WorldWideScience

Sample records for 209bi target wheels

  1. Developments of 207Pb, 208Pb and 209Bi target wheels in the synthesis of 107Ns, 108Hs and 109Mt

    The developments of 207Pb, 208Pb and 209Bi target wheels and their applications in heavy-ion fusion reactions are reviewed. In both, fabrication and use, the centers of the evaporator or accelerator beams are focussed at wheel radii of 155 mm to specially shaped frames which generate very homogeneous target layers and very constant reaction and counting rates in the experiment. Target areas of up to ∼98% of a wheel's circumference of 974 mm can be provided. The preparation procedures for necessary C backings and protecting layers of C are described, and details are given for the developments of high-vacuum evaporations of 207Pb, 208Pb and 209Bi with deposition yields of 35-55% from tantalum crucibles. The applications of the target wheels in heavy-ion fusion reactions with beams of 54Cr and 58Fe at energies near the Coulomb barrier and intensities of ∼1012 particles/s are mentioned. The target parameters for the production runs of the new chemical elements 107Ns, 108Hs and 109Mt are included. (orig.)

  2. Experimental Cross Sections for Reactions of Heavy Ions and 208Pb, 209Bi, 238U, and 248Cm Targets

    The study of the reactions between heavy ions and 208Pb, 209Bi, 238U, and 248 Cm targets was performed to look at the differences between the cross sections of hot and cold fusion reactions. Experimental cross sections were compared with predictions from statistical computer codes to evaluate the effectiveness of the computer code in predicting production cross sections. Hot fusion reactions were studied with the MG system, catcher foil techniques and the Berkeley Gas-filled Separator (BGS). 3n- and 4n-exit channel production cross sections were obtained for the 238U(18O,xn)256-xFm, 238U(22Ne,xn)260-xNo, and 248Cm(15N,xn)263-xLr reactions and are similar to previous experimental results. The experimental cross sections were accurately modeled by the predictions of the HIVAP code using the Reisdorf and Schaedel parameters and are consistent with the existing systematics of 4n exit channel reaction products. Cold fusion reactions were examined using the BGS. The 208Pb(48Ca,xn)256-xNo, 208Pb(50Ti,xn)258-xRf, 208Pb(51V,xn)259-xDb, 209Bi(50Ti,xn)259-xDb, and 209Bi(51V,xn)260-xSg reactions were studied. The experimental production cross sections are in agreement with the results observed in previous experiments. It was necessary to slightly alter the Reisdorf and Schaedel parameters for use in the HIVAP code in order to more accurately model the experimental data. The cold fusion experimental results are in agreement with current 1n- and 2n-exit channel systematics

  3. Experimental Cross Sections for Reactions of Heavy Ions and 208Pb, 209Bi, 238U, and 248Cm Targets

    Patin, Joshua B.

    2002-05-24

    The study of the reactions between heavy ions and {sup 208}Pb, {sup 209}Bi, {sup 238}U, and {sup 248} Cm targets was performed to look at the differences between the cross sections of hot and cold fusion reactions. Experimental cross sections were compared with predictions from statistical computer codes to evaluate the effectiveness of the computer code in predicting production cross sections. Hot fusion reactions were studied with the MG system, catcher foil techniques and the Berkeley Gas-filled Separator (BGS). 3n- and 4n-exit channel production cross sections were obtained for the {sup 238}U({sup 18}O,xn){sup 256-x}Fm, {sup 238}U({sup 22}Ne,xn){sup 260-x}No, and {sup 248}Cm({sup 15}N,xn){sup 263-x}Lr reactions and are similar to previous experimental results. The experimental cross sections were accurately modeled by the predictions of the HIVAP code using the Reisdorf and Schaedel parameters and are consistent with the existing systematics of 4n exit channel reaction products. Cold fusion reactions were examined using the BGS. The {sup 208}Pb({sup 48}Ca,xn){sup 256-x}No, {sup 208}Pb({sup 50}Ti,xn){sup 258-x}Rf, {sup 208}Pb({sup 51}V,xn){sup 259-x}Db, {sup 209}Bi({sup 50}Ti,xn){sup 259-x}Db, and {sup 209}Bi({sup 51}V,xn){sup 260-x}Sg reactions were studied. The experimental production cross sections are in agreement with the results observed in previous experiments. It was necessary to slightly alter the Reisdorf and Schaedel parameters for use in the HIVAP code in order to more accurately model the experimental data. The cold fusion experimental results are in agreement with current 1n- and 2n-exit channel systematics.

  4. Comparative study of fusion barrier distribution in 16O and 18O induced reactions on 232Th and 209Bi targets

    In order to investigate the influence of projectile excitations and transfer channels, quasi-elastic excitation function measurements with 16,18O projectile on two targets, one heavy (232Th) and the other a lighter target (209Bi) at energies around their Coulomb barrier are investigated. The results are compared with a new CC code CCFULL

  5. Fission cross section calculations for 209Bi target nucleus based on fission reaction models in high energy regions

    Kaplan Abdullah

    2015-01-01

    Full Text Available Implementation of projects of new generation nuclear power plants requires the solving of material science and technological issues in developing of reactor materials. Melts of heavy metals (Pb, Bi and Pb-Bi due to their nuclear and thermophysical properties, are the candidate coolants for fast reactors and accelerator-driven systems (ADS. In this study, α, γ, p, n and 3He induced fission cross section calculations for 209Bi target nucleus at high-energy regions for (α,f, (γ,f, (p,f, (n,f and (3He,f reactions have been investigated using different fission reaction models. Mamdouh Table, Sierk, Rotating Liquid Drop and Fission Path models of theoretical fission barriers of TALYS 1.6 code have been used for the fission cross section calculations. The calculated results have been compared with the experimental data taken from the EXFOR database. TALYS 1.6 Sierk model calculations exhibit generally good agreement with the experimental measurements for all reactions used in this study.

  6. Wet-chemistry method for the separation of no-carrier-added 211At/211gPo from 209Bi target irradiated by alpha-beam in cyclotron

    We present a fast and effective wet-chemistry method, used to obtain the pure alpha-emitter 211At/211gPo (T1/2 = 7.214 h/516 ms), produced by 209Bi(α,2n) reaction in NCA form. It is a selective radiochemical separation of the At radionuclides from the target and the impurities, characterized by a radionuclidic purity close to 100%, based on the dissolution and the dilution of the irradiated target in acidic medium, on the extraction with DIPE, followed by the back-extraction with NaOH. As a result, we obtain a yield greater than 90-97% in a range from 0.75M to 2.00M. (author)

  7. Multinucleon photonuclear reactions on {sup 209}Bi: Experiment and evaluation

    Belyshev, S.S.; Kurilik, A.S. [Lomonosov Moscow State University, Department of Physics, Moscow (Russian Federation); Filipescu, D.M.; Tesileanu, O. [Extreme Light Infrastructure - Nuclear Physics/Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering, Bucharest-Magurele (Romania); Gheoghe, I. [Extreme Light Infrastructure - Nuclear Physics/Horia Hulubei National Institute for R and D in Physics and Nuclear Engineering, Bucharest-Magurele (Romania); University of Bucharest, Faculty of Physics, Bucharest-Magurele (Romania); Ishkhanov, B.S. [Lomonosov Moscow State University, Department of Physics, Moscow (Russian Federation); Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow (Russian Federation); Khankin, V.V.; Kuznetsov, A.A.; Orlin, V.N.; Peskov, N.N.; Stopani, K.A.; Varlamov, V.V. [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow (Russian Federation)

    2015-06-15

    Photon activation technique using bremsstrahlug with end-point energy 55.6 MeV is used to induce photonuclear reactions in a {sup 209}Bi target. Absolute yields and integrated cross sections of multiparticle reactions (γ, 2n-6n), (γ, 4n1p), and (γ, 5n1p) are obtained. The results are compared to predictions of statistical models using systematical and microscopic description of photoabsorption and to the result of evaluation of the partial photoneutron reaction cross sections. Based on a comparison with existing experimental photoneutron cross sections and model calculations, we make a conclusion that neutron multiplicity assignment in available photoneutron cross sections on {sup 209}Bi can be corrected and evaluated cross sections of (γ, 1n) and (γ, 2n) are obtained that are in an agreement with the obtained experimental results. (orig.)

  8. Pion-Induced Fission of 209Bi and 119Sn:. Measurements, Calculations, Analyses and Comparison

    Rana, Mukhtar Ahmed; Sher, Gul; Manzoor, Shahid; Shehzad, M. I.

    Cross-sections for the π--induced fission of 209Bi and 119Sn have been measured using the most sensitive CR-39 solid-state nuclear track detector. In experiments, target-detector stacks were exposed to negative pions of energy 500, 672, 1068, and 1665 MeV at the Brookhaven National Laboratory, USA. An important aspect of the present paper is the comparison of pion-induced fission fragment spectra of above mentioned nuclei with the spontaneous fission fragment spectra of 252Cf. This comparison is made in terms of fission fragment track lengths in the CR-39 detectors. Measurement results are compared with calculations of Monte Carlo and statistical weight functions methods using the computer code CEM95. Agreement between measurements and calculations is fairly good for 209Bi target nuclei whereas it is indigent for the case of 119Sn. The possibilities of the trustworthy calculations, using the computer code CEM95, comparable with measurements of pion-induced fission in intermediate and heavy nuclei are explored by employing various systematics available in the code. Energy dependence of pion-induced fission in 119Sn and 209Bi is analyzed employing a newly defined parameter geometric-size-normalized fission cross-section (χfg). It is found that the collective nuclear excitations, which may lead to fission, become more probable for both 209Bi and 119Sn nuclei with increasing energy of negative pions from 500 to 1665 MeV.

  9. Radiationless transition probabilities in muonic 209Bi

    The probability for non-radiative (n.r.) excitations in muonic 209Bi was determined from a (μ-, γγ)-measurement by comparing the intensities of muonic X-ray transitions in single and coincidence spectra. The values of Pn.r.(3p→1s)=(17.9±2.0)% and Pn.r.(3d→1s)=(3.0±2.2)% were measured for the first time. The strength of the n.r. decay of the 2p-level was found to be (4.2±2.2)%. The n.r. transition probabilities of two subcomplexes of the (2p→1s)-transition leading to different mean excitation energies are (3.2±1.8)% and (5.0±2.0)%, respectively. (orig.)

  10. Simultaneous description of CF, ICF and TF data of 6,7Li + 209Bi reaction using new ICF mode

    The systematic behavior of the fusion suppression factors and ICF probability as a function of target mass is not well understood, despite the CF experimental data being available for a number of projectile-target systems. In our recent paper, a new method was proposed to calculate the ICF probability which is based on absorption cross sections obtained from the CDCC calculations. In continuation of this work, we have also carried out similar calculations for 6,7Li + 209Bi where the experimental data of CF and ICF is available. In the recent paper by Marta et al., the semi-classical model calculations were attempted to understand CF and ICF data for 6,7Li + 209Bi, which was not explaining the data quite well. Here, we have demonstrated the use of quantum mechanical treatment for simultaneous explanation of CF, ICF and TF over a large energy range

  11. Rotating target wheel for the FMA

    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.

  12. Evaluation and calculation of photonuclear reaction data for 209Bi below 30 MeV

    Based on available experimental data of neutron and photonuclear reaction, both neutron optical potential parameter and giant resonance parameters of gamma for 209Bi were obtained. The photonuclear reaction data for 209Bi were calculated, compared with experimental data and recommended below 30 MeV

  13. Breakup of 9Be on 209Bi above and near the Coulomb barrier as a molecular single-particle effect: Its influence on complete fusion and scattering

    The breakup of the 9Be projectile on the 209Bi target at bombarding energies above and near the Coulomb barrier is studied in the adiabatic two-center shell model approach. The effect of 9Be→n+2α breakup channel on complete fusion, elastic and inelastic cross sections is investigated. Results show that the breakup of the projectile 9Be could be due to a molecular single-particle effect shortly before the colliding nuclei reach the Coulomb barrier

  14. Determination of the {sup 209}Bi(n,{gamma}){sup 210}Bi and {sup 209}Bi(n,{gamma}){sup 210m,g}Bi reaction cross sections in a cold neutron beam

    Borella, A. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Belgya, T. [Institute of Isotope, Hungarian Academy of Sciences, POB 77, H-1525 Budapest (Hungary); Kopecky, S. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Gunsing, F. [CEA/Saclay, DSM/Irfu, F-91191 Gif-sur-Yvette (France); Moxon, M. [Hyde Copse 3, Marcham (United Kingdom); Rejmund, M. [GANIL, F-14076 Caen (France); Schillebeeckx, P., E-mail: peter.schillebeeckx@ec.europa.e [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, B-2440 Geel (Belgium); Szentmiklosi, L. [Institute of Isotope, Hungarian Academy of Sciences, POB 77, H-1525 Budapest (Hungary)

    2011-01-15

    Gamma-ray transitions following neutron capture in {sup 209}Bi have been studied at the cold neutron beam facility of the Budapest Neutron Centre. Measurements have been performed using a coaxial HPGe detector with Compton suppression. Partial capture cross sections at a velocity of 2200 m/s (or a neutron energy of 25.3 meV) have been deduced relatively to the one for the 4055 keV transition after thermal neutron capture in {sup 209}Bi. This partial cross section of (8.07 {+-} 0.14) mb has in turn been obtained from measurements with a bismuth nitrate target relatively to the cross section for the 1884 keV transition after thermal neutron capture in {sup 14}N. Shell model calculations have been performed to deduce the half-life of the 3rd excited state at 320 keV and to assign the M1 multipolarity of the 320 keV transition to the ground state. Lower limits of (21.4 {+-} 0.8) mb and (18.2 {+-} 0.7) mb for the cross sections to the ground state and to the isomeric state, respectively, have been deduced from the data for the gamma rays feeding these states. The results obtained in this work are in good agreement with experimental data reported in the literature. The thermal total capture cross section has been compared with the contribution due to observed s-wave resonances.

  15. Cross Sections of the (HI, αn) Channel in the Cold-Fusion-Type Reactions 209 Bi + 40 Ar and 208 Pb + 37 Cl

    By using an off-line radiochemistry technique, production cross sections of 240 Cm(T1/2 = 27 d) in the 209 Bi + 40 Ar and 208 Pb + 37 Cl reactions at the bombarding energy Elab ≤ 230 MeV were determined to be 0,5 ± 0,2 and 0,6 ± 0,3 n b, respectively. The production of 240 Cm was attributed to the 1 n-deexcitation channel of the composite systems 249 Md and 245 Es. The measured 240 Cm production cross sections represent upper cross section limits for the (HI, αn) channel of the reactions under study, which limits are about 100 times lower than the section values reported by Nomura et al. for the (40 Ar, αx n) channels with x = 1,2 of the 209 Bi + 40 Ar reaction at Elab208 MeV. In this connection, presented and discussed is an up-to-date summary of the available data on cross sections of the (HI, αx n) channels in the cold-fusion-type reactions induced by projectiles 37 Cl to 50 Ti on targets of 203,205 Tl, 208 Pb and 209 Bi. Appreciable E C(β+)-delayed fission effects were detected in the 209 Bi + 40 Ar and 206,208 Pb + 37 Cl reactions. In particular, our data reveal the occurrence of E C(β+)-delayed fission in the decay chains 242 Es(E C, ∼7 s) 242 Cf and 238 Bk(E C, ∼2 m) 238 Cm. 28 refs., 4 figs., 4 tabs

  16. ILC TARGET WHEEL RIM FRAGMENT/GUARD PLATE IMPACT ANALYSIS

    Hagler, L

    2008-07-17

    A positron source component is needed for the International Linear Collider Project. The leading design concept for this source is a rotating titanium alloy wheel whose spokes rotate through an intense localized magnetic field. The system is composed of an electric motor, flexible motor/drive-shaft coupling, stainless steel drive-shaft, two Plumber's Block tapered roller bearings, a titanium alloy target wheel, and electromagnet. Surrounding the target wheel and magnet is a steel frame with steel guarding plates intended to contain shrapnel in case of catastrophic wheel failure. Figure 1 is a layout of this system (guard plates not shown for clarity). This report documents the FEA analyses that were performed at LLNL to help determine, on a preliminary basis, the required guard plate thickness for three potential plate steels.

  17. Synthesis of element 113 in the reaction 209Bi(70Zn, n)278113

    The convincing candidate event of the isotope of the 113th element, were observed, for the first time, in the 209Bi+70Zn reaction at a beam energy of 349.0 MeV with a total dose of 1.7 x 1019. Alpha decay energies and decay times of the candidates, 278113, 274111, and 270Mt, were (11.68±0.04 MeV, 0.344 ms), (11.15±0.07 MeV, 9.26 ms), and (10.03±0.07 MeV, 7.16 ms), respectively. The production cross section of the isotope was deduced to be 55-45+150 fb(10-39 cm2). The experiment was performed at RIIKEN (The Institute of Physical and Chemical Research) Linear Accelerator (RILAC) Facility. The evaporation residues produced by the reaction with a 70Zn beam provided by the RILAC and the bismuth targets, were separated by a gas-filled recoil separator (GARIS) from the beam particles and the target recoils, and collected at the focus of GARIS. We observed an event of implantation of an evaporation residue in the position-sensitive semiconductor detector followed by four consecutive alpha decays terminated by a spontaneous fission decay. Assignment of the event was based on genetic correlation of sequential alpha decays to the already known nuclides 266Bh and 262Db. The fourth alpha decay and the following spontaneous fission decay were assigned to be the decays of 266Bh and 262Db, respectively because of agreements of decay energies and decay times with the reported values. As a consequence, the preceding three alpha decays were assigned to be ones of 278113, 274111, and 270Mt.

  18. High-energy neutron transport file for the 209Bi isotope

    The simulation of the nuclear processes, occurring in media irradiated with high-energy particles, promote the elaboration of high-energy transport files. These files being used in versatile computer codes, such as MCNP, allow to simulate with high accuracy particle transport. High-energy transport files are very important for the investigation of accelerator-driven systems. The detailed description of the methods and codes used for the elaboration of the file for 209Bi is presented in this paper. (orig.)

  19. Towards measurement of the 209Bi(n,γ)210m,gBi cross sections at SARAF

    The Main Incentives For This Work Is To Exploit The Large Proton Currents And High Neutron Flux Capabilities At The Soreq Applied Research Accelerator Facility (Saraf)Along Witha Liquid Lithium Target To Perform Sensitive Measurements Of Interest In Reactor Design And Safety. The First Measurement To Be Performed Is Neutron Activation Of209bi. This Measurement Is Important For Proposed Pb-Bi Eutectic Coolants For Gen Iv Reactors And For Targets For Accelerator Driven Systems (Ads). The Activity Of One Of The Reaction Products,210mbi, Is Very Difficult To Measure Because Of Long Half-Life (3 Million Years). Successful Measurements And Comparison With The Activation Of 210gbi (The 210bi Ground State) Requires High Neutron Flux And Very Sensitive Measurements. We Plan To Perform The Activation Using The 30 Kevmaxwellianlike Neutron Spectrum Produced By The 7li(P,N)7be Reaction Near Threshold. Subsequent To The Activation, The Plan Is To Measure Directly The γ-Decays From The Decay Products,206tl For The 210mbiand 206pb For The 210gbi Activation, In The Underground Laboratory Hades At Sck-Cen In Mol, Belgium.Level Diagram And Previous Measurements Of This Ratio Are Shown . This Reaction Is Also Of Significance For Nuclear Astrophysics Since It Is The End Of The Chain For S-Process For Nucleo-Synthesis In Heavy Stars, With The Maxwellianneutrons Mimicking Environment In Asymptotic Giant Branch (Agb) Stars

  20. Neutron density distributions from antiprotonic 208Pb and 209Bi atoms

    Klos, B.; Trzcinska, A.; Jastrzebski, J.; Czosnyka, T.; Kisielinski, M.; Lubinski, P.; Napiorkowski, P.; Pienkowski, L.; Hartmann, F. J.; Ketzer, B.; Ring, P.; Schmidt, R.; von Egidy, T.; Smolanczuk, R.; S. Wycech

    2007-01-01

    The X-ray cascade from antiprotonic atoms was studied for 208Pb and 209Bi. Widths and shifts of the levels due to the strong interaction were determined. Using modern antiproton-nucleus optical potentials the neutron densities in the nuclear periphery were deduced. Assuming two parameter Fermi distributions (2pF) describing the proton and neutron densities the neutron rms radii were deduced for both nuclei. The difference of neutron and proton rms radii /\\r_np equal to 0.16 +-(0.02)_{stat} +-...

  1. Lightest Isotope of Bh Produced via the 209Bi(52Cr,n)260Bh Reaction

    The lightest isotope of Bh was produced in the new 209Bi(52Cr,n)260Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. 260Bh decays with a 35-9+19 ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59-20+29 pb is compared to model predictions. The influence of the N=152 and Z=108 shells on alpha decay properties is discussed

  2. Precision laser spectroscopy of the ground state hyperfine splitting of hydrogenlike ^209 Bi^82+

    Klaft, Ingo; Borneis, Stefan; Engel, Thomas; Fricke, Burkhard; Grieser, Ralf; HUBER, GERHARD; Kühl, Thomas; Marx, Dieter; Neumann, Reinhard; Schröder, Sönke; Seelig, Peter; Völker, Lothar

    1994-01-01

    The first direct observation of a hyperfine splitting in the optical regime is reported. The wavelength of the M1 transition between the F = 4 and F = 5 hyperfine levels of the ground state of hydrogenlike ^209 Bi^82+ was measured to be \\lamda_0 = 243.87(4) nm by detection of laser induced fluorescence at the heavy-ion storage ring ESR at GSI. In addition, the lifetime of the laser excited F = 5 sublevel was determined to be \\tau_0 = 0.351(16) ms. The method can be applied to a number of othe...

  3. Study of the di-nuclear system $^{A}$Rb + $^{209}$Bi (Z$_{1}$ + Z$_{2}$ = 120)

    The exact location of the next spherical shell closures beyond Z = 82, N = 126 is still an open question. According to model predictions shell closures are expected at Z = 114 or 120 or 126 and N = 184. Also experimental data cannot yet give a definite answer. Known nuclei with Z = 114 are too neutron‐deficient with respect to the N = 184 shell and nuclei with Z = 120 and beyond are still unknown. An option for studying reactions of super-heavy systems at Z = 120 and neutron numbers up to 184 becomes possible with the use of $^{209}$Bi targets and neutron‐rich beams. By studying quasi-fission and fusion‐fission reactions, which have significantly larger production cross‐sections than the evaporation residues, a possible influence of shell closures at Z = 120, N = 184 can be explored. Well suitable for such studies will be neutron‐rich rubidium beams at energies of about 5 MeV/u delivered by the HIE‐ISOLDE facility.

  4. Exploring contributions from incomplete fusion in Li,76+209Bi and Li,76+198Pt reactions

    Parkar, V. V.; Jha, V.; Kailas, S.

    2016-08-01

    We use the breakup absorption model to simultaneously describe the measured cross sections of complete fusion (CF), incomplete fusion (ICF), and total fusion (TF) in nuclear reactions induced by weakly bound nuclei Li,76 on 209Bi and 198Pt targets. The absorption cross sections are calculated using the continuum discretized coupled channels (CDCC) method with different choices of short-range imaginary potentials to get the ICF, CF, and TF cross sections. It is observed that the cross sections for deuteron ICF / deuteron capture and α ICF / α capture are of similar magnitude, in the case of the 6Li projectile, while the cross sections for the triton ICF / triton capture is more dominant than that of α ICF / α capture in the case of the 7Li projectile. Both these observations are also corroborated by the experimental data. The ratio of ICF to TF cross sections, which defines the value of fusion suppression factor, is found to be in agreement with the data available from the literature. The cross-section ratios of CF/TF and ICF/TF show opposite behavior at below-barrier energies the former decreases while the latter increases as the energy is lowered, which shows the dominance of ICF at below-barrier energies. We have also studied the correlation of the ICF cross sections with the noncapture breakup (NCBU) cross sections as a function of energy, which shows that the NCBU is more significant than ICF at below-barrier energies.

  5. Exploring contributions from incomplete fusion in $^{6,7}$Li+$^{209}$Bi and $^{6,7}$Li+$^{198}$Pt reactions

    Parkar, V V; Kailas, S

    2016-01-01

    We use the breakup absorption model to simultaneously describe the measured cross-sections of the Complete fusion (CF), Incomplete fusion (ICF), and Total fusion (TF) in nuclear reactions induced by weakly bound nuclei $^{6,7}$Li on $^{209}$Bi and $^{198}$Pt targets. The absorption cross-sections are calculated using the Continuum Discretized Coupled Channels (CDCC) method with different choices of short range imaginary potentials to get the ICF, CF and TF cross-sections. It is observed that the cross-sections for deuteron-ICF/deuteron-capture are of similar magnitude as the $\\alpha$-ICF/$\\alpha$-capture, in case of $^{6}$Li projectile, while the cross-sections for triton-ICF/triton-capture is more dominant than $\\alpha$-ICF/$\\alpha$-capture in case of $^{7}$Li projectile. Both these observations are also corroborated by the experimental data. The ratio of ICF to TF cross-sections, which defines the value of fusion suppression factor is found to be in agreement with the data available from the literature. The...

  6. Target chamber and rotating target wheel for synthesis of superheavy elements at radioactive ion beam line of Lanzhou

    The target chamber and the rotating target wheel for synthesis of superheavy elements at Radioactive Ion Beam Line of Lanzhou (RIBLL) are described in the paper. The modified vacuum isolating magnetic coupling rotation device driven by step-motor is also shown. The rotating target wheel is composed of a programmable brushless motor, a vacuum sealing magnetic liquid feed-through and high torque-drive (HTD) strap. The rotation speed of the wheel can be turned from 0 to 600 r·min-1. The vibration of the target wheel is <0.2 mm. (authors)

  7. Measurements of high-energy neutron-induced fission ofnatPb and 209Bi

    Couture A.

    2010-10-01

    Full Text Available The CERN Neutron Time-Of-Flight (n_TOF facility is well suited to measure low cross sections as those of neutron-induced fission in subactinides. The cross section ratios of natPb and 209Bi relative to 235U and 238U were measured using PPAC detectors and a fragment coincidence method that allows us to identify the fission events. The present experiment provides first results for neutron-induced fission up to 1 GeV. Good agreement is found with previous experimental data below 200 MeV. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross sections is close to 1 GeV.

  8. Energy dependence of the optical potentials for the 9Be +208Pb and 9Be +209Bi systems at near-Coulomb-barrier energies

    Gómez Camacho, A.; Yu, N.; Zhang, H. Q.; Gomes, P. R. S.; Jia, H. M.; Lubian, J.; Lin, C. J.

    2015-04-01

    We analyze the energy dependence of the interacting optical potential, at near barrier energies, for two systems involving the weakly bound projectile 9Be and the heavy 208Pb and 209Bi targets, by the simultaneous fit of elastic scattering angular distributions and fusion excitation functions. The approach used consists of dividing the optical potential into two parts. A short-range potential VF+i WF that is responsible for fusion, and a superficial potential VDR+i WDR for direct reactions. It is found, for both systems studied, that the fusion imaginary potential WF presents the usual threshold anomaly (TA) observed in tightly bound systems, whereas the direct reaction imaginary potential WDR shows a breakup threshold anomaly (BTA) behavior. Both potentials satisfy the dispersion relation. The direct reaction polarization potential predominates over the fusion potential and so a net overall behavior is found to follow the BTA phenomenon.

  9. Analysis of 209 Bi and 238 U photofission cross section in the quasi-deuteron region of photonuclear absorption

    An analysis of the photofission reactions in the quasi-deuteron energy range of photonuclear absorption (∼ 30-140 MeV) has been performed for 209 Bi and 238 U nuclei. Experimental cross section data available in the literature have been compared with calculated values obtained from a model in which the incoming photon is assumed to be absorbed by a neutron-proton pair (Levinger's quasi-deuteron photoabsorption), followed by a mechanism of evaporation-fission competition for the excited residual nuclei. The model has been shown to reproduce the main experimental features of 209 Bi and 238 U photofission cross section, although unexplained differences still remain in the case of 238 U-fission by 30-50 MeV incident photons. (author). 49 refs, 10 figs, 2 tabs

  10. Fission fragment angular distributions in proton-induced fission of 209 Bi(p,t) and 197 Au(p,f)

    De, S S; N H; M. L.

    2001-01-01

      The fission fragment angular distributions have been measured for proton-induced fission of 209Bi and 197Au nuclei using surface barrier detectors at several energies between 25 MeV and 30 MeV. The experimental anisotropies are found to be in agreement with the predictions of the Standard Saddle-Point Statistical Model (SSPSM). The fission cross sections of 209Bi 197Au nuclei were also measured and compared with the previous works.

  11. Fission fragment angular distributions in proton-induced fission of 209 Bi(p,t and 197 Au(p,f

    S. S.

    2001-12-01

    Full Text Available   The fission fragment angular distributions have been measured for proton-induced fission of 209Bi and 197Au nuclei using surface barrier detectors at several energies between 25 MeV and 30 MeV. The experimental anisotropies are found to be in agreement with the predictions of the Standard Saddle-Point Statistical Model (SSPSM. The fission cross sections of 209Bi 197Au nuclei were also measured and compared with the previous works.

  12. Life time of the HFS transition in Li-like {sup 209}Bi{sup 80+}

    Geppert, C.; Noertershaeuser, W. [Institut fuer Kernchemie, Uni Mainz (Germany); GSI, Darmstadt (Germany); Hannen, V.; Joehren, R.; Ortjohann, H.W.; Vollbrecht, J.; Weinheimer, C. [Institut fuer Kernphysik, Uni Muenster (Germany); Kuehl, T. [Institut fuer Kernchemie, Uni Mainz (Germany); GSI, Darmstadt (Germany); Helmholtz Institut Jena (Germany); S' anchez, R.; Winters, D. [GSI, Darmstadt (Germany); Stoehlker, T. [Institut fuer Kernchemie, Uni Mainz (Germany); GSI, Darmstadt (Germany); Helmholtz Institut Jena (Germany); Uni Jena (Germany)

    2014-07-01

    Measuring the hyperfine splitting of heavy, highly charged ions enables tests of QED in strong fields. HFS calculations have a relative uncertainty of more than 10{sup -3} due to the distribution of the magnetic moment (Bohr-Weisskopf-Effekt). With an appropriate comparison of H- and Li-like ions this nuclear structure contribution can be suppressed. Bismuth is a suitable element for these studies, as the HFS splitting for both configurations are in a wavelength range suitable for laser spectroscopy. For this purpose the two ion species were stored in the Experimental Storage Ring at GSI at a velocity of β = 0.71. To efficiently collect the forward emitted photons a specially developed movable detector system was used. Thereby the HFS of Li-like {sup 209}Bi{sup 80+} was successfully measured for the first time. Besides the determination of the transition energy it was possible to extract the lifetime of the transition out of the collected data. The corresponding analysis and the results are presented on this poster.

