biomarkers. We found that adaptation to voluntary wheel......GPRC6A is an amino acid-sensing receptor highly expressed in the brain and in skeletal muscle. Although recent evidence suggests that genetically engineered GPRC6A receptor knockout (KO) mice are susceptible to develop subtle endocrine and metabolic disturbances, the underlying disruptions...... running is affected by GPRC6A, as ablation of the receptor significantly enhances wheel running in KO relative to WT mice. Both genotypes responded to voluntary exercise by increasing food intake and improving body composition to a similar degree. In conclusion, these data demonstrate that the GPRC6A...

  13. Automatic stair-climbing algorithm of the planetary wheel type mobile robot in nuclear facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Soo; Kim, Seung Ho; Lee, Jong Min [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-10-01

    A mobile robot, named KAEROT, has been developed for inspection and maintenance operations in nuclear facilities. The main feature of locomotion system is the planetary wheel assembly with small wheels. This mechanism has been designed to be able to go over the stairs and obstacles with stability. This paper presents the inverse kinematic solution that is to be operated by remote control. The automatic stair climbing algorithm is also proposed. The proposed algorithms the moving paths of small wheels and calculates the angular velocity of 3 actuation wheels. The results of simulations and experiments are given for KAEROT performed on the irregular stairs in laboratory. It is shown that the proposed algorithm provides the lower inclination angle of the robot body and increases its stability during navigation. 14 figs., 16 refs. (Author).

  14. Study on the ride comfort of vehicles driven by in-wheel motors

    Directory of Open Access Journals (Sweden)

    Liqiang Jin

    2016-02-01

    Full Text Available Vehicles driven by in-wheel motors have received more and more attention. However, due to the introduction of in-wheel motors, the ratio between unsprung and sprung mass is increased. In this article, to study the influence of this change on ride comfort of vehicles driven by in-wheel motors, an 11 degrees of freedom of vehicle ride comfort model will be presented and studied with MATLAB/Simulink. Then, road tests will be conducted to corroborate the simulation results. It can be obtained that the vehicle ride comfort becomes poor with the increasing unsprung mass. Finally, semi-active air-suspension proportional–integral–derivative control system will be proposed to improve the vehicle ride comfort. Through the simulation results, one can come to a conclusion that the proportional–integral–derivative control system for air suspension is feasible and effective to improve the ride comfort of the vehicles driven by in-wheel motors.

  15. 29 CFR 1910.177 - Servicing multi-piece and single piece rim wheels.

    Science.gov (United States)

    2010-07-01

    ...” and “Multi-piece Rim Matching Chart,” or any other poster which contains at least the same... mounting and inflation. (4) The size (bead diameter and tire/wheel widths) and type of both the tire...

  16. Dynamic Measurement for the Diameter of A Train Wheel Based on Structured-Light Vision.

    Science.gov (United States)

    Gong, Zheng; Sun, Junhua; Zhang, Guangjun

    2016-04-20

    Wheels are very important for the safety of a train. The diameter of the wheel is a significant parameter that needs regular inspection. Traditional methods only use the contact points of the wheel tread to fit the rolling round. However, the wheel tread is easily influenced by peeling or scraping. Meanwhile, the circle fitting algorithm is sensitive to noise when only three points are used. This paper proposes a dynamic measurement method based on structured-light vision. The axle of the wheelset and the tread are both employed. The center of the rolling round is determined by the axle rather than the tread only. Then, the diameter is calculated using the center and the contact points together. Simulations are performed to help design the layout of the sensors, and the influences of different noise sources are also analyzed. Static and field experiments are both performed, and the results show it to be quite stable and accurate.

  17. THREE DIMENSIONAL MODELING AND DYNAMIC ANALYSIS OF FOUR-WHEEL-STEERING VEHICLES

    Institute of Scientific and Technical Information of China (English)

    胡海岩; 韩强

    2003-01-01

    The paper presents a nonlinear dynamic model of 9 degrees of freedom for four-wheelsteering vehicles. Compared with those in previous studies, this model includes the pitch and roll of the vehicle body, the motion of 4 wheels in the accelerating or braking process, the nonlinear coupling of vehicle body and unsprung part, as well as the air drag and wind effect. As a result, the model can be used for the analysis of various maneuvers of the four-wheel-steering vehicles. In addition, the previous models can be considered as a special case of this model. The paper gives some case studies for the dynamic performance of a four-wheel-steering vehicle under step input and saw-tooth input of steering angle applied on the front wheels, respectively.

  18. Effects of setting angle on performance of fish-bionic wind wheel

    Science.gov (United States)

    Li, G. S.; Yang, Z. X.; Song, L.; Chen, Q.; Li, Y. B.; Chen, W.

    2016-08-01

    With the energy crisis and the increasing environmental pollutionmore and more efforts have been made about wind power development. In this paper, a new type of vertical axis named the fish-bionic wind wheel was proposed, and the outline of wind wheel was constructed by curve of Fourier fitting and polynomial equations. This paper attempted to research the relationship between the setting angle and the wind turbine characteristics by computational fluid dynamics (CFD) simulation. The results showed that the setting angle of the fish-bionic wind wheel has some significant effects on the efficiency of the wind turbine, Within the range of wind speed from 13m/s to 15m/s, wind wheel achieves the maximum efficiency when the setting angle is at 37 degree. The conclusion will work as a guideline for the improvement of wind turbine design.

  19. The Wheel of Competency Assessment: Presenting Quality Criteria for Competency Assessment Programs

    NARCIS (Netherlands)

    Baartman, Liesbeth; Bastiaens, Theo; Kirschner, Paul A.; Van der Vleuten, Cees

    2009-01-01

    Baartman, L. K. J., Bastiaens, T. J., Kirschner, P. A., & Van der Vleuten, C. P. M. (2006). The wheel of competency assessment: Presenting quality criteria for Competency Assessment Programmes. Studies in Educational Evaluation, 32, 153-170.

  20. The Dynamic Tensile Behavior of Railway Wheel Steel at High Strain Rates

    Science.gov (United States)

    Jing, Lin; Han, Liangliang; Zhao, Longmao; Zhang, Ying

    2016-11-01

    The dynamic tensile tests on D1 railway wheel steel at high strain rates were conducted using a split Hopkinson tensile bar (SHTB) apparatus, compared to quasi-static tests. Three different types of specimens, which were machined from three different positions (i.e., the rim, web and hub) of a railway wheel, were prepared and examined. The rim specimens were checked to have a higher yield stress and ultimate tensile strength than those web and hub specimens under both quasi-static and dynamic loadings, and the railway wheel steel was demonstrated to be strain rate dependent in dynamic tension. The dynamic tensile fracture surfaces of all the wheel steel specimens are cup-cone-shaped morphology on a macroscopic scale and with the quasi-ductile fracture features on the microscopic scale.

  1. Dynamic Measurement for the Diameter of A Train Wheel Based on Structured-Light Vision

    Directory of Open Access Journals (Sweden)

    Zheng Gong

    2016-04-01

    Full Text Available Wheels are very important for the safety of a train. The diameter of the wheel is a significant parameter that needs regular inspection. Traditional methods only use the contact points of the wheel tread to fit the rolling round. However, the wheel tread is easily influenced by peeling or scraping. Meanwhile, the circle fitting algorithm is sensitive to noise when only three points are used. This paper proposes a dynamic measurement method based on structured-light vision. The axle of the wheelset and the tread are both employed. The center of the rolling round is determined by the axle rather than the tread only. Then, the diameter is calculated using the center and the contact points together. Simulations are performed to help design the layout of the sensors, and the influences of different noise sources are also analyzed. Static and field experiments are both performed, and the results show it to be quite stable and accurate.

  2. Microstructure and Failure Analysis of Flash Butt Welded HSLA 590CL Steel Joints in Wheel Rims

    Science.gov (United States)

    Lu, Ping; Xu, Zhixin; Shu, Yang; Ma, Feng

    2016-11-01

    The aim of the present investigation was to evaluate the microstructures, mechanical properties and failure behavior of flash butt welded high strength low alloy 590CL steel joints. Acicular ferrite, Widmanstatten ferrite and granular bainite were observed in the weld. The micro-hardness values of the welded joints varied between 250 HV and 310 HV. The tensile strength of the welded joints met the strength standard of the wheel steel. The Charpy V-notch impact absorbing energy of the welded joints was higher than the base metal, and the impact fracture of the welded joints was composed of shearing and equiaxed dimples. The fracture mode of the wheel rim in the flaring and expanding process was brittle fracture and ductile fracture, respectively. A limited deviation was found in the terminal of the crack for the wheel in the flaring process. A transition from the weld to the Heat Affected Zone was observed for the wheel in the expanding process.