  13. Life time of the HFS transition in Li-like 209Bi80+

    Measuring the hyperfine splitting of heavy, highly charged ions enables tests of QED in strong fields. HFS calculations have a relative uncertainty of more than 10-3 due to the distribution of the magnetic moment (Bohr-Weisskopf-Effekt). With an appropriate comparison of H- and Li-like ions this nuclear structure contribution can be suppressed. Bismuth is a suitable element for these studies, as the HFS splitting for both configurations are in a wavelength range suitable for laser spectroscopy. For this purpose the two ion species were stored in the Experimental Storage Ring at GSI at a velocity of β = 0.71. To efficiently collect the forward emitted photons a specially developed movable detector system was used. Thereby the HFS of Li-like 209Bi80+ was successfully measured for the first time. Besides the determination of the transition energy it was possible to extract the lifetime of the transition out of the collected data. The corresponding analysis and the results are presented on this poster.

  14. Real-time Non-linear Target Tracking Control of Wheeled Mobile Robots

    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.

  15. Excitation functions of residual nuclei production from 40–2600 MeV proton-irradiated 206,207,208,natPb and 209Bi

    Yu E Titarenko; V F Batyaev; V M Zhivun; V O Kudryashov; K A Lipatov; A V Ignatyuk; S G Mashnik

    2007-02-01

    The work is aimed at experimental determination of the independent and cumulative yields of radioactive residual nuclei produced in intermediate-energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb) and 209Bi. 5972 radioactive product nuclide yields have been measured in 55 thin targets induced by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6 and 2.6 GeV protons extracted from the ITEP U-10 proton synchrotron. The measured data have been compared with data obtained at other laboratories as well as with theoretical simulations by seven codes. We found that the predictive power of the tested codes is different but is satisfactory for most of the nuclides in the spallation region, though none of the codes agree well with the data in the whole mass region of product nuclides and all should be improved further.

  16. Measurement of cross sections of the 210Po production reaction by keV-neutron capture of 209Bi

    The cross sections of the 209Bi(n, γ)210gBi reaction were measured in the keV-neutron region, using an activation method with the detection of α rays from 210Po. Pulsed keV neutrons were generated from the 7Li(p, n)7Be reaction by a 1.5-ns bunched proton beam from the 3-MV Pelletron accelerator of the Research Laboratory for Nuclear Reactors at the Tokyo Institute of Technology. The 209Bi samples were metallic bismuth evaporated on a gold backing. After sample irradiation, the 412-keV γrays from the gold backing were measured with on HPGe detector, and then the α rays from 210Po nuclei in the bismuth sample were measured with a Si surface barrier detector. The derived cross sections were 1.9±0.4 mb and 0.62±0.14 mb at the average neutron energies of 30 keV and 534 keV, respectively. The present value at 30 keV is in agreement with the previous measurement at 24 keV of Booth et al., but about a quarter of the evaluation of JENDL Activation cross section File. The present result at 534 keV is the first experimental one around 500 keV, and is about a half of the evaluation of JENDL Activation cross section File. (author)

  17. Fission Cross Sections of {209}Bi, {232}Th, {235}U, {238}U and {237}Np for Intermediate Energy Protons and Deuterons

    Yurevich, V I; Yakovlev, R M; Sosnin, A N

    2001-01-01

    Fission cross sections of {209}Bi, {232}Th, {235}U, {238}U and {237}Np have been measured with 1.0-3.7 GeV protons and 1.0 GeV deuterons. The results are compared with other experimental data, available evaluations and predictions of the theoretical model.

  18. Modes of transference and rupture of the nucleus with neutron halos 6 He on 209 Bi near of the Coulomb barrier

    In recent experiments, the fusion of the exotic radioactive nucleus 6 He with 209 Bi has been studied for the first time at energies above and below the Coulomb barrier. A considerable enhancement in the fusion was observed, which implies a reduction of about 25% in the nominal fusion barrier. Some previous theoretical works suggest that this striking effect may be caused by the coupling to neutron transfer channels with a positive Q-value which would lead to a neutron flow and the consequent formation of a neck between the projectile and the target. Later, in the current work, we ran two new experiments on the same reaction using the FN Tandem Van de Graaff (10 MV) accelerator and the dual superconducting TwinSol system, both of them belonging to the University of Notre Dame, USA. This time, the purpose was to study one- and two-neutron transfer and the 6 He projectile breakup at laboratory energies of 14.7, 16.2, 17.9, 19.0 and 22.5 MeV. A strong group of 4 He was observed (with an effective Q-value about .5 MeV) whose integrated cross section results exceptionally high, exceeding the fusion cross section both above and below the barrier. The simultaneously measured elastic scattering angular distribution required high total cross sections so that this yield is confirmed. Preliminary coupled channels calculations sing the computer program called Fresco developed at the University of Surrey (England) suggested that the reaction mechanisms may be better described as a direct nuclear breakup and two-neutron transfer to unbound states in 211 Bi. These calculations predicted also an enhancement in the fusion cross section below the barrier due to the transfer and breakup channel coupling, which strongly suggests that this channel is the 'doorway state' that explains the fusion barrier reduction observed in previous experiments. It was found that the 4 He group fully dominates the total reaction cross section at the measured energies and we show evidence that a new

  19. Lightest Isotope of Bh Produced Via the 209Bi(52Cr,n)260BhReaction

    Nelson, Sarah L.; Gregorich, Kenneth E.; Dragojevic, Irena; Garcia, Mitch A.; Gates, Jacklyn M.; Sudowe, Ralf; Nitsche, Heino

    2007-05-07

    The lightest isotope of Bh known was produced in the new {sup 209}Bi({sup 52}Cr,n){sup 260}Bh reaction at the Lawrence Berkeley National Laboratory's 88-Inch Cyclotron. Positive identification was made by observation of eight correlated alpha particle decay chains in the focal plane detector of the Berkeley Gas-Filled Separator. {sup 260}Bh decays with a 35{sub -9}{sup +19} ms half-life by alpha particle emission mainly by a group at 10.16 MeV. The measured cross section of 59{sub -20}{sup +29} pb is approximately a factor of four larger than compared to recent model predictions. The influences of the N = 152 and Z = 108 shells on alpha decay properties are discussed.

  20. Complete and incomplete fusion cross sections for 6Li+209Bi reaction in multi-body classical molecular dynamical model

    Using the multi-body Classical Molecular Dynamics simulation of 6Li+209Bi reaction it is shown that: (i) the breakup of a projectile fragment near the barrier leads to substantial increase in the ICF probabilities; (ii) the expected increase in σCF on relaxation of the rigid-body (RB) constraint on the projectile is compensated by reduction in the flux leading to CF, due to ICF events; (iii) the breakup probability increases with ECM and, for given ECM it also increases as b increases and peaks around some b>0, while cross sections σCF and σTF were calculated for b=0 only Therefore, we present the results of σCF (Complete Fusion) and σTF (Total Fusion) calculations which are obtained at critical impact parameter, bcr, where many ICF channels open up and compare with the calculations performed at b=0 only, where only few ICF channels open up

  1. Study of viscosity on the fission dynamics of the excited nuclei 228U produced in 19F + 209Bi reactions

    A two-dimensional (2D) dynamical model based on Langevin equations was applied to study the fission dynamics of the compound nuclei 228U produced in 19F + 209Bi reactions at intermediate excitation energies. The distance between the centers of masses of the future fission fragments was used as the first dimension and the projection of the total spin of the compound nucleus onto the symmetry axis, K, was considered as the second dimension in Langevin dynamical calculations. The magnitude of post-saddle friction strength was inferred by fitting measured data on the average pre-scission neutron multiplicity for 228U. It was shown that the results of calculations are in good agreement with the experimental data by using values of the post-saddle friction equal to 6–8 × 1021s-1. (author)

  2. Extended optical model analyses for the 11B+209Bi system at near-Coulomb-barrier energies

    In the framework of an extended optical model approach in which the polarization potential is decomposed into direct-reaction (DR) and fusion parts, simultaneous χ2 analyses of elastic scattering and fusion cross-section data for the 11B+209Bi system at near-Coulomb-barrier energies are performed. We show that the DR and fusion potentials extracted from χ2 analyses separately satisfy the dispersion relation and that the threshold anomaly exhibits in both DR and fusion parts. We find that the analyses using only elastic scattering and fusion data can produce reliable predictions of cross-sections even though the direct reaction cross-section data are not complete. By using the extracted DR potential, we investigate the effects of the projectile breakup on fusion cross-sections. (orig.)

  3. Calculations of Branching Ratios for Radiative-Capture, One-Proton, and Two-Neutron Channels in the Fusion Reaction $^{209}$Bi+$^{70}$Zn

    Ichikawa, Takatoshi; 10.1143/JPSJ.79.074201

    2010-01-01

    We discuss the possibility of the non-one-neutron emission channels in the cold fusion reaction $^{70}$Zn + $^{209}$Bi to produce the element Z=113. For this purpose, we calculate the evaporation-residue cross sections of one-proton, radiative-capture, and two-neutron emissions relative to the one-neutron emission in the reaction $^{70}$Zn + $^{209}$Bi. To estimate the upper bounds of those quantities, we vary model parameters in the calculations, such as the level-density parameter and the height of the fission barrier. We conclude that the highest possibility is for the 2n reaction channel, and its upper bounds are 2.4$%$ and at most less than 7.9% with unrealistic parameter values, under the actual experimental conditions of [J. Phys. Soc. Jpn. {\\bf 73} (2004) 2593].

  4. Interaction at the barrier in the systems 9,10,11Be+209Bi: Well-established facts and open questions

    The experimental data relative to the interaction for the systems 9,10,11Be+209Bi at the Coulomb barrier are critically discussed and compared also with present theories. The break-up (BU) of the two loosely bound projectiles, 9,11Be, seems to influence the fusion process by ''hindering'' the fusion cross-sections; but, contrary to expectations, the 11Be halo structure has no influence, since no ''enhancement'' is evident from the existing data. Attempt to describe simultaneously all the 9Be+209Bi system data: fusion, elastic scattering and BU, within a coupled-channel (CC) approach is only partly successful. It is important, from a theoretical viewpoint, to include in the CC formalism as well as possible the BU process both to continuum states as well as to unbound resonances. More accurate and well-focused experiments are also necessary to pin down this problem. (orig.)

  5. Calculations of branching ratios for radiative-capture, one-proton, and two-neutron channels in the fusion reaction 209Bi+70Zn

    We discuss the possibility of the non-one-neutron emission channels in the cold fusion reaction 70Zn+209Bi to produce the element Z=113. For this purpose, we calculate the evaporation-residue cross sections of one-proton, radiative-capture, and two-neutron emissions relative to the one-neutron emission in the reaction 70Zn+209Bi. To estimate the upper bounds of those quantities, we vary model parameters in the calculations, such as the level-density parameter and the height of the fission barrier. We conclude that the highest possibility is for the 2n reaction channel, and its upper bounds are 2.4% and at most less than 7.9% with unrealistic parameter values, under the actual experimental conditions of [J.Phys.Soc.Jpn.73(2004)2593]. (author)

  6. Modes of transference and rupture of the nucleus with neutron halos {sup 6} He on {sup 209} Bi near of the Coulomb barrier; Modos de transferencia y rompimiento del nucleo con halo neutronico {sup 6} He sobre {sup 209} Bi cerca de la barrera de Coulomb

    Lizcano C, D

    2003-07-01

    In recent experiments, the fusion of the exotic radioactive nucleus {sup 6} He with {sup 209} Bi has been studied for the first time at energies above and below the Coulomb barrier. A considerable enhancement in the fusion was observed, which implies a reduction of about 25% in the nominal fusion barrier. Some previous theoretical works suggest that this striking effect may be caused by the coupling to neutron transfer channels with a positive Q-value which would lead to a neutron flow and the consequent formation of a neck between the projectile and the target. Later, in the current work, we ran two new experiments on the same reaction using the FN Tandem Van de Graaff (10 MV) accelerator and the dual superconducting TwinSol system, both of them belonging to the University of Notre Dame, USA. This time, the purpose was to study one- and two-neutron transfer and the {sup 6} He projectile breakup at laboratory energies of 14.7, 16.2, 17.9, 19.0 and 22.5 MeV. A strong group of {sup 4} He was observed (with an effective Q-value about .5 MeV) whose integrated cross section results exceptionally high, exceeding the fusion cross section both above and below the barrier. The simultaneously measured elastic scattering angular distribution required high total cross sections so that this yield is confirmed. Preliminary coupled channels calculations sing the computer program called Fresco developed at the University of Surrey (England) suggested that the reaction mechanisms may be better described as a direct nuclear breakup and two-neutron transfer to unbound states in {sup 211} Bi. These calculations predicted also an enhancement in the fusion cross section below the barrier due to the transfer and breakup channel coupling, which strongly suggests that this channel is the 'doorway state' that explains the fusion barrier reduction observed in previous experiments. It was found that the {sup 4} He group fully dominates the total reaction cross section at the

  7. Calculation of neutron cross sections for 90Zr, 208Pb and 209Bi in the energy range of 0.5-25 MeV by using the optical model potentials

    Neutron total cross sections and differential elastic scattering cross sections for the nuclides 90Zr, 208Pb and 209Bi were calculated using different global spherical optical potential (SOP) parameter sets at neutron energies from 0.5-25 MeV. Calculated cross sections for the corresponding nuclides were compared with their experimental data obtained by the EXFOR file to select the best fit parameter sets. It is found that the parameter sets of Ferer Rapaport for 90Zr and Bechetti and Greenless for 208Pb and 209Bi are the best fitted set to obtain the experimental data of total cross sections and angular distributions of these nuclides. (author)

  8. The damping of the single-particle proton strengths in 1isub(11/2) and 1jsub(15/2) states of 209Bi

    15 proton states have been mixed with the low-lying vibrational states as well as the vibrational states arising from the giant resonances in 208Pb to search for the broad fragmentations of the 1 'one' j15/2 and 'one' i11/2 states as observed in the most recent (α,t) reaction on 208Pb. The distribution of the shell-model strengths of these two high-spin states can be explained on the basis of the core polarisation effect on these two proton states of 209Bi. Knowledge of the altered shell-model energies of the proton states of 208Pb is necessary for the search for magicity in the superheavy nuclei. (author)

  9. Neutron-induced fission cross section of (nat)Pb and (209)Bi from threshold to 1 GeV: An improved parametrization

    Tarrio, D; Audouin, L; Berthier, B; Duran, I; Ferrant, L; Isaev, S; Le Naour, C; Paradela, C; Stephan, C; Trubert, D; Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Badurek, G; Baumann, P; Becvar, F; Belloni, F; Berthoumieux, E; Calvino, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapico, C; Carrillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Eleftheriadis, C; Embid-Segura, M; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Koelbl, H; Fujii, K; Furman, W; Goncalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Kadi, Y; Kappeler, F; Karadimos, D; Karamanis, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lederer, C; Lindote, A; Lopes, I; Losito, R; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Martinez, T; Massimi, C; Mastinu, P; Mendoza, E; Mengoni, A; Milazzo, P.M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M.T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Sarmento, R; Savvidis, I; Tagliente, G; Tain, J.L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross sections for (nat)Pb and (209)Bi were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n\\_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to (235)U and (238)U in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range.

  10. Comparison of reactions for the production of 258,257Db: 208Pb(51V,xn) and 209Bi(50Ti,xn)

    Gates, Jacklyn M.

    2008-01-01

    Excitation functions for the 1n and 2n exit channels of the 208Pb(51V,xn)259-xDb reaction were measured. A maximum cross section of the 1n exit channel of 2070+1100/-760 pb was measured at an excitation energy of 16.0 +- 1.8 MeV. For the 2n exit channel, a maximum cross section of 1660+450/-370 pb was measured at 22.0 +- 1.8 MeV excitation energy. The 1n excitation function for the 209Bi(50Ti,n)258Db reaction was remeasured, resulting in a cross section of 5480+1750/-1370 pb at an excitati...

  11. Word wheels

    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.

  12. Determination of the neutron resonance parameters for 206Pb and of the thermal neutron capture cross section for 206Pb and 209Bi

    Chapter 1 describes the motivation of the measurements (accelerator driven systems, stellar nucleosynthesis, neutron induced reactions on 206Pb), the present status of the neutron capture data for 206Pb and 209Bi and the structure of this work. In Chapter 2 the basic reaction theory underlying this work is described. The neutron induced reaction mechanism and formalism are explained. The parameterisation of the cross section in terms of R-matrix theory is discussed and we put particular emphasis on the statistical behaviour of the resonance parameters and the impact of the angular distribution of gamma rays following neutron capture. The relation between experimental observables and the resonance parameters is discussed together with general comments related to resonance shape analysis. Chapter 3 is focused on the determination of resonance parameters for 206Pb. We performed high-resolution transmission and capture measurements at the Time-Of-Flight (TOF) facility GELINA of the IRMM at Geel (B) and determined the resonance parameters. For nuclei like 206Pb, where the total width is dominated by Γn, the capture area allows to determine G. Transmission measurements were carried out to determine Γn, and the statistical factor g of resonances. Before performing a Resonance Shape Analysis (RSA) on the transmission and capture data, we verified the neutron flux and resolution at GELINA. We also compared the characteristics of GELINA with those of the n-TOF facility at CERN. A special emphasis is placed on the total energy detection technique using C6D6 detectors. This technique was applied for the determination of the capture cross section. To reduce systematic bias effects on the capture cross section, the response of the detectors was determined by Monte Carlo simulations, which has been validated by experiments. Using these response functions the partial capture cross sections for individual resonances of 206Pb have been deduced, by unfolding the response of the C6D

  13. A new evaluation of neutron data for the 209Bi between 10-5 eV and 20 MeV

    A new evaluation of neutron induced cross-sections on 209Bi has been completed within the full energy range 10-5 eV - 20 MeV and put under ENDF format. A careful study of the resonance region led to a consistent set of resonance parameters. On this basis, the tabulated cross-sections (total, elastic, capture) have been calculated using the Reich-Moore formalism. At higher energies a consistent set of optical model parameters has been obtained by fitting mainly the total cross-section between 0.7 and 150 MeV and elastic scattering angular distributions from 4 to 24 MeV. The so obtained neutron penetrabilities have been used for Hauser-Feshbach statistical model calculations which have been completed with pre-equilibrium and direct interaction components to get elastic and inelastic cross sections, angular distributions, secondary neutron spectra and gamma production. All the results are generally in good agreement with the available experimental data

  14. Fission of 209Bi, natPb and 197Au in the particle field of a fast accelerator driven system

    Highlights: ► Fission rates of Bi, Pb and Au were measured in a particle field similar to that of fast ADS. ► The experimental results on fission rates are in agreement with MCNPX calculations. ► The most up to date fission cross-sections and related parameterizations were used. ► New parameterizations were produced from the published cross-section data. - Abstract: Accelerator driven systems (ADS) are expected to have particle spectra of significantly greater energy range than that of current power reactors. The Energy plus Transmutation (EpT) set-up of the Joint Institute for Nuclear Research, Dubna, Russia, is designed to emulate the neutron spectrum in a fast ADS through the use of a spallation target surrounded by a blanket of natural uranium. The spectrum is further modified by a reflective layer of polyethylene and an internal absorbing layer of cadmium. The spallation target of EpT was irradiated with a beam of 4 GeV deuterons, and the fission rates of bismuth, lead and gold samples, placed in the target-blanket region were recorded using a fission track detector technique. The fission rates were also calculated using the MCNPX Monte Carlo code with the INCL4 cascade model and cross sections for nucleon induced fission obtained from literature. Agreement between the measured and calculated results indicates the model’s ability to predict the particle spectra and spatial distribution

  15. Residual nuclide formation in 206,207,208,natPb and 209Bi induced by 0.04 - 2.6 GeV protons as well as in 56Fe induced by 0.3 - 2.6 GeV protons

    This work is aimed at experimental determination of independent and cumulative yields of radioactive residual product nuclei in the intermediate energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb), bismuth (209Bi), and highly isotopic enriched iron (56Fe). 5972 independent and cumulative yields of radioactive residuals nuclei have been measured in 55 thin Pb and Bi targets irradiated by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV protons. Besides, 219 yields have been measured in 0.3, 0.5, 0.75, 1.0, 1.5, and 2.6 GeV proton-irradiated Fe target. In both cases, the protons were extracted from the ITEP U-10 synchrotron. The measured data are compared with experimental results obtained elsewhere and with theoretical calculations by seven codes. The predictive power was found to be different for each of the codes tested, but was satisfactory on the whole in the case of spallation products. At the same time, none of the codes can describe well the product yields throughout the whole product mass range, and all codes must be further improved. (authors)

  16. Q- and Z-dependence of angular momentum transfer in deeply inelastic collisions of 86Kr with 209Bi

    The dependence of the in-plane and out-of-plane angular correlations of fragments from fissioning heavy products on the kinetic energy and Z of the light reaction partner have been measured. From the dependence of the angular correlations on Q-value and hence energy loss, together with existing data from which the total angular-integrated cross section as a function of energy loss can be extracted, the dependence of the angular momentum transferred to the heavy product on the initial orbital angular momentum or impact parameter has been determined. The resulting dependence is qualitatively consistent with the sticking limit for a reaction intermediate of touching deformed fragments. More specific nuclear models generally underestimate the angular momentum transfer, although the one-body proximity-friction model accounts for the major fraction of the angular momentum transfer. A recent model incorporating both one-body proximity friction and collective excitations accounts quite well for the observed angular momentum transfer. The Z-dependence of the anisotropy shows the importance of angular momentum fractionation for the less probable events, where the Z of the fissioning system is appreciably less than that of the target. The transferred angular momentum is shown to be fairly strongly aligned along the perpendicular to the reaction plane, with alignment values of 0.6 to 0.8. The component of angular momentum not along the perpendicular to the reaction plane is found to be primarily oriented perpendicular rather than parallel to the recoil directions. The absolute fission probabilities are found to be qualitatively consistent with J-dependent calculations using the J-values deduced from the angular correlations. (Auth.)

  17. Measurements of Neutron-Induced Fission Cross Sections of 205Tl, 204, 206, 207, 208Pb, and 209Bi using Quasi-Monoenergetic Neutrons in the Energy Range 35 - 174 MeV

    Tutin, Gennady A.; Ryzhov, Igor V.; Eismont, Vilen P.; Mitryukhin, Andrey G.; Oplavin, Valery S.; Soloviev, Sergey M.; Blomgren, Jan; Condè, Henri; Olsson, Nils; Renberg, Per-Ulf

    2005-05-01

    Cross sections for neutron-induced fission of 205Tl, 204, 206, 207, 208Pb, and 209Bi were measured in the energy range from 35 MeV to 174 MeV. The experiments were done at the neutron beam facility of The Svedberg Laboratory, using a multi-section Frisch-gridded ionization chamber for detection of the fission fragments. The neutron-induced fission cross section of 238U was employed as a reference. The results of the measurements are compared with existing experimental data.

  18. Measurements of neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi with a multi-section Frisch-gridded ionization chamber

    Ryzhov, I. V.; Tutin, G. A.; Mitryukhin, A. G.; Oplavin, V. S.; Soloviev, S. M.; Blomgren, J.; Renberg, P.-U.; Meulders, J. P.; El Masri, Y.; Keutgen, Th.; Prieels, R.; Nolte, R.

    2006-06-01

    Neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi have been measured in the energy range from 30 to 180 MeV. The measurements were performed with quasi-monoenergetic neutron beams using a multi-section Frisch-gridded ionization chamber. The neutron-induced fission cross-sections of 238U were used as reference data. The experimental techniques are described in detail as well as the data processing. The results are compared with existing experimental data.

  19. Measurements of neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi with a multi-section Frisch-gridded ionization chamber

    Neutron-induced fission cross-sections of 205Tl, 204,206,207,208Pb and 209Bi have been measured in the energy range from 30 to 180 MeV. The measurements were performed with quasi-monoenergetic neutron beams using a multi-section Frisch-gridded ionization chamber. The neutron-induced fission cross-sections of 238U were used as reference data. The experimental techniques are described in detail as well as the data processing. The results are compared with existing experimental data

  20. Preparation of targets for the gas-filled recoil separator TASCA by electrochemical deposition and design of the TASCA target wheel assembly

    The Transactinide Separator and Chemistry Apparatus (TASCA) is a recoil separator with maximized transmission designed for performing advanced chemical studies as well as nuclear reaction and structure investigations of the transactinide elements (Z>103) on a one-atom-at-a-time basis. TASCA will provide a very clean transactinide fraction with negligible contamination of lighter elements from nuclear side reactions in the target. For TASCA a new target chamber was designed and built at GSI including the rotating target wheel assembly ARTESIA for beam intensities up to 2 μA (particle). For the production of longer-lived isotopes of neutron-rich heavier actinide and transactinide elements, hot fusion reactions with actinide targets are required. Here, possible target materials range from thorium up to curium or even heavier elements. For the deposition of lanthanide and actinide elements on thin aluminum and titanium backings by means of Molecular Plating (MP), a new deposition cell has been constructed that allows precise temperature control of the organic solvent and stirring of the solution. The electrode geometry ensures homogeneity of the electric field inside the cell. With the new set-up, holmium and gadolinium layers (500 μg/cm2) on 2-5 μm thin titanium backings have been produced with deposition yields of the order of 90%. Systematic investigations are under way to further optimize the deposition conditions for other lanthanide and actinide elements including uranium and plutonium on different backing materials

  1. Asymptotic and near-target direct breakup of 6Li and 7Li

    Kalkal, Sunil; Simpson, E. C.; Luong, D. H.; Cook, K. J.; Dasgupta, M.; Hinde, D. J.; Carter, I. P.; Jeung, D. Y.; Mohanto, G.; Palshetkar, C. S.; Prasad, E.; Rafferty, D. C.; Simenel, C.; Vo-Phuoc, K.; Williams, E.; Gasques, L. R.; Gomes, P. R. S.; Linares, R.

    2016-04-01

    Background: Li,76 and 9Be are weakly bound against breakup into their cluster constituents. Breakup location is important for determining the role of breakup in above-barrier complete fusion suppression. Recent works have pointed out that experimental observables can be used to separate near-target and asymptotic breakup. Purpose: Our purpose is to distinguish near-target and asymptotic direct breakup of Li,76 in reactions with nuclei in different mass regions. Method: Charged particle coincidence measurements are carried out with pulsed Li,76 beams on 58Ni and 64Zn targets at sub-barrier energies and compared with previous measurements using 208Pb and 209Bi targets. A detector array providing a large angular coverage is used, along with time-of-flight information to give definitive particle identification of the direct breakup fragments. Results: In interactions of 6Li with 58Ni and 64Zn, direct breakup occurs only asymptotically far away from the target. However, in interactions with 208Pb and 209Bi, near-target breakup occurs in addition to asymptotic breakup. Direct breakup of 7Li into α -t is not observed in interactions with 58Ni and 64Zn. However, near-target dominated direct breakup was observed in measurements with 208Pb and 209Bi. A modified version of the Monte Carlo classical trajectory model code platypus, which explicitly takes into account lifetimes associated with unbound states, is used to simulate sub-barrier breakup reactions. Conclusions: Near-target breakup in interactions with Li,76 is an important mechanism only for the heavy targets 208Pb and 209Bi. There is insignificant near-target direct breakup of 6Li and no direct breakup of 7Li in reactions with 58Ni and 64Zn. Therefore, direct breakup is unlikely to suppress the above-barrier fusion cross section in reactions of Li,76 with 58Ni and 64Zn nuclei.

  2. Complete and incomplete fusion competition in 11B-induced fission reaction on medium mass targets at intermediate energies

    Demekhina, N. A.; Karapetyan, G. S.; Balabekyan, A. R.

    2014-01-01

    The cross sections for the binary fission of 197Au, 181Ta and 209Bi targets induced by 11B ions were measured at intermediate energies. The fission products cross sections were studied by means of activation analysis in off-line regime observed gamma-ray spectra. The fission cross section is reconstructed on the basis of charge and mass distribution of the fission products.

  3. Running Wheel for Earthworms

    Wilson, W. Jeffrey; Johnson, Brandon A.

    2016-01-01

    We describe the construction and use of a running wheel responsive to the movement of the earthworm. The wheel employs readily available, inexpensive components and is easily constructed. Movement of the wheel can be monitored visually or via standard behavioral laboratory computer interfaces. Examples of data are presented, and possibilities for use in the teaching classroom are discussed.

  4. Reinventing the Wheel

    Kim, Mihyeon; Bland, Lori C.; Chandler, Kimberley

    2009-01-01

    "The Wheel of Scientific Investigation and Reasoning" (Kramer 1987; Paul and Binker 1992) is a graphic representation of the scientific investigative process. The scientific process is depicted in a wheel rather than in a list because "the process of scientific inquiry can begin from any stage, and that stage may be revisited as often as the…

  5. The Reaction Wheel Pendulum

    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

  6. Wheeled hopping robot

    Fischer, Gary J.

    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.

  7. Target Object Tracking and Grasping of Wheeled Mobile Robot Equipped with the Manipulator%配置机械手的轮式移动机器人目标物体跟踪与抓取

    张和平; 段锁林; 姜小娟

    2011-01-01

    For the problem of target object recognition, tracking and grabbing of wheeled mobile robot e-quipped with the manipulator, this paper adopted a object recognition and robot localization method , also used a wheeled mobile robot visual servo tracking control method based on fuzzy control. For the process of robot target tracking and grabbing, which is influenced by environmental change, the image processing method of HIS color model and the threshold-based segmentation are used so that the robot can rapidly recognize the target color object. According to the robot target positioning method based on the PTZ camera's angle information and fuzzy control theory, a fuzzy controller is designed to output the appropriate line speed and angle velocity, and realize the robot tracking target. At the same time the robot moves closely to the target object and grabs it. Simulation and real-time experimental results show that the designed system has a good ability to recognize, track and grab the target object accurately.%针对配置机械手的室内轮式移动机器人目标物体识别、跟踪和抓取问题,采用一种目标物体识别和机器人定位的方法,利用一种基于模糊控制的轮式移动机器人视觉伺服跟踪控制的方法.针对机器人目标识别跟踪及抓取过程中受环境条件变化的影响,采用HSI颜色模型和基于阈值的区域分割的图像处理方法可以完成目标颜色物体的快速准确识别.基于云台摄像机角度信息的机器人小车目标定位方法和模糊控制理论,设计了模糊跟踪控制器,使机器人输出合适的线速度和角速度,能够实现机器人目标跟踪,使移动机器人趋近目标物体位置,并完成机械手目标物体抓取任务.仿真和实时实验结果表明:所设计的系统具有良好的目标物体识别、跟踪和准确抓取目标的能力.