  3. Application of rare- earth and nano elements on diamond cup wheels

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Diamond cup wheel is used widely as an important tool for machining ceramic tile. In this paper,nano rare - earth oxide and nano carbide were added in the segments of seven kinds of diamond cup wheels.The performance of diamond cup wheels were tested on a special designed test machine by grinding two kinds of ceramic tiles. The surface morphology of the segments was examined by Scanning Election Microscopy (SEM) and the micro-hardness of segments was measured. The results showed that nano rare-earth oxide and nano carbide can fine segment micro structure, make grain boundary clear and increase grasping of diamond grits. They can increase also the wear resistance of diamond cup wheels as well as the grinding ratio.

  4. Adaptive Noise Cancellation Method Used for Wheel Speed Signal of Integrate ABS/ASR System

    Institute of Scientific and Technical Information of China (English)

    MA Yue-feng; LIU Zhao-du; QI Zhi-quan; CUI Hai-feng

    2006-01-01

    A novel adaptive noise cancellation method for wheel speed signal of the anti-lock braking system/anti-slip regulation(ABS/ASR) control system is proposed. Based on the spectrum distribution of vehicle's wheel speed signal got from fast Fourier transform under various conditions, the high-pass filter is used to deal with original wheel speed signals sampled to get reference noise signal and the original wheel speed signals are used as adaptive filter's desired outputs. The difference between original signals and reference noise signals is used as the error signal for the adaptive FIR filter and also used as the whole adaptive noise cancellation system's final output. This method can obtain the noise signal on-line and is easy to use for real control system,which is useful to improve the performance of integrate system ABS/ASR.

  5. Two wheel speed robust sliding mode control for electric vehicle drive

    Directory of Open Access Journals (Sweden)

    Abdelfatah Nasri

    2008-01-01

    Full Text Available Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels.

  6. Characteristics of Hand Transmitted Vibration through Steering Wheel of Tractor during Ploughing Field

    Directory of Open Access Journals (Sweden)

    Md Zakaullah Zaka

    2015-02-01

    Full Text Available The paper presents the transmission of vibrations through the steering wheel of the tractor during the ploughing field. The measurements of vibration were carried out on the tractor randomly chosen. An investigation was conducted to determine the transmission of vibration from the steering wheel of the tractor to the wrists and upper arms of the operator under actual field conditions during ploughing field. The vibrations transmitted through the steering wheel of the tractor to the hand of the operator was measured and the frequency spectra for the chosen working conditions were obtained. The maximum transmissibility of vibration were observed in the first two frequency interval (in Hz i.e. 1-20 and 20-40. The vibration, which is transmitted from the steering wheel of the tractor to the wrists, arms and shoulders causes discomfort to the operator and results in early fatigue.

  7. Assessing institutional capacities to adapt to climate change - integrating psychological dimensions in the Adaptive Capacity Wheel

    Science.gov (United States)

    Grothmann, T.; Grecksch, K.; Winges, M.; Siebenhüner, B.

    2013-03-01

    Several case studies show that "soft social factors" (e.g. institutions, perceptions, social capital) strongly affect social capacities to adapt to climate change. Many soft social factors can probably be changed faster than "hard social factors" (e.g. economic and technological development) and are therefore particularly important for building social capacities. However, there are almost no methodologies for the systematic assessment of soft social factors. Gupta et al. (2010) have developed the Adaptive Capacity Wheel (ACW) for assessing the adaptive capacity of institutions. The ACW differentiates 22 criteria to assess six dimensions: variety, learning capacity, room for autonomous change, leadership, availability of resources, fair governance. To include important psychological factors we extended the ACW by two dimensions: "adaptation motivation" refers to actors' motivation to realise, support and/or promote adaptation to climate. "Adaptation belief" refers to actors' perceptions of realisability and effectiveness of adaptation measures. We applied the extended ACW to assess adaptive capacities of four sectors - water management, flood/coastal protection, civil protection and regional planning - in North Western Germany. The assessments of adaptation motivation and belief provided a clear added value. The results also revealed some methodological problems in applying the ACW (e.g. overlap of dimensions), for which we propose methodological solutions.

  8. Assessing institutional capacities to adapt to climate change: integrating psychological dimensions in the Adaptive Capacity Wheel

    Science.gov (United States)

    Grothmann, T.; Grecksch, K.; Winges, M.; Siebenhüner, B.

    2013-12-01

    Several case studies show that social factors like institutions, perceptions and social capital strongly affect social capacities to adapt to climate change. Together with economic and technological development they are important for building social capacities. However, there are almost no methodologies for the systematic assessment of social factors. After reviewing existing methodologies we identify the Adaptive Capacity Wheel (ACW) by Gupta et al. (2010), developed for assessing the adaptive capacity of institutions, as the most comprehensive and operationalised framework to assess social factors. The ACW differentiates 22 criteria to assess 6 dimensions: variety, learning capacity, room for autonomous change, leadership, availability of resources, fair governance. To include important psychological factors we extended the ACW by two dimensions: "adaptation motivation" refers to actors' motivation to realise, support and/or promote adaptation to climate; "adaptation belief" refers to actors' perceptions of realisability and effectiveness of adaptation measures. We applied the extended ACW to assess adaptive capacities of four sectors - water management, flood/coastal protection, civil protection and regional planning - in northwestern Germany. The assessments of adaptation motivation and belief provided a clear added value. The results also revealed some methodological problems in applying the ACW (e.g. overlap of dimensions), for which we propose methodological solutions.

  9. Effect of automobile operating condition on the subjective equivalence of steering wheel vibration and sound

    OpenAIRE

    2007-01-01

    For the manufacturers of automobiles, automobile components and fuels, subjective equivalence relationships between vibration and sound can be used as a reference against which to plot the results from simulations or tests of specific operational conditions. The research described here was performed to define curves of subjective equivalence between steering wheel rotational vibration and sound using stimuli from different automobile operating conditions. The steering wheel acceleration stimu...

  10. Real-time Non-linear Target Tracking Control of Wheeled Mobile Robots

    Institute of Scientific and Technical Information of China (English)

    YU Wenyong

    2006-01-01

    A control strategy for real-time target tracking for wheeled mobile robots is presented. Using a modified Kalman filter for environment perception, a novel tracking control law derived from Lyapunov stability theory is introduced. Tuning of linear velocity and angular velocity with mechanical constraints is applied. The proposed control system can simultaneously solve the target trajectory prediction, real-time tracking, and posture regulation problems of a wheeled mobile robot. Experimental results illustrate the effectiveness of the proposed tracking control laws.

  11. Optimal control of 2-wheeled mobile robot at energy performance index

    Science.gov (United States)

    Kaliński, Krzysztof J.; Mazur, Michał

    2016-03-01

    The paper presents the application of the optimal control method at the energy performance index towards motion control of the 2-wheeled mobile robot. With the use of the proposed method of control the 2-wheeled mobile robot can realise effectively the desired trajectory. The problem of motion control of mobile robots is usually neglected and thus performance of the realisation of the high level control tasks is limited.

  12. The Simulation of Grinding Wheels and Ground Surface Roughness Based on Virtual Reality Technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The paper describes the feasibility and method of the application of virtual reality technology to grinding process, and introduces the modeling method of object entity in the environment of virtual reality. The simulation process of grinding wheels and ground surface roughness is discussed, and the computation program system of numerical simulation is compiled with Visual C++ programming language. At the same time, the three-dimensional simulation models of grinding wheels and ground surface roughness are ...

  13. [The differential diagnosis of the types of trauma caused by wheeled tractors].

    Science.gov (United States)

    Zaval'niuk, A Kh

    1993-01-01

    Examinations of 23 corpses and study of 282 expert conclusions concerning the deaths of subjects aged 6 to 78 dead because of wheeled tractor injuries under agricultural conditions helped detect the specific characteristic signs of tractor injury types. Mathematical method of analysis of the characteristic features' quantitative parameters permitted the author to find statistically reliable criteria for differential diagnosis of the types of injuries inflicted by wheeled tractors. The possibility of correct conclusions of an expert using this method is at least 95%.

  14. Research on Integrated Casting and Forging Process of Aluminum Automobile Wheel

    OpenAIRE

    Zhang, Qi; Cao, Miao; ZHANG, DAWEI; Zhang, Shuai; Sun, Jue

    2014-01-01

    Integrated casting and forging process (ICFP) is a new manufacturing method combining the advantages of both casting and forging. Aluminum structure parts, such as aluminum alloy automobile wheel, with complex shape and excellent mechanical properties can be produced by this process. The effects of different process parameters on the ICFP of the automobile wheel were simulated by Forge software. Microstructure of forging region and the nonforging region were studied by experiment. The results...

  15. CB1 receptor deficiency decreases wheel-running activity: consequences on emotional behaviours and hippocampal neurogenesis.

    Science.gov (United States)

    Dubreucq, Sarah; Koehl, Muriel; Abrous, Djoher N; Marsicano, Giovanni; Chaouloff, Francis

    2010-07-01

    Chronic voluntary wheel-running activity has been reported to hypersensitise central CB1 receptors in mice. On the other hand, pharmacological findings suggest that the CB1 receptor could be involved in wheel-running behaviour and in running-induced neurogenesis in the hippocampus. We analysed wheel-running behaviour for 6 weeks and measured its consequences on hippocampal neurogenesis in CB1 knockout (CB1(-/-)) animals, compared to wild-type (CB1(+/+)) littermates. Because wheel running has been shown to affect locomotor reactivity in novel environments, memory for aversive events and depression-like behaviours, we also assessed these behaviours in control and running CB1(+/+) and CB1(-/-) mice. When compared with running CB1(+/+) mice, the distance covered weekly by CB1(-/-) mice was decreased by 30-40%, an observation accounted for by decreased time spent and maximal velocity on the wheels. Analyses of running distances with respect to the light/dark cycle revealed that mutant covered less distance throughout both the inactive and the active phases of that cycle. Locomotion in an activity cage, exploration in an open field, and immobility time in the forced swim test proved insensitive to chronic wheel running in either genotype. Wheel running, per se, did not influence the expression and extinction of cued fear memory but counteracted in a time-dependent manner the deficiency of extinction measured in CB1(-/-) mice. Hippocampal neurogenesis, assessed by doublecortin labelling of immature neurons in the dentate gyrus, was lowered by 40% in control CB1(-/-) mice, compared to control CB1(+/+) mice. Although CB1(-/-) mice ran less than their wild-type littermates, the 6-week running protocol increased neurogenesis to similar extents (37-39%) in both genotypes. This study suggests that mouse CB1 receptors control wheel running but not its neurogenic consequences in the hippocampus.

  16. A novel mouse running wheel that senses individual limb forces: biomechanical validation and in vivo testing

    OpenAIRE

    Roach, Grahm C.; Edke, Mangesh; Griffin, Timothy M.

    2012-01-01

    Biomechanical data provide fundamental information about changes in musculoskeletal function during development, adaptation, and disease. To facilitate the study of mouse locomotor biomechanics, we modified a standard mouse running wheel to include a force-sensitive rung capable of measuring the normal and tangential forces applied by individual paws. Force data were collected throughout the night using an automated threshold trigger algorithm that synchronized force data with wheel-angle dat...

  17. A novel mouse running wheel that senses individual limb forces: biomechanical validation and in vivo testing.

    Science.gov (United States)

    Roach, Grahm C; Edke, Mangesh; Griffin, Timothy M

    2012-08-15

    Biomechanical data provide fundamental information about changes in musculoskeletal function during development, adaptation, and disease. To facilitate the study of mouse locomotor biomechanics, we modified a standard mouse running wheel to include a force-sensitive rung capable of measuring the normal and tangential forces applied by individual paws. Force data were collected throughout the night using an automated threshold trigger algorithm that synchronized force data with wheel-angle data and a high-speed infrared video file. During the first night of wheel running, mice reached consistent running speeds within the first 40 force events, indicating a rapid habituation to wheel running, given that mice generated >2,000 force-event files/night. Average running speeds and peak normal and tangential forces were consistent throughout the first four nights of running, indicating that one night of running is sufficient to characterize the locomotor biomechanics of healthy mice. Twelve weeks of wheel running significantly increased spontaneous wheel-running speeds (16 vs. 37 m/min), lowered duty factors (ratio of foot-ground contact time to stride time; 0.71 vs. 0.58), and raised hindlimb peak normal forces (93 vs. 115% body wt) compared with inexperienced mice. Peak normal hindlimb-force magnitudes were the primary force component, which were nearly tenfold greater than peak tangential forces. Peak normal hindlimb forces exceed the vertical forces generated during overground running (50-60% body wt), suggesting that wheel running shifts weight support toward the hindlimbs. This force-instrumented running-wheel system provides a comprehensive, noninvasive screening method for monitoring gait biomechanics in mice during spontaneous locomotion.

  18. Torque split between left and right drive shaft over a front wheel drive differential

    OpenAIRE

    Ollé Bernades, Marc

    2011-01-01

    Steering feel and vehicle steering motion is affected by wheel torques from propulsion, especially for front wheel drive cars. Often these problems are referred to as “torque steer”. Many systems interact to cause these problems: propulsion, steering and suspension. Torque steer contributors are not only the differential (friction, self locking effect, Torsen differential), but also the input from the ground and car geometry such as road conditions (friction and surface), the vehicle state...

  19. The noise generated by a landing gear wheel with hub and rim cavities

    Science.gov (United States)

    Wang, Meng; Angland, David; Zhang, Xin

    2017-03-01

    Wheels are one of the major noise sources of landing gears. Accurate numerical predictions of wheel noise can provide an insight into the physical mechanism of landing gear noise generation and can aid in the design of noise control devices. The major noise sources of a 33% scaled isolated landing gear wheel are investigated by simulating three different wheel configurations using high-order numerical simulations to compute the flow field and the FW-H equation to obtain the far-field acoustic pressures. The baseline configuration is a wheel with a hub cavity and two rim cavities. Two additional simulations are performed; one with the hub cavity covered (NHC) and the other with both the hub cavity and rim cavities covered (NHCRC). These simulations isolate the effects of the hub cavity and rim cavities on the overall wheel noise. The surface flow patterns are visualised by shear stress lines and show that the flow separations and attachments on the side of the wheel, in both the baseline and the configuration with only the hub cavity covered, are significantly reduced by covering both the hub and rim cavities. A frequency-domain FW-H equation is used to identify the noise source regions on the surface of the wheel. The tyre is the main low frequency noise source and shows a lift dipole and side force dipole pattern depending on the frequency. The hub cavity is identified as the dominant middle frequency noise source and radiates in a frequency range centered around the first and second depth modes of the cylindrical hub cavity. The rim cavities are the main high-frequency noise sources. With the hub cavity and rim cavities covered, the largest reduction in Overall Sound Pressure Level (OASPL) is achieved in the hub side direction. In the other directivities, there is also a reduction in the radiated sound.

  20. Sensor and actuator modeling of a realistic wheeled mobile robot simulator

    OpenAIRE

    José Gonçalves; José Lima; Hélder Filipe Pinto de Oliveira; Paulo José Cerqueira Gomes da Costa

    2008-01-01

    This paper describes the sensor and actuator modelingof a realistic wheeled mobile robot simulator. The motivationof developing such simulator is to produce a personalizedversatile tool that allows production and validationof robot software reducing considerably the developmenttime. The mobile robot simulator was developed in ObjectPascal with its dynamics based on the ODE (OpenDynamics Engine), allowing to develop robot software fora three wheel omnidirectional robot equipped with Infra-Red ...

  1. A rational fraction polynomials model to study vertical dynamic wheel-rail interaction

    OpenAIRE

    Correa García, Nekane; García Vadillo, Ernesto; Santamaría Manrique, Javier; Gómez López, Josu

    2012-01-01

    This paper presents a model designed to study vertical interactions between wheel and rail when the wheel moves over a rail welding. The model focuses on the spatial domain, and is drawn up in a simple fashion from track receptances. The paper obtains the receptances from a full track model in the frequency domain already developed by the authors, which includes deformation of the rail section and propagation of bending, elongation and torsional waves along an infinite track. Transformation b...

  2. Effects of voluntary wheel running on satellite cells in the rat plantaris muscle

    OpenAIRE

    Atsushi Kojima; Mitsutoshi Kurosaka; Yuji Ogura; Hisashi Naito; Shizuo Katamoto; Katsumasa Goto

    2009-01-01

    This study investigated the effects of voluntary wheel running on satellite cells in the rat plantaris muscle. Seventeen 5-week-old male Wistar rats were assigned to a control (n = 5) or training (n = 12) group. Each rat in the training group ran voluntarily in a running-wheel cage for 8 weeks. After the training period, the animals were anesthetized, and the plantaris muscles were removed, weighed, and analyzed immunohistochemically and biochemically. Although there were no significant diffe...

  3. Systems Engineering Technology Readiness Assessment of Hybrid-Electric Technologies for Tactical Wheeled Vehicles

    Science.gov (United States)

    2014-09-01

    Department of Energy. 2007. Energy Efficiency and Renewable Energy. “Freedom CAR and vehicle technology program; Plug-In hybrid- electric vehicle R&D Plan...ENGINEERING TECHNOLOGY READINESS ASSESSMENT OF HYBRID- ELECTRIC TECHNOLOGIES FOR TACTICAL WHEELED VEHICLES by Eddie E. McCown September 2014 Thesis...HYBRID- ELECTRIC TECHNOLOGIES FOR TACTICAL WHEELED VEHICLES 5. FUNDING NUMBERS 6. AUTHOR(S) Eddie E. McCown 7. PERFORMING ORGANIZATION NAME(S) AND

  4. An approach for modeling the influence of wheel tractor loads and vibration frequencies on soil compaction

    Science.gov (United States)

    Verotti, M.; Servadio, P.; Belfiore, N. P.; Bergonzoli, S.