  8. Wheel Electrometer System

    Calle, Carlos I.; Buehler, Martin G.; Mantovani, James G.; Buhler, Charles; Nomicki, Andrew

    2005-01-01

    Two documents describe a prototype system of electrometers for measuring electrostatic fields and electrostatic responses of soils on Mars and the Moon. The electrodes of this electrometer are embedded in a wheel of an exploratory robotic vehicle, utilizing the wheel motion to bring the electrodes into proximity or contact with the soil. Each electrode resides in one of two types of sensor modules: electric-field (ELF) or triboelectric (TRIBO). In either type, what is measured is simply the electric charge induced on the electrode by exposure to the external distribution of electrostatic charge. In an ELF module, the electrode is bare and recessed radially from the wheel surface. The ELF sensor provides a measure of the charge on a small patch of undisturbed soil as the wheel rolls forward. In a TRIBO module, the electrode is only slightly recessed and covered with a polymeric insulator flush with the wheel surface. Through contact electrification, the insulator exchanges charge with the soil. There are five TRIBO sensors, each containing an insulator made of a different polymer. The charge data gathered by the five TRIBO sensors can be used to determine how the soil fits into a triboelectric series.

  9. The prospects for retail wheeling

    This paper as published is an outline of a presentation on retail wheeling of electric power. The topics discussed are development of increased wholesale transmission access, government regulatory policies on wholesale transmission, examples of past and present retail transmission access agreements, examples of Federal Energy Regulatory Commission jurisdiction over retail wheeling, and state policies on retail wheeling

  10. Wheel Diameter and Speedometer Reading

    Murray, Clifton

    2010-01-01

    Most introductory physics students have seen vehicles with nonstandard wheel diameters; some may themselves drive "low-rider" cars or "big-wheel" pickup trucks. But how does changing wheel diameter affect speedometer readout for a given speed? Deriving the answer can be followed readily by students who have been introduced to rotation, and it…

  11. 3-D Color Wheels

    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…

  12. Getting Behind the Wheel

    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

  13. Color Wheel Windows

    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.)

  14. The ubiquitous photonic wheel

    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...

  15. Experiments with Electrodynamic Wheels

    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.

  16. Robotic Two-Wheeled Vehicle

    Nesnas, Issa A. D. (Inventor); Matthews, Jaret B. (Inventor); Edlund, Jeffrey E. (Inventor); Burdick, Joel (Inventor); Abad-Manterola, Pablo (Inventor)

    2014-01-01

    A robotic two-wheeled vehicle comprising a connection body interposed between the two wheels are described. A drum can be coaxially located in a central region of the connection body and can support a hollow arm projecting radially from the drum. A tether can be inserted in the arm and connected to a second drum. Instruments and sensors can be accommodated in a case housed inside each wheel.

  17. CRANE WHEELS PRODUCTION QUALITY CONTROL

    OTTO GRIGOROV; SERHY GUBSKIY; ANTON OKUN

    2014-01-01

    Quality control of crane wheels is an important part for support of crane mechanisms permanent operation. Normal functioning of logistics systems requires preventing of crane downtimes and delays. The research results of the impact of the crane wheels (710 mm diameter, 65 steel) surface hardness on coercivity indicators are presented in this paper. Obtained research results of dependence between the coercivity indicators and the crane wheels rolling surface hardness for their use in practice ...

  18. Driver at the wheel?

    Taede Tillema, Jaco Berveling, George Gelauff, Jan van der Waard, Lucas Harms en Harry Derriks

    2015-01-01

    Self-driving cars can change our society radically. Whether that happens depends on how much the car can actually do itself, but also on what the consumer wants. Will cars become a luxury second home or does a car driver remain a necessity? Also the sharing-economy has an impact. If many people will share self-driving vehicles and rides, this may change the traffic and transport system fundamentally.These are some of the conclusions of the report 'Driver at the wheel - Self-driving vehicles a...

  19. A Country on Wheels

    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.

  20. Reaction Wheel with Embedded MEMS IMU Project

    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...

  1. Mechanical Design Engineering Enabler Project wheel and wheel drives

    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.

  2. The outlook for wheeling

    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.

  3. GM Prototype Moon Buggy Wheel

    1967-01-01

    Under the direction of Marshall Space Flight Center (MSFC), the Lunar Roving Vehicle (LRV) was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions. During the development process, LRV prototype wheels underwent soil tests in building 4481 at Marshall Space Flight Center (MSFC). Pictured is the GM wheel design.

  4. Squeaky Wheel Optimization

    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...

  5. PHENOMENON OF CARVED DRIVING WHEELS

    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.

  6. 49 CFR 570.63 - Wheel assemblies.

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Wheel assemblies. 570.63 Section 570.63 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... 10,000 Pounds § 570.63 Wheel assemblies. (a) Wheel integrity. A tire rim, wheel disc or spider...

  7. Wheels lining up for ATLAS

    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.

  8. Strain measurements at railway wheels

    The development of the radial strain component in railway wheels was investigated by neutron diffraction. In the as manufactured state four railway wheels were investigated. In all four wheels no significant strains were found. After 18,400 km usage first strain gradients close to the outer surface of the wheels were detected. In axial middle ranges the changes in strain are weak. After an usage of 61,000 km the gradients becomes strong at the axial outer position between about +700 με close below the tread and -500 με in a depth of 12.5 mm below the tread. At axial middle positions also strain gradients are formed. The end of live state (510,000 km) differs only slightly from the state measured after a usage of 61,000 km

  9. The big wheels of ATLAS

    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.

  10. The wheel of retail gravitation?

    Brown, S.

    1992-01-01

    Reilly's Law of Retail Gravitation ranks among the classics of marketing geography. In this paper an examination of the evolution of Reilly's law is made, the contemporaneous wheel of retailing theory being used as an organisational framework. In line with the wheel, the gravity model commenced as a simple conceptualisation of consumer spatial behaviour, became increasingly sophisticated through time, and thereby created conditions conducive to the reemergence of the basic interaction model. ...

  11. Chopping-Wheel Optical Attenuator

    Leviton, Douglas B.

    1988-01-01

    Star-shaped rotating chopping wheel provides adjustable time-averaged attenuation of narrow beam of light without changing length of optical path or spectral distribution of light. Duty cycle or attenuation factor of chopped beam controlled by adjusting radius at which beam intersects wheel. Attenuation factor independent of wavelength. Useful in systems in which chopping frequency above frequency-response limits of photodetectors receiving chopped light. Used in systems using synchronous detection with lock-in amplifiers.

  12. New measurement of neutron capture resonances of 209Bi

    Domingo-Pardo, C; Abbondanno, U; Aerts, G; Alvarez-Pol, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, Panayiotis; Audouin, L; Badurek, G; Baumann, P; Becvar, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carrillode Albornoz, A; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Dolfini, R; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fitzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Gallino, R; Gonçalves, I; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Kadi, Y; Kappeler, F; Karamanis, D; Karadimos, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Mastinu, P; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; Oshima, M; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K

    2006-01-01

    The neutron capture cross section of Bi209 has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of gamma-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. Gamma-ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because Bi209 is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by alpha-decays. In the relevant stellar range of thermal energies between kT=5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At th...

  13. Estimating the Backup Reaction Wheel Orientation Using Reaction Wheel Spin Rates Flight Telemetry from a Spacecraft

    Rizvi, Farheen

    2013-01-01

    A report describes a model that estimates the orientation of the backup reaction wheel using the reaction wheel spin rates telemetry from a spacecraft. Attitude control via the reaction wheel assembly (RWA) onboard a spacecraft uses three reaction wheels (one wheel per axis) and a backup to accommodate any wheel degradation throughout the course of the mission. The spacecraft dynamics prediction depends upon the correct knowledge of the reaction wheel orientations. Thus, it is vital to determine the actual orientation of the reaction wheels such that the correct spacecraft dynamics can be predicted. The conservation of angular momentum is used to estimate the orientation of the backup reaction wheel from the prime and backup reaction wheel spin rates data. The method is applied in estimating the orientation of the backup wheel onboard the Cassini spacecraft. The flight telemetry from the March 2011 prime and backup RWA swap activity on Cassini is used to obtain the best estimate for the backup reaction wheel orientation.

  14. A 6-MJ P4 target for heavy ion inertial fusion

    A new target option for energy applications of the heavy ion inertial fusion is analyzed. It has a spherical hohlraum and is irradiated by ion beams along the directions of the zeros of the fourth Legendre polynomial P4. The target performance is simulated with a one-dimensional (1-D) three-temperature hydrodynamics code and with a two-dimensional view factor code. Its efficiency is shown to depend crucially on the structure of the hohlraum wall which, simultaneously, plays a role of the X-ray converter. For the optimized pulse power profile, a 1-D energy gain of G = 78 is calculated with the input energy of Edr = 6.1 MJ in the form of 5 GeV 209Bi ions focused on the target sphere with the outer radius of R = 6.37 mm. (author)

  15. Research on the 2-axis cup-wheel dressing technology of arc-diamond grinding wheel

    Chang, X. L.; Wu, H. Y.; Peng, Y. F.

    2014-08-01

    The precision dressing of arc-diamond wheel is very hard, expensive and time-consuming because of the super-hard diamond particles and complicated geometrical shape. This paper aims to investigate the cup-wheel dressing technology to realize the high-efficiency regeneration of the arc-diamond wheel. A two-axis cup-wheel dressing technique for precision dressing arc-diamond wheel was suggested and tested. The dressing mechanism of 2-axis cup-wheel was studied. The dressing algorithm and error compensation method were further investigated to improve the dressing precision and efficiency. The experimental results show that the 2-axis cup-wheel dressing technique is valid and applicable to realize the precision dressing of arc-diamond wheel. The machined optical surface condition was apparently improved with the cup-wheel dressed diamond wheel and even became much better when the error compensation algorithm was performed on the arc-diamond wheel.

  16. Two new wheels for ATLAS

    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...

  17. A route for polonium 210 production from alpha-particle irradiated bismuth-209 target

    A method is proposed for production of polonium-210 via the 209Bi(α,3n)210 At nuclear reaction. Bombardment of a bismuth-209 target was performed with a 37 MeV alpha-particle beam that leads to the production of astatine-210 (T1/2 = 8.1 h), which decays to polonium-210. It is purified from the bismuth target matrix by employing liquid-liquid extraction using tributyl phosphate (TBP) in para-xylene from 7 M hydrochloric acid. Back extraction of polonium-210 was performed by 9 M nitric acid. This method allows to purify a tracer amount of Po-210 (2.6 x 10-13 mol) from macroscopic amount of Bi (2.8 x 10-2 mol).

  18. Decay analysis of 9Be induced reactions using stable and non deformed targets

    The pursuit of investigation of decay of compound and non compound nuclear reactions inscribes the cogitation of various processes subsequent to collision between projectile and target nuclei. Hitherto extensive studies have been devoted to understand the structure aspect associated with numerous dominant reaction mechanisms of nuclei. The Decay cross-sections of 217Rn* and 218Fr* formed in reactions 9Be+208Pb and 9Be+209Bi have been studied in framework of DCM at energies varying from Ec.m=(42.0- 67.0) MeV where both the targets have same neutron magicity (N = 126) effect. All calculations have been done for β2-deformed choice of fragmentation and optimum orientation approach

  19. Reaction Wheel Disturbance Model Extraction Software Project

    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....

  20. Evaluation of wheel dampers on an intercity train

    Färm, J.

    2003-10-01

    Pass-by noise from high-speed trains is one important area that has to be handled in all new train projects. For the new line between Oslo and the Gardemoen Airport which opened in 1998, very stringent requirements were set out regarding external noise. To reach the target it was decided that the train should be equipped with wheel dampers. Two different types of wheel dampers were used on the train; a ring damper was mounted on the wheels of the driven bogies, whilst plate dampers divided into tuned absorber fins were mounted on the wheels of the trailer bogies. During the type testing of the Airport Express Train, additional measurements were performed in order to evaluate the acoustic effect of the plate wheel dampers. Two test series were performed with the same train set; first with the train in standard configuration and secondly with the wheel dampers removed from the second and third bogie. The external noise was measured at 5 and 25 m distance from the centre of the track at speeds ranging from 80 to 200 km/h. The third-octave filtered time histories were analyzed to calculate the effect of the wheel dampers. As expected, there was a significant reduction of 4-6 dB at frequencies above 2000 Hz, but there was also a reduction of 2 dB for frequencies as low as 800 Hz. This reduction was also found in the parts of the time histories when the rail should be dominating. This implies that the wheel dampers also reduce the rail noise. The total rolling noise reduction for the trailer bogie was 3 dB at 200 km/h and 1 dB at 80 km/h. From comparison with TWINS-calculated sound power levels it was estimated that the wheel noise would be reduced by 5 dB and the rail noise would be reduced by 1 dB at 200 km/h.

  1. New steering mechanism for wheeled mobile robots

    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.

  2. Some peculiarities of corrosion of wheel steel

    Alexander SHRAMKO; Alfred KOZLOWSKY; Elena BELAJA; Yuriy PROIDAK; Pinchuk, Sofia; Gubenko, Svetlana

    2009-01-01

    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 corrosi...

  3. 49 CFR 570.10 - Wheel assemblies.

    2010-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... Pounds or Less § 570.10 Wheel assemblies. (a) Wheel integrity. A tire rim, wheel disc, or spider shall... rim bead area shall not exceed one-eighth of an inch of total indicated runout. (1)...

  4. 49 CFR 215.103 - Defective wheel.

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System..., is 11/2 inches, or more; (c) The thickness of a rim of a wheel on the car is 11/16 of an inch, or less; (d) A wheel rim, flange, plate, or hub area on the car has a crack or break; (e) A wheel on...

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

    Paul Molyneux-Berry; Claire Davis; Adam Bevan

    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 variati...

  6. Wheel Wear and Rail Damage Prediction for Wheels Turned with Thin Flanges

    Muhamedsalih, Yousif; Bevan, Adam; Stow, Julian

    2016-01-01

    Economic Tyre Turning (ETT) is the process of turning wheels to a profile that has the same tread shape but a thinner flange than the design case, allowing less material to be removed from the wheel diameter. ETT can allow maintainers to extend wheel life, particularly when the wheel is approaching its minimum diameter. Modern wheel lathes are typically capable of turning such profiles but GB railway group standards do not currently permit their use. This paper investigates the effect of usin...

  7. ATLAS- lowering the muon small wheel

    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.

  8. Finite element simulation of wheel impact test

    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

  9. Wheeling and Banking Strategies for Optimal Renewable Energy Deployment. International Experiences

    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.

  10. Measurement error analysis of the 3D four-wheel aligner

    Zhao, Qiancheng; Yang, Tianlong; Huang, Dongzhao; Ding, Xun

    2013-10-01

    Positioning parameters of four-wheel have significant effects on maneuverabilities, securities and energy saving abilities of automobiles. Aiming at this issue, the error factors of 3D four-wheel aligner, which exist in extracting image feature points, calibrating internal and exeternal parameters of cameras, calculating positional parameters and measuring target pose, are analyzed respectively based on the elaborations of structure and measurement principle of 3D four-wheel aligner, as well as toe-in and camber of four-wheel, kingpin inclination and caster, and other major positional parameters. After that, some technical solutions are proposed for reducing the above error factors, and on this basis, a new type of aligner is developed and marketed, it's highly estimated among customers because the technical indicators meet requirements well.

  11. Preventing Disruptive Behavior via Classroom Management: Validating the Color Wheel System in Kindergarten Classrooms.

    Watson, Tiffany L; Skinner, Christopher H; Skinner, Amy L; Cazzell, Samantha; Aspiranti, Kathleen B; Moore, Tara; Coleman, MariBeth

    2016-07-01

    Evidence suggests that installing a classroom management system known as the Color Wheel reduced inappropriate behaviors and increased on-task behavior in second- and fourth-grade classrooms; however, no systematic studies of the Color Wheel had been disseminated targeting pre-school or kindergarten participants. To enhance our understanding of the Color Wheel System (CWS) as a prevention system, a multiple-baseline design was used to evaluate the effects of the Color Wheel on inappropriate vocalizations (IVs) in three general education kindergarten classrooms. Partial-interval time-sampling was used to record classwide IVs, which were operationally defined as any comment or vocal noise that was not solicited by the teacher. Time series graphs and effect size calculations suggest that the CWS caused immediate, large, and sustained decreases in IVs across the three classrooms. Teacher acceptability and interview data also supported the CWS. Implications related to prevention are discussed and directions for future research are provided. PMID:26802118

  12. Entropy parameters for desiccant wheel design

    In this work a thermodynamic analysis of a desiccant wheel is proposed to investigate and identify the optimum size and operating regime of this device. A steady state entropy generation expression, based on effectiveness parameters suitable for desiccant wheels operability, is obtained applying a control volume approach and assuming perfect gas behaviour of the binary air–vapour mixture. A new entropy generation number NL is defined using a minimum indicative value of the entropy generation SL,min and investigated in order to obtain useful criteria for desiccant wheels optimization. The effectiveness-NTU design method is employed by combining solution of thermal exchange efficiency for rotary heat exchanger with the characteristic potential method, under the conditions of heat and mass transfer analogy. The analysis is applied to a specific desiccant wheel and NL variation with NTU is explored under various operative conditions and wheels characteristics in terms of dimensionless velocity and flow unbalance ratio. - Highlights: • Steady state entropy generation based on effectiveness parameters for heat and mass transfer. • Definition of a new entropy generation number NL for desiccant wheel. • Least irreversible features for a defined dehumidification rate of the desiccant wheel. • NL can be used as an optimization parameter for desiccant wheels design and control

  13. Development of the FASTER Wheeled Bevameter

    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

  14. Eddy current arrays for wheel inspection

    Leclerc, Rémi

    2001-04-01

    Wheel inspections are routine and very time-consuming, especially for large aircraft wheels where a single-coil probe is moved manually taking precious long minutes. Eddy current arrays can decrease the inspection time by reducing to one the number of rotations needed to completely cover the wheel surface. Since the EC array probe fits the profile of the wheel, manipulation is easy and the lift-off is kept constant improving signal quality. C-scan displays assist the analysis and help locate the defect by dividing the inspected wheel surface into a small grid. Furthermore, the impedance plane and the strip chart, for all the channels used to build the C-scan, are accessible to provide better sizing accuracy of the defect.

  15. Biaxial wheel/hub test facility. Proceedings

    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)

  16. Influence of polygonal wear of railway wheels on the wheel set axle stress

    Wu, Xingwen; Chi, Maoru; Wu, Pingbo

    2015-11-01

    The coupled vehicle/track dynamic model with the flexible wheel set was developed to investigate the effects of polygonal wear on the dynamic stresses of the wheel set axle. In the model, the railway vehicle was modelled by the rigid multibody dynamics. The wheel set was established by the finite element method to analyse the high-frequency oscillation and dynamic stress of wheel set axle induced by the polygonal wear based on the modal stress recovery method. The slab track model was taken into account in which the rail was described by the Timoshenko beam and the three-dimensional solid finite element was employed to establish the concrete slab. Furthermore, the modal superposition method was adopted to calculate the dynamic response of the track. The wheel/rail normal forces and the tangent forces were, respectively, determined by the Hertz nonlinear contact theory and the Shen-Hedrick-Elkins model. Using the coupled vehicle/track dynamic model, the dynamic stresses of wheel set axle with consideration of the ideal polygonal wear and measured polygonal wear were investigated. The results show that the amplitude of wheel/rail normal forces and the dynamic stress of wheel set axle increase as the vehicle speeds rise. Moreover, the impact loads induced by the polygonal wear could excite the resonance of wheel set axle. In the resonance region, the amplitude of the dynamic stress for the wheel set axle would increase considerably comparing with the normal conditions.

  17. Theoretical considerations of machining with grinding wheels

    Andrew Oyakhobo Odior

    2013-03-01

    Full Text Available Grinding is one of the most versatile methods of removing material from machine parts by the cutting action of the countless hard and sharp abrasive particles of a revolving grinding wheel. It works by forcing the abrasive grains into the surface of the workpiece so that each grain cuts away a small bit of material in the form of chips. Abrasive grinding wheel is an expendable wheel that carries an abrasive compound on its periphery. They are made of small, sharp and very hard natural or synthetic abrasive minerals, bonded together in a matrix to form a wheel. The paper presents a review of some of the characteristics as well as theoretical considerations of operations of abrasive grinding wheel. The relationships among the various grinding parameters; the radial force f, the force on individual grit of grinding wheel F, velocity of grinding wheelg Vg, velocity of work piecew Vw, the wheel diameterg Dg, and the diameter of the work piece Dw were established for given grinding operations.

  18. Minisatellite Attitude Guidance Using Reaction Wheels

    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.

  19. Loading and damageability of wheels and rails

    George TUMANISHVILI

    2009-01-01

    Full Text Available Friction, rolling resistance and durability of rails and wheels at operation, belong to a number of the most important problems of railway transportation because they have strong impact on derailment, energy consumption and restorative maintenance. Various aspects of these problems are insufficiently investigated, have only partial solution. The sources of creep and slipping of a wheel on a rail and ways of its reduction are specified in the work. These approaches alongside with the traditional methods (lubrication, radial steering bogie, etc. will ensure the reduction both the power and the thermal loading of the contact zone and wear rate of rails and wheels.

  20. 29 CFR 1910.215 - Abrasive wheel machinery.

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a... wheel in motion. (5) Excluded machinery. Natural sandstone wheels and metal, wooden, cloth, or...

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

    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. PMID:22161268

  2. Computer Calculations of Eddy-Current Power Loss in Rotating Titanium Wheels and Rims in Localized Axial Magnetic Fields

    Mayhall, D J; Stein, W; Gronberg, J B

    2006-05-15

    We have performed preliminary computer-based, transient, magnetostatic calculations of the eddy-current power loss in rotating titanium-alloy and aluminum wheels and wheel rims in the predominantly axially-directed, steady magnetic fields of two small, solenoidal coils. These calculations have been undertaken to assess the eddy-current power loss in various possible International Linear Collider (ILC) positron target wheels. They have also been done to validate the simulation code module against known results published in the literature. The commercially available software package used in these calculations is the Maxwell 3D, Version 10, Transient Module from the Ansoft Corporation.

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

    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.

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

    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. PMID:24526883

  5. Cylindrical Wire Electrical Discharge Machining of Metal Bond Diamond Wheels- Part II: Wheel Wear Mechanism

    McSpadden, SB

    2002-01-22

    The use of stereo scanning Electron Microscopy (SEM) to investigate the wear mechanism of the wire EDM true metal bond diamond wheel for ceramic grinding is presented. On the grinding wheel, a wedge-shape removal part was machined to enable the examination and measurement of the worn wheel surfaces using the stereo SEM. The stereo SEM was calibrated by comparing results of depth profile of a wear groove with the profilometer measurements. On the surface of the grinding wheel after wire EDM truing and before grinding, the diamond protruding heights were measured in the level of 35 {micro}m, comparing to the 54 {micro}m average size of the diamond in the grinding wheel. The gap between the EDM wire and rotating grinding wheel is estimated to be about 35 to 40 {micro}m. This observation indicates that, during the wire EDM, electrical sparks occur between the metal bond and EDM wire, which leaves the diamond protruding in the gap between the wire and wheel. The protruding diamond is immediately fractured at the start of the grinding process, even under a light grinding condition. After heavy grinding, the grinding wheel surface and the diamond protrusion heights are also investigated using the stereo SEM. The height of diamond protrusion was estimated in the 5 to 15 {micro}m range. This study has demonstrated the use of stereo SEM as a metrology tool to study the grinding wheel surface.

  6. Reaction Wheel with Embedded MEMS IMU Project

    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...

  7. Multiple Wheel Throwing: And Chess Sets.

    Sapiro, Maurice

    1978-01-01

    A chess set project is suggested to teach multiple throwing, the creation on a potter's wheel of several pieces of similar configuration. Processes and finished sets are illustrated with photographs. (SJL)

  8. Mechanics of wheel-soil interaction

    Houland, H. J.

    1973-01-01

    An approximate theory for wheel-soil interaction is presented which forms the basis for a practical solution to the problem. It is shown that two fundamental observations render the problem determinate: (1) The line of action of the resultant of radial stresses acting at the wheel soil interface approximately bisects the wheel-soil contact angle for all values of slip. (2) A shear stress surface can be hypothesized. The influence of soil inertia forces is also evaluated. A concept of equivalent cohesion is introduced which allows a convenient experimental comparison for both cohesive and frictional soils. This theory compares favorably with previous analyses and experimental data, and shows that soil inertia forces influencing the motion of a rolling wheel can be significant.

  9. Reaction Wheel Disturbance Model Extraction Software Project

    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...

  10. Improved Squeaky Wheel Optimisation for Driver Scheduling

    Aickelin, Uwe; Burke, Edmund; Li, Jingpeng

    2006-01-01

    This paper presents a technique called Improved Squeaky Wheel Optimisation (ISWO) for driver scheduling problems. It improves the original Squeaky Wheel Optimisation’s (SWO) 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...

  11. Minisatellite Attitude Guidance Using Reaction Wheels

    Ion STROE; Dan N. Dumitriu

    2015-01-01

    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 ...

  12. Roulette-wheel selection via stochastic acceptance

    Lipowski, Adam; Lipowska, Dorota

    2011-01-01

    Roulette-wheel selection is a frequently used method in genetic and evolutionary algorithms or in modeling of complex networks. Existing routines select one of N individuals using search algorithms of O(N) or O(log(N)) complexity. We present a simple roulette-wheel selection algorithm, which typically has O(1) complexity and is based on stochastic acceptance instead of searching. We also discuss a hybrid version, which might be suitable for highly heterogeneous weight distributions, found, fo...

  13. Aerodynamic analysis of an isolated vehicle wheel

    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.

  14. A rotating target for Ra production

    A target wheel with pyrolytic graphite targets is designed and constructed at the TRIμP facility to boost the production rate of Ra isotopes. Simulation, design properties and production results are discussed.

  15. Experimental investigations on desiccant wheels

    Experimental investigations on several commercially available and newly fabricated rotors are conducted in two different laboratories to evaluate performance trends. Experimental uncertainties are analysed and the parameters determining the rotor performance are investigated. It is found that the optimal rotation speed is lower for lithium chloride or compound rotors than for silica gel rotors. Higher regeneration air temperatures lead to higher dehumidification potentials at almost equal dehumidification efficiencies, but with increasing regeneration specific heat input and enthalpy changes of the process air. The influence of the regeneration air humidity was also notable and low relative humidities increase the dehumidification potential. Finally, the measurements show that rising water content in the ambient air causes the dehumidification capacity to rise, while the dehumidification efficiency is not much affected and both specific regeneration heat input and latent heat change of the process air decrease. For desiccant cooling applications in humid climates this is a positive trend. - Highlights: ► New experimental results on a range of desiccant wheels. ► High dehumidification capacities and low enthalpy changes for process air high water content. ► Higher regeneration temperature increases capacity, but lowers energy efficiency.

  16. Low intensity beam target unit

    1976-01-01

    This is a wheel fitted with many targets around its periphery (each with three longitudinally arranged thin rods) of which one is placed into the beam via a rotation of the wheel. Upstream of each target is placed a luminescent screen, aligbed on each target axis and viewed with a TV camera, to make sure that one is hitting the target. This target unit was probably used to study target's behaviour (like beam heating). Gualtiero Del Torre stands on the left, Pierre Gerdil on the right.

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

    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.

  18. Reaction Wheel Disturbance Model Extraction Software - RWDMES

    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

  19. Wheeling rates evaluation using optimal power flows

    Wheeling is the transmission of electrical power and reactive power from a seller to a buyer through a transmission network owned by a third party. The wheeling rates are then the prices charged by the third party for the use of its network. This paper proposes and evaluates a strategy for pricing wheeling power using a pricing algorithm that in addition to the fuel cost for generation incorporates the optimal allocation of the transmission system operating cost, based on time-of-use pricing. The algorithm is implemented for the IEEE standard 14 and 30 bus system which involves solving a modified optimal power flow problem iteratively. The base of the proposed algorithm is the hourly spot price. The analysis spans a total time period of 24 hours. Unlike other algorithms that use DC models, the proposed model captures wheeling rates of both real and reactive power. Based on the evaluation, it was concluded that the model has the potential for wide application in calculating wheeling rates in a deregulated competitive power transmission environment. 9 refs., 3 tabs

  20. Brush-Wheel Samplers for Planetary Exploration

    Rivellini, Tommaso

    2003-01-01

    A report proposes brush-wheel mechanisms for acquiring samples of soils from remote planets. In simplest terms, such a mechanism would contain brush wheels that would be counter-rotated at relatively high speed. The mechanism would be lowered to the ground from a spacecraft or other exploratory vehicle. Upon contact with the ground, the counter-rotating brush wheels would kick soil up into a collection chamber. Thus, in form and function, the mechanism would partly resemble traditional street and carpet sweepers. The main advantage of using of brush wheels (in contradistinction to cutting wheels or other, more complex mechanisms) is that upon encountering soil harder than expected, the brushes could simply deflect and the motor(s) could continue to turn. That is, sufficiently flexible brushes would afford resistance to jamming and to overloading of the motors used to rotate the brushes, and so the motors could be made correspondingly lighter and less power hungry. Of course, one could select the brush stiffnesses and motor torques and speeds for greatest effectiveness in sampling soil of a specific anticipated degree of hardness.

  1. Bucket wheel excavators for varying mining conditions

    Schachtschneider, H.; Seliger, E.

    1987-06-01

    TAKRAF bucket wheel excavators have proven their efficiency through the achievement of daily production rates in excess of 300,000 bcm, and have accomplished this under the most difficult geological and climatic conditions. Even heavy, plastic, very sticky clays, very abrasive soils, and rocky partings have been successfully mined with bucket wheel excavators. The use of BWEs to mine the hard coal deposits at the Ekibastus surface mine in the U.S.S.R., has broadened the field of application of these machines. Based on the experience gained in heavy-duty service, the bucket wheel excavators designed in the future will be capable of successfully coping with even more difficult site conditions.

  2. Wheels and Butterflies: Title, Structure, Cover Design

    Gould, Warwick

    2015-01-01

    The gold-stamped heraldic design of Yeats’s Wheels and Butterflies (London: Macmillan, 1934; Wade 175), together with a colour to approximate to that of the cloth on that book, have been represented on the top board of the present volume. In Wheels and Butterflies that device was also replicated in black on the title-page. It was created by an unknown (and probably in-house) artist commissioned by Macmillan, working from photographs of masks by Hildo Van Krop for Vrouwe Emer’s Groote Strijd, ...

  3. Wheeled foot quadruped robot HITAN-I

    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.

  4. Roulette-wheel selection via stochastic acceptance

    Lipowski, Adam

    2011-01-01

    Roulette-wheel selection is a frequently used method in genetic or evolutionary algorithms. Existing routines select one of N individuals using search algorithms of O(N) or O(\\log N) complexity. We present a simple roulette-wheel selection algorithm that typically has O(1) complexity and is based on stochastic acceptance instead of searching. With minor modifications the algorithm might be also used for sampling with fitness being cut-off at a certain value or for sampling without replacement.

  5. Roulette-wheel selection via stochastic acceptance

    Lipowski, Adam; Lipowska, Dorota

    2012-03-01

    Roulette-wheel selection is a frequently used method in genetic and evolutionary algorithms or in modeling of complex networks. Existing routines select one of N individuals using search algorithms of O(N) or O(logN) complexity. We present a simple roulette-wheel selection algorithm, which typically has O(1) complexity and is based on stochastic acceptance instead of searching. We also discuss a hybrid version, which might be suitable for highly heterogeneous weight distributions, found, for example, in some models of complex networks. With minor modifications, the algorithm might also be used for sampling with fitness cut-off at a certain value or for sampling without replacement.