    2012-04-01

    Both soil compaction and ground vibration are forms of environmental degradation that may be understood in the context of the vehicle-soil interaction process considered (Hildebrand et al., 2008). The transit of tractors on agricultural soil is often the main cause of soil compaction increasing. As known, this can be a serious problems for tillage and sowing and therefore the influence of all the affecting factors have been extensively studied in the last decades in order to understand their impact on the biosystem. There are factors related to the climate, namely to the rainfalls and temperature, and many others. Hence, it is not simple to figure out a complete model for predicting an index of compaction, for a given situation. Soil compaction models are important tools for controlling soil compaction due to agricultural field traffic and they are potentially useful technique to provide information concerning correct soil management. By means of such models, strategies and recommendations for prevention of soil compaction may be developed and specific advice may be given to farmers and advisers. In order to predict field wheeled and tracked vehicle performance, some empirical methods, used for off-road vehicle, were applied by Servadio (2010) on agricultural soil. The empirical indexes included, besides the soil strength, the load carried by the tire or track, some technical characteristics of the tire or track of the vehicle (tire or track width, tire or track wheel diameter, unloaded tire section height, number of wheel station in one track, tire deflection, total length of the belt track, the track pitch) as well as the vehicle passes. They have been validated with the tests results of agricultural vehicles over a range of soil in central Italy. Among the parameters which affect soil compaction, the water content of the soil, the axle load and number of vehicle passes proved to be the most important ones. The present paper concerns mainly vehicle

  5. An interactive game-based shoulder wheel system for rehabilitation

    Directory of Open Access Journals (Sweden)

    Chou LW

    2012-11-01

    Full Text Available Chun-Ming Chang,1,* Yen-Ching Chang,2,3 Hsiao-Yun Chang,4 Li-Wei Chou5,6,* 1Department of Applied Informatics and Multimedia, Asia University, Taichung, Taiwan; 2Department of Medical Informatics, Chung Shan Medical University, Taichung, Taiwan; 3Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan; 4Department of Biotechnology, Asia University, Taichung, Taiwan; 5Department of Physical Medicine and Rehabilitation, China Medical University Hospital, Taichung, Taiwan; 6School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan*These authors contributed equally to this workBackground: Increases in the aging population and in the number of accidents have resulted in more people suffering from physical impairments or disabilities. Rehabilitation therapy thus attracts greater attention as a means of helping patients recover and return to a normal life. With the extremely long and tedious nature of traditional rehabilitation, patients are reluctant to continue the entire process, thus the expected effects of the therapy cannot be obtained. Games are well known to help patients improve their concentration and shift their attention away from the discomfort of their injuries during rehabilitation. Thus, incorporating game technology into a rehabilitation program may be a promising approach.Methods: In this study, a gaming system used for shoulder rehabilitation was developed. The mechanical parts and electric circuits were integrated to mimic the functionalities of a shoulder wheel. Several games were also designed to suit the rehabilitation needs of the patients based on the age and gender differences among the individual users, enabling individuals to undergo the rehabilitation process by playing games. Two surveys were conducted to evaluate the satisfaction of the participants regarding the gaming system.Results: The results of the online survey among a larger population

  6. Road Identification for Anti-Lock Brake Systems Equipped with Only Wheel Speed Sensors

    Institute of Scientific and Technical Information of China (English)

    吴卫东; 尹用山

    2001-01-01

    Anti-lock brake systems (ABS) are now widely used on motor vehicles. To reduce product cost andto use currently available technologies, standard ABS uses only wheel speed sensors to detect wheel angularvelocities, which is not enough to directly obtain wheel slip ratios needed by the control unit, but can be usedto calculate reference slip ratios with measured wheel angular velocities and the estimated vehicle speed.Therefore, the road friction coefficient, which determines the vehicle deceleration during severe braking, is animportant parameter in estimating vehicle speed. This paper analyzes wheel acceleration responses insimulations of severe braking on different road surfaces and selects a pair of specific points to identify thewheel acceleration curve for each operating condition, such as road surface, pedal-braking torque and wheelvertical load. It was found that the curve using the selected points for each road surface clearly differs fromthat of the other road surfaces. Therefore, different road surfaces can be distinguished with these selectedpoints which represent their corresponding road surfaces. The analysis assumes that only wheel speed sensorsare available as hardware and that the road cohesion condition can be determined in the initial part of thesevere braking process.``

  7. Prior experience does not alter modulation of cutaneous reflexes during manual wheeling and symmetrical arm cycling.

    Science.gov (United States)

    MacGillivray, Megan K; Klimstra, Marc; Sawatzky, Bonita; Zehr, E Paul; Lam, Tania

    2013-05-01

    Previous research has reported that training and experience influence H-reflex amplitude during rhythmic activity; however, little research has yet examined the influence of training on cutaneous reflexes. Manual wheelchair users (MWUs) depend on their arms for locomotion. We postulated that the daily dependence and high amount of use of the arms for mobility in MWUs would show differences in cutaneous reflex modulation during upper limb cyclic movements compared with able-bodied control subjects. We hypothesized that MWUs would demonstrate increased reflex response amplitudes for both manual wheeling and symmetrical arm cycling tasks. The superficial radial nerve was stimulated randomly at different points of the movement cycle of manual wheeling and symmetrical arm cycling in MWUs and able-bodied subjects naive to wheeling. Our results showed that there were no differences in amplitude modulation of early- or middle-latency cutaneous reflexes between the able-bodied group and the MWU group. However, there were several differences in amplitude modulation of cutaneous reflexes between tasks (manual wheeling and symmetrical arm cycling). Specifically, differences were observed in early-latency responses in the anterior and posterior deltoid muscles and biceps and triceps brachii as well as in middle-latency responses in the anterior and posterior deltoid. These data suggest that manual wheeling experience does not modify the pattern of cutaneous reflex amplitude modulation during manual wheeling. The differences in amplitude modulation of cutaneous reflexes between tasks may be a result of mechanical differences (i.e., hand contact) between tasks.

  8. Dethridge wheel for pico-scale hydropower generation: An experimental and numerical study

    Science.gov (United States)

    Paudel, Shakun; Saenger, Nicole

    2016-11-01

    This study aims to assess the potential of the Dethridge wheel for developing power from very low head sites in open channel flow. The Dethridge wheel has been in use since early 20th century for measuring flow in irrigation canals. Being robust and simple in design, this technology served as a reliable flow metering solution for more than a century. Working in a similar principle to the conventional waterwheel, this wheel could be a viable option of power generation for decentralized application in remote areas. Two different methods, experimental and numerical, are used for investigating the potential of the wheel. An experimental approach in which a physical model of the Dethridge wheel is built and tested at the hydraulics laboratory of Darmstadt University of Applied Sciences. Whereas a three dimensional numerical model of the Dethridge wheel is simulated using a commercial Computational Fluid Dynamics (CFD) code Flow-3D. Efficiency of around 60% is achieved in the model tests. Computed results are also in good agreement with the physical model results. The results from the physical and the numerical model are presented in this paper.

  9. Nonlinear dynamics modeling and simulation of two-wheeled self-balancing vehicle

    Directory of Open Access Journals (Sweden)

    Yunping Liu

    2016-11-01

    Full Text Available Two-wheeled self-balancing vehicle system is a kind of naturally unstable underactuated system with high-rank unstable multivariable strongly coupling complicated dynamic nonlinear property. Nonlinear dynamics modeling and simulation, as a basis of two-wheeled self-balancing vehicle dynamics research, has the guiding effect for system design of the project demonstration and design phase. Dynamics model of the two-wheeled self-balancing vehicle is established by importing a TSi ProPac package to the Mathematica software (version 8.0, which analyzes the stability and calculates the Lyapunov exponents of the system. The relationship between external force and stability of the system is analyzed by the phase trajectory. Proportional–integral–derivative control is added to the system in order to improve the stability of the two-wheeled self-balancing vehicle. From the research, Lyapunov exponent can be used to research the stability of hyperchaos system. The stability of the two-wheeled self-balancing vehicle is better by inputting the proportional–integral–derivative control. The Lyapunov exponent and phase trajectory can help us analyze the stability of a system better and lay the foundation for the analysis and control of the two-wheeled self-balancing vehicle system.

  10. The effect of mountain bike wheel size on cross-country performance.

    Science.gov (United States)

    Hurst, Howard Thomas; Sinclair, Jonathan; Atkins, Stephen; Rylands, Lee; Metcalfe, John

    2016-08-01

    The purpose of this study was to determine the influence of different wheel size diameters on indicators of cross-country mountain bike time trial performance. Nine competitive male mountain bikers (age 34.7 ± 10.7 years; stature 177.7 ± 5.6 cm; body mass 73.2 ± 8.6 kg) performed 1 lap of a 3.48 km mountain bike (MTB) course as fast as possible on 26″, 27.5″ and 29″ wheeled MTB. Time (s), mean power (W), cadence (revs · min(-1)) and velocity (km · h(-1)) were recorded for the whole lap and during ascent and descent sections. One-way repeated measure ANOVA was used to determine significant differences. Results revealed no significant main effects for any variables by wheel size during all trials, with the exception of cadence during the descent (F(2, 16) = 8.96; P = .002; P(2) = .53). Post hoc comparisons revealed differences lay between the 26″ and 29″ wheels (P = .02). The findings indicate that wheel size does not significantly influence performance during cross-country when ridden by trained mountain bikers, and that wheel choice is likely due to personal choice or sponsorship commitments.