  6. Evaluation of the 30 Ton CHA Crane Wheel Axle Modification

    An existing design for eccentric bushings was utilized and updated as necessary to accommodate minor adjustment as required to correct wheel alignment on the North West Idler wheel. The design is revised to install eccentric bushings on only one end

  7. Bucket wheel excavators: variable mining equipment in the focus

    Nies, G.; Jurisch, H. (Schwermaschinenbau Lauchhammerwerk AG, Lauchhammer (Germany). TAKRAF Tagebautechnik)

    1992-01-01

    Specifications and performance parameters of different types of bucket wheel excavators are given. Factors discussed include: bucket wheel power requirement, discharge of the bucket wheel boom, structure of the digging unit, variations in the loading units, and adaptation of the crawler vehicle. 15 figs., 4 refs.

  8. 14 CFR 23.745 - Nose/tail wheel steering.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Nose/tail wheel steering. 23.745 Section 23.745 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must...

  9. 14 CFR 23.499 - Supplementary conditions for nose wheels.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Supplementary conditions for nose wheels... Structure Ground Loads § 23.499 Supplementary conditions for nose wheels. In determining the ground loads on nose wheels and affected supporting structures, and assuming that the shock absorbers and tires are...

  10. Steady state modeling of desiccant wheels

    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...

  11. The time has come for retail wheeling

    Retail wheeling, the transmission and distribution of electric power for end users, fosters competition and promotes the efficient use of resources. Access to electric-utility transmission and distribution systems would establish competitive electric markets by permitting retail customers to obtain the lowest cost for energy which would meet their specific needs. Among electric utilities and their customers, the idea of allowing market forces to attract supply and set prices is a current controversy. To counter the anticompetitive effects of recent mergers in the wholesale market, the Federal Energy Regulatory Commission (FERC) has mandated open transmission access for wholesale customers. However, the FERC denied access to retail customers and qualifying facilities (QF) in both its Northeast Utilities (FERC case No. EC-90-1 90) and PacifiCorp (U.S. Circuit Court of Appeals for D.C., 89-1333) decisions. Retail wheeling will benefit both consumers and producers. The ability of large customers to purchase power from the lowest cost sources and have it transmitted to their facilities, will save American industrial and commercial customers at least $15 billion annually. The Increased efficiency resulting from competition would also reduce residential electric bills. Through retail wheeling, independent power producers can market their capacity to a greater customer base, and traditional utilities will benefit from access to other utilities markets with the more efficient utilities prospering. Retail wheeling will, therefore, reward efficient utilities and encourage inefficient utilities to improve

  12. Before the Outline--The Writing Wheel.

    Rae, Colleen

    1986-01-01

    To help students write more effectively, a technique for writing from thesis statements is described that requires students to create a picture of a wheel. The hub is a word that is the essence of the topic; the spokes are concrete examples; and the tire is the thesis statement. (MLW)

  13. Rolling Friction on a Wheeled Laboratory Cart

    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…

  14. A Technique for Extracting Highly Precise Photometry for the Two-Wheeled Kepler Mission

    Vanderburg, Andrew

    2014-01-01

    The original Kepler mission achieved high photometric precision thanks to ultra-stable pointing enabled by use of four reaction wheels. The loss of two of these reaction wheels reduced the telescope's ability to point precisely for extended periods of time, and as a result, the photometric precision has suffered. We present a technique for generating photometric light curves from pixel-level data obtained with the two-wheeled extended Kepler mission, K2. Our photometric technique accounts for the non-uniform pixel response function of the Kepler detectors by correlating flux measurements with the spacecraft's pointing and removing the dependence. When we apply our technique to the ensemble of stars observed during the Kepler Two-Wheel Concept Engineering Test, we find improvements over raw K2 photometry by factors of 2-5, with noise properties qualitatively similar to Kepler targets at the same magnitudes. We find evidence that the improvement in photometric precision depends on each target's position in the ...

  15. Fault-tolerant control of electric vehicles with in-wheel motors using actuator-grouping sliding mode controllers

    Li, Boyuan; Du, Haiping; Li, Weihua

    2016-05-01

    Although electric vehicles with in-wheel motors have been regarded as one of the promising vehicle architectures in recent years, the probability of in-wheel motor fault is still a crucial issue due to the system complexity and large number of control actuators. In this study, a modified sliding mode control (SMC) is applied to achieve fault-tolerant control of electric vehicles with four-wheel-independent-steering (4WIS) and four-wheel-independent-driving (4WID). Unlike in traditional SMC, in this approach the steering geometry is re-arranged according to the location of faulty wheels in the modified SMC. Three SMC control laws for longitudinal velocity control, lateral velocity control and yaw rate control are designed based on specific vehicle motion scenarios. In addition the actuator-grouping SMC method is proposed so that driving actuators are grouped and each group of actuators can be used to achieve the specific control target, which avoids the strong coupling effect between each control target. Simulation results prove that the proposed modified SMC can achieve good vehicle dynamics control performance in normal driving and large steering angle turning scenarios. In addition, the proposed actuator-grouping SMC can solve the coupling effect of different control targets and the control performance is improved.

  16. Influence of Tire Dynamics on Slip Ratio Estimation of Independent Driving Wheel System Influence of Tire Dynamics on Slip Ratio Estimation of Independent Driving Wheel System

    LI Jianqiu; SONG Ziyou; WEI Yintao; OUYANG Minggao

    2014-01-01

    The independent driving wheel system, which is composed of in-wheel permanent magnet synchronous motor(I-PMSM) and tire, is more convenient to estimate the slip ratio because the rotary speed of the rotor can be accurately measured. However, the ring speed of the tire ring doesn’t equal to the rotor speed considering the tire deformation. For this reason, a deformable tire and a detailed I-PMSM are modeled by using Matlab/Simulink. Moreover, the tire/road contact interface(a slippery road) is accurately described by the non-linear relaxation length-based model and the Magic Formula pragmatic model. Based on the relatively accurate model, the error of slip ratio estimated by the rotor rotary speed is analyzed in both time and frequency domains when a quarter car is started by the I-PMSM with a definite target torque input curve. In addition, the natural frequencies(NFs) of the driving wheel system with variable parameters are illustrated to present the relationship between the slip ratio estimation error and the NF. According to this relationship, a low-pass filter, whose cut-off frequency corresponds to the NF, is proposed to eliminate the error in the estimated slip ratio. The analysis, concerning the effect of the driving wheel parameters and road conditions on slip ratio estimation, shows that the peak estimation error can be reduced up to 75% when the LPF is adopted. The robustness and effectiveness of the LPF are therefore validated. This paper builds up the deformable tire model and the detailed I-PMSM models, and analyzes the effect of the driving wheel parameters and road conditions on slip ratio estimation.

  17. Numerical analysis of small recessed silicon carbide grinding wheels

    M.J. Jackson

    2010-11-01

    Full Text Available Purpose: Silicon carbide grinding wheels are tools used in manufacturing industry to form precision componentsand continue to be used to increase production rates due to their ability to remove high volumes of material athigh speeds. There is a demand to increase the speed of rotation of the grinding wheel in order to achieve highremoval rates. The increase in speed creates a situation where the grinding machine and the operator are subjectedto a possible catastrophic failure of the wheel due to the stresses generated in the coarse brittle structure of thevitrified grinding wheel. The study focused on building and analyzing computer models of grinding wheels withrecessed features spinning at different rotational speeds. By employing a computational approach, it was possibleto determine the maximum principal stresses in the wheel together with the location of the stresses. The geometryof vitrified wheels considered included a plain-sided rotating wheel and a recessed rotating wheel.Design/methodology/approach: The paper shows how stresses and factors of safety are calculated in order topredict the bursting speeds of small recessed SiC grinding wheels. The main methods used include finite elementanalysis and mechanical testing of abrasive materials. The approach of the paper is to integrate the use of numericalanalysis techniques and experimental techniques to predict the safe operating conditions of SiC abrasive products.Findings: Calculations were conducted to determine maximum stress in parallel-sided and recessed cup wheels.Relevant factors of safety and bursting speed were also calculated and compared with experimental data. Thepaper proves the usefulness and applicability of a method developed for taking account of stress concentrationsat the recess of small cup-shaped silicon carbide grinding wheels.Research limitations/implications: The paper is limited to analyzing small recessed SiC grinding wheels.Further work should focus on large

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

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

    than at the periphery of the wheel rut (0.4 m) or outside the wheel rut. At least one of these differences εa was significant at all soil depths . At all matric potentials, the ka was lowest at the periphery of the wheel rut and highest outside the wheel rut, with intermediate values inside the wheel...... catena running from center of the wheel rut to un wheeled part of the field ( 0, 20, 40, 50,60 and 400 cm horizontal distance). We measured water retention and air permeability (ka) at -30, -100 and -300 hPa matric potentials. At -100 hPa, we obtained consistently lower air filled under the wheel rut......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...

  19. Improved Squeaky Wheel Optimisation for Driver Scheduling

    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...

  20. Smart Wheel Chair for Visually Impaired

    Dev Pratap Singh

    2014-08-01

    Full Text Available The visually impaired persons suffer from lack of confidence, restricted mobility and dependence on others in their daily life. This paper proposes an embedded system design of a smart wheel chair aiming for visually impaired using high-end technical tools like AVR Studio, ATMEGA 16 Development Board (Atmel Corporation, proximity sensors and DTMF Decoder. The movement of wheelchair is controlled by cellular phones specifically designed for the visually challenged people (Toshiba, Huawei, Sens are companies that manufacture such specific mobiles. In this paper existing designs of wheel chair are also discussed. In addition to being user-friendly, the proposed design also provides a high degree of mobility and defence against obstacles for the visually impaired. Further the design is also tested using Printed Circuit Board (PCB and the results obtained are in perfect accordance with the expectations. This proposed smart chair design outperforms the existing designs in terms of obstacle avoidance and technology.

  1. Advanced Control of Wheeled Inverted Pendulum Systems

    Li, Zhijun; Fan, Liping

    2013-01-01

    Advanced Control of Wheeled Inverted Pendulum Systems is an orderly presentation of recent ideas for overcoming the complications inherent in the control of wheeled inverted pendulum (WIP) systems, in the presence of uncertain dynamics, nonholonomic kinematic constraints as well as underactuated configurations. The text leads the reader in a theoretical exploration of problems in kinematics,dynamics modeling, advanced control design techniques,and trajectory generation for WIPs. An important concern is how to deal with various uncertainties associated with the nominal model, WIPs being characterized by unstable balance and unmodelled dynamics and being subject to time-varying external disturbances for which accurate models are hard to come by.   The book is self-contained, supplying the reader with everything from mathematical preliminaries and the basic Lagrange-Euler-based derivation of dynamics equations to various advanced motion control and force control approaches as well as trajectory generation met...

  2. A magneto-electric quantum wheel

    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.

  3. Bucket wheel excavators VABE 550 in China

    In June 1989, China National Machinery Import and Export Corporation (CNM Corp.) and Voest-Alpine Bergtechnik (VA-Bergteknik) signed a contract for the engineering and delivery of 3 bucket wheel excavators type VABE 550 to be used in a large open pit brown coal mine in Yunnan Province, P.R. China. This article provides technical data relating to the excavators and discusses the results of a performance test conducted after completion of erection and commissioning. 2 photos.

  4. Tram wheel modelling for dynamic analysis

    Pešek, Luděk; Veselý, Jan; Podruh, J.

    Brno : SVS FEN s.r.o., 2003, s. 1-7. ISBN 80-239-1598-3. [ANSYS & STAR-CD Users' Meeting /11./. Znojmo (CZ), 25.09.2003-26.09.2003] R&D Projects: GA ČR GA101/02/0241 Institutional research plan: CEZ:AV0Z2076919 Keywords : tram wheel * experimental modal analysis Subject RIV: BI - Acoustics

  5. Hybrid uranyl-vanadium nano-wheels.

    Senchyk, G A; Wylie, E M; Prizio, S; Szymanowski, J E S; Sigmon, G E; Burns, P C

    2015-06-25

    Hybrid uranyl-vanadium oxide clusters intermediate between transition metal polyoxometalates and uranyl peroxide cage clusters were obtained by dissolving uranyl nitrate in the ionic liquid 3-ethyl-1-methylimidazolium ethyl sulfate mixed with an aqueous solution containing vanadium. Where sulfate was present, wheel-shaped {U20V20} crystallized and contains ten sulfate tetrahedra, and in the absence of added sulfate, {U2V16}, a derivative of {V18}, was obtained. PMID:26008125

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

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

    2015-04-01

    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 biomechanical responses to submaximal and maximal effort propulsion specific to wheelchair basketball. Eight able-bodied individuals participated in the laboratory-based testing, which took place on a wheelchair ergometer at two fixed speeds (1.1 and 2.2 m s(-1)). Outcome measures were power output and physiological demand (oxygen uptake and heart rate). Three participants with experience of over-ground sports wheelchair propulsion also performed 2 × 20 m sprints in each wheel configuration. Results revealed that wheels differed significantly in lateral stiffness with the 'new' Spinergy wheel shown to be the stiffest (678.2 ± 102.1 N mm(-1)). However the effects of stiffness on physiological demand were minimal compared to tyre type whereby tubular tyres significantly reduced the rolling resistance and power output in relation to clincher tyres. Therefore tyre type (and subsequently inflation pressure) remains the most important aspect of wheel specification for athletes to consider and monitor when configuring a sports wheelchair. PMID:25726151

  7. Flow Visualization around a Simplified Two-Wheel Landing Gear

    Ekmekci, Alis; Feltham, Graham

    2013-11-01

    The flow topology around a simplified two-wheel landing gear model is investigated experimentally by employing the hydrogen bubble flow visualization technique in a recirculating water channel. The landing gear test model consists of two identical wheels, an axle, a main strut and a support strut. The flow Reynolds number based on wheel diameter is 31,500 and wheels with varying geometric details are considered. Flow structures have been identified through analysis of long-time video recordings and linked to the model geometry. In the flow region above the wheels (wing side), the flow in the inter-wheel region either separates prematurely from the inner surfaces of the wheels and forms slant vortices in the near-wake, or remains attached till the aft wheel perimeter. Inclusion of interior wheel wells are found to result in a jet-like ejection as a result of the interaction with the axle and main strut. In the flow region below the wheels (ground side) the near wake contains periodically forming, complex, large-scale structures.

  8. Parametric analysis of wheel wear in high-speed vehicles

    Na Wu; Jing Zeng

    2014-01-01

    In order to reduce the wheel profile wear of high-speed trains and extend the service life of wheels, a dynamic model for a high-speed vehicle was set up, in which the wheelset was regarded as flexible body, and the actual mea-sured track irregularities and line conditions were considered. The wear depth of the wheel profile was calculated by the well-known Archard wear law. Through this model, the influence of the wheel profile, primary suspension stiffness, track gage, and rail cant on the wear of wheel profile were studied through multiple iterative calculations. Numerical simulation results show that the type XP55 wheel profile has the smallest cumulative wear depth, and the type LM wheel profile has the largest wear depth. To reduce the wear of the wheel profile, the equivalent conicity of the wheel should not be too large or too small. On the other hand, a small primary vertical stiffness, a track gage around 1,435-1,438 mm, and a rail cant around 1:35-1:40 are beneficial for dynamic per-formance improvement and wheel wear alleviation.

  9. Examination of the causes of a bucket wheel fracture in a bucket wheel excavator

    Rusinski, E.; Harnatkiewicz, P.; Kowalczyk, M.; Moczko, P. [Wroclaw University of Technology, Wroclaw (Poland). Faculty of Mechanical Engineering

    2010-09-15

    A bucket wheel excavator failure occurred in a brown-coal mine. The failure was caused by a fractured shaft of the bucket wheel. An attempt to determine the causes of the bucket wheel shaft fracture has been made. To that end, the character of changing loads and their maximum amplitudes has been determined by performing measurements on the excavator. A discreet model of the shaft was built and a numerical simulation of the shaft operation using the FEM method was achieved. An analysis of the materials in the fracture area was also implemented. Macroscopic and microscopic images of the fracture area are provided. The shaft fracture was mainly caused by a non-metallic inclusion located below the surface of the shaft as a result of its being rolled. Moreover, it was discovered that the shaft had not been heat-treated.

  10. Problems of locomotive wheel wear in fleet replacement

    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.

  11. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    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.

  12. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    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.

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

    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.

  14. A simulation model for risk assessment of turbine wheels

    Safie, Fayssal M.; Hage, Richard T.

    A simulation model has been successfully developed to evaluate the risk of the Space Shuttle auxiliary power unit (APU) turbine wheels for a specific inspection policy. Besides being an effective tool for risk/reliability evaluation, the simulation model also allows the analyst to study the trade-offs between wheel reliability, wheel life, inspection interval, and rejection crack size. For example, in the APU application, sensitivity analysis results showed that the wheel life limit has the least effect on wheel reliability when compared to the effect of the inspection interval and the rejection crack size. In summary, the simulation model developed represents a flexible tool to predict turbine wheel reliability and study the risk under different inspection policies.

  15. Numerical and experimental analysis of a solid desiccant wheel

    Koronaki Irene P.; Papoutsis Efstratios; Papaefthimiou Vassilis; Rogdakis Emmanouel

    2016-01-01

    The rotary desiccant dehumidifier is an important component which can be used in air conditioning systems in order to reduce the electrical energy consumption and introduce renewable energy sources. In this study a one dimensional gas side resistance model is presented for predicting the performance of the desiccant wheel. Measurements from two real sorption wheels are used in order to validate the model. One wheel uses silica gel as desiccant material and ...

  16. MODELING AND STRUCTURAL ANALYSIS OF ALLOY WHEEL USING ANSYS

    Mr. Sasank Shekhar Panda*; Mr. Dibya Narayan Behera; Mr. Satya Narayan Tripathy

    2016-01-01

    Wheel spokes are the supports consisting of a radial member of a wheel joining the hub to the rim with Carbon Fiber, Magnesium Alloy, Titanium Alloy and Aluminum Alloy. The two main types of motorcycle rims are solid wheels, in which case the rim and spokes are all cast as one unit, usually in Aluminum or magnesium alloys and the other spoke wheels, where the motorcycle rims are laced with spokes which require high spoke tension, since the load is carried by fewer spokes. If a spoke does brea...

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

    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.

  18. REDUCING THE NEGATIVE INFLUENCE OF KINEMATIC DISCREPANCY IN THE TRANSMISSION OF FOUR-WHEEL DRIVE WHEELED VEHICLES

    Ismailov V. A.

    2015-12-01

    Full Text Available The article discusses different types of drive axles of all-wheel drive machine. It is shown that if blocked drive of driving axle easy, it is able to provide the best traction drive qualities of the all-wheel car, if compensation of kinematic mismatch in movement of front and rear wheels. The article provides analysis of the causes of kinematic mismatch and its consequences. The analysis was given for the existing methods to reduce negative influence of kinematic discrepancy on the work of the four-wheel drive wheeled machine in locked mode. The method of reduction of kinematic mismatch by regulations of the air pressure in the tires of the wheels with one-time control of the leading moments on the axes was suggested. We show the relationship between the difference of kinematic radii of the wheels of different axles and the difference of the moments leading to them. The algorithm and description for the system of automatic control of air pressure in the tire, which realizes the proposed method, were presented. We have described experimental methods of determining the energy losses evaluation from kinematic mismatch when moving all-wheel drive machine. The article presents the results of the this assessment in relation to the agricultural wheel tractor of class 5 moving at different substructures

  19. Strangulation--Suicide at the wheel.

    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. PMID:26594000

  20. Analysis of Wheel Hubs : Student Car

    Rincón García, Jesús

    2014-01-01

    The aim of this thesis work is to do the study and analysis of Student Car wheel hubs. The first part is a briefing of the “StudentCar” competition and a short explanation of the problem. Also it talks about the information and files that the team have about their hubs. After that, the document has short information about the basics knowledge of Strength of Materials necessary for to do the analysis in hubs and information about the material used by the team (Aluminum Alloy 7075-T6). ...

  1. MULTIAXIAL FATIGUE OF A RAILWAY WHEEL STEEL

    CHIN-SUNG CHUNG; HO-KYUNG KIM

    2015-01-01

    Uniaxial and biaxial torsional fatigue specimens were extracted from a railway wheel steel. The fatigue tests were performed with the stress ratio of R= -1 by using uniaxial and biaxial torsional fatigue test specimens at room temperature in air. The ultimate and yield strengths of the steel were evaluated. The uniaxial fatigue limit was 422.5 MPa, which corresponds to 67% of the ultimate tensile strength. The ratio of e  e  / was 0.63. Appropriate parameters to predict the fatigue life ...

  2. Yaw control using rear wheel steering

    Westbom, Daniel; Frejinger, Petter

    2002-01-01

    The purpose of this project is to continue the work on a vehicle model developed in ADAMS/Car and applied with the concept of ACM (Autonomous Corner Module). The project is divided up in two parts. The objective of the first part is to setup a co-simulation environment between ADAMS/Car and MATLAB/Simulink, and evaluate the vehicle model. In the second part a yaw controller is developed using only the rear wheel steering possibilities. The controller will be evaluated when it is applied on th...

  3. Innovative stair climber using associated wheels

    Modak, Girish Sudhir; Bhoomkar, Manmohan Manikrao

    2016-03-01

    The study proposes an innovative and completely new but low-cost configuration of a platform that can easily climb stairs. This platform serves the purpose of a chassis. Different versions, such as staircase-climbing wheelchair or staircase-climbing trolley for material transferring, can be derived depending on the structure built on the platform. The driving wheels have a shape that completely matches with the profile of the steps. Complex components are eliminated. Thus, this platform is conveniently applicable in the configurations useful for climbing staircases.

  4. Simulation of Intelligent Single Wheel Mobile Robot

    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

  5. New Small Wheel Technical Design Report

    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...

  6. Fatigue Properties of Cast Magnesium Wheels

    Li, Zhenming; Luo, Alan A.; Wang, Qigui; Peng, Liming; Zhang, Peng

    2016-05-01

    This paper investigates the fatigue properties and deformation behavior of a newly developed Mg-2.96Nd-0.21Zn-0.39Zr magnesium alloy wheel in both as-cast and T6 conditions. Compared with the as-cast alloy, the T6-treated alloy shows a significant increase in fatigue strength and cyclic stress amplitude. This is believed to be attributed to the change of defect type from porosity to oxides and the increased matrix strength in the T6 (peak-aged) condition. For the as-cast alloy wheel, fatigue failure mainly originated from the cast defects including porosity, oxide film, and inclusion at or near the sample surface. In the T6-treated alloy, however, oxides and inclusions or slip bands initiate the fatigue cracks. Solution treatment appears to reduce or eliminate the shrinkage porosity because of grain growth and dissolution of as-cast eutectic phases in the grain boundaries. The cyclic stress amplitude of the as-cast alloy increases with increasing the number of cycles, while the T6-treated alloy shows cyclic softening after the stress reaches a maximum value. The Coffin-Manson law and Basquin equation can be used to evaluate the life of low cycle fatigue. The developed long crack model and multi-scale fatigue (MSF) models can be used to predict high-cycle fatigue life of the Mg-2.96Nd-0.21Zn-0.39Zr alloys with or without casting defects.

  7. Study on target spallation reaction cross sections induced by high energy neutrons and heavy ions

    Nakamura, Takashi [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center

    1996-03-01

    The target spallation reaction cross sections of neutrons and heavy ions which have not been observed are determined in this paper. The object of this work is to make clear the differences between the spallation reaction cross section of neutron and that of proton by comparing the obtained value of neutron with the known value of proton. To this end, the quasi monochromatic neutron field of 20{approx}50 MeV was developed in 4 cyclotrons, INS, CYRIC, TIARA and RIKEN. The nuclear spallation reaction cross sections of C, Al and Bi were measured in the above field and the distribution of nuclear spallation reaction products in Cu determined by C ion beam of HIMAC. {sup 12}C(n,2n){sup 11}C reaction cross section shows the maximum value of about 20 mb at near 40{approx}50 MeV and then the value gradually decreased to 10 mb. The cross sections of {sup 209}Bi(n,Xn) are shown. The distribution of {sup 61}Cu is lower at the entrance and higher in the depth. (S.Y.)

  8. Automatic detection of flats on the rolling stock wheels

    J. Madejski

    2006-04-01

    Full Text Available Purpose: The goal of this work was increasing safety of tram, metro and trams operation.Design/methodology/approach: The accelerometers were fixed directly to the rail to provide the system with the best defect signal quality. Analysis of the acoustic signals collected using microphones proved that too much of the background noise limited their usefulness.Findings: It has been proven that all wheel geometry defects can be reliably detected and classified according to the experimentally established defect categories.Research limitations/implications: Exact measurements of the wheel defect geometry may be possible only after collecting huge signals time series along with the wheel measurements taken with other methods to reveal the relationships between them. This goal is hard to achieve, as the system performs already very well, and such experiments would be very costly and time consuming.Practical implications: Integrated wheel geometrical data collected from the wheel ovality, flat spots, and build-up detection system along with the wheel profile information have eliminated all derailments due to faulty wheel geometry.Originality/value: The system presented is the first wheel monitoring application in Poland, its unique feature is that it can be used at low speeds, like those allowed in depots.

  9. Wheeling and transmission system service policy in North America

    This paper provides a review and discussion of the status of wheeling in the USA and Canada; the pros and cons of the new policies that are evolving and under consideration for wheeling and transmission access; specific case examples of some of the difficulties that have arisen; and the potential for new transmission technology. (author)

  10. 14 CFR 25.497 - Tail-wheel yawing.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tail-wheel yawing. 25.497 Section 25.497 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.497 Tail-wheel yawing. (a) A...

  11. First Wheel of the Hadronic EndCap Calorimeter Completed

    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 ...

  12. Hybrid Control Design for a Wheeled Mobile Robot

    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...

  13. Hybrid Control Design for a Wheeled Mobile Robot

    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...

  14. The Wheels of Stress Go 'Round and 'Round

    Brey, Rebecca A.; Clark, Susan E.

    2012-01-01

    "The Wheels of Stress Go Round and Round" teaching idea uses three activity wheels to reinforce stress-related content and concepts. After presenting a definition of stress, the instructor assists students in identifying stressors, and aids in formulating a list of negative, reactive behaviors and a list of positive coping mechanisms. Using…

  15. Considering the Influence of Prerequisite Performance on Wheel Spinning

    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…

  16. Hybrid Control Design for a Wheeled Mobile Robot

    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...

  17. Controlling omni-directional Wheels of a MSL RoboCup autonomous mobile robot

    Ribeiro, António Fernando; Moutinho, Ivo; Silva, Pedro; Fraga, Carlos; Pereira, Nino

    2004-01-01

    Autonomous Mobile Locomotion is of extreme importance in RoboCup robots. Even though in 2050 the robotic team will very likely use legs rather than wheels, at the moment all teams on middle size league use wheels to overcome other problems first. Most teams are using two driving wheels (with one or two cast wheels), four driving wheels and even three driving wheels. The Minho team has been using two driving wheels for the last 5 years (with two caster wheels), but for reaction speed optimi...

  18. Fission fragment mass distribution studies for 28Si + 197Au, 209Bi, 235U reactions

    In reactions with heavy ions, complete fusion and quasi-fission are the competing processes at energies above the Coulomb barrier. The quasi-fission process, in which the system reseparates before reaching a compact compound nucleus, is a major hurdle in forming heavy and superheavy evaporation residues (ER) in heavy-ion reactions. Fission fragment mass distribution for the fully equilibrated compound nucleus is decided at the scission point due to a long descent from saddle to scission. At higher excitation energies, the shell effects are washed out and the mass distribution is expected to be symmetric. The width of the distribution strongly depends on the entrance channel properties, such as mass asymmetry, deformation of interacting nuclei, collision energy, and the Coulomb factor Z1 Z2. Any sudden change in the width of the mass distribution would indicate departure from full equilibration, while onset of mass asymmetry or a sudden increase in width would be a strong signal of quasi fission

  19. A method for testing railway wheel sets on a full-scale roller rig

    Liu, Binbin; Bruni, Stefano

    2015-09-01

    Full-scale roller rigs for tests on a single axle enable the investigation of several dynamics and durability problems related with the design and operation of the railway rolling stock. In order to exploit the best potential of this test equipment, appropriate test procedures need to be defined, particularly in terms of actuators' references, to make sure that meaningful wheel -rail contact conditions can be reproduced. The aim of this paper is to propose a new methodology to define the forces to be generated by the actuators in the rig in order to best reproduce the behaviour of a wheel set and especially the wheel -rail contact forces in a running condition of interest as obtained either from multi-body system (MBS) simulation or from on-track measurements. The method is supported by the use of a mathematical model of the roller rig and uses an iterative correction scheme, comparing the time histories of the contact force components from the roller rig test as predicted by the mathematical model to a set of target contact force time histories. Two methods are introduced, the first one considering a standard arrangement of the roller rig, the second one assuming that a differential gear is introduced in the rig, allowing different rolling speeds of the two rollers. Results are presented showing that the deviation of the roller rig test results from the considered targets can be kept within low tolerances (1% approximately) as far as the vertical and lateral contact forces on both wheels are concerned. For the longitudinal forces, larger deviations are obtained except in the case where a differential gear is introduced.

  20. Nonlinear analysis of the GFRP material wheel hub

    Dong Yun-Feng

    2015-01-01

    Full Text Available In this paper, the current bicycle wheel was replaced by the ones which composed by the wheel hub with Glassfiber Reinforced Plastic (alkali free thin-walled cylinder material, hereinafter referred to as GFRP material and the protective components made up of rubber outer pneumatic pad. With the help of the basic theory of elastic-plastic mechanics, the finite element “Nonlinear buckling” analysis of the wheel was carried out. The results show that the maximum elastic deformation of the wheel hub and the critical value of buckling failure load were restricted by the elasticity under the condition of external loads. Considering with the tensile strength and elastic modulus of the GFRP value of the material, it is demonstrated that the material is feasible to be used for wheel hub.

  1. A fully omnidirectional wheeled assembly for robotic vehicles

    A large number of wheeled or tracked platform mechanisms have been studied and developed to provide their mobility capability to teleoperated and autonomous robot vehicles. This paper presents an original wheeled platform based on an orthogonal wheel assembly that provides a full (three-degrees-of-freedom) omnidirectionality of the platform without wheel slippage and with the capability for simultaneous motions in rotation and translation (including sideways movements). A schematic of the basic wheel assembly is shown. The motion of the assembly is unconstrained (freewheeling) in the direction parallel to the main assembly shaft, while it is constrained in the direction perpendicular to the shaft, being driven in this direction by rotation of the shaft. A prototype platform was constructed to demonstrate the feasibility of this new concept

  2. Intranuclear cascade model for 50-MeV-region (p, p'x) reactions over a wide target mass range

    In our previous study, the applicable range of the intranuclear cascade model was successfully extended to lower incident energy (p, p'x) reactions by introducing trajectory deflections and low-energy-loss process due to collective excitations. However, the model's validity was confirmed only for a 56Fe target. In the present work we widen the applicable range of masses of the target nucleus. First, we derive an expression for the response function, which gives the probability of collective excitation strengths, to fit the distorted-wave Born approximation results as a function of the target mass number and the beam energy. Second, the barrier transmission coefficient was investigated. An expression with a modified Gamow penetration factor was chosen from four phenomenological forms of one-dimensional barrier transmission coefficients. Calculations with the proposed model followed by a generalized evaporation model were carried out for double-differential cross sections of (p, p'x) reactions at 30–60 MeV. Although the response function and the transmission coefficient were only parameterized approximately, the proposed model showed good agreements with experimental observations for a variety of nuclear targets from 12C to 209Bi. (author)

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

    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

  4. Infinity properads and infinity wheeled properads

    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.

  5. Well-to-wheel energy analysis study

    The analysis evaluates separately the fuel cycle (well to tank) and the propulsion (and emission control) systems (tank to wheel). The analysis assessed 75 different fuel pathways (gasoline diesel, Fischer Tropsch diesel, ethanol, methanol, hydrogen, and natural gas) and 15 different propulsion systems (conventional, conventional hybrid, and fuel cell) on a single vehicle type (GM full-size pickup). The results show that in terms of primary energy consumption, petroleum hybrid engines or fuel cell engines are significantly better than most natural gas options and all renewable options. However, in terms of greenhouse gas emissions, fuel-cell vehicles offer a clear edge (although diesel-engine hybrid vehicles are close), but renewable fuel options using ethanol (from biomass fermentation) offer the lowest emissions. (author)

  6. The sensory wheel of virgin olive oil

    Mojet, Jos

    1994-04-01

    Full Text Available During a 3-year FLAIR study extra virgin olive oils, varying in species, degree of ripeness and extraction method, were evaluated by 6 different institutes according to QDA or GDI-methods in order to identify parameters related to the quality of extra virgin olive oil. The current COI-method yields a poor between-panel reproducibility. This could well be caused by a difference in the perception of positive quality aspects. Whereas the QDA-method is especially suitable for determining sensory profiles according to the perception of the consumer, the COI-method should be tailored to detect possible defects only.
    In order to cluster all attributes to one condensed set of sensory attributes for describing virgin olive oil, the COI and QDA data of ail panels were pooled and analyzed separately for appearance, texture and flavour. This approach resulted in a set of 3 appearance, 3 texture and 12 flavour descriptors which can be conveniently represented graphically in the form of a "sensory wheel".
    On the basis of the findings it is recommended to base the "extra virgin" qualification for olive oils solely on the absence of defects. The between-panel reproducibility of such a simplified COI-test can be assessed by means of ring tests and improved by training with reference products. When an oil passes this screening it can be profiled subsequently using the attributes of the sensory wheel. Such a profile can be linked to preferential profiles derived from consumer studies enabling the production of most preferred olive oils.

  7. Online measurement for geometrical parameters of locomotive wheel set

    Wu, Kaihua; Li, Zhengjie; Ban, Tao

    2009-11-01

    Locomotive is the most important parts of a train. Wheel set is the major running components of a locomotive. Wheel set tread is the contacting part with the rail and tread will be worn down gradually. The wearing degree of the wheel set tread is one of the main factors that influence the safety and stability of running train. The measurement of wheel set wear is usually static and by handwork, which limits the accuracy and reliability. An automatic measurement method for geometrical parameters of locomotive wheel set based on optoelectronic technique was proposed. Geometrical parameters include flange thickness, flange height and rim inside distance. Linear structured laser light was projected on the wheel tread surface. The geometrical parameters can be deduced from the profile image. An online image acquisition system was designed based on asynchronous reset of CCD. Precision hardware time-delay and asynchronous reset pulse generation circuits were designed. The entire time sequence of asynchronous reset was researched. Images were acquired only when wheel sets moved into the designed position. The image acquisition was fulfilled by hardware interrupt mode. The measuring system was installed along the straight railway section. When the locomotive was running in a limited speed, the devices placed alone railway line can measure the geometrical parameters automatically.

  8. Sustainable Rural Energy: Traditional Water Wheels in Padang (PWW) Indonesia

    Ibrahim, Gusri Akhyar; Haron, Che Hassan Che; Azhari, Che Husna

    2010-06-01

    Renewable and sustainable energy is increasingly gaining interest in current research circles due to the debates on renewable energy resources. It is essential for scientists and researchers to search for solutions in renewable energy resources, with effective technologies, and low cost in operation and maintenance. Hydro resources can be considered a potential renewable energy resource. The traditional water wheel with simple construction coupled with a basic concept of technology can be utilised as a renewable and sustainable rural energy system. This paper discusses the case of the water wheel as a renewable energy system employed in Padang, Indonesia. The Padang water wheel is constructed from hardwood material with a diameter of 300 cm and width of 40 cm. It is built on a river using water flow to generate the movement of the wheel. The water wheel application in the area showed that it is suitable to be utilised to elevate and distribute water to rice fields located at a higher level than the water level of the river. The water wheel capacity is about 100-120 liters/min. It could continuously irrigate ±5 ha. of the rice fields. One of the advantages of this water wheel type is to function as a green technology concept promising no negative effect on the environment. The traditional water wheel has also a big economic impact on the rural economy, increasing the productivity of the rice fields. The people of Padang live in a water landscape encompassing the water wheel as an ubiquitous part of their lives, hence they relate to it and the technology of fabrication as well as the utilisation, making it an amenable and effective technology, finding relevance in the modern world.

  9. Interaction between a railway track and uniformly moving tandem wheels

    Belotserkovskiy, P. M.

    2006-12-01

    Interaction among loaded wheels via railway track is studied. The vertical parametric oscillations of an infinite row of identical equally spaced wheels, bearing constant load and uniformly moving over a railway track, are calculated by means of Fourier series technique. If the distance between two consecutive wheels is big enough, then one can disregard their interaction via the railway track and consider every wheel as a single one. In this case, however, the Fourier series technique represents an appropriate computation time-saving approximation to a Fourier integral transformation technique that describes the oscillations of a single moving wheel. Two schemes are considered. In the first scheme, every wheel bears the same load. In the second one, consecutive wheels bear contrarily directed loads of the same magnitude. The second scheme leads to simpler calculations and so is recommended to model the wheel-track interaction. The railway track periodicity due to sleeper spacing is taken into account. Each period is the track segment between two adjacent sleepers. A partial differential equation with constant coefficients governs the vertical oscillations of each segment. Boundary conditions bind the oscillations of two neighbour segments and provide periodicity to the track. The shear deformation in the rail cross-section strongly influences the parametric oscillations. It also causes discontinuity of the rail centre-line slope at any point, where a concentrated transverse force is applied. Therefore, Timoshenko beam properties with respect to the topic of this paper are discussed. Interaction between a railway track and a bogie moving at moderate speed is studied. The study points to influence of the bogie frame oscillations on variation in the wheel-rail contact force over the sleeper span. The simplified bogie model considered includes only the primary suspension. A static load applied to the bogie frame centre presents the vehicle body.

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

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

    2006-01-01

    The rotary regenerator (also called the heat wheel) is an important component of energy intensive sectors, which is used in many heat recovery systems. In this paper, a model-based analysis of a rotary regenerator is carried out with a major emphasis given to the development and implementation 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) on...

  11. Symbolic derivation of bicycle kinematics with toroidal wheels

    Wang Everett X.

    2015-01-01

    Full Text Available Bicycle kinematics with toroidal wheels is presented in this paper. Using symbolic mathematic tool Maple, we obtain two holonomic and four nonholonomic constraint equations due to front and rear wheels of a bicycle. We show that the two holonomic constraints cannot be expressed in quartic form for bicycle rear body pitch angle unless the minor (crown radius of the torus are the same for both the front and rear wheels. In addition, we show that all the constraints can be written in differential form, from which a constraint matrix is constructed, according to standard procedure for developing dynamics in robotics.

  12. Impulsive dynamics and stabilization of a single wheel robot

    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.

  13. Identification of wheeling paths by an extended sensitivity analysis

    This paper proposes a practical method for identifying wheeling paths in deregulated electricity markets based on an extended sensitivity analysis. Using this method, it becomes possible to decide the proper and fair wheeling rate according to the degree of burden on transmission lines by each power flow transaction. Moreover, a wheeling rate based on the real power flow burden is also an important signal to new power suppliers in the markets. In order to show the validity of the proposed method, a series of simulations on the IEEE 30-bus test system were conducted. (author)

  14. Motion planning of a robotic arm on a wheeled vehicle on a rugged terrain

    Hwang, Yong K.

    1996-03-01

    This paper presents a set of motion planners for an exploration vehicle on a simulated rugged terrain. The vehicle has four wheels for its movement and a robotic arm mounted on the vehicle for object manipulation. Given a target point to reach with the hand of the arm, our planners first compute a path for the vehicle to the vicinity of the target, then compute an optimal vehicle position from which the arm can reach the target point, and then plans a path for the arm to reach the target. The vehicle path is planned in two stages. A rough path is planned considering only global features of the terrain, and the path is modified by a local planner to avoid more detailed features of the terrain. The planners are expected to increase the autonomy of robots and improve the efficiencies of exploration missions.

  15. REDUCING THE NEGATIVE INFLUENCE OF KINEMATIC DISCREPANCY IN THE TRANSMISSION OF FOUR-WHEEL DRIVE WHEELED VEHICLES

    Ismailov V. A.; Melikov I. M.

    2015-01-01

    The article discusses different types of drive axles of all-wheel drive machine. It is shown that if blocked drive of driving axle easy, it is able to provide the best traction drive qualities of the all-wheel car, if compensation of kinematic mismatch in movement of front and rear wheels. The article provides analysis of the causes of kinematic mismatch and its consequences. The analysis was given for the existing methods to reduce negative influence of kinematic discrepancy on the work of t...

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

    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.

  17. Vehicle wheels vibration suppression by dynamic vibration absorber

    Zinovij STOTSKO

    2007-01-01

    Full Text Available The article deals with the methods of calculation and optimization ofdynamic processes in vibroexcitated constructions with dynamic absorbers. The improved constructions of such absorbers for vehicle wheels vibration suppression are discussed.

  18. Forces on wheels and fuel consumption in cars

    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.

  19. Fluid Mechanics of a High Performance Racing Bicycle Wheel

    Mercat, Jean-Pierre; Cretoux, Brieuc; Huat, Francois-Xavier; Nordey, Benoit; Renaud, Maxime; Noca, Flavio

    2013-11-01

    In 2012, MAVIC released the most aerodynamic bicycle wheel on the market, the CXR 80. The french company MAVIC has been a world leader for many decades in the manufacturing of bicycle wheels for competitive events such as the Olympic Games and the Tour de France. Since 2010, MAVIC has been in a research partnership with the University of Applied Sciences in Geneva, Switzerland, for the aerodynamic development of bicycle wheels. While most of the development up to date has been performed in a classical wind tunnel, recent work has been conducted in an unusual setting, a hydrodynamic towing tank, in order to achieve low levels of turbulence and facilitate quantitative flow visualization (PIV). After a short introduction on the aerodynamics of bicycle wheels, preliminary fluid mechanics results based on this novel setup will be presented.

  20. Miniature Reaction Wheel for Small Satellite Control Project

    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....

  1. Numerical and experimental analysis of a solid desiccant wheel

    Koronaki Irene P.

    2016-01-01

    Full Text Available The rotary desiccant dehumidifier is an important component which can be used in air conditioning systems in order to reduce the electrical energy consumption and introduce renewable energy sources. In this study a one dimensional gas side resistance model is presented for predicting the performance of the desiccant wheel. Measurements from two real sorption wheels are used in order to validate the model. One wheel uses silica gel as desiccant material and the other lithium chloride. The simulation results are in good agreement with the experimental data. The model is used to compare the counter flow with the co-current wheel arrangements and to explain why the counter flow one is more efficient for air dehumidification.

  2. BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL DEPAINTING

    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 point from aircraft wheels. he evaluation was conducted in the Paint Stripping Shop ...

  3. BICARBONATE OF SODA BLASTING TECHNOLOGY FOR AIRCRAFT WHEEL PAINTING

    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...

  4. Forces on wheels and fuel consumption in cars

    Motivated by real classroom discussions, we analyze the forces acting on moving vehicles, specifically friction on their wheels. In typical front-wheel-drive cars 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 paper we also study the thermodynamical aspects of an accelerating car, relating the distance traveled to 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 into the thermodynamical description of the accelerating car. The more realistic case of the car's motion with the dragging forces taken into account is also discussed. (paper)

  5. Characterization of grinding wheels: An annotated Bibliography. Final report

    McClung, R.W.

    1995-12-01

    The characteristics of grinding wheels, after both fabrication and periods of operation, have a significant effect on the processed surface and the mechanical properties of advanced ceramics. An extensive literature survey and review has been conducted to determine and catalogue the various characterization methods that have been investigated and reported. Although many of the references have addressed the grinding of metals, the historical and technical merit justify their inclusion in this bibliography. For convenience, the references have been subdivided into nine subheadings: Nondestructive examination; elasticity and stiffness; wheel hardness; topography and profilometry; observation of texture of wheel surfaces wheel wear; in process monitoring of grinding, acoustic emission, other; characteristics of ground surfaces; and miscellaneous.

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

    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

  7. Damage evolution assessment and modeling for CBN grinding wheel wear

    YU, TIANYU; Bastawros, Ashraf F; Chandra, Abhijit

    2014-01-01

    The wear rate of a grinding wheel directly affects the workpiece surface integrity and tolerances. This paper summarizes a combined experimental-modeling framework for life expectancy of an electroplated Cubic Boron Nitride (CBN) grinding wheel, typically utilized in nickel-based superalloy grinding. The article presents an experimental framework to facilitate the formulation of a micromechanics based modeling framework. The presented study investigates the topological evolution of the grindi...

  8. High Speed, Low Weight Momentum/Reaction Wheels

    Wilhide, Larry; Brothers, Louis; Breyer, Eugene

    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...

  9. The influence of different steering systems on a wheel slip

    D. Stajnko

    2012-12-01

    Full Text Available Purpose: Modern and advanced mountain tractor allows four different modes of steering wheels: front wheels, back wheels, four wheels and crab steering. The current paper presents the impact of different ways of steering to control the slip in the work transverse on the steep hill slope (39.08%. Design/methodology/approach: For each mode of steering eight measurements were made; four measurements at a forecasted speed of 0.69 m/s and four measurements at a speed of 1.39 m/s. During the two of four measurements the travelling direction was from the left to the right, and vice versa.Findings: The measured slip depended significantly on the steering system, while the driving direction did not cause any differences in the slip.Research limitations/implications: The experiment results presented herein can be applied only with the similar mountain tractors, which allows four different modes of steering wheels. Additional limitation represents the working polygon and the growing conditions of grass.Practical implications: The crab - steering resulted in the smallest slip (5.96% at the average driving speed of 1.08 m/s. When steering with all four wheels, the slip at the average speed of 1.03 m/s increased to 7.27%. The biggest slip was measured when steering with only front wheels was applied. In this case the slip was 8.07% at the average speed of 1.01 m/s.Originality/value: The findings from our experiments indicated that it is very useful to have all wheels steering tractor when working on step slope, because it is grass friendly, offers bigger agility of tractor and improve the safety of the operator.

  10. Electric Power Controller for Steering Wheel Management in Electric Cars

    Milanés, Vicente; Pérez Rastelli, Joshué; Onieva, Enrique; González, Carlos; Pedro, Teresa de

    2009-01-01

    International audience Driverless driving is one of the most interesting topics in the field of the intelligent transportation systems. Among these topics, the automation of the actuators involved in the management of a car, and out of them the control of the steering wheel constitute one of the most complex. In this paper, automatic power steering architecture to manage the steering wheel via Ethernet controller is developed. An on-board PC is connected to the controller to permit handlin...

  11. Integrated control strategies for railway vehicles with independently-driven wheel motors

    Jinzhi FENG; Jun LI; R. M. Goodall

    2008-01-01

    This paper studies the development of inte-grated control strategies for railway vehicles with inde-pendently-driven wheel motors. First, a non-linear vehicle dynamic model and motor drive strategy are pre-sented, which are followed by an investigation of the inte-grated control of stabilization, steering, and traction for the vehicle. Meanwhile a reformulated Kalman filter is developed and applied to estimate the required feedback by the control system. Finally, the effectiveness and prac-ticality of the proposed integrated controller are examined and assessed by real-time simulation based on host-target computer technology provided by Matlab/Simulink.

  12. Railway ground vibrations induced by wheel and rail singular defects

    Kouroussis, Georges; Connolly, David P.; Alexandrou, Georgios; Vogiatzis, Konstantinos

    2015-10-01

    Railway local irregularities are a growing source of ground-borne vibration and can cause negative environmental impacts, particularly in urban areas. Therefore, this paper analyses the effect of railway track singular defects (discontinuities) on ground vibration generation and propagation. A vehicle/track/soil numerical railway model is presented, capable of accurately predicting vibration levels. The prediction model is composed of a multibody vehicle model, a flexible track model and a finite/infinite element soil model. Firstly, analysis is undertaken to assess the ability of wheel/rail contact models to accurately simulate the force generation at the wheel/rail contact, in the presence of a singular defect. It is found that, although linear contact models are sufficient for modelling ground vibration on smooth tracks, when singular defects are present higher accuracy wheel/rail models are required. Furthermore, it is found that the variation in wheel/rail force during the singular defect contact depends on the track flexibility, and thus requires a fully coupled vehicle/track/foundation model. Next, a parametric study of ground vibrations generated by singular rail and wheel defects is undertaken. Six shapes of discontinuity are modelled, representing various defect types such as transition zones, switches, crossings, rail joints and wheel flats. The vehicle is modelled as an AM96 train set and it is found that ground vibration levels are highly sensitive to defect height, length and shape.

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

    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...

  14. Optimization of Angular-Momentum Biases of Reaction Wheels

    Lee, Clifford; Lee, Allan

    2008-01-01

    RBOT [RWA Bias Optimization Tool (wherein RWA signifies Reaction Wheel Assembly )] is a computer program designed for computing angular momentum biases for reaction wheels used for providing spacecraft pointing in various directions as required for scientific observations. RBOT is currently deployed to support the Cassini mission to prevent operation of reaction wheels at unsafely high speeds while minimizing time in undesirable low-speed range, where elasto-hydrodynamic lubrication films in bearings become ineffective, leading to premature bearing failure. The problem is formulated as a constrained optimization problem in which maximum wheel speed limit is a hard constraint and a cost functional that increases as speed decreases below a low-speed threshold. The optimization problem is solved using a parametric search routine known as the Nelder-Mead simplex algorithm. To increase computational efficiency for extended operation involving large quantity of data, the algorithm is designed to (1) use large time increments during intervals when spacecraft attitudes or rates of rotation are nearly stationary, (2) use sinusoidal-approximation sampling to model repeated long periods of Earth-point rolling maneuvers to reduce computational loads, and (3) utilize an efficient equation to obtain wheel-rate profiles as functions of initial wheel biases based on conservation of angular momentum (in an inertial frame) using pre-computed terms.

  15. In-wheel hub SRM simulation and analysis

    Sager, Milton W., III

    Is it feasible to replace the conventional gasoline engine and subsequent drive system in a motorcycle with an electric switched reluctance motor (SRM) by placing the SRM inside the rear wheel, thereby removing the need for things such as a clutch, chain, transmission, gears and sprockets? The goal of this thesis is to study the theoretical aspect of prototyping and analyzing an in-wheel electric hub motor to replace the standard gasoline engine traditionally found on motorcycles. With the recent push for clean energy, electric vehicles are becoming more common. All currently produced electric motorcycles use conventional, prefabricated electric motors connected to the traditional sprocket and chain design. This greatly restricts the efficiency and range of these motorcycles. My design stands apart by turning the rear wheel into a SRM which uses electromagnets around a non-magnetic core to convert electrical energy into mechanical force driving the rear wheel. To my knowledge, there is currently no motorcycle designed with an in-wheel hub SRM. A three-phase SRM and a five-phase SRM will be simulated and analyzed using MATLAB with Simulink. Factors such as friction, weight, power, etc. will be taken into account in order to create a realistic simulation as if it were inside the rear wheel of a motorcycle. Since time and finances will not allow for a full scale build, a scaled model three-phase SRM will be attempted for demonstration purposes.

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

    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. PMID:26994970

  17. Residual stresses in railway wheels and their effect on damage rates through the life of a wheel

    Molyneux-Berry, Paul; Bevan, Adam

    2013-01-01

    Wheelset maintenance and renewal comprises a significant portion of the whole-life cost of railway rolling stock. At present, many GB passenger trains have their wheels turned on a lathe at regular intervals to prevent the propagation of Rolling Contact Fatigue (RCF) cracks in the rim. Evidence from a number of fleets suggests that RCF damage occurs much more quickly as the wheelsets near the end of their life. Wheel manufacturing processes are intended to induce a compressive hoop stress in ...

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

    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.

  19. Control for 4-Wheel Individual Steering and 4-Wheel Driving Electronic Vehicle

    Oshima, Hiroyasu; Tani, Masashi; Kobayashi, Nobuaki; Ishii, Akira; Imai, Katsuya

    An indoor 4-wheel individual steering and driving vehicle with full electronics was built for evaluating the system ability and the performance in practical use. Mechanical parts such as the connecting rod and the differential gear are not provided for this vehicle. From trial operation, the characteristics are fully performed as in design, but some problems that originated from the design concept are disclosed. Rotating radius (R) of the vehicle was taken for steering command parameter, but it was found that it is not an appropriate parameter for driving operation. The reasons are as follows 1) R has much different sense of driving conformability for the driver, because it doesn’t refer to the running direction, but to the rotating radius of crosswise direction. 2) Sensitivity of each wheel steering angle against R differs over double figures in full range of R. 3) R changed from plus to minus and also the other way in most practical situations around go-straight operation. For these reasons, the steering command parameter was changed from R to α, where α is the angle between vehicle lengthwise direction and the moving direction. The steering control algorithm using α parameter has been proven to solve the above mentioned problems 1), 2), and 3).

  20. 高速立方氮化硼砂轮与绿色制造%High speed CBN grinding wheel and the green manufacturing

    杨威; 刘将先; 王帅; 李学文; 李学仁; 李世华

    2014-01-01

    In this study the vitrified bond CBN wheels are compared with the conventional corundum wheels in the grinding of automotive engine camshaft and crankshaft The results show that the durability of the high speed vitrified bond CBN wheels is 100 times that of the conventional corundum wheels and its service life is 44 4 times that of the conventional corundum wheels but the raw material consumption is only 1 5 6 When in the same amounts preparation the abrasive consumption of using corundum wheels is more than 400 times that of the high speed vitrified bond CBN wheels When the conventional corundum wheels are replaced by the high speed vitrified bond CBN wheels it would improve production efficiency more than 30% and save more than 60% production cost The high speed grinding wheel is an environment-protection products with high precision high efficiency low production costs less environment pollution which make it be a sharp weapon for realizing the target of green process.%以磨削加工汽车发动机凸轮轴、曲轴为例,对陶瓷 CBN 砂轮与普通刚玉砂轮进行了加工效果对比。结果表明:高速陶瓷 CBN 砂轮的耐用度是普通陶瓷刚玉砂轮的100倍,寿命是普通砂轮的的44.4倍,而原材料消耗仅为其1/56;加工相同的工件数量,使用刚玉砂轮进行加工,磨料消耗是高速CBN砂轮的400余倍;采用高速陶瓷CBN砂轮代替刚玉砂轮可提高生产效率30%以上,综合生产成本比刚玉砂轮磨削降低60%。高速CBN砂轮具有高效率、高精度、低磨削成本,低环境污染的技术优势,其代表了当今世界磨具产品发展的一个主要方向,是实现绿色加工目标的有效手段。

  1. Applied design methodology for lunar rover elastic wheel

    Cardile, Diego; Viola, Nicole; Chiesa, Sergio; Rougier, Alessandro

    2012-12-01

    In recent years an increasing interest in the Moon surface operations has been experienced. In the future robotic and manned missions of Moon surface exploration will be fundamental in order to lay the groundwork for more ambitious space exploration programs. Surface mobility systems will be the key elements to ensure an efficient and safe Moon exploration. Future lunar rovers are likely to be heavier and able to travel longer distances than the previously developed Moon rover systems. The Lunar Roving Vehicle (LRV) is the only manned rover, which has so far been launched and used on the Moon surface. Its mobility system included flexible wheels that cannot be scaled to the heavier and longer range vehicles. Thus the previously developed wheels are likely not to be suitable for the new larger vehicles. Taking all these considerations into account, on the basis of the system requirements and assumptions, several wheel concepts have been discussed and evaluated through a trade-off analysis. Semi-empirical equations have been utilized to predict the wheel geometrical characteristics, as well as to estimate the motion resistances and the ability of the system to generate thrust. A numerical model has also been implemented, in order to define more into the details the whole wheel design, in terms of wheel geometry and physical properties. As a result of the trade-off analysis, the ellipse wheel concept has shown the best behavior in terms of stiffness, mass budget and dynamic performance. The results presented in the paper have been obtained in cooperation with Thales Alenia Space-Italy and Sicme motori, in the framework of a regional program called STEPS . STEPS-Sistemi e Tecnologie per l'EsPlorazione Spaziale is a research project co-financed by Piedmont Region and firms and universities of the Piedmont Aerospace District in the ambit of the P.O.R-F.E.S.R. 2007-2013 program.

  2. Investigation of the Wheel-Flange Lubrication of Railway Trains

    A tracer method was applied to investigate the wheel-flange lubrication action of the new Austrian multiple-unit train ''Transalpin''. On electric engines the flanges of the first pair of wheels are lubricated by a pendulum oil pump. This pump starts to work when there is lateral movement of the engine in curves or at high speed on straight lines. The lubricating oil is transferred, while the train is underway, from the first wheel to the inner surface of the rail. From there it should be taken up by the following wheels of the train. In this way the friction between the rails and the wheel flanges can be reduced and as a consequence the wear of material is decreased. Until the present investigation it has not been possible to get quantitative information about the action of this type of lubrication. By adding the tracer 198Au in the form of a colloid to the lubricating oil (specific activity 0.5 Ci/litre), quantitative measurements of the oil transport mechanism could be made on the moving train. The detection of the labelled lubricant was possible even on the last wheels of a train of 44 axles. The oil films which were still detectable on the wheel flanges had a thickness of about 0. 3 microns. By this tracer method, the dependence of lubrication on the speed and the line conditions can also be determined. The tracer method has a wide range of applications in the study of underway conditions in railroad operation including the investigation of the sine movement of trains. (author)

  3. Economic efficiency, independent power producers and wheeling

    Traditionally, electric utilities have sought to decrease the cost of production by such means as merit order running of machines, by improving equipment efficiency, by fuel mix, by interconnection and exchange of cheap energy, and by unit participation and firm purchase and sale contracts for long term savings. In the ''new look'', it was suggested that financial and technical competition is not enough, and that economic gains could be achieved through fostering independent power producers, i.e., non-utility generators (NUG's), greater exchanges of economy energy, unrestricted access to the transmission network for moving cheap energy through facilities of third parties, and by bidding to supply energy to non-generators, etc. Naturally, the proposals to change the comfortable and time-hallowed practices by which utility business had been carried out in the past has created an ongoing debate both pro and con, much of it acrimonious, and, unfortunately, some of it ill-informed. The turmoil in the political context impacts on a utility's technical and financial planners, and on their managements, all of whom contribute to justifying and maintaining the flow of capital to the industry and energy to the customer. They must now seek new ways to implement both short- and long-term planning of power supply. Some of the factors that were neglected in the past will demand more attention in the future. This paper discusses some of the costs that, under the anticipated modus operandi, must be integrated into the planning process while meeting the new challenges. The costs are those relating to third-parties, costs of transmission constraints, and costs of wheeling. The opinion is ventured that much of the efficiency improvement anticipated during the debate has already been achieved by conscientious utility managements. (author)

  4. Car Gestures - Advisory warning using additional steering wheel angles.

    Maag, Christian; Schneider, Norbert; Lübbeke, Thomas; Weisswange, Thomas H; Goerick, Christian

    2015-10-01

    Advisory warning systems (AWS) notify the driver about upcoming hazards. This is in contrast to the majority of currently deployed advanced driver assistance systems (ADAS) that manage emergency situations. The target of this study is to investigate the effectiveness, acceptance, and controllability of a specific kind of AWS that uses the haptic information channel for warning the driver. This could be beneficial, as alternatives for using the visual modality can help to reduce the risk of visual overload. The driving simulator study (N=24) compared an AWS based on additional steering wheel angle control (Car Gestures) with a visual warning presented in a simulated head-up display (HUD). Both types of warning were activated 3.5s before the hazard object was reached. An additional condition of unassisted driving completed the experimental design. The subjects encountered potential hazards in a variety of urban situations (e.g. a pedestrian standing on the curbs). For the investigated situations, subjective ratings show that a majority of drivers prefer visual warnings over haptic information via gestures. An analysis of driving behavior indicates that both warning approaches guide the vehicle away from the potential hazard. Whereas gestures lead to a faster lateral driving reaction (compared to HUD warnings), the visual warnings result in a greater safety benefit (measured by the minimum distance to the hazard object). A controllability study with gestures in the wrong direction (i.e. leading toward the hazard object) shows that drivers are able to cope with wrong haptic warnings and safety is not reduced compared to unassisted driving as well as compared to (correct) haptic gestures and visual warnings. PMID:26264518

  5. Electric pulse treatment of rim wheel metal after operation

    L.I.Vakulenko

    2013-02-01

    Full Text Available Introduction. Load increase on the wheel pair ax requires the use of railway wheels with the advanced complex of properties. Except strength properties, the properties of metal resistance to defect nucleation on the wheel thread are of high importance. The above mentioned properties increase is possible by using different technological decisions: alloying and heat strengthening. Purpose. The purpose is an attempt to estimate the softening degree of the wheel thread metal using the electric pulse treatment. Methodology. Electric pulse treatment (ET was carried out on the special plant in the conditions of JSC DS (Nikolayev city. As the property of metal strength the Vickers hardness number is used. The microstructure research was carried out using the light microscope. The material for research is the carbon steel of the rim fragment of railway wheel №181732, withdrawn after operation, containing 0,55%С, 0,74%Mn, 0,33%Si, 0,009%P, 0,01%S, 0,06% Ni, 0,1%Cr, 0,08%Cu. Findings. Exposing the rim fragment to electric pulse treatment (ET, the qualitative changes of internal structure of the wheel rim metal corresponded to the experimentally observed geometrical dimensions change of the specimen, depending on the cycles number. As a result of the treatment the reduction of cold strained metal hardness is observed. It was found out 20 % softening on the wheel thread for the І rim area the, for the ІІ rim area the 8% softening and for the ІІІ 11% softening in relation to the initial state. Originality. As a result of electric pulse treatment, the change of the specimen geometrical dimensions is observed. Depending on the number of cycles it causes softening effect. It is proved that the observed softening value during ET is qualitatively connected with the cold strain level on the rail wheel thread. Practical value. As a result of metal cold work on the wheel thread its resistance to the defect nucleation is being reduced. The resulted data can

  6. Parametric study of wheel transitions at railway crossings

    Wan, C.; Markine, V. L.