  11. Need for airbag and seatbelt to reduce orbital injuries from steering wheel knob.

    Science.gov (United States)

    Hwang, Kun; Kim, Joo Ho

    2014-11-01

    The aims of this study are to report a blowout fracture of the orbital floor and medial wall caused by being struck by a steering wheel knob of an automobile and to discuss the use of airbags and seatbelts as a preventive measure for orbital injuries. A 58-year-old man was struck in the left eye by a steering wheel. His car hit a telephone pole, and he had a frontal collision injury. In this frontal impact, his left eye was hit by a Brodie knob attached to the steering wheel. At the time of injury, the speed of the car was about 65 km/h. He was not wearing a seatbelt, and the airbag had not deployed. Swelling and ecchymosis were observed at the left periorbital area, and he had diplopia on a left-side gaze. A CT revealed fractures in the medial and inferior wall of the left orbit. Entrapped soft tissues were reduced, and the medial wall and floor were reconstructed with a resorbable sheet. His diplopia disappeared 12 days after surgery. To prevent the injury from the steering wheel knob, an airbag should be installed in any vehicle, which has a steering wheel knob. Legislation mandating the use of airbags as well as seatbelts in vehicles with attached steering wheel knobs should be made.

  12. In-process electrical discharge dressing of arc-shaped metal bonded diamond wheels

    Science.gov (United States)

    Wang, Kai; Fan, Fei; Tian, Guoyu; Zhang, Feihu; Liu, Zhongde

    2016-10-01

    Due to the high hardness of SiC ceramics, the wear of the arc-shaped metal bonded diamond wheels is very serious during the grinding process of large-aperture aspheric SiC mirrors. The surface accuracy and surface/sub-surface quality of the aspheric mirror will be affected seriously if the grinding wheel is not timely dressed. Therefore, this paper focus on the in-process dressing of the arc-shaped metal bonded diamond wheels. In this paper, the application of the asymmetric arc profile grinding wheel in the grinding of aspheric mirrors is discussed first. Then a rotating cup-shaped electrode in-process electro discharge dressing device for the arc-shaped wheels is developed based on the analysis. The dressing experiments are carried out with the device. The experimental results show that the in-process dressing device can did the dressing for the asymmetric and symmetric arc-shaped wheel. The profile error of the arc can reach to 3μm with the in-process dressing device.

  13. Mathematical description of the position of mining chain links on a driving chain wheel

    Energy Technology Data Exchange (ETDEWEB)

    Dolipski, M.

    1982-01-01

    The paper analyzes effects of geometry on interaction between the chain and chain wheels of face conveyors in underground coal mines. Interaction between chain links and wheel toothing is investigated using mathematical models. Three mesh types are comparatively evaluated, so-called normal mesh, nominal mesh and special mesh. Chain position on the chain wheel is shown in 3 schemes. Mathematical formulae used for characterizing mesh types are derived. Effects of the following factors on interaction between a chain link and a chain wheel are analyzed: link quality and differences in quality and dimensions among chain links, friction wear of links and toothing, elastic and plastic chain elongation, friction between links and toothing. A geometric model of the interaction between the chain wheel and haulage chain (in the form of a double polygon) is used. The mathematical model permits the following problems to be analyzed: load distribution among chain links on a chain wheel, load distribution on toothing, load fluctuations, effects of friction wear of chain and toothing. Examples of practical use of the formulae are discussed. (14 refs.)

  14. Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

    Directory of Open Access Journals (Sweden)

    Chen Zhenzhen

    2014-08-01

    Full Text Available For high-efficiency grinding of difficult-to-cut materials such as titanium and nickel alloys, a high porosity is expected and also a sufficient mechanical strength to satisfy the function. However, the porosity increase is a disadvantage to the mechanical strength. As a promising pore forming agent, alumina bubbles are firstly induced into the abrasive layer to fabricate porous cubic boron nitride (CBN wheels. When the wheel porosity reaches 45%, the bending strength is still high up to 50 MPa with modified orderly pore distribution. A porous CBN wheel was fabricated with a total porosity around 30%. The grinding performance of the porous composite-bonded CBN wheel was evaluated in terms of specific force, specific grinding energy, and grinding temperature, which were better than those of the vitrified one under the same grinding conditions. Compared to the vitrified CBN wheel, clear straight cutting grooves and less chip adhesion are observed on the ground surface and there is also no extensive loading on the wheel surface after grinding.

  15. Recognition of diamond grains on surface of fine diamond grinding wheel

    Institute of Scientific and Technical Information of China (English)

    Fengwei HUO; Zhuji JIN; Renke KANG; Dongming GUO; Chun YANG

    2008-01-01

    The accurate evaluation of grinding wheel sur-face topography, which is necessary for the investigation of the grinding principle, optimism, modeling, and simu-lation of a grinding process, significantly depends on the accurate recognition of abrasive grains from the measured wheel surface. A detailed analysis of the grain size distri-bution characteristics and grain profile wavelength of the fine diamond grinding wheel used for ultra-precision grinding is presented. The requirements of the spatial sampling interval and sampling area for instruments to measure the surface topography of a diamond grinding wheel are discussed. To recognize diamond grains, digital filtering is used to eliminate the high frequency disturb-ance from the measured 3D digital surface of the grinding wheel, the geometric features of diamond grains are then extracted from the filtered 3D digital surface, and a method based on the grain profile frequency characteris-tics, diamond grain curvature, and distance between two adjacent diamond grains is proposed. A 3D surface pro-filer based on scanning white light interferometry is used to measure the 3D surface topography of a #3000 mesh resin bonded diamond grinding wheel, and the diamond grains are then recognized from the 3D digital surface. The experimental result shows that the proposed method is reasonable and effective.

  16. Mist-jetting Electrical Discharge Dressing Technology for Superabrasive Grinding Wheels

    Institute of Scientific and Technical Information of China (English)

    CAI Lan-rong; HU De-jin; JIA yan

    2008-01-01

    The technology of superabrasive grinding has been developed in order to achieve high-quality finish in extremely hard and brittle materials.Thereafter,truing and dressing technology on super abrasive grinding wheel is one of the most important subjects on precise machining field at present.In this paper,mist-jetting electrical discharge technology was applied to dressing metai-bonded superabrasive wheels.And a systematical study on the mechanism of selective removal of the bond was proposed.Experiments on dressing bronze bonded diamond grind wheels were carried out on a die-sinking electrical discharge machine.The diamond wheel topographies before and after electrical discharge dressing were observed by VH-800 3D digital microscope.The wheel profiles before and after dressing were observed.The results of electrical discharge dressing under different electrical parameters were compared.Experimental results indicate that the favorable surface topography can be obtained under suitable processing parameters and mist-jetting electrical discharge dressing (MEDD) is feasible for metal-bonded diamond grinding wheel.

  17. Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide

    Directory of Open Access Journals (Sweden)

    Tae-Il Seo

    2013-05-01

    Full Text Available Plastic worm wheel is widely used in the vehicle manufacturing field because it is favorable for weight lightening, vibration and noise reduction, as well as corrosion resistance. However, it is very difficult for general plastics to secure the mechanical properties that are required for vehicle gears. If the plastic resin is reinforced by glass fiber in the fabrication process of plastic worm wheel, it is possible to achieve the mechanical properties of metallic material levels. In this study, the mechanical characteristic analysis of the glass-reinforced plastic worm wheel, according to the contents of glass fiber, is performed by analytic and experimental methods. In the case of the glass fiber-reinforced resin, the orientation and contents of glass fibers can influence the mechanical properties. For the characteristic prediction of plastic worm wheel, computer-aided engineering (CAE analysis processes such as structural and injection molding analysis were executed with the polyamide resin reinforcement glass fiber (25 wt %, 50 wt %. The injection mold for fabricating the prototype plastic worm wheel was designed and made to reflect the CAE analysis results. Finally, the durability of prototype plastic worm wheel fabricated by the injection molding process was evaluated by the experimental method and the characteristics according to the glass fiber contents.

  18. Design Optimization of Heat Wheels for Energy Recovery in HVAC Systems

    Directory of Open Access Journals (Sweden)

    Stefano De Antonellis

    2014-11-01

    Full Text Available Air to air heat exchangers play a crucial role in mechanical ventilation equipment, due to the potential primary energy savings both in case of refurbishment of existing buildings or in case of new ones. In particular, interest in heat wheels is increasing due to their low pressure drop and high effectiveness. In this paper a detailed optimization of design parameters of heat wheels is performed in order to maximize sensible effectiveness and to minimize pressure drop. The analysis is carried out through a one dimensional lumped parameters heat wheel model, which solves heat and mass transfer equations, and through appropriate correlations to estimate pressure drop. Simulation results have been compared with experimental data of a heat wheel tested in specific facilities, and good agreement is attained. The device optimization is performed through the variation of main design parameters, such as heat wheel length, channel base, height and thickness and for different operating conditions, namely the air face velocity and the revolution speed. It is shown that the best configurations are achieved with small channel thickness and, depending on the required sensible effectiveness, with appropriate values of wheel length and channel base and height.

  19. Stiffness determination of the controlled wheel module of a two-axle vehicle

    Directory of Open Access Journals (Sweden)

    Belevtseva N.V.

    2016-08-01

    Full Text Available The conditions of a secure loss of stability of a two-axle wheel vehicle with absolutely hard steering have been found before. The analytically derived conditions of a secure stability loss in case of torsional stiffness are dependent on the relationship between the slipping resistance coefficients, the transverse clutch coefficients on the axes, and the torsional stiffness of the controlled wheel module. In this case, the trail distance is taken into account in the wheel module control system, the mass of the module being neglected. The approach suggested in the paper does take into account the mass of the controlled wheel module. The slipping forces are presented accurate to a cubic term of expansion in slipping angles. The torsional stiffness intervals have been found that provide a secure loss of stability of a two-axle wheel vehicle model. The intervals have been obtained on the basis of a bifurcation analysis of actual bifurcations of the stationary states in the vicinity of the rectilinear motion of the model. Diagrams that illustrate the fulfillment of secure stability loss conditions and allow using the results obtained in designing a wheel module are presented in the paper. The technique used is alternative to the well-known M. Bautin’s approach to determination of secure-insecure conditions in case of a divergent loss of stability.

  20. Soil Parameter Identification for Wheel-terrain Interaction Dynamics and Traversability Prediction

    Institute of Scientific and Technical Information of China (English)

    Suksun Hutangkabodee; Yahya Hashem Zweiri; Lakmal Dasarath Seneviratne; Kaspar Althoefer

    2006-01-01

    This paper presents a novel technique for identifying soil parameters for a wheeled vehicle traversing unknown terrain. The identified soil parameters are required for predicting vehicle drawbar pull and wheel drive torque, which in turn can be used for traversability prediction, traction control, and performance optimization of a wheeled vehicle on unknown terrain. The proposed technique is based on the Newton Raphson method. An approximated form of a wheel-soil interaction model based on Composite Simpson's Rule is employed for this purpose. The key soil parameters to be identified are internal friction angle, shear deformation modulus, and lumped pressure-sinkage coefficient. The fourth parameter, cohesion, is not too relevant to vehicle drawbar pull, and is assigned an average value during the identification process. Identified parameters are compared with known values, and shown to be in agreement. The identification method is relatively fast and robust.The identified soil parameters can effectively be used to predict drawbar pull and wheel drive torque with good accuracy.The use of identified soil parameters to design a traversability criterion for wheeled vehicles traversing unknown terrain is presented.

  1. Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

    Institute of Scientific and Technical Information of China (English)

    Chen Zhenzhen; Xu Jiuhua; Ding Wenfeng; Ma Changyu

    2014-01-01

    For high-efficiency grinding of difficult-to-cut materials such as titanium and nickel alloys, a high porosity is expected and also a sufficient mechanical strength to satisfy the function. However, the porosity increase is a disadvantage to the mechanical strength. As a promising pore forming agent, alumina bubbles are firstly induced into the abrasive layer to fabricate porous cubic boron nitride (CBN) wheels. When the wheel porosity reaches 45%, the bending strength is still high up to 50 MPa with modified orderly pore distribution. A porous CBN wheel was fabricated with a total porosity around 30%. The grinding performance of the porous composite-bonded CBN wheel was evaluated in terms of specific force, specific grinding energy, and grinding temper-ature, which were better than those of the vitrified one under the same grinding conditions. Com-pared to the vitrified CBN wheel, clear straight cutting grooves and less chip adhesion are observed on the ground surface and there is also no extensive loading on the wheel surface after grinding.

  2. A study on high-speed rolling contact between a wheel and a contaminated rail

    Science.gov (United States)

    Zhao, Xin; Wen, Zefeng; Zhu, Minhao; Jin, Xuesong

    2014-10-01

    A 3-D explicit finite element model is developed to investigate the transient wheel-rail rolling contact in the presence of rail contamination or short low adhesion zones (LAZs). A transient analysis is required because the wheel passes by a short LAZ very quickly, especially at high speeds. A surface-to-surface contact algorithm (by the penalty method) is employed to solve the frictional rolling contact between the wheel and the rail meshed by solid elements. The LAZ is simulated by a varying coefficient of friction along the rail. Different traction efforts and action of the traction control system triggered by the LAZ are simulated by applying a time-dependent driving torque to the wheel axle. Structural flexibilities of the vehicle-track system are considered properly. Analysis focuses on the contact forces, creepage, contact stresses and the derived frictional work and plastic deformation. It is found that the longitudinal contact force and the maximum surface shear stress in the contact patch become obviously lower in the LAZ and much higher as the wheel re-enters the dry rail section. Consequently, a higher wear rate and larger plastic flow are expected at the location where the dry contact starts to be rebuilt. In other words, contact surface damages such as wheel flats and rail burns may come into being because of the LAZ. Length of the LAZ, the traction level, etc. are varied. The results also show that local contact surface damages may still occur as the traction control system acts.

  3. Ultra-precision ductile grinding of BK7 using super abrasive diamond wheel

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qingliang; Brinksmeier Ekkard; Riemer Oltmann; Rickens Kai

    2007-01-01

    In this paper,a novel conditioning technique using copper bonded diamond grinding wheels of 91 μm grain size and electrolytic in-process dressing (ELID) is first developed to precisely and effectively condition a nickelelectroplated monolayer coarse-grained diamond grinding wheel of 151 μm grain size.Under optimised conditioning parameters,the super abrasive diamond wheel was well conditioned in terms of a minimized run-out error and flattened diamond grain surfaces of constant peripheral envelope.The conditioning force was monitored by a force transducer,while the modified wheel surface status was in-situ monitored by a coaxial optical distance measurement system.Finally,the grinding experiment on BK7 was conducted using the well-conditioned wheel with the corresponding surface morphology and subsurface damage measured by atomic force microscope (AFM) and scanning electric microscope (SEM),respectively.The experimental result shows that the newly developed conditioning technique is applicable and feasible to ductile grinding optical glass featuring nano scale surface roughness,indicating the potential of super abrasive diamond wheels in ductile machining brittle materials.

  4. A rational fraction polynomials model to study vertical dynamic wheel-rail interaction

    Science.gov (United States)

    Correa, N.; Vadillo, E. G.; Santamaria, J.; Gómez, J.

    2012-04-01

    This paper presents a model designed to study vertical interactions between wheel and rail when the wheel moves over a rail welding. The model focuses on the spatial domain, and is drawn up in a simple fashion from track receptances. The paper obtains the receptances from a full track model in the frequency domain already developed by the authors, which includes deformation of the rail section and propagation of bending, elongation and torsional waves along an infinite track. Transformation between domains was secured by applying a modified rational fraction polynomials method. This obtains a track model with very few degrees of freedom, and thus with minimum time consumption for integration, with a good match to the original model over a sufficiently broad range of frequencies. Wheel-rail interaction is modelled on a non-linear Hertzian spring, and consideration is given to parametric excitation caused by the wheel moving over a sleeper, since this is a moving wheel model and not a moving irregularity model. The model is used to study the dynamic loads and displacements emerging at the wheel-rail contact passing over a welding defect at different speeds.

  5. Influence of photoperiod and running wheel access on the entrainment of split circadian rhythms in hamsters

    Directory of Open Access Journals (Sweden)

    Elliott Jeffrey A

    2005-06-01

    Full Text Available Abstract Background In the laboratory, behavioral and physiological states of nocturnal rodents alternate, with a period near 24 h, between those appropriate for the night (e.g., elevated wheel-running activity and high melatonin secretion and for the day (e.g., rest and low melatonin secretion. Under appropriate 24 h light:dark:light:dark conditions, however, rodents may be readily induced to express bimodal rest/activity cycles that reflect a global temporal reorganization of the central neural pacemaker in the hypothalamus. We examine here how the relative length of the light and dark phases of the environmental cycle influences this rhythm splitting and the necessity of a running wheel for expression of this entrainment condition. Results Rhythm splitting was observed in wheel-running and general locomotion of Siberian and Syrian hamsters. The latter also manifest split rhythms in body temperature. Access to a running wheel was necessary neither for the induction nor maintenance of this entrainment pattern. While rhythms were only transiently split in many animals with two 5 h nights, the incidence of splitting was greater with twice daily nights of shorter duration. Removal of running wheels altered the body temperature rhythm but did not eliminate its clear bimodality. Conclusion The expression of entrained, split circadian rhythms exhibits no strict dependence on access to a running wheel, but can be facilitated by manipulation of ambient lighting conditions. These circadian entrainment patterns may be of therapeutic value to human shift-workers and others facing chronobiological challenges.