    2015-12-01

    Vehicle-track interaction at railway crossings is complex due to the discontinuity of the crossings. In this study, the effect of the local crossing geometry, the track alignment, and the wheel profiles on the wheel transition behaviour is investigated using the multi-body system software package VI-Rail. The transition behaviour is evaluated based on the location of the transition point along the crossing (and the location of impact), the contact pressure and the energy dissipation during the wheel-rail contact. A detailed parametric study of the crossing geometry has been performed, through which the most effective parameters for defining the crossing geometry are identified. These parameters are the cross-sectional shape of the nose rail, which can be tuned by one variable, and the vertical distance between the top of the wing rail and the nose rail. Additionally, a parametric study on the interaction influence of the crossing geometry, the track alignment and the wheel profile is performed using the design of experiments method with a two-level full factorial design. The longitudinal height profile of the crossing and the wheel profile are the most significant factors.

  7. Transmission access and retail wheeling. The key questions

    Casazza, J.A. [CSA Energy Consultants, Inc., Arlington, VA (United States)

    1996-12-31

    The key questions involving transmission access and retail wheeling are discussed, distinguishing between opposing views regarding the effect on system costs and the environment, particularly on optimal planning involving matching capacity and demand, generation use, demand side management, and economic operations. Also discussed are contrasting views regarding the effect of cost control pressures, regulatory advantages and disadvantages, the impact on system reliability, and the stranding of investment. The author`s key concern is the effect of retail wheeling upon optimal planning and operation i.e., will competitors be willing to provide one another with the cost and technical information required for coordination? In his worst scenario, retail wheeling may lead to substantial production cost increases, lessened reliability, and unfair cost-shifting between customer classes. More optimistically, production costs and reliability may be unaffected and the cost-shifting could be salubrious. 7 figs., 11 refs.

  8. Model Design for Water Wheel Control System of Heumgyeonggaknu

    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.

  9. Fuzzy model for predicting the number of deformed wheels

    Ž. Đorđević

    2015-10-01

    Full Text Available Deformation of the wheels damage cars and rails and affect on vehicle stability and safety. Repair and replacement cause high costs and lack of wagons. Planning of maintenance of wagons can not be done without estimates of the number of wheels that will be replaced due to wear and deformation in a given period of time. There are many influencing factors, the most important are: weather conditions, quality of materials, operating conditions, and distance between the two replacements. The fuzzy logic model uses the collected data as input variables to predict the output variable - number of deformed wheels for a certain type of vehicle in the defined period at a particular section of the railway.

  10. Fabrication of low cost cutting wheel via thermal spray process

    Anasyida, A. S.; Nurulakmal, M. S.

    2012-09-01

    The present study is mainly focused on development of metal cutting wheel. The process involved hard particles (abrasives) being bonded on the wheel to enhance the cutting capability by thermal spraying process and followed by polymer bonding. The purpose of this work is to produce low cost cutting wheel and study the performance of cutting behavior. Two different types of powders; silicon carbide (SiC) as bonding agent and chromium carbide (Cr3C2) as abrasives were used. Wear loss and depth of cut as function of load, cutting time and cutting speed were evaluated. The results showed that the speed and load were the main factors that affected the cutting efficiency and the optimum cutting process can be performed at low cutting speed and high load or at high cutting speed and low load.

  11. Transmission access and retail wheeling. The key questions

    The key questions involving transmission access and retail wheeling are discussed, distinguishing between opposing views regarding the effect on system costs and the environment, particularly on optimal planning involving matching capacity and demand, generation use, demand side management, and economic operations. Also discussed are contrasting views regarding the effect of cost control pressures, regulatory advantages and disadvantages, the impact on system reliability, and the stranding of investment. The author's key concern is the effect of retail wheeling upon optimal planning and operation i.e., will competitors be willing to provide one another with the cost and technical information required for coordination? In his worst scenario, retail wheeling may lead to substantial production cost increases, lessened reliability, and unfair cost-shifting between customer classes. More optimistically, production costs and reliability may be unaffected and the cost-shifting could be salubrious. 7 figs., 11 refs

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

    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.

  13. NSTS Orbiter auxiliary power unit turbine wheel cracking risk assessment

    Cruse, T. A.; Mcclung, R. C.; Torng, T. Y.

    1992-01-01

    The present investigation of turbine-wheel cracking problems in the hydrazine-fueled APU turbine wheel of the Space Shuttle Orbiter's Main Engines has indicated the efficacy of systematic probabilistic risk assessment in flight certification and safety resolution. Nevertheless, real crack-initiation and propagation problems do not lend themselves to purely analytical studies. The high-cycle fatigue problem is noted to generally be unsuited to probabilistic modeling, due to its extremely high degree of intrinsic scatter. In the case treated, the cracks appear to trend toward crack arrest in a low cycle fatigue mode, due to a detuning of the resonance model.

  14. Fabrication of micro gear wheels by micropowder injection molding

    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.

  15. Effect of food toxicants on voluntary wheel running in rats.

    Squibb, R E; Squibb, R L

    1979-05-01

    Voluntary wheel running in rats in reaction to a dietary deficiency of iron or food toxicants of natural (dioscin) and environmental (cadmium) origins was used to develop a behavioral model by which rapid detection of food contaminants was accomplished following induction of spontaneous activity by techniques of feed restriction. High levels of voluntary wheel running in reference controls were followed by significant depressions in running activity in animals fed the dietary toxicants. Analyses of blood and liver tissues and depressions of testes size confirmed the presence of the insults to metabolism. PMID:438894

  16. Unusual orbitocranial penetrating injury by a grinding wheel: case report

    Murat Vural; Yakup Karabagli; Hikmet Basmak; Baki Adapinar; Ramazan Durmaz; Metin Ant Atasoy

    2009-01-01

    @@ Orbitocranial penetrating injuries are uncommon and usually life threatening, which constitute about 0.4% of all head injuries, 24% of penetrating head trauma in adults, and 45% in children.1,2,3They may occur accidentally or due to an assault and may have serious consequences and can be potentially fatal.4,5 Immediate plastic and reconstructive surgery, ophthalmology and radiology consultations are essential for the proper diagnosis and treatment. We reported an adult patient with a transorbital cerebral injury by an unusual material---grinding wheel. To our knowledge, this is the first reported case of transorbital penetrating injury by a grinding wheel in the literature.

  17. A Feasability Study of the Wheel Electrostatic Spectrometer

    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.

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

    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.

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

    A. Kliuchnikov

    2014-01-01

    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. 

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

    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. 

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

    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.

  2. Residual Stress in Wheels: Comparison of Neutron Diffraction and Ultrasonic Methods, with Trends in RCF

    Molyneux-Berry, Paul; Bevan, Adam; Zhang, S. Y.; S Kabra

    2014-01-01

    The critical damage mechanism on many GB passenger train wheels is Rolling Contact Fatigue (RCF) cracking in the rim. Evidence from field observations suggests that RCF damage occurs much more quickly as the wheelsets near the end of their life. Wheel manufacturing processes induce a compressive hoop stress in the wheel rim; variations in residual stress through the life of a wheel may influence the observed RCF damage rates. This paper describes experiments to measure residual stresses in...

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

    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.

  4. 14 CFR 29.497 - Ground loading conditions: landing gear with tail wheels.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground loading conditions: landing gear... Requirements Ground Loads § 29.497 Ground loading conditions: landing gear with tail wheels. (a) General. Rotorcraft with landing gear with two wheels forward and one wheel aft of the center of gravity must...

  5. 14 CFR 27.497 - Ground loading conditions: landing gear with tail wheels.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground loading conditions: landing gear... Requirements Ground Loads § 27.497 Ground loading conditions: landing gear with tail wheels. (a) General. Rotorcraft with landing gear with two wheels forward, and one wheel aft, of the center of gravity must...

  6. 14 CFR 25.499 - Nose-wheel yaw and steering.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Nose-wheel yaw and steering. 25.499 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.499 Nose-wheel yaw and... nose wheel ground contact equal to 0.8 of the vertical ground reaction at that point are assumed....

  7. The iPhone on Training Wheels

    2007-01-01

    @@ Nearly five months have passed since Steve Jobs unleashed his flashy iPhone upon the world, and the sleek,do-everything gadget has met his ambitious initial sales targets and then some-so far, more than 1.5 million have been sold.

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

    Jackson, Bob; Silgram, Martyn; Quinton, John

    2010-05-01

    sprayer, cultivator and tyre manufacturers, and the associated development and evaluation of novel tools for sustainable land management. Preliminary results from the first winter of monitoring focus on soil physics assessments (such as surface roughness, near-surface compaction, bulk density) and event-based losses associated with surface runoff. Research is initially investigating the relative importance of soil compaction, rather than the lack of vegetation cover, in accounting for the much greater losses of surface runoff, sediment and P loss identified down tramline wheelings compared to the uncompacted, cropped area. Treatments being investigated on three sites with contrasting soil textures and climatic regimes include: • The effect of correctly inflated, "Xeobib" low ground pressure tractor and sprayer tyres compared to conventional tyres and "common practice" tyre pressures • The effect of drilling the wheeling areas and using new GPS technology to guide spraying operations, compared to conventional practice of using undrilled tramline areas for that purpose. Subsequent monitoring periods will explore the cost-effectiveness of techniques to lift the soil compaction in the autumn using novel tools attached to the sprayer unit. Results from such applied, field scale cost-effectiveness studies provide evidence to help identify source areas of diffuse pollution, improve our process understanding of the response of soil systems to land management practices, and thereby support the targeting of practical pollution control measures across a range of soil types and climatic regimes. This project will provide practical recommendations to the farming industry, help inform farm scale evaluations of diffuse pollution risk such as the new Soil Protection Review recently introduced by the UK Department for the Environment Food and Rural Affairs (Defra), and yield data to help parameterise and refine diffuse pollution models used for policy support at a range of scales.

  9. The wagon wheel illusion in movies and reality.

    Purves, D.; Paydarfar, J A; Andrews, T J

    1996-01-01

    Wheels turning in the movies or in other forms of stroboscopic presentation often appear to be rotating backward. Remarkably, a similar illusion is also seen in continuous light. The occurrence of this perception in the absence of intermittent illumination suggests that we normally see motion, as in movies, by processing a series of visual episodes.

  10. Effect of machinery wheel load on grass yield

    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...

  11. 49 CFR 229.75 - Wheels and tire defects.

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229... in width. (c) A broken rim, if the tread, measured from the flange at a point five-eighths inch above... crack or break in the flange, tread, rim, plate, or hub. (l) A loose wheel or tire. (m) Fusion...

  12. 16 CFR 1512.11 - Requirements for wheels.

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for wheels. 1512.11 Section 1512.11 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT... lbf) and tested in accordance with the rim test, § 1512.18(j). Sidewalk bicycles need not meet...

  13. Design of wheel-type walking-assist device

    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

  14. Development of morphology in laser dressed grinding wheels

    M.J. Jackson

    2007-05-01

    Full Text Available Purpose: The paper describes the development of faceted morphology in laser dressed grinding wheels.Design/methodology/approach: The approach used in the paper is based on locally melting a vitrified grinding wheel and measuring features such as grain size, cooling rate and melt depth as a function of laser fluence and relating these measures to the morphology shown in the microstructures presented in the paper.Findings: The findings of this course of research lead the authors to believe that a specific morphology is dependent upon cooling rate and laser fluence.Research limitations/implications: The findings show that further research is required to fully understand how certain morphologies form as a function of cooling rate and laser fluence. It should be noted that morphologies observed in laser processed grinding wheels include cellular and fully dendritic morphologies in addition to faceted vertices.Practical implications: The results imply that laser dressed grinding wheels can be used for machining different materials at different grinding speeds. The paper also shows that much development is needed to identify laser processing conditions that are appropriate for different workpiece materials.Originality/value: The paper shows that different morphologies can be used to machine workpiece materials under different conditions. The originality in the paper is focused on the formation on minute cutting points using increasing laser fluences.

  15. Estimating Friction Parameters in Reaction Wheels for Attitude Control

    Valdemir Carrara

    2013-01-01

    Full Text Available The ever-increasing use of artificial satellites in both the study of terrestrial and space phenomena demands a search for increasingly accurate and reliable pointing systems. It is common nowadays to employ reaction wheels for attitude control that provide wide range of torque magnitude, high reliability, and little power consumption. However, the bearing friction causes the response of wheel to be nonlinear, which may compromise the stability and precision of the control system as a whole. This work presents a characterization of a typical reaction wheel of 0.65 Nms maximum angular momentum storage, in order to estimate their friction parameters. It used a friction model that takes into account the Coulomb friction, viscous friction, and static friction, according to the Stribeck formulation. The parameters were estimated by means of a nonlinear batch least squares procedure, from data raised experimentally. The results have shown wide agreement with the experimental data and were also close to a deterministic model, previously obtained for this wheel. This model was then employed in a Dynamic Model Compensator (DMC control, which successfully reduced the attitude steady state error of an instrumented one-axis air-bearing table.

  16. Design of wheel-type walking-assist device

    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.

  17. Assessing the sustainability of water governance systems: the sustainability wheel

    Schneider F.; Bonriposi M.; Graefe O.; Herweg K.; Homewood C.; Huss M.; Kauzlaric M.; Liniger H.; Rey E.; Reynard E. (ed.); Rist S.; Schädler B.; Weingartner R.

    2015-01-01

    We present and test a conceptual and methodological approach for interdisciplinary sustainability assessments of water governance systems based on what we call the sustainability wheel. The approach combines transparent identification of sustainability principles, their regional contextualization through sub-principles (indicators), and the scoring of these indicators through deliberative dialogue within an interdisciplinary team of researchers, taking into account their various qualitative a...

  18. Wheel-rail interaction at short-wave irregularities

    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

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

    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. PMID:27217986

  20. Using the Pottery Wheel to Explore Topics in Calculus

    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…

  1. A Switching Controller System for a Wheeled Mobile Robot

    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.

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

    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.

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

    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.

  4. Curve Squeal of Train Wheels, Part 3: Active Control

    HECKL, MARIA A.; HUANG, X. Y.

    2000-01-01

    This paper presents a new method to annul the squeal noise that is produced by trains traversing a curve. The method is a special form of active control, applied to suppress the bending oscillations of a squealing wheel. It is essentially a feedback system with the following components: sensor, narrowband filter, phase-shifter, amplifier and actuator. The control signal driving the actuator has only a single frequency (set at the filter), and that frequency typically corresponds to one of the bending modes of the wheel. Two versions of the feedback system are considered. In the first version, the actuator exerts a control force on the wheel, and in the second version, the actuator imposes a velocity on the rail. A mathematical model is presented and predictions are made for the performance of both versions. The coupling of the different wheel modes by the control system is discussed. A model rig is described which was used for a practical demonstration of this form of active control. Differences from more conventional forms of active control are pointed out.

  5. Determination of quaternary strata diggability with bucket wheel excavators

    Ural, S.; Onur, A.H. [Afsin-Elbistan Lignite Establishment (Turkey)

    1994-12-31

    This paper relates the field investigations of the Quaternary strata series diggability with a bucket wheel excavator (BWE), carried out in Afsin-Elbistan Lignite Establishment (AEL). The investigations were intended to determine the Quaternary strata diggability and, in particular, to define the relative difficulty of excavating in-situ and preblasted layers. 3 refs., 11 figs., 3 tabs.

  6. Low cost attitude control system reaction wheel development

    Bialke, William

    1991-01-01

    In order to satisfy a growing demand for low cost attitude control systems for small spacecraft, development of a low power and low cost Reaction Wheel Assembly was initiated. The details of the versatile design resulting from this effort are addressed. Tradeoff analyses for each of the major components are included, as well as test data from an engineering prototype of the hardware.

  7. Mechatronics Design of a Mecanum Wheeled Mobile Robot

    Xu, Peter

    2005-01-01

    The motor driver circuit board designed for the drive of the Mecanum wheels met all the specifications given in Section 3. The limitation to its current handling capacity was the relays which are rated at five amps. The board has provided a cheap and compact 72

  8. Characterizing the Performance of the Wheel Electrostatic Spectrometer

    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

  9. Visual control of wheeled mobile robots unifying vision and control in generic approaches

    Becerra, Héctor M

    2014-01-01

    Vision-based control of wheeled mobile robots is an interesting field of research from a scientific and even social point of view due to its potential applicability. This book presents a formal treatment of some aspects of control theory applied to the problem of vision-based pose regulation of wheeled mobile robots. In this problem, the robot has to reach a desired position and orientation, which are specified by a target image. It is faced in such a way that vision and control are unified to achieve stability of the closed loop, a large region of convergence, without local minima, and good robustness against parametric uncertainty. Three different control schemes that rely on monocular vision as unique sensor are presented and evaluated experimentally. A common benefit of these approaches is that they are valid for imaging systems obeying approximately a central projection model, e.g., conventional cameras, catadioptric systems and some fisheye cameras. Thus, the presented control schemes are generic approa...

  10. The Filter Wheel and Filters development for the X-IFU instrument on-board Athena

    Bozzo, E; Genolet, L; Paltani, S; Sordet, M; Branduardi-Raymont, G; Rauw, G; Sciortino, S; Barret, D; Herder, J W Den

    2016-01-01

    Athena is the large mission selected by ESA in 2013 to investigate the science theme "Hot and Energetic Universe" and presently scheduled for launch in 2028. One of the two instruments located at the focus of the 12 m-long Athena telescope is the X-ray Integral Field Unit (X-IFU). This is an array of TES micro-calorimeters that will be operated at temperatures of 50 mK in order to perform high resolution spectroscopy with an energy resolution down to 2.5 eV at energies < 7 keV. In order to cope with the large dynamical range of X-ray fluxes spanned by the celestial objects Athena will be observing, the X-IFU will be equipped with a filter wheel. This will allow the user to fine tune the instrument set-up based on the nature of the target, thus optimizing the scientific outcomes of the observation. A few positions of the filter wheel will also be used to host a calibration source and to allow the measurement of the instrument intrinsic background.

  11. Wheel-running activity and energy metabolism in relation to ambient temperature in mice selected for high wheel-running activity

    Vaanholt, Lobke M.; Garland, Theodore; Daan, Serge; Visser, G. Henk; Garland Jr., Theodore; Heldmaier, G

    2007-01-01

    Interrelationships between ambient temperature, activity, and energy metabolism were explored in mice that had been selectively bred for high spontaneous wheel-running activity and their random-bred controls. Animals were exposed to three different ambient temperatures (10, 20 and 30 degrees C) and wheel-running activity and metabolic rate were measured simultaneously. Wheel-running activity was decreased at low ambient temperatures in all animals and was increased in selected animals compare...

  12. Creep feed grinding of a nickel base superalloy with a segmented wheel containing coated CBN

    Xu, X.P.; Huang, H. [Huaqiao Univ., Quanzhou (China). Dept. of Mechanical Engineering; Xu, H.J. [Nanjing Univ. of Aeronautics and Astronautics, JS (China)

    2001-07-01

    An investigation is reported of the creep feed grinding of a cast superalloy with segmented CBN wheels. The temperature at the wheel-workpiece interface was measured using a workpiece-wire thermocouple and the forces were detected using a dynamometer. Coupled with previous studies on thermal behavior of intermittent grinding and material removal mechanisms for creep feed grinding of the superalloy using either Al{sub 2}O{sub 3} wheels or continuous CBN wheels, a segmented CNB wheel was introduced to cost-effectively machining of the superalloy by incorporating coated CBN abrasives into the resin bonded segments. (orig.)

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

    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.

  14. Casting defects in low-pressure die-cast aluminum alloy wheels

    Zhang, B.; Cockcroft, S. L.; Maijer, D. M.; Zhu, J. D.; Phillion, A. B.

    2005-11-01

    Defects in automotive aluminum alloy casting continue to challenge metallurgists and production engineers as greater emphasis is placed on product quality and production cost. A range of casting-related defects found in low-pressure die-cast aluminum wheels were examined metallographically in samples taken from several industrial wheel-casting facilities. The defects examined include macro- and micro- porosity, entrained oxide films, and exogenous oxide inclusions. Particular emphasis is placed on the impact of these defects with respect to the three main casting-related criteria by which automotive wheel quality are judged: wheel cosmetics, air-tightness, and wheel mechanical performance.

  15. Stability enhancement and fuel economy of the 4-wheel-drive hybrid electric vehicles by optimal tyre force distribution

    Goodarzi, Avesta; Mohammadi, Masoud

    2014-04-01

    In this paper, vehicle stability control and fuel economy for a 4-wheel-drive hybrid vehicle are investigated. The integrated controller is designed within three layers. The first layer determines the total yaw moment and total lateral force made by using an optimal controller method to follow the desired dynamic behaviour of a vehicle. The second layer determines optimum tyre force distribution in order to optimise tyre usage and find out how the tyres should share longitudinal and lateral forces to achieve a target vehicle response under the assumption that all four wheels can be independently steered, driven, and braked. In the third layer, the active steering, wheel slip, and electrical motor torque controllers are designed. In the front axle, internal combustion engine (ICE) is coupled to an electric motor (EM). The control strategy has to determine the power distribution between ICE and EM to minimise fuel consumption and allowing the vehicle to be charge sustaining. Finally, simulations performed in MATLAB/SIMULINK environment show that the proposed structure could enhance the vehicle stability and fuel economy in different manoeuvres.

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

    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.

  17. Double-layered target and identification method of individual target correlated with evaporation residues

    A double-layered target system and an identification method (target ID) for individual targets mounted on a rotating wheel using correlation with evaporation residues were newly developed for the study of superheavy elements (SHE). The target system can be used in three modes: conventional single-layered mode, double-layered mode, and energy-degrader mode. The target ID method can be utilized for masking a target, measuring an excitation function without changing the beam energy from the accelerator, and searching for SHE nuclides using multiple targets during a single irradiation

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

    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.

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

    Tsukishima, Takahiro; Sasaki, Ken; Takano, Masaharu; Inoue, Kenji

    1992-03-01

    This paper proposes a general theory of kinematics and dynamics of wheeled mobile robots (WMRs). Unlike robotic manipulators which are modeled as 3-dimensional serial link mechanism, WMRs will be modeled as planar linkage mechanism with multiple links branching out from the base and/or another link. Since this model resembles a tree with branches, it will be called 'tree-structured-link'. The end of each link corresponds to the wheel which is in contact with the floor. In dynamics of WMR, equation of motion of a WMR is derived from joint input torques incorporating wheel dynamics. The wheel dynamics determines forces and moments acting on wheels as a function of slip velocity. This slippage of wheels is essential in dynamics of WMR. It will also be shown that the dynamics of WMR reduces to kinematics when slippage of wheels is neglected. Furthermore, the equation of dynamics is rewritten in velocity input form, since most of industrial motors are velocity controlled.

  20. Designing a range modulator wheel to spread-out the Bragg peak for a passive proton therapy facility

    Jia, S. Bijan; Romano, F.; Cirrone, Giuseppe A. P.; Cuttone, G.; Hadizadeh, M. H.; Mowlavi, A. A.; Raffaele, L.

    2016-01-01

    In proton beam therapy, a Spread-Out Bragg peak (SOBP) is used to establish a uniform dose distribution in the target volume. In order to create a SOBP, several Bragg peaks of different ranges, corresponding to different entrance energies, with certain intensities (weights) should be combined each other. In a passive beam scattering system, the beam is usually extracted from a cyclotron at a constant energy throughout a treatment. Therefore, a SOBP is produced by a range modulator wheel, which is basically a rotating wheel with steps of variable thicknesses, or by using the ridge filters. In this study, we used the Geant4 toolkit to simulate a typical passive scattering beam line. In particular, the CATANA transport beam line of INFN Laboratori Nazionali del Sud (LNS) in Catania has been reproduced in this work. Some initial properties of the entrance beam have been checked by benchmarking simulations with experimental data. A class dedicated to the simulation of the wheel modulators has been implemented. It has been designed in order to be easily modified for simulating any desired modulator wheel and, hence, any suitable beam modulation. By using some auxiliary range-shifters, a set of pristine Bragg peaks was obtained from the simulations. A mathematical algorithm was developed, using the simulated pristine dose profiles as its input, to calculate the weight of each pristine peak, reproduce the SOBP, and finally generate a flat dose distribution. Therefore, once the designed modulator has been realized, it has been tested at CATANA facility, comparing the experimental data with the simulation results.

  1. New Vitrified Bond Diamond Grinding Wheel for Grinding the Cylinder of Polycrystalline Diamond Compacts

    2007-01-01

    In this work, a kind of new vitrified bond based on Li2O-Al2O3-SiO2 glass ceramics was used to bond the diamond grains, which is made into grinding wheel and the cylindrical grinding process of polycrystalline diamond compacts (PDCs) by using the new vitrified bond diamond grinding wheel was discussed. Several factors which influence the properties of grinding wheel such as amount of vitrified bond and the kinds and amount of stuff in grinding wheel were also investigated. It was found that the new vitrified bond can firmly combine diamond grains, when there are only diamonds and vitrified bond in the structure of grinding wheel, the longevity of the grinding wheel is about 2.5-3 times as that of resin bond grinding wheel for processing PDCs. The grinding size precision of PDCs can be improved from ±0.03 mm to ±0.01 mm because of larger Young's modulus of vitrified bond than resin bond. The grinding time of a PDC product can be 1.75-2.0 min from 3.25-3.5 min, so this kind of grinding wheel can save much time for processing PDCs. Also, there is hardly noise when using this new vitrified bond diamond grinding wheel to process PDCs. The amount of vitrified bond in grinding wheel influences the longevity of grinding wheel. When the size of diamond grains is 90-107 μm, the optimal amount of vitrified bond in grinding wheel is 21% (wt pet). When the amount of vitrified bond exceeds 21%, there are many pores in grinding block, which will decrease the longevity of grinding wheel. The existence of addition stuff such as Al2O3 or SiC can reduce the longevity of grinding wheel.

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

    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.

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

    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.

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

    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

  5. Experimental and theoretical studies of the yields of residual product nuclei produced in thin Pb and Bi targets irradiated by 40 - 2600 MeV protons

    The Project is aimed at experimental determining and computer-aided theoretical simulating the independent and cumulative yields of residual radioactive product nuclei in high-energy protonirradiated thin targets made of high-isotopic and natural lead (206Pb, 207Pb, 208PB, natPb) and bismuth (209Bi) that are the most probable choice to be the target materials in the acceleratordriven (hybrid) systems (ADS) coupled to a high-current proton accelerator. The yields of residual product nuclei are of great importance when estimating such basic radiation-technology characteristics of the hybrid facility targets as the total target activity, the target 'poisoning', the buildup of long-lived nuclides, the α-activity, the content of low-pressure evaporated nuclides (Hg), the content of the chemically-active nuclides that drastically spoil the corrosion resistance of the facility structure materials, etc. In view of the above, the radioactive product nuclide yields from targets materials were experimentally determined using the ITEP U-10 proton accelerator in 55 measurement runs using the monoisotopic and natural lead (206Pb, 207Pb, 208PB, natPb) and bismuth (209Bi) targets within the proton energy range fractionated minutely, namely at 0.04, 0.07, 0.10, 0.8, 1.2, 1.4, 1.6, and 2.6 GeV to cover the entire range of the internuclear hadron cascading. As a result, 5972 cumulative and independent yields of residual radioactive product nuclei, whose lifetimes range from 8 minutes to 32 years, have been measured. Besides, the cross sections for the 27Al(p,x)24Na and 27Al(p,x)7Be monitor reactions have been measured at the same proton energies together with the 27Al(n,p)27Mg reaction rate that characterizes the neutron background contributions in each experiment. The experimental nuclide yields are determined by the direct γ-spectrometry method. The γ-spectrometer resolution is 1.8 keV in the 1332 keV 60Co γ-line. The experimental γ-spectra are processed by the GENIE2000 code

  6. The use of a running wheel to measure activity in rodents: Relationship to energy balance, general activity, and reward

    Novak, Colleen M.; Burghardt, Paul R.; Levine, James A.

    2012-01-01

    Running wheels are commonly employed to measure rodent physical activity in a variety of contexts, including studies of energy balance and obesity. There is no consensus on the nature of wheel-running activity or its underlying causes, however. Here, we will begin by systematically reviewing how running wheel availability affects physical activity and other aspects of energy balance in laboratory rodents. While wheel running and physical activity in the absence of a wheel commonly correlate i...

  7. Experimental test of a new neutron threshold detector and its application

    2002-01-01

    The possibility of using 209Bi as a new threshold detector to measurc high-energy neutrons was investigated for the first time. At the same time the experiment measured successfully the emitted neutron fiuence rate, energy spectrum and dose equivalent rate distributions in the heavy ion target area using a detector complex including 209Bi, 115In, 27A1, 19F and 12C samples.

  8. Low-cycle fatigue of turbine rotor wheels

    By means of low cycle fatigue achieved by the application of cyclic speed tests on turbine rotor wheels and in comparison with test values and by evaluating the formation of rim cracks caused by temperature change stress, the dangers of cracks appearing during operation in integrally moulded small gas turbine rotor wheels are assessed with the aid of fracture mechanisms. It was determined in short cycle tests that the objects under test with a higher stress gradient (1.0 mm-1) exhibited a higher endurance strength (104 stress cycle) than objects tested under a lower stress gradient. The results of these tests were put to discussion. In spite of a large dispersion of the cracking resistance factor Ksub(c), an additional operational life of up to 1,000 h could be approximated. Following further operational experience, it was shown that this approximation could be increased up to 2,000 h. (orig.)

  9. Local cyclic deformation behavior and microstructure of railway wheel materials

    The current investigations concentrate on the relation between the loading and environmental conditions, the local microstructure and the fatigue behavior of highly stressed railway wheel and tire steels. Experiments under stress control and total strain control were performed at ambient temperature with servohydraulic testing systems. Superimposed mean loadings allow an evaluation of cyclic creep and mean stress relaxation effects. Strain, temperature and electrical measuring techniques were used to characterize the cyclic deformation behavior of specimens from different depth positions of the cross-sections of UIC-specified wheel components (UIC: International Railway Union). The measured values show a strong interrelation. The microstructural characterization of the different material conditions was done by light and scanning electron microscopy together with digital image processing

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

    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.

  11. Soil compaction and structural morphology under tractor wheelings

    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.

  12. Characterizing the Perfonnance of the Wheel Electrostatic Spectrometer

    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.

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

    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 ...