  6. Linking two distinct layered networks of nanosized {Ln18} and {Cu24} wheels through isonicotinate ligands.

    Science.gov (United States)

    Cheng, Jian-Wen; Zhang, Jie; Zheng, Shou-Tian; Yang, Guo-Yu

    2008-01-01

    A new series of heterolanthanide(III)-copper(I) wheel-cluster complexes [Ln6(micro3-O)2](IN)18-[Cu8(micro4-I)2(micro2-I)3].H3O (IN=isonicotinate; Ln=Y 1, Nd 2, Dy 3, Gd 4, Sm 5, Eu 6, Tb 7) were prepared by hydrothermal reaction at low pH. X-ray crystallographic studies reveal that two unusual trinuclear [Ln3(micro3-O)] and tetranuclear [Cu4(micro4-I)] cores are successfully used as secondary building units to make two different nanosized wheels [Ln18(micro3-O)6(CO2)48](6-), {Ln18}, and [Cu24(micro4-I)6(micro2-I)12]6+, {Cu24}, with 12-rings and a diameter of 26.7 and 26.4 A, respectively. The wheels are further assembled into two-dimensional (2D) {Ln18} and {Cu24} networks, the linkages between two distinct layered networks of {Ln18} and {Cu24} wheels by IN pillars along the c axis giving a series of unprecedented three-dimensional (3D) sandwich frameworks. To our knowledge, compounds 1-7 are the first examples containing two different layered networks of nanosized Ln and transition metal (TM) wheels in wheel-cluster chemistry. The IR, UV/Vis, thermogravimetric analysis (TGA), luminescent, and magnetic properties of these complexes were also studied.

  7. Water

    Directory of Open Access Journals (Sweden)

    E. Sanmuga Priya

    2017-05-01

    Full Text Available Phytoremediation through aquatic macrophytes treatment system (AMATS for the removal of pollutants and contaminants from various natural sources is a well established environmental protection technique. Water hyacinth (Eichhornia crassipes, a worst invasive aquatic weed has been utilised for various research activities over the last few decades. The biosorption capacity of the water hyacinth in minimising various contaminants present in the industrial wastewater is well studied. The present review quotes the literatures related to the biosorption capacity of the water hyacinth in reducing the concentration of dyestuffs, heavy metals and minimising certain other physiochemical parameters like TSS (total suspended solids, TDS (total dissolved solids, COD (chemical oxygen demand and BOD (biological oxygen demand in textile wastewater. Sorption kinetics through various models, factors influencing the biosorption capacity, and role of physical and chemical modifications in the water hyacinth are also discussed.

  8. Application of the Coastal Hazard Wheel methodology for coastal multi-hazard assessment and management in the state of Djibouti

    DEFF Research Database (Denmark)

    Appelquist, Lars Rosendahl; Balstrøm, Thomas

    2014-01-01

    coastal classification system that incorporates the main static and dynamic parameters determining the characteristics of a coastal environment. The methodology provides information on the hazards of ecosystem disruption, gradual inundation, salt water intrusion, erosion and flooding and can be used...... to support management decisions at local, regional and national level, in areas with limited access to geophysical data. The assessment for Djibouti applies a geographic information system (GIS) to develop a range of national hazard maps along with relevant hazard statistics and is showcasing the procedure......This paper presents the application of a new methodology for coastal multi-hazard assessment and management in a changing global climate on the state of Djibouti. The methodology termed the Coastal Hazard Wheel (CHW) is developed for worldwide application and is based on a specially designed...

  9. Cassini Thruster Calibration Algorithm Using Reaction Wheel Biasing Data

    Science.gov (United States)

    Rizvi, Farheen

    2012-01-01

    Thrust force estimates for the reaction control thrusters on-board Cassini spacecraft are presented in this paper. Cassini consists of two thruster branches (A and B) each with eight thrusters. The four Z-thrusters control the X and Y-axes, while the four Y-thrusters control the Z-axis. It is important to track the thrust force estimates in order to detect any thruster degradation and for supporting various activities in spacecraft operations (Titan flyby, spacecraft maneuvers). The Euler equation, which describes the rotational motion of the spacecraft during a reaction wheel bias event, is used to develop the algorithm. The thrust estimates are obtained from the pseudo inverse solution using flight telemetry during the bias. Results show that the A-branch Z3A and Z4A thrusters exhibited degraded thrust in November 2008. Due to the degraded thrust performance of Z3A and Z4A, A-branch usage was discontinued and prime branch was swapped to B-branch in March 2009. The thrust estimates from the B-branch do not show any degradation to date. The algorithm is used to trend the B-branch thrust force estimates as the mission continues.

  10. Patient satisfaction with telerehabilitation assessments for wheeled mobility and seating.

    Science.gov (United States)

    Schein, Richard M; Schmeler, Mark R; Saptono, Andi; Brienza, David

    2010-01-01

    Wheeled mobility and seating assessments for individuals with mobility impairments living in rural or distant locations are problematic due to the lack of expertise and available resources. The objective of this study was to measure satisfaction based on one's evaluation and prescription as well as comfort level when being evaluated by telerehabilitation (TR). Patient satisfaction data from real-time interactive TR clinical consultations between an expert practitioner located at least 125 miles away and four remote wheelchair clinics set up by the research team were collected and evaluated. The results revealed that there was a statistically significant difference between participants' pre- and postevaluation scores, t(39) = -13.92, p < .05, as well as pre- and postprescription scores, t(39) = -13.15, p < .05. In addition, all mean scores were significantly higher than the scale midpoint of3.5 on a TR survey. The study's findings are consistent with those of previous telemedicine satisfaction studies. Overall, the results indicate a high level of patient satisfaction using TR.

  11. Analysis and Testing of Microvibrations Produced by Momentum Wheel Assemblies

    Institute of Scientific and Technical Information of China (English)

    ZHOU Weiyong; LI Dongxu; LUO Qing; LIU Kun

    2012-01-01

    The microvibrations produced by momentum wheel assemblies (MWA) can degrade the performance of instruments with high pointing precision and stability on spacecraft.This paper concentrates on analyzing and testing the microvibrations produced by MWA.We analyze the disturbance sources produced by mass imbalance,structural mode,beating irregularity and nonlinear stiffness,and random noise; then,test a well-balanced MWA by a highly sensitive measurement system consisting of a Kistler table and an optical tabletop.The results show that the test system has a resolution of less than 0.003 N in the frequency range of 3-300 Hz.The dynamic imbalance of the MWA cannot excite the radial rocking mode,but there are dynamic amplifications when the poly-harmonic disturbances intersect with the structural modes.Especially at high rotational speed (>3 000 rev/min),the main disturbance sources of the MWA come from the bearing irregularity interacting with radial translation mode in the high frequency range.Thus,bearing noise deserves more attention for the well-balanced MWA,and alternative of high quality bearings are proposed to reduce the microvibrations.

  12. Geometric contributions to chopper wheel optical attenuation uncertainty

    Science.gov (United States)

    Spidell, M.; Hadler, J.; Stephens, M.; Williams, P.; Lehman, J.

    2017-08-01

    Calibrated optical choppers are used in high-power laser calibration services at the National Institute of Standards and Technology for beam power reduction due to their advantages in performance and safety over wedges and semi-transparent materials. While the design, operation, and calibration of such choppers is generally straightforward, fabrication tolerances and edge geometry must be taken into account for low transmission (powers (upwards of 10 kW) available for the calibration service. The slit edge is presented to the beam at non-zero angles of incidence and for edge thicknesses on order of 10% of the slit width, the relative error from design transmission can exceed 2% (depending on beam diameter and angle of incidence). Both slit edge presentation at non-zero angles of incidence and displacement of the slit edges due to minor variation in fabrication or coating yield significant changes in transmission with radial displacement of the beam over the chopper face. While diffraction effects play a smaller role under typical setup conditions, they become an appreciable factor for detectors having small entrance apertures or located far from the chopper wheel. Here we demonstrate a close agreement between the calculated and measured transmission ratio for two optical choppers when considering these three effects.

  13. Supporting the paralympic athlete: focus on wheeled sports.

    Science.gov (United States)

    Goosey-Tolfrey, Victoria

    2010-01-01

    The complexity of wheelchair sports provides the scientist with a unique challenge. There are two major components that contribute towards 'wheeled sports' performance: the athlete and the chair. It is the interaction of these two components that enable wheelchair propulsion and the sporting movements required within a given sport. This article will describe three discrete case studies on how sport scientists have worked with Great Britain coaches and practitioners to help optimise training leading to a major competition through evidence base practise. A fourth area will describe on-going work designed to address the optimisation of wheelchair configurations for wheelchair court sports. It will focus on four sports: wheelchair racing, wheelchair tennis, wheelchair basketball and wheelchair rugby. The first topic will discuss the concept of pushing economy and mechanical efficiency of wheelchair propulsion. The second topic will show how technology assists the coaching process. The third topic will illustrate the concept of sports classification, and show how training volume 'in terms of basketball shooting' may need to be individually assigned and finally future research within wheelchair team sports and chair configurations will be examined.

  14. Experimental Setup for Diamond Grinding Using Electrochemical InProcess Controlled Dressing (ECD of Grinding Wheel

    Directory of Open Access Journals (Sweden)

    M. A. Shavva

    2014-01-01

    Full Text Available The most effective method for finish machining of hard-metals and alloys is to use the diamond grinding wheels for grinding. An application of diamond wheels significantly increases the employee output, reduces costs, and raises manufacturing efficiency with achieving the high performance properties of treated surfaces.During grinding a working surface of diamond wheel wears out. It adversely affects the cutting capability of the diamond grains, and depending on the grinding conditions can occur through different mechanisms. Wear of diamond wheel causes distortion of its shape and reduces cutting properties. However, dressing of diamond wheels is a complicated and time-consuming operation in terms of manufacturing technique.Methods to make dressing of diamond grinding wheel have different types of classification. Classification of dressing methods by the type of energy used is as follows: mechanical, chemical, electrophysical, electromechanical, and electrochemical. All these methods have their advantages and disadvantages.Electrochemical method of dressing is the most productive and efficient. Electrochemical method comprises anode-mechanical dressing and electrochemical (electrolytic one. The paper presents the electrochemical in-process dressing (ECD and the electrolytic in-process dressing (ELID.The source of energy, grinding a wheel with metal bond, and an electrode are necessary for providing ELID. The ELID consists of several stages. The first stage is preliminary electrolytic dressing of diamond wheel. The electrolyte is placed into the gap between the wheel and electrode. The bond of the wheel is oxidized. An insulating layer is formed. It reduces an electrical conductivity of the wheel and controls consumption of diamond grains, as well as polishes the surface of the work piece. Further, the insulating layer is destroyed. The cycle of dressing begins anew.The ECD proceeds in the same way as ELID. However during the ECD-process there

  15. Feasibility Study of Two Candidate Reaction Wheel/thruster Hybrid Control Architecture Designs for the Cassini Spacecraft

    Science.gov (United States)

    Macala, Glenn A.; Lee, Allan Y.; Wang, Eric K.

    2012-01-01

    As the first spacecraft to achieve orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for a first and second extended mission through 2017. Cassini carries a set of three "fixed" reaction wheels and a backup reaction wheel (reaction wheel #4) is mounted on top of an articulable platform. If necessary, this platform could be articulated to orient the backup reaction wheel with the degraded wheel. The reaction wheels are used primarily for attitude control when precise and stable pointing of a science instrument such as the narrow angle camera is required. In 2001-02, reaction wheel #3 exhibited signs of bearing cage instability. As a result, reaction wheel #4 was articulated to align with reaction wheel #3. Beginning in July 2003, Cassini was controlled using wheel #1, #2, and #4. From their first use in the spring of 2000 until today, reaction wheels #1 and #2 have accumulated more than3.5 billions revolutions each. As such, in spite of very carefully management of the wheel spin rates by the mission operation team, there are some observed increases in the drag torque of the wheels' bearings. Hence, the mission operations team must prepare for the contingency scenario in which the reaction wheel #1 (in addition to wheel #3) had degraded. In this hypothetical fault scenario, the two remaining reaction wheels (#2 and #4) will not be able to provide precise and stable three-axis control of the spacecraft. In this study, we evaluate the feasibility of controlling Cassini using the two remaining reaction wheels and four thrusters to meet the science pointing requirements for two key science operational modes: the Optical Remote Sensing and Downlink, Fields, Particles, & Waves operation modes. The performance (e.g., pointing control error, pointing stability, hydrazine consumption rate, etc.) of the hybrid controllers in both operations scenarios will be compared with those achieved

  16. Feasibility Study of Two Candidate Reaction Wheel/thruster Hybrid Control Architecture Designs for the Cassini Spacecraft

    Science.gov (United States)

    Macala, Glenn A.; Lee, Allan Y.; Wang, Eric K.

    2012-01-01

    As the first spacecraft to achieve orbit at Saturn in 2004, Cassini has collected science data throughout its four-year prime mission (2004-08), and has since been approved for a first and second extended mission through 2017. Cassini carries a set of three "fixed" reaction wheels and a backup reaction wheel (reaction wheel #4) is mounted on top of an articulable platform. If necessary, this platform could be articulated to orient the backup reaction wheel with the degraded wheel. The reaction wheels are used primarily for attitude control when precise and stable pointing of a science instrument such as the narrow angle camera is required. In 2001-02, reaction wheel #3 exhibited signs of bearing cage instability. As a result, reaction wheel #4 was articulated to align with reaction wheel #3. Beginning in July 2003, Cassini was controlled using wheel #1, #2, and #4. From their first use in the spring of 2000 until today, reaction wheels #1 and #2 have accumulated more than3.5 billions revolutions each. As such, in spite of very carefully management of the wheel spin rates by the mission operation team, there are some observed increases in the drag torque of the wheels' bearings. Hence, the mission operations team must prepare for the contingency scenario in which the reaction wheel #1 (in addition to wheel #3) had degraded. In this hypothetical fault scenario, the two remaining reaction wheels (#2 and #4) will not be able to provide precise and stable three-axis control of the spacecraft. In this study, we evaluate the feasibility of controlling Cassini using the two remaining reaction wheels and four thrusters to meet the science pointing requirements for two key science operational modes: the Optical Remote Sensing and Downlink, Fields, Particles, & Waves operation modes. The performance (e.g., pointing control error, pointing stability, hydrazine consumption rate, etc.) of the hybrid controllers in both operations scenarios will be compared with those achieved

  17. The effect of wheel size on mobility performance in wheelchair athletes.

    Science.gov (United States)

    Mason, B; van der Woude, L; Lenton, J P; Goosey-Tolfrey, V

    2012-10-01

    The purpose of the current study was to investigate the effects of different wheel sizes, with fixed gear ratios, on maximal effort mobility performance in wheelchair athletes. 13 highly trained wheelchair basketball players, grouped by classification level, performed a battery of 3 field tests in an adjustable wheelchair with 3 different wheel sizes (0.59 m, 0.61 m and 0.65 m). Performance was assessed using the time taken to perform drills, with velocity and acceleration data also collected via a wheelchair velocometer. 20 m sprint time improved in the 0.65 m condition (5.58 ± 0.43 s, P=0.029) compared with 0.59 m (5.72 ± 0.40 s). Acceleration performance over the first 2 (P=0.299) and 3 (P=0.145) pushes was not statistically influenced by wheel size. However, the peak velocities reached were greater in the 0.65 m condition (4.77 ± 0.46 m ∙ s(-1), P=0.078, Effect Size [ES]=0.63) compared with 0.59 m (4.61 ± 0.40 m ∙ s(-1)). Impact velocity, calculated as the change in velocity from the onset of a push to the following impact peak, to define coupling performance, was also significantly improved in 0.65 m wheels (0.14 ± 0.14 m ∙ s(-1), P=0.006) than 0.59 m wheels (0.05 ± 0.10 m ∙ s(-1)). The time taken to complete the linear mobility (P=0.630) and the agility drill (P=0.505) were not affected by wheel size. Finally, no significant interactions existed between wheel size, classification and any performance measure. To conclude, larger 0.65 m wheels improved the maximal sprinting performance of highly trained wheelchair basketball players, without any negative effects on acceleration or manoeuvrability. Improvements in sprinting were attributed to a combination of the reduced drag forces experienced and improvements in coupling thought to be due to the lower angular velocities of the wheel/hand-rim when developing high wheelchair velocities in larger wheels.

  18. Modelling of a mecanum wheel taking into account the geometry of road rollers

    Science.gov (United States)

    Hryniewicz, P.; Gwiazda, A.; Banaś, W.; Sękala, A.; Foit, K.

    2017-08-01

    During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of

  19. Plasma adiponectin is increased in mice selectively bred for high wheel-running activity, but not by wheel running per se

    NARCIS (Netherlands)

    Vaanholt, L. M.; Meerlo, P.; Garland, T.; Visser, G. H.; van Dijk, G.

    2007-01-01

    Mice selectively bred for high wheel-running activity (S) have decreased fat content compared to mice from randomly bred control (C) lines. We explored whether this difference was associated with alterations in levels of circulating hormones involved in regulation of food intake and energy balance,

  20. A comparison of aircraft tire skid with initial wheel\\ud rotational speed using ANSYS transient simulation

    OpenAIRE

    Alroqi, Abdurrhman A; Wang, Weiji

    2016-01-01

    Based on heavy aircraft main landing gear tires touchdown skidding process, patents have been registered since the 1940s to improve tire safety, decrease the substantial wear and smoke that results from every landing by spinning the rear wheels before touchdown. A single wheel has been modeled as a mass-spring-damper system using ANSYS mechanical transient simulation to analyze static and pre-rotating wheels behavior during a short period between touchdown and skidding, to spin-up to reach th...