  14. Numerical Simulation Analysis of an Oversteer In-Wheel Small Electric Vehicle Integrated with Four-Wheel Drive and Independent Steering

    Muhammad Izhar Ishak

    2016-01-01

    Full Text Available Similar to conventional vehicle, most in-wheel small EVs that exist today are designed with understeer (US characteristic. They are safer on the road but possess poor cornering performance. With recent in-wheel motor and steer-by wire technology, high cornering performance vehicle does not limit to sport or racing cars. We believe that oversteer (OS design approach for in-wheel small EV can increase the steering performance of the vehicle. However, one disadvantage is that OS vehicle has a stability limit velocity. In this paper, we proposed a Four-Wheel Drive and Independent Steering (4WDIS for in-wheel small EV with OS characteristic. The aim of implementing 4WDIS is to develop a high steer controllability and stability of the EV at any velocity. This paper analyses the performance of OS in-wheel small EV with 4WDIS by using numerical simulation. Two cornering conditions were simulated which are (1 steady-state cornering at below critical velocity and (2 steady-state cornering over critical velocity. The objective of the simulation is to understand the behavior of OS in-wheel small EV and the advantages of implementing the 4WDIS. The results show that an in-wheel small EV can achieve high cornering performance at low speed while maintaining stability at high speed.

  15. Modelling the effects of repeated wheel loads on soil profiles

    Gräsle W.; Horn R.; Baumgartl T.; Richards B.C.

    1997-01-01

    Compaction of soil caused by increasing mechanical loads and repeated wheeling may result in reduced soil productivity. The physical response of soils to such loading is analysed with a non-linear finite element program using incremental tangential moduli with incremental loading and unloading from known initial conditions. During each load increment an iterative procedure is used to determine more accurately the stresses and the stress dependent moduli. This program is designed to model the ...

  16. EXPERIMENTAL EVALUATION OF ARTICULATED WHEELED VEHICLES POSITION STABILITY

    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.

  17. How Much Inflation is Necessary to Grease the Wheels?

    Kim, Jinill; RUGE-MURCIA, Francisco J.

    2007-01-01

    This paper studies Tobin's proposition that inflation "greases" the wheels of the labor market. The analysis is carried out using a simple dynamic stochastic general equilibrium model with asymmetric wage adjustment costs. Optimal inflation is determined by a benevolent government that maximizes the households' welfare. The Simulated Method of Moments is used to estimate the nonlinear model based on its second-order approximation. Econometric results indicate that nominal wages are downwardly...

  18. Wear estimation of the wheel tyre in different service conditions

    Henryk BĄKOWSKI

    2014-06-01

    Full Text Available In this article presented the results of fatigue strength test aluminium alloys using in car industry. Demonstrated distributions and values of stresses the wheel tyre made of aluminium alloys by means of FEM. In fatigue test used special machine, which can allow to determine Wohler diagram. In this way to determine the allowable stresses values in which do not occurring the damages.

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

    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.

  20. Damage Caused by Wheeled Skidders on Cambisols of Central Europe

    Allman, Michal; Ferenčík, Michal; Jankovský, Martin; Stanovský, Miroslav; Messingerová, Valéria

    2015-01-01

    Machine traffic and timber skidding significantly affect the soil surface and soil properties. The effects are mostly negative and result in soil erosion, worsening of soil properties and inhibition of the growth of roots and soil organisms. In this study, we evaluated forest soil damage caused by the HSM 805 HD wheeled skidder during timber skidding in selected forest stands in the School Forest Enterprise in Zvolen. We estimated the limits for operation of forest machines in the stands and ...

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

    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.

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

    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.

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

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

    2015-01-01

    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. Wheel arch aerodynamics of a modern road vehicle

    A geometrically faithful model of the Aston Martin V12 Vanquish was formed in 3D CAD and used to perform an extensive CFD study into the airflow in and around the wheel arch of the vehicle. Parameters such as spin ratio, ground clearance, vertical and horizontal insertion into the wheel arch and the yaw angles experienced during cornering, were all under investigation. The additional aim of the research was to validate or refute the use of CFD as a tool in this complex area of fluid flow. This research serves to highlight a number of problems and potential solutions in the use of CFD. Meshing problems can be eliminated with increased computational power and suggestions have been made to improve the modeling of rotating boundaries that include radial features such as wheel spokes. Much of the CFD data ties well with previously conducted experimental work, if not numerically then in trend. Without additional physical validation however, it is difficult to ascertain the overall accuracy and usefulness of the remaining results, which have not yet been conducted in physical reality. Despite its limitations, the use of CFD permitted an extensive analysis in a comparatively short length of time and served to highlight potential areas for increased scrutiny. As an example, results from the final yaw angle case drew attention to a potential concern for aerodynamic destabilisation of the vehicle during cornering, generating lift on the front arch of the car that is already lifted due to cornering forces and body roll. (author)

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

    In the upgrade process of the ATLAS detector, the innermost stations of the endcaps (Small Wheels) will be replaced. The New Small Wheel will have two chamber technologies, small-strip Thin Gap Chambers and Micromegas, each providing triggering and precision track measurement. Custom front-end Application Specific Integrated Circuits will be used to read and filter information from both types of detectors. In the context of the New Small Wheel data path, the Read Out Controller ASIC is used for handling, preprocessing and formatting the data generated by the VMM upstream chips. The Read Out Controller will concentrate the data streams from 8 VMMs, filter data based on the ATLAS Level-1 trigger which identifies bunch crossings of interest and transmit the data to FELIX via the L1DDC. The Read Out Controller is composed of 8 VMM Capture modules, a cross-bar and 4 sROC modules. The output data is sent via up to 4 serial links with a configurable speed of 80, 160 or 320 Mbps per link

  6. Stability Simulation of a Vehicle with Wheel Active Steering

    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.

  7. ANALYSIS OF CREEP FORCES OF WHEEL/RAIL

    2001-01-01

    The effects of structure elastic deformations of wheelset and track on creep forces of wheel and rail are investigated.Finite element method is used to calculate the influence coefficients expressing the relations between structure elastic deformations of wheelset and track and the corresponding loads in the rolling direction and the lateral direction of wheelset,respectively.The influence coefficients of wheelset and track are used to revise some of the influence coefficients obtained with the formula of Bossinesq and Cerruti in Kalker's theory of three-dimensional elastic bodies in rolling contact with non-Hertzian form.The theory of Kalker and the modified theory of Kalker are respectively employed to analyze creep forces of wheelset and track.The numerical results obtained show a great influence of structure elastic deformations of wheelset and track on the creep forces.Therfore it is not reasonable that wheel and rail are treated as elastic half space in the analysis of wheel and rail in rolling contact,and the present theories of rolling contact based on the assumption of elastic half space need to be further improved.

  8. Structure Analysis of a Turbocharger Compressor Wheel Using FEA

    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.

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

    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.

  10. Effect of wheelset flexibility on wheel-rail contact behavior and a specific coupling of wheel-rail contact to flexible wheelset

    Zhong, Shuoqiao; Xiao, Xinbiao; Wen, Zefeng; Jin, Xuesong

    2016-04-01

    The flexibility of a train's wheelset can have a large effect on vehicle-track dynamic responses in the medium to high frequency range. To investigate the effects of wheelset bending and axial deformation of the wheel web, a specific coupling of wheel-rail contact with a flexible wheelset is presented and integrated into a conventional vehicle-track dynamic system model. Both conventional and the proposed dynamic system models are used to carry out numerical analyses on the effects of wheelset bending and axial deformation of the wheel web on wheel-rail rolling contact behaviors. Excitations with various irregularities and speeds were considered. The irregularities included measured track irregularity and harmonic irregularities with two different wavelengths. The speeds ranged from 200 to 400 km/h. The results show that the proposed model can characterize the effects of flexible wheelset deformation on the wheel-rail rolling contact behavior very well.

  11. Pneumatic locking device for magnetic bearing reaction wheel

    Privat, Michel; da Costa, Arlindo

    2003-09-01

    Due to the launch vibration environment, the use of locking device is necessary for large or heavy mechanisms. This remark is true in particular for the inertial actuators like magnetic bearing reaction wheels. These actuators have a rotor that is in magnetic levitation without any contact with the stator. Locking device is mandatory to maintain the rotor during the launch vibrations. To avoid contact between rotor and stator during the functional phase, the link created by the locking device must be completely released. This article presents a pneumatic locking device with pyrotechnical sub-systems that have been realised by "ALCATEL Space Industries" for the reaction wheels development in the frame of a CNES satellites family. The first paragraph presents the wheel functioning and briefly describes the Electro-mechanical components of the reaction wheel. The second paragraph describes a device based on a metallic bellows ring. A nitrogen pressure in the ring allows pushing the rotor against the stator. The rotor release is obtained by drilling the system tubing with a pyrotechnic valve. The third point describes the qualification tests and the resulting data. Some functional tests are made in warm and cold case with the locking device in order to improve some mechanical characteristics including the locking effort generated and the leakage rate. Launch vibrations and thermal tests have been realised and the good functioning of the mechanism is proven. At the end of these tests, the qualification has been pronounced. The device is now implemented within the reaction wheel. This equipment should flight in 2004. The next paragraph presents the works realised under CNES Research and Technology contract. The objectives were the characterisation of metallic bellows and some technological studies to improve the knowledge of the mechanical and functional characteristics of these elements. The first study was to create a Finite Element model of a bellow in order to

  12. Serotonin-mediated central fatigue underlies increased endurance capacity in mice from lines selectively bred for high voluntary wheel running.

    Claghorn, Gerald C; Fonseca, Ivana A T; Thompson, Zoe; Barber, Curtis; Garland, Theodore

    2016-07-01

    Serotonin (5-hydroxytryptamine; 5-HT) is implicated in central fatigue, and 5-HT1A pharmaceuticals are known to influence locomotor endurance in both rodents and humans. We studied the effects of a 5-HT1A agonist and antagonist on both forced and voluntary exercise in the same set of mice. This cohort of mice was taken from 4 replicate lines of mice that have been selectively bred for high levels of voluntary wheel running (HR) as compared with 4 non-selected control (C) lines. HR mice run voluntarily on wheels about 3× as many revolutions per day as compared with C, and have greater endurance during forced treadmill exercise. We hypothesized that drugs targeting serotonin receptors would have differential effects on locomotor behavior of HR and C mice. Subcutaneous injections of a 5-HT1A antagonist (WAY-100,635), a combination of 5-HT1A agonist and a 5-HT1A/1B partial agonist (8-OH-DPAT+pindolol), or physiological saline were given to separate groups of male mice before the start of each of three treadmill trials. The same manipulations were used later during voluntary wheel running on three separate nights. WAY-100,635 decreased treadmill endurance in HR but not C mice (dose by linetype interaction, P=0.0014). 8-OH-DPAT+pindolol affected treadmill endurance (P<0.0001) in a dose-dependent manner, with no dose by linetype interaction. Wheel running was reduced in HR but not C mice at the highest dose of 8-OH-DPAT+pindolol (dose by linetype, P=0.0221), but was not affected by WAY-100,635 treatment. These results provide further evidence that serotonin signaling is an important determinant of performance during both forced and voluntary exercise. Although the elevated wheel running of HR mice does not appear related to alterations in serotonin signaling, their enhanced endurance capacity does. More generally, our results indicate that both forced and voluntary exercise can be affected by an intervention that acts (primarily) centrally. PMID:27106566

  13. Multispectral Imager With Improved Filter Wheel and Optics

    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. Plastic Deformation and Softening of the Surface Layer of Railway Wheel

    Ławrynowicz Z.

    2015-12-01

    Full Text Available In this study scanning electron microscope (SEM and optical micrograph observations were used to investigate the plastic deformation near the surface of the worn railway wheel following service. Microstructure, plastic deformation and micro-hardness of the material in the outermost tread layer of used passenger railway wheel were characterised. It was found that the material in the contact surface of wheel undergoes severe plastic deformation. Vickers micro-hardness measurements in the highly deformed layer could be correlated with softening of the outer wheel rim and the spheroidisation of the cementite phase. Examination of worn, railway wheel taken out of service, has indicated that cracks are predominantly initiated at the wheel surface down the edges of highly strained, pro-eutectoid ferrite zones (situated along prior austenite grain boundaries and that such pro-eutectoid ferrite zones also facilitate crack propagation.

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

    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.

  16. A quasi-static model of wheel-tissue interaction for surgical robotics.

    Wang, Xin; Sliker, Levin J; Qi, H Jerry; Rentschler, Mark E

    2013-09-01

    Wheel-driven mobile in vivo robotic devices can provide an unconstrained platform for visualization and task performance. Careful understanding of the wheel-tissue interaction is necessary to predict in vivo performance of medical mobility systems. Here, an analytical study of the friction involving rolling contact of a surgical wheel, moving at constant velocities over soft tissue, is presented and verified. A quasi-static frictionless solution is first derived from existing theory, and newly developed theory considering frictional effects is later introduced. In this analysis, the effect of friction on wheel mobility over a viscoelastic substrate is analyzed with wheel velocity as the only changing variable. The analytical model is later verified by experiments and Finite Element Method (FEM) simulations. A simple application of this model to help design a surgical robot is also presented. Additional results indicate that the resistance force, which arises from the tissue viscosity, approaches zero for small and very large wheel velocities. PMID:23582337

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

    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.

  18. Three-dimensional elastic-plastic finite element analysis for wheel-rail rolling contact fatigue

    Taek-Young Kim

    2014-07-01

    Full Text Available Rolling contact fatigue of an urban railway wheel was analysed during its rolling FEM analysis was performed using 3D modelling of rail and wheel, in which the slope of the rail and nonlinear isotropic and kinematic hardening behavior of the rail and the wheel were considered. The maximum von Mises stress and contact pressure between the rail and wheel were determined under an axial load of 85 kN. The contact pressure distributions calculated using elastic Hertz theory and three-dimensional elastic–plastic stress analysis are compared. The maximum contact pressure of the wheel from the elasticplastic FE method is slightly lower than the value from Hertz contact theory with elastic deformation. The rolling contact fatigue (RCF of the wheel due to rolling contact was determined to be infinite by Dang Van criterion.

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

    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.

  20. Two-wheel drive-based DNA nanomachine and its sensing potential for highly sensitive analysis of cancer-related gene.

    Xu, Jianguo; Wu, Zai-Sheng; Wang, Zhenmeng; Li, Hongling; Le, Jingqing; Jia, Lee

    2016-09-01

    With the biological significance and important advances of nano-scale DNA devices, scientific activities have been directed toward developing molecular machinery. In this work, we present a novel two-wheel drive-based DNA nanomachine composed of one signaling recognition probe (SRP), one label-free recognition probe (LRP), and one driving primer (DP). Target DNA hybridization can activate LRP-based wheel driving by resorting to DP-mediated polymerization/nicking/displacement cycles. This in turn results in the accumulation of nicked strand 1 (NS1) that can initiate extended SRP-based wheel driving. As a result, the hairpin structure of SRP is stretched and pre-quenched fluorescence is restored. Meanwhile, lots of nicked strand 2 (NS2) are produced, which could hybridize perfectly with SRP and lead to further fluorescence amplification. It is worth noting that, because the nanomachine operation relies strongly on inputted target trigger, the unwanted background is completely eliminated. The detection limit of 1 pM and an excellent capability to recognize the single-base mutation were achieved. Significantly, the interrogating of target trigger extracted from cancer cells is already available, reflecting the potential for practical applications. As a proof-of-concept building, the unique analytical properties would significantly benefit the DNA nanomachines and reveal great promise in biochemical and biomedical studies. PMID:27254471

  1. Plastic Deformation and Softening of the Surface Layer of Railway Wheel

    Ławrynowicz Z.

    2015-01-01

    In this study scanning electron microscope (SEM) and optical micrograph observations were used to investigate the plastic deformation near the surface of the worn railway wheel following service. Microstructure, plastic deformation and micro-hardness of the material in the outermost tread layer of used passenger railway wheel were characterised. It was found that the material in the contact surface of wheel undergoes severe plastic deformation. Vickers micro-hardness measurements in the highl...

  2. A comparison of aircraft tire skid with initial wheel rotational speed using ANSYS transient simulation

    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...

  3. Design and Development of a Compact Magnetic Bearing Momentum Wheel for Micro and Small Satellites

    Scharfe, Michael; Roschke, Thomas; Bindl, Enrico; Blonski, Daniel

    2001-01-01

    Reaction and momentum wheels have become standard equipment for three-axis attitude stabilisation of conventional satellite classes as used e.g. for telecommunication and remote sensing missions. Owing to very compact mechanical designs and highly integrated electronics, wheels are now also more and more interesting for small satellites up to 100…200 kg with increasingly demanding requirements on attitude control. Wheels suitable for small satellites have a typical momentum capacity up to app...

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

    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.

  5. On graphs that do not contain a theta nor a wheel Part I: two subclasses

    Diot, Emilie; Radovanovic, Marko; Trotignon, Nicolas; Vuskovic, Kristina

    2015-01-01

    Truemper configurations are four types of graphs (namely thetas, wheels, prisms and pyramids) that play an important role in the proof of several decomposition theorems for hereditary graph classes. In this paper, we prove two structure theorems: one for graphs with no thetas, wheels and prisms as induced subgraphs, and one for graphs with no thetas, wheels and pyramids as induced subgraphs. A consequence is a polynomial time recognition algorithms for these two classes.

  6. TangiWheel: A widget for manipulating collections on tabletop displays supporting hybrid Input modality

    Catalá Bolós, Alejandro; García Sanjuan, Fernando; Jaén Martínez, Francisco Javier; Mocholi Agües, Jose Antonio

    2012-01-01

    In this paper we present TangiWheel, a collection manipulation widget for tabletop displays. Our implementation is flexible, allowing either multi-touch or interaction, or even a hybrid scheme to better suit user choice and convenience. Different TangiWheel aspects and features are compared with other existing widgets for collection manipulation. The study reveals that TangiWheel is the first proposal to support a hybrid input modality with large resemblance levels between touch and tangible ...

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

    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.

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

    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.

  9. The Structure of Wheel Check Valve Influence on Air Block Phenomenon of Piezoelectric Micro-Pump

    Song Chen; Yong Liu; Yanhu Shen; Jiantao Wang; Zhigang Yang

    2015-01-01

    To improve the stability and reliability of the piezoelectric micro-pump, the cause of air block phenomenon is analyzed on the structure of wheel check valve. During the movement of the bubble in the micro-channel, pressure drop occurs, the main factor which influences the bubble going through is opening height of the wheel check valve. Five groups of wheel check valves with different structures are used to test the wheel check valve opening height and air block probability. The experiment re...

  10. Reaction Wheel Friction Telemetry Data Processing Methodology and On-Orbit Experience

    Hacker, Johannes M.; Ying, Jiongyu; Lai, Peter C.

    2015-09-01

    A Globalstar 2nd generation satellite experienced a reaction wheel mechanical failure, and in response Globalstar has been closely monitoring reaction wheel bearing friction. To prevent another reaction wheel hardware failure and subsequent shortened satellite mission life, a friction data processing methodology was developed as an on-orbit monitoring tool for the ground to issue early warning and take appropriate action on any hardware degradation or potential failure. The methodology, reaction wheel friction behavior, and its application to an on-orbit anomaly experience will be presented.

  11. Simulation analysis of grinding wheel motion trajectory on SiC ceramics aspheric surface grinding

    Zhang, Feihu; Liu, Lifei; Li, Chunhui

    2014-08-01

    In grinding process of SiC ceramics aspheric surface, the motion trajectory of grinding wheel has great influence on the surface forming. The paper provides mathematical models of grinding wheel movements; analytical simulation was done to describe the trajectories of the grinding wheel in manufacturing an aspherical workpiece. The effect of grinding parameters (including the rotation speed of the workpiece, the feed rate of grinding wheel etc.) on the aspheric surface coverage rate was conducted and discussed in detail. An experimental study was done according to the simulation results and an aspheric surface with form error less than 10μm was gained.

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

    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.

  13. STM manipulation of a subphthalocyanine double-wheel molecule on Au(111)

    A new class of double-wheel molecules is manipulated on a Au(111) surface by the tip of a scanning tunneling microscope (STM) at low temperature. The double-wheel molecule consists of two subphthalocyanine wheels connected by a central rotation carbon axis. Each of the subphthalocyanine wheels has a nitrogen tag to monitor its intramolecular rolling during an STM manipulation sequence. The position of the tag can be followed by STM, allowing us to distinguish between the different lateral movements of the molecule on the surface when manipulated by the STM tip.

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

    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.

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

    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.

  16. Fatigue Property of Low Cost and High Strength Wheel Steel for Commercial Vehicle

    WANG Ning; LI Yi; DU Lin-xiu; WU Di; LIU Xiang-hua

    2009-01-01

    The fatigue properties of the newly developed wheel steel used for commercial vehicles were studied using push-pull axial loading fatigue tests with stress ratio R=-1. Q235B steel, which is conventionally applied to commercial vehicle wheels, was also analyzed for comparison. Although the chemical composition and microstructure(ferrite and pearlite) of newly developed wheel steel were similar to those of Q235B, the 107 cycles fatigue limit of the new wheel steel was 260 MPa, which is 24% higher than that of Q235B (210 MPa). The improvement of the fatigue strength of the new wheel steel can be attributed to grain refinement. In order to investigate the effect of the decrease in thickness of the wheel steel on the fatigue property of the wheel, dynamic cornering fatigue tests were conducted on full scale wheels with the model of 8. 25×22.5. The results indicated that the newly developed wheel steel had outstanding fatigue life even if the mass loss was 10% in comparison with Q235B.

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

    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.

  18. Wheel torque control for a rough terrain rover

    Lamon, Pierre; Krebs, Ambroise; Lauria, Michel; Siegwart, Roland,; Shooter, Steven

    2004-01-01

    Navigating in rough terrain is a complex task that requires the robot to be considered as a holistic system. Algorithms, which don’t consider the physical dimensions and capabilities of the mobile robot lead to inefficient motion and suffer from a lack of robustness. A physical model of the robot is necessary for trajectory control. In this paper, quasi-static modeling of a six-wheeled robot with a passive suspension mechanism is presented together with a method for selecting the optima...

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

    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.

  20. Three-wheeled scooter taxi: A safety analysis

    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.

  1. Reaction Wheel Control Design Using Linear Quadratic Controller

    Nubli Muhamad, Nur; Susanto, Erwin; Syihabuddin, Budi; Prasetya Dwi Wibawa, Ig.

    2016-01-01

    This paper studies the design of active attitude control system of a nanosatellite in a single axis. In this paper, we consider dc motor based reaction wheel as an actuator, because of its pointing accuracy. However, the power consumption of the dc motor is often relatively large and needed to be optimized. Linear quadratic controller is supposed to have an ability to minimize power consumption and able to enhance the system performance. To show the advantage of this method, simulation result of attitude response, state trajectory, and trajectory of DC motor voltage are presented.

  2. MOBILITY EVALUATION AND INNOVATION OF WHEELED SPACE ROVER

    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.

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

    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...

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

    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.

  5. Rollover Dynamics of a Narrow Tilting Three-Wheeled Vehicle

    Jubin Antony J

    2016-01-01

    Full Text Available A narrow-track vehicle possesses many advantages like fuel efficiency and reduced road footprint among others. But the main drawback of this model stems from the fact that they tend to rollover more easily due to their narrow base area. In order to overcome this rollover instability, these vehicles are made to tilt to obtain increased virtual base area. The focus of this paper is to analyse the minimum lean angle necessary for a narrow three-wheeled vehicle under lateral acceleration to negotiate a curve safely. In addition, the influence of the horizontal positions of the centre of mass of the vehicle over the rollover speeds is studied.

  6. Nuclear studies of different target systems for the European Spallation Source (ESS)

    This paper summarizes nuclear simulation calculations to study various target concepts for the 'European Spallation Source (ESS)' concerning a proton beam power of 5 MW. For different target systems as rotating wheel target, stationary targets and liquid metal targets results of beam energy - and target material investigations, induced radioactivity and afterheat production as well as usable neutron fluxes are discussed. (author) 11 figs., 5 tabs., 5 refs

  7. Improvement of the operation of wheels mobile robot TRASMAR2

    In the Instituto Nacional de Investigaciones Nucleares (ININ), personnel have been working in the development of wheels mobile robots for the surveillance and supervision of contaminated areas, and for the radioactive material transport. One of these achievements is the wheels mobile robot denominated TRASMAR2, which is sought that works in the tele operated form using net technologies, in particular, using a Web page by means of the client-servant technology. For this, diverse circuits and control programs have been development with the purpose that the robot carries out the movements that are required, being considered the use of sensors to avoid collisions. The different programs have been implemented in different micro controllers, and although the robot was working, is necessary to optimize and to concentrate these programs on a single micro controller. In this work are presented the analysis of the previously implemented programs, as the realized changes, including new programs required to improve the robot operation. As complement, was development and implemented an alternative proposal of the robot's tele operation by means of a Web page using Lab view, which is described in the work. With this proposal tele operate the robot was achieved, although its application is evaluating due to the resources that is consumes. (author)

  8. Non-Harmonic Fourier Analysis for bladed wheels damage detection

    Neri, P.; Peeters, B.

    2015-11-01

    The interaction between bladed wheels and the fluid distributed by the stator vanes results in cyclic loading of the rotating components. Compressors and turbines wheels are subject to vibration and fatigue issues, especially when resonance conditions are excited. Even if resonance conditions can be often predicted and avoided, high cycle fatigue failures can occur, causing safety issues and economic loss. Rigorous maintenance programs are then needed, forcing the system to expensive shut-down. Blade crack detection methods are beneficial for condition-based maintenance. While contact measurement systems are not always usable in exercise conditions (e.g. high temperature), non-contact methods can be more suitable. One (or more) stator-fixed sensor can measure all the blades as they pass by, in order to detect the damaged ones. The main drawback in this situation is the short acquisition time available for each blade, which is shortened by the high rotational speed of the components. A traditional Discrete Fourier Transform (DFT) analysis would result in a poor frequency resolution. A Non-Harmonic Fourier Analysis (NHFA) can be executed with an arbitrary frequency resolution instead, allowing to obtain frequency information even with short-time data samples. This paper shows an analytical investigation of the NHFA method. A data processing algorithm is then proposed to obtain frequency shift information from short time samples. The performances of this algorithm are then studied by experimental and numerical tests.

  9. IntellWheels: Modular development platform for intelligent wheelchairs

    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.

  10. Multiaxial motorcycle wheel load transducer; Mehrkomponenten-Motorradmessnabe

    Kuchler, M.; Schrupp, R. [BMW AG, Muenchen (Germany)

    2001-07-01

    Knowing the loads between road and wheel is one of the elementary inputs during the virtual CAE-based motorcycle design process and the real hardware test in the laboratory and on the track. Up to now, load measurements have been done by expensive strain gage applications on chassis components of the motorcycle, which forced extensive and time-wasting calibrations and calculations. The solution to that problem was the development of the worldwide unique multiaxial wheel load transducer for motorcycles, a joint project of the fatigue strength division and the motorcycle measuring division. (orig.) [German] Die Kenntnis der Kraefte zwischen Rad und Strasse ist eine der wesentlichen Eingangsgroessen sowohl fuer den CAE-gestuetzten virtuellen Produktentstehungsprozess als auch fuer die Versuche im Labor und auf der Teststrecke. In der Vergangenheit wurden die Lasten im Fahrbetrieb durch teuere Dehnungsmessstreifen-Applikationen an Fahrwerksbauteilen ermittelt, die umfangreiche und zeitaufwaendige Kalibrierungen und Signalverrechnungen erforderten. Die Loesung dieses Problems war die Entwicklung der weltweit ersten Mehrkomponenten-Motorradmessnabe, einem Gemeinschaftsprojekt der Abteilung Betriebsfestigkeit und der Motorradmesstechnik. (orig.)

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

    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.

  12. Modelling the effects of repeated wheel loads on soil profiles

    Gräsle W.

    1997-09-01

    Full Text Available Compaction of soil caused by increasing mechanical loads and repeated wheeling may result in reduced soil productivity. The physical response of soils to such loading is analysed with a non-linear finite element program using incremental tangential moduli with incremental loading and unloading from known initial conditions. During each load increment an iterative procedure is used to determine more accurately the stresses and the stress dependent moduli. This program is designed to model the linear elastic and plastic behaviour of soils with stress and moisture dependent properties with strain softening and irreversible load responses. The relevant material parameters are discussed and suggested methods of measuring them in standard soil mechanics test procedures are proposed. The use of such models in predicting soil behaviour must always involve a balanced integration of the measurement of the material parameters and boundary conditions for the problem, the use of appropriate analytical techniques and field verification. Practical examples are given to show how this has been done in interpreting field experiments and to confirm that the techniques can predict the physical response of soil profiles to repeated wheeling.

  13. Solving conformal wheel-rail rolling contact problems

    Vollebregt, Edwin; Segal, Guus

    2014-05-01

    The stresses between railway wheels and rails can be computed using different types of contact models: simplified methods, half-space-based boundary element approaches and finite element models. For conformal contact situations, particularly the contact between flange root and rail gauge corner, none of these models work satisfactorily. Finite element methods are too slow, half-space approaches ignore the effects of conformality, and simplified approaches schematise the elasticity of the material even further. This paper presents a thorough investigation of the conformal wheel-rail rolling contact problem. We use CONTACT's boundary element approach together with numerical influence coefficients, that are computed using the finite element approach. The resulting method is fast and detailed and can be embedded into vehicle system dynamics simulation. The results indicate that the contact area is longer and narrower, with smaller area and reduced stiffness, than is predicted by the half-space approach. The predicted maximum pressures are increased by 30%. Finally the longitudinal and lateral forces changed up to 15% of the Coulomb maximum.

  14. Numerical Analysis of Asphalt Pavements under Moving Wheel Loads

    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.

  15. Vibration Characteristics of Roundabout Swing of HAWT Wind Wheel

    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.

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

    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°.

  17. The Structure of Wheel Check Valve Influence on Air Block Phenomenon of Piezoelectric Micro-Pump

    Song Chen

    2015-11-01

    Full Text Available To improve the stability and reliability of the piezoelectric micro-pump, the cause of air block phenomenon is analyzed on the structure of wheel check valve. During the movement of the bubble in the micro-channel, pressure drop occurs, the main factor which influences the bubble going through is opening height of the wheel check valve. Five groups of wheel check valves with different structures are used to test the wheel check valve opening height and air block probability. The experiment results show that reducing the wheel check valve thickness or diameter ratio can both increase the wheel check valve opening height, and decrease the air block probability. Through experiment, the optimum combination of the wheel check valve structure is obtained within the samples: as the thickness is 0.02 mm, the diameter ratio is 1.2, the wheel check valve opening height gets 252 µm, and within the given bubble volume, the air block probability is less than 2%.

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

    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

  19. 49 CFR 238.119 - Rim-stamped straight-plate wheels.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Rim-stamped straight-plate wheels. 238.119 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PASSENGER EQUIPMENT SAFETY STANDARDS Safety Planning and General Requirements § 238.119 Rim-stamped straight-plate wheels. (a)(1) Except as provided in paragraph (a)(2) of...

  20. 16 CFR Figure 8 to Part 1512 - Reflectorized Bicycle Wheel Rim Abrasion Test Device

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Reflectorized Bicycle Wheel Rim Abrasion Test Device 8 Figure 8 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL...—Reflectorized Bicycle Wheel Rim Abrasion Test Device EC03OC91.074...

  1. Resource-saving technology for producing blanks wheel rims with the unit longitudinal-transverse cutting

    Кононенко, Д. Ю.; Павлюк, А. В.; Антоненко, А. В.; Разиньков, Н. А.

    2013-01-01

    Analysis of the grade and dimensional range of original metal used in the manufacture of wheels andrims was carried out. Defined are the parameters and characteristics of rolls cutting, required for selecting aplant unit. One of the ways of increasing economical efficiency of wheel rims production was investigated,in order to optimize blanks manufacturing technology with considerations for the production program.

  2. The Grinding Wheel Performance in the Transverse Cylindrical Grinding of an Eutetic Alloy

    Bianchi Eduardo Carlos

    2002-01-01

    Full Text Available This paper presents a research in which the performance of two different grinding wheels (a conventional and a CBN wheel was evaluated in a transverse cylindrical grinding of a eutectic alloy. Three cutting conditions were tested: rough, semi-finishing and finishing. As evaluating parameters, the cutting force, the roughness and the wheel wear were measured. As a result, the best values of the cutting force and the roughness were obtained when grinding with the conventional wheel, due to the best dressing operation performed, for all the cutting conditions. The CBN presented the best G ratio values. Although, the G ratio values observed for the CBN wheel were lower than the expected one due to the non-effective dressing operation applied. In the conditions tested, in terms of cutting force and roughness, the conventional wheel is the best choice. In terms of G ratio, a cost analysis is crucial to determine if the differences observed among the wheels can justify the use of the CBN wheel. In a positive case, the dressing operation must be improved.

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

    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...

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

    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...

  5. Effects of Post-Session Wheel Running on Within-Session Changes in Operant Responding

    Aoyama, Kenjiro

    2007-01-01

    This study tested the effects of post-session wheel running on within-session changes in operant responding. Lever-pressing by six rats was reinforced by a food pellet under a continuous reinforcement (CRF) schedule in 30-min sessions. Two different flavored food pellets were used as reinforcers. In the wheel conditions, 30-min operant-sessions…

  6. 16 CFR 1420.4 - Restrictions on three-wheel ATVs.

    2010-01-01

    ... Section 1420.4 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... consumer product safety standard applicable to three-wheel ATVs promulgated pursuant to the Consumer Product Safety Act is in effect, new three wheel ATVs may not be imported into or distributed in...

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

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

    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…

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

    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.

  10. [A specific sign of the injury inflicted by the front wheel of a bicycle].

    Leonov, S V; Pinchuk, P V; Molchanov, D V

    2016-01-01

    The authors report the results of the comprehensive forensic medical expertise of the injury inflicted by the front wheel of a bicycle that revealed a new specific sign of the contact between the protruding part of the wheel of the bicycle (the brake disk) and the pedestrian's body. PMID:27070037

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

    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.

  12. Effects of genetic background and environmental novelty on wheel running as a rewarding behaviour in mice

    de Visser, Leonie; van den Bos, Ruud; Stoker, Astrid K; Kas, Martien J H; Spruijt, Berry M

    2007-01-01

    Recent studies suggest running wheel activity to be naturally rewarding and reinforcing; considering the shared neuro-behavioural characteristics with drug-induced reward situations, wheel running behaviour gains interest as a tool to study mechanisms underlying reward-sensitivity. Previously, we sh

  13. Proton-induced nuclide production in heavy target elements at medium energies

    Cross sections for the proton-induced production of residual nuclei in natPb and 209Bi were measured for proton energies between 70 MeV and 1.6 GeV. A comparison with calculated cross sections using an INC/E-model, the hybrid model of preequilibrium reactions and a semiempirical formula has been performed showing that for applications which depend on accurate data it is still necessary to measure cross sections. 21 refs., 5 figs

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

    Silva Eraldo Jannone da

    2002-01-01

    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.

  15. Split roller bearings in bucket wheel excavators. Geteilte Waelzlager in Schaufelradbaggern

    Herles, G. (FAG Kugelfischer Georg Schaefer KGaA, Schweinfurt (Germany))

    1991-09-01

    Roller bearings for bucket wheel gearing and for bucket wheel shafts have to meet high requirements to cope with the rugged conditions of opencast workings. Operating safety and reliability, long service life and easy maintenance are factors of primary importance. Since 1970 the heavy-duty machine construction firm Lauchhammer TAKRAF has used split cylinder roller bearings manufactured by the firm of FAG Kugelfischer Georg Schaefer for the gear driven wheels in bucket wheel gear systems instead of the orginally installed split journal bearings. Split self-aligning roller bearings have proved a satisfactory solution as bearings for bucket wheel shafts. The bearings developed in co-operation with FAG are economical in design, ensure high operating safety and reliability and can be assembled or dismantled easily and quickely. A total number of more than 120 FAG split cylindrical roller bearings and self-aligning roller bearings are already in service in TAKRAF excavators. (orig.).

  16. Application of modern calculation and design methods for bucket wheel sleeve shafts

    Moeser, H. (VEB Schwermaschinenbau Lauchhammerwerk, Lauchhammer-Ost (German Democratic Republic))

    1989-01-01

    Explains design of the bucket wheel sleeve shaft for the large SRs 6,300 bucket wheel excavator, built by TAKRAF, GDR. The excavator has a production capacity of 14,500 m{sup 3}/h and a bucket wheel diameter of 17 m. The bucket wheel shaft is 7 m long and weighs 33 t. A scheme of the shaft is provided. The design was developed by computer calculations with the ROSCHA program system of the Dresden Technical University. Shaft groove geometry was determined with the ALPHA program. The shaft was welded from segments that fulfilled requirements of the TGL 19 340 industrial standard. Measurements of load on this bucket wheel shaft and assessment of service life have been made during excavator operations in brown coal surface mines. 5 refs.

  17. Feature Extraction in Radar Target Classification

    Z. Kus

    1999-09-01

    Full Text Available This paper presents experimental results of extracting features in the Radar Target Classification process using the J frequency band pulse radar. The feature extraction is based on frequency analysis methods, the discrete-time Fourier Transform (DFT and Multiple Signal Characterisation (MUSIC, based on the detection of Doppler effect. The analysis has turned to the preference of DFT with implemented Hanning windowing function. We assumed to classify targets-vehicles into two classes, the wheeled vehicle and tracked vehicle. The results show that it is possible to classify them only while moving. The feature of the class results from a movement of moving parts of the vehicle. However, we have not found any feature to classify the wheeled and tracked vehicles while non-moving, although their engines are on.

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

    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. PMID:26631601

  19. Analysis and control of high-speed wheeled vehicles

    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

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

    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.

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

    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.

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

    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.

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

    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.

  4. REVIEW OF DRESSING AND TRUING OPERATIONS FOR GRINDING WHEELS

    UJJAWAL MAYANK SRIVASTAVA

    2013-01-01

    Full Text Available Grinding is an operation applied in almost every type of manufacturing process. It aims to produce high surface finish and to maintain close tolerances in the manufactured product. To make the grinding operation more productive and efficient, dressing and truing operations are performed on the grinding wheels. Various techniques are available and are used for the same. Since many permutations and combinations exists among the factors like economics, efficiency, accuracy, complexity, etc. of the dressing process, so continuous efforts are made to develop or adopt a technique that gives the best result while fulfilling the maximum number of factors. This can be accomplished by comparing the present techniques on the same ground. With this aim, the unconventional techniques with in-process configuration were developed that have several advantages over theirconventional counterparts.

  5. Mechanisms of Spin-Mixing Instabilities in Antiferromagnetic Molecular Wheels

    Soncini, Alessandro; Chibotaru, Liviu F.

    2007-08-01

    The microscopic theory of field-induced spin-mixing instabilities in antiferromagnetic molecular wheels CsFe8 is proposed. The basic features of magnetic torque measurements [O. Waldmann , Phys. Rev. Lett. 96, 027206 (2006)PRLTAO0031-900710.1103/PhysRevLett.96.027206] are well explained by the interplay of three basic ingredients: the spin-mixing vibronic interaction with field-dependent vibronic constants, cooperative elastic interactions, and spin-mixing interactions independent from vibrations. The main contribution to spin mixing comes from second-order zero-field splitting mechanisms. At variance with previous interpretations, we find that the observed anomalies are not associated with a phase transition.

  6. Analysis of wheel speed vibrations for road friction classification

    Schmeitz, A. J. C.; Alirezaei, M.

    2016-04-01

    With higher level of vehicle automation, it becomes increasingly important to know the maximum possible tyre forces during normal driving. An interesting method in this respect is estimating the tyre-road friction from the resonance peak in the wheel speed signal, excited by road roughness. A simulation environment using the MF-Swift tyre model is proposed, which gives insight in the correctness and functioning of this method. From implementing the estimation algorithm and considering the tyre torsional vibration system, it is concluded that frequencies and damping ratios can be estimated with reasonable accuracy and that the trends observed with changing road friction are consistent. Furthermore, the proposed simulation environment gives opportunity to investigate other issues like robustness of the estimation method to road roughness. Additionally, the tyre modelling aspect of the estimation method is analysed and improvements are proposed.

  7. Movement Simulation for Wheeled Mobile Robot Based on Stereo Vision

    Gao, Hongwei; Chen, Fuguo; Li, Dong; Yu, Yang

    According to the application of the planet detection, the kinematics model of six wheels rock-bogie robot was studied in this paper. A corresponding robot movement simulation system based on stereo vision and virtual reality was developed. The system provided motion parameters of virtual robot to real robot by means of out-line teaching, which ensured the robot's safety. The visual orientation theory and the simulation system realization based on OpenGL were introduced in detail. The simulation was finished based on synthesis terrain and real terrain, and the results show that the system possesses preferable interactive characteristic, and will provide some key techniques for virtual navigation, teleoperation of planetary exploration robot.

  8. From wheels to wings with evolutionary spiking circuits.

    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. PMID:15811223

  9. Discrete neural dynamic programming in wheeled mobile robot control

    Hendzel, Zenon; Szuster, Marcin

    2011-05-01

    In this paper we propose a discrete algorithm for a tracking control of a two-wheeled mobile robot (WMR), using an advanced Adaptive Critic Design (ACD). We used Dual-Heuristic Programming (DHP) algorithm, that consists of two parametric structures implemented as Neural Networks (NNs): an actor and a critic, both realized in a form of Random Vector Functional Link (RVFL) NNs. In the proposed algorithm the control system consists of the DHP adaptive critic, a PD controller and a supervisory term, derived from the Lyapunov stability theorem. The supervisory term guaranties a stable realization of a tracking movement in a learning phase of the adaptive critic structure and robustness in face of disturbances. The discrete tracking control algorithm works online, uses the WMR model for a state prediction and does not require a preliminary learning. Verification has been conducted to illustrate the performance of the proposed control algorithm, by a series of experiments on the WMR Pioneer 2-DX.

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

    Mi Guofa

    2009-02-01

    Full Text Available 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-fi lling and solidifi cation 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.

  11. Evaluation of Silicon Nitride for Brayton Turbine Wheel Application

    Freedman, Marc R.

    2008-01-01

    Silicon nitride (Si3N4) is being evaluated as a risk-reduction alternative for a Jupiter Icy Moons Orbiter Brayton turbine wheel in the event that the Prometheus program design requirements exceed the creep strength of the baseline metallic superalloys. Five Si3N4 ceramics, each processed by a different method, were screened based on the Weibull distribution of bend strength at 1700 F (927 C). Three of the Si3N4 ceramics, Honeywell AS800, Kyocera SN282, and Saint-Gobain NT154, had bend strengths in excess of 87 ksi (600 MPa) at 1700 F (927 C). These were chosen for further assessment and consideration for future subcomponent and component fabrication and testing.

  12. Narrow-track wheeled agricultural tractor parameter variation.

    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. PMID:24673034

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

    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.

  14. Cross-stream ejection in the inter-wheel region of aircraft landing gears

    McCarthy, Philip; Ekmekci, Alis

    2014-11-01

    The reduction of aircraft noise is an important challenge currently faced by aircraft manufacturers. During approach and landing, the landing gears contribute a significant proportion of the aircraft generated noise. It is therefore critical that the key noise sources be identified and understood in order for effective mitigation methods to be developed. For a simplified two-wheel nose landing gear, a strong cross stream flow ejection phenomena has been observed to occur in the inter-wheel region in presence of wheel wells. The location and orientation of these flow ejections causes highly unsteady, three dimensional flow between the wheels that may impinge on other landing gear components, thereby potentially acting as a significant noise generator. The effects of changing the inter-wheel geometry (inter-wheel spacing, the wheel well depth and main strut geometry) upon the cross-stream ejection behaviour has been experimentally investigated using both qualitative flow visualisation and quantitative PIV techniques. A summary of the key results will be presented for the three main geometrical parameters under examination and the application of these findings to real life landing gears will be discussed. Thanks to Messier-Bugatti-Dowty and NSERC for their support for this project.

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

    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.

  16. Laser dressing process of porous cast-iron bonded diamond grinding wheels for machining ceramics

    Dressing using Yttrium Aluminum Garnet-Second Harmonic Generation (YAG-SHG) laser for porous cast-iron bonded diamond grinding wheels is a unique method. Diamond as an abrasive grain shows transparency with the laser, while cast-iron employed as a bonding and bridging material for the present diamond grinding wheels absorbs it. Hence, it is possible for laser to remove cast-iron selectively with a minimal damage on diamond so that dressing can be optimized. In this investigation a newly proposed dressing process using YAG-SHG laser with the wavelength of 532 nm was conducted upon porous cast-iron bonded diamond grinding wheels with fine grains. It revealed that application of laser for dressing evaporates cast-iron and the amount of evaporation increases with laser flux densities, resulting in an increment of protrusion heights. The wheel dressed with laser allows about six times of removal volume rate on ZrO2 at the maximum rather than the same wheel mechanically dressed. It also achieves 90 times less specific grinding energy. With the increase of laser flux density, the removal volume of ground work pieces can be increased or the specific grinding energy decreased. The laser dressed wheels can also achieve the same surface roughness on ground surfaces as mechanically dressed wheels. Copyright (2000) AD-TECH - International Foundation for the Advancement of Technology Ltd

  17. ANALYSIS OF THERMAL-ELASTIC STRESS OF WHEEL-RAIL IN ROLLING-SLIDING CONTACT

    ZHAO Xin; JIN Xuesong; ZHAI Wanming

    2007-01-01

    A coupling thermo-mechanical model of wheel/rail in rolling-sliding contact is put forward using finite element method. The normal contact pressure is idealized as the Hertzian distribution, and the tangential force presented by Carter is used. In order to obtain thermal-elastic stress, the thermal-elastic plane stress problem is transformed to an elastic plane stress problem with equivalent fictitious thermal body force and fictitious boundary distributed force. The temperature rise and thermal-elastic stress of wheel and rail in rolling-sliding are analyzed. The non-steady state heat transfer between the contact surfaces of wheel and rail, heat-convection and radiation between the wheel/rail and the ambient are taken into consideration. The influences of the wheel rolling speed and wear rate For rolling-sliding case, the thermal stress in the thin layer near the contact patch due to the friction temperature rise is severe. The higher rolling speed leads to the lower friction temperature rise and wheel rise quickly in the initial sliding stage, and then get into a steady state gradually. The expansion of the contact patch, due to material wear, can affect the friction temperature rise and the thermal stress during wear process. The higher wear rate generates lower stress. The results can help understand the influence of friction temperature and thermal-elastic stress on wheel and rail damage.

  18. Fatigue behavior of magnesium alloy and application in auto steering wheel frame

    2008-01-01

    The low-cycle fatigue behaviors of AZ91HP-F, AZ91HP-T6, AZ91HP-T4 and AM50HP-F were investigated, and the potential application of AM50HP-F in steering wheel frame was studied. The steering wheel properties were characterized by bend fatigue and tensile testing, and the fatigue fracture was analyzed by SEM. The results show that the fatigue lives of AZ91HP-F and AZ91HP-T6 have little difference by comparing the low-cycles fatigue properties of different heat treatment states. The crack propagation velocity of AZ91HP-T4 is lower than that of AZ91HP-F and AZ91HP-T6. The die casting technological parameters of the magnesium steering wheel have been optimized with the aid of flow-3D software. The tensile testing results of the different part of magnesium steering wheel show that the ultimate tensile strength and elongation in the wheel arm and wheel rim have no difference and the average value are 220 MPa and 5%, respectively. The fracture is in the brittleness mode and the fatigue crack initiates at the outside of the wheel rim.

  19. Reaction wheel with HTS bearings for mini-satellite attitude control

    We have developed a small reaction wheel, designed to be lightweight, compact and energy efficient. The main innovation is the use of the HTS magnet's bearings that promise low friction so that high momentum storage can be achieved with high spin speed. The bearings consist of seeded growth superconducting discs arranged in rings located above and below the rotating levitated wheel containing ring-magnets embedded at the top and bottom. The reaction wheel is in the shape of a hollow stainless steel cylinder. A brushless dc motor is installed inside the hollow cylinder to provide the necessary torque to the reaction wheel. The maximum design spin speed is 15 000 RPM to store 3.5 J s-1 of angular momentum. Spin-down test of the reaction wheel was performed in air. We have also measured the input power required to sustain rotational speed of the reaction wheel in air. Results from both of these measurements, when extrapolated to full speed in vacuum, indicate that power consumption, even accounting for the needs of the cooling system, is significantly smaller than that for state of the art commercial reaction wheels using mechanical ball bearings. (author)

  20. ULTRASONIC EVALUATION OF STRESS STATES OF RIMS OF RAILROAD WHEELS. PART 2 — EXPERIENCES AND FUTURE ADAPTATIONS

    Schneider, E.; DYMKIN G.

    2013-01-01

    An ultrasonic technique was developed and different systems are in use to evaluate the stress state of the rim of solid railroad wheels. The measure results received with the UER system versions developed by IZFP as well as the Russian version УКОН-01 was shown and described in the paper. Because the stress state of new wheels is smaller in value than the stress in braked wheels, the influence of a slightly developed texture in new wheels cannot be neglected as it can in case of used wheels. ...

  1. Application of CBN Grinding Wheel in Engine Manufacturing%CBN砂轮在发动机制造中的应用

    刘将先; 杨威; 王香丽

    2015-01-01

    Cubic boron nitride ( CBN) is a superhard material with many outstanding advantages and wide uses. Also there are many outstanding performances for the grinding wheel made by CBN. With the appearances of high speed, ultra-high speed numerical control grinding machines, the CBN grinding wheel is widely used in mechanical processes. The high speed grinding wheel is an environment-protection product with high precision, high efficiency, low materials con-sumed, low production costs, less environment pollution and highly automated, which makes it be a sharp weapon for reali-zing the target of green process.%立方氮化硼( CBN)是一类性能优越、用途广泛的超硬材料,用CBN制造的砂轮同样具有优异的性能。随着高速、超高速数控磨床的出现,CBN砂轮在机械加工中得到广泛应用。由于高速CBN砂轮是一种具有高精度、高效率、低消耗、低生产成本、低污染、自动化程度高等优异性能的环保磨具,因此采用高速CBN砂轮进行磨削加工是实现绿色加工目标的利器。

  2. Detumbling of a rigid spacecraft via torque wheel assisted gyroscopic motion

    Lin, Yiing-Yuh; Wang, Chin-Tzuo

    2014-01-01

    A time and energy efficient two-part method for detumbling a rigid spacecraft using an onboard torque wheel and a set of three-axis magnetic torquer is presented in this paper. Part-1 of the method manipulates the speed of the wheel, whose spin axis is parallel to a designated body axis of a tumbling spacecraft, and induces a desired gyroscopic-like motion to align the designated axis with its total angular momentum, H. The procedure in effect detumbles the spacecraft to rotate about the designated axis and distributes H, which is conserved during this control period, between the body and the wheel. After the alignment is achieved, Part-2 control, activated with a specified momentum transfer parameter, η, can either quickly stop the body rotation by transferring its angular momentum to the wheel or offload most of the momentum into space, using the wheel and the magnetic torquer. Convergence criteria and control laws for both parts are derived from the Lyapunov stability analysis and the method of feedback linearization. The wheel performs as a momentum storing and transferring device regulating the angular momentum between the wheel and the body. It can also provide gyroscopic stiffness to stabilize the system while the magnetic torquer is offloading the momentum. Simulation results from the included cases indicate that significantly fast detumbling of the spacecraft can be achieved with Part-1 of the proposed method. The results also show that, under the same condition, either by transferring almost all H to the wheel or dumping it, the two-part method, with a chosen η and final residual momentum condition, requires much less time and energy needed than the B-dot method does. Moreover, the stability nature of the two-part method is heuristically substantiated as the wheel torques and the dipole moment were constrained in the simulation.

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

    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.

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

    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.

  5. High-precision cryogenic wheel mechanisms for the JWST NIRSpec instrument

    Weidlich, Kai; Fischer, Manfred; Ellenrieder, Marc M.; Gross, Torsten; Salvignol, Jean-Christophe; Barho, Reiner; Neugebauer, Christian; Königsreiter, Günter; Trunz, Michael; Müller, Friedrich; Krause, Oliver

    2008-07-01

    The Grating and Filter Wheel Mechanisms of the JWST NIRSpec instrument allow for reconfiguration of the spectrograph in space in a number of NIR sub-bands and spectral resolutions. Challenging requirements need to be met simultaneously including high launch loads, the large temperature shift to cryo-space, high position repeatability and minimum deformation of the mounted optics. The design concept of the NIRSpec wheel mechanisms is based on the ISOPHOT Filter Wheels but with significant enhancements to support much larger optics. A well-balanced set of design parameters was to be found and a considerable effort was spent to adjust the hardware within narrow tolerances.

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

    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.

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

    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.

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

    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.

  9. Improved Infrared-Sensing Running Wheel Systems with an Effective Exercise Activity Indicator

    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 thick...

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

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

    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 was allocated to sucrose and more reinforcements were obtained from that alternative. Allocation of behavior to wheel running decreased, but obtained...

  11. Assessing the influence of wheel defects of a rolling stockon railway tracks

    Loktev Aleksey Alekseevich; Mazov Yuriy Nikolaevich; Sychev Vyacheslav Petrovich

    2015-01-01

    Transfer of the load from the wheels on the rail occurs at a very small area compared with the size of the wheels and rails. The materials near this site have a very large voltage. Determination of contact stresses is complicated by the fact that the magnitude of these stresses in the rails under actually revolving wheel load exceeds the yield and compressive strength of modern rail steel. We should note that the metal of the rail head, experiencing contact stresses, especially when the locat...

  12. A fly-wheel drive with controlled-torque clutch for a reactors cooling circuit pumps

    After a theoretical study on the slowing down of a centrifugal pump, the motion equations have been checked by means of experimental tests. In order to have important slowing down times (which is the case of the cooling pumps of a research reactor) it is necessary to add a fly-wheel. To prevent troubles when starting, a block pump-fly-wheel with clutch under controlled torque was developed. It is so possible to start the fly-wheel progressively without increasing too much power of the driving motor. (author)

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

    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.

  14. Evolutionary Fuzzy Control and Navigation for Two Wheeled Robots Cooperatively Carrying an Object in Unknown Environments.

    Juang, Chia-Feng; Lai, Min-Ge; Zeng, Wan-Ting

    2015-09-01

    This paper presents a method that allows two wheeled, mobile robots to navigate unknown environments while cooperatively carrying an object. In the navigation method, a leader robot and a follower robot cooperatively perform either obstacle boundary following (OBF) or target seeking (TS) to reach a destination. The two robots are controlled by fuzzy controllers (FC) whose rules are learned through an adaptive fusion of continuous ant colony optimization and particle swarm optimization (AF-CACPSO), which avoids the time-consuming task of manually designing the controllers. The AF-CACPSO-based evolutionary fuzzy control approach is first applied to the control of a single robot to perform OBF. The learning approach is then applied to achieve cooperative OBF with two robots, where an auxiliary FC designed with the AF-CACPSO is used to control the follower robot. For cooperative TS, a rule for coordination of the two robots is developed. To navigate cooperatively, a cooperative behavior supervisor is introduced to select between cooperative OBF and cooperative TS. The performance of the AF-CACPSO is verified through comparisons with various population-based optimization algorithms for the OBF learning problem. Simulations and experiments verify the effectiveness of the approach for cooperative navigation of two robots. PMID:25398185

  15. Front and Back Movement Analysis of a Triangle-Structured Three-Wheeled Omnidirectional Mobile Robot by Varying the Angles between Two Selected Wheels.

    Mohanraj, A P; Elango, A; Reddy, Mutra Chanakya

    2016-01-01

    Omnidirectional robots can move in all directions without steering their wheels and it can rotate clockwise and counterclockwise with reference to their axis. In this paper, we focused only on front and back movement, to analyse the square- and triangle-structured omnidirectional robot movements. An omnidirectional mobile robot shows different performances with the different number of wheels and the omnidirectional mobile robot's chassis design. Research is going on in this field to improve the accurate movement capability of omnidirectional mobile robots. This paper presents a design of a unique device of Angle Variable Chassis (AVC) for linear movement analysis of a three-wheeled omnidirectional mobile robot (TWOMR), at various angles (θ) between the wheels. Basic mobility algorithm is developed by varying the angles between the two selected omnidirectional wheels in TWOMR. The experiment is carried out by varying the angles (θ = 30°, 45°, 60°, 90°, and 120°) between the two selected omniwheels and analysing the movement of TWOMR in forward direction and reverse direction on a smooth cement surface. Respectively, it is compared to itself for various angles (θ), to get its advantages and weaknesses. The conclusion of the paper provides effective movement of TWOMR at a particular angle (θ) and also the application of TWOMR in different situations. PMID:26981585

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

    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

  17. The relationship between four-wheel drives and risky driving behaviours

    Abdulbari Bener

    2014-07-01

    Full Text Available Background: Given the increased number of four wheel drive (4WD vehicles in Qatar and their involvement in crashes, casualties and road fatalities, it is important to understand the association between risky driving behavior and 4WD crashes. Aim/Objective: This study aimed to determine the association between risky driving behaviours and 4WD vehicles and its impact on road traffic accidents in the State of Qatar. Materials and Methods: A cross sectional survey was conducted using a multistage stratified cluster sampling technique to recruit 1824 drivers of two wheel drive (small cars and 4WD across different primary health centres (PHCs in Qatar. The Driver Behaviour Questionnaire (DBQ and Driver Skill Inventory (DSI were used to collect the data. Information regarding socio-demographic and road traffic crashes during last three years was also obtained. Multivariate logistic regression was used to analyse the data. Results: 762 (41.8% owned 4WD vehicles. Drivers of 4WD were significantly higher between 30-50 years age (P < 0.001, urban dwellers (P = 0.003, having more driving experience (atleast 5 years (P < 0.001 and annual mileage higher than the drivers of small cars (P < 0.001. A significantly higher proportion of 4WD drivers had previous penalties for traffic violations such as crossing a red traffic signal (51.6% vs. 21.4%; P < 0.001 or exceeding the speed limit (35% vs. 27.8%; P < 0.001. A higher proportion of 4WDs' drivers reported previous involvement in accidents as compared to the drivers of small cars (42.4% vs. 35.7%; p 0.004. The risk of accident involvement was 1.21 times higher among drivers of 4WD as compared to the counterparts (OR 1.21; 95%CI; 1.01-1.46. Besides, excessive speed, annual mileage, male gender, traffic violations, lapses, errors and driving skills were significantly associated with crashes. Conclusion: The drivers of 4WD cars are at higher risk of crashes as compared to the drivers of small cars. Also, they have

  18. Dynamic Measurement for the Diameter of A Train Wheel Based on Structured-Light Vision

    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.

  19. A Bearing Cartridge Assembly for Longterm Performance of Momentum/Reaction Wheels used in Spacecraft

    K. Sathyan

    2014-03-01

    Full Text Available Momentum/reaction wheels are used in a spacecraft for the attitude control. They are used for the real time control of spacecraft attitude towards the desired direction as required by the mission. These are one of the few systems of a spacecraft which need to work continuously from the beginning to end of the mission. Thus the life of a space mission depends largely on the performance of the attitude control wheels. The common mode of failure in momentum/reaction wheel is mechanical and mostly related to the bearing and lubrication. This paper presents the design and development of a bearing cartridge assembly including the lubrication system for long-term performance of spacecraft attitude control wheels. The results of both theoretical and experimental analysis are presented. The experimental study of the assembly shows that it can perform continuously for a period of 30 years with reduced frictional losses.

  20. The effect of material properties on the thermal efficiency of the Minto solar wheel

    Lin, S.; Bhardwaj, R.

    1980-04-01

    The characteristic of the thermal performance of the Minto solar wheel is that its thermal efficiency is strongly dependent on the material properties of the working fluid. For a specified working fluid, the thermal efficiency of the ideal cycle of the Minto solar wheel is dependent only on the mean diameter of the wheel. To study the effect of the material properties of the working fluid on the ideal thermal efficiency, 14 working fluids are selected, and their thermal efficiencies as functions of the mean diameter of the wheel are calculated and compared with each other. Among these fluids, R-12, R-115, R-500, R-22 and R-13B1 achieve better thermal performance than the others.

  1. Enhanced voluntary wheel running in GPRC6A receptor knockout mice

    Clemmensen, Christoffer; Pehmøller, Christian; Klein, Anders B;

    2013-01-01

    wheel 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 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 in...... 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...

  2. Rotor-blade wheel solves the sediment problems; Loepehjul loeser sedimentproblemer

    Bakken, Marte

    2009-07-01

    Test period in Peru is over for the recently developed rotor-blade wheel from the Norwegian firm DynaVec. The result shows that the wear and tear problems caused by sediments in great extent is solved. (AG)

  3. Dynamic Measurement for the Diameter of A Train Wheel Based on Structured-Light Vision.

    Gong, Zheng; Sun, Junhua; Zhang, Guangjun

    2016-01-01

    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. PMID:27104543

  4. Two wheel speed robust sliding mode control for electric vehicle drive

    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.

  5. Automatic stair-climbing algorithm of the planetary wheel type mobile robot in nuclear facilities

    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)

  6. Analysis of the performance of superabrasive and alumina grinding wheels with different bonds and machining conditions

    Eduardo Carlos Bianchi

    2003-06-01

    Full Text Available This paper presents a review of researches on CBN (cubic boron nitride grinding wheels with the purpose of identifying the state of art in abrasive machining and serving as the basis for future researches and laboratory tests. The scientific studies investigated here report on interesting results involving grinding, published by Brazilian and foreign authors. The methods and the results are presented and discussed. In addition, a grinding setup is presented which provides more reliable experimental results about the surface integrity of fragile materials. This setup was obtained for grinding tests in several grinding conditions during the wheel service life, using alumina and vitrified and resin bond CBN grinding wheels. Results of cutting force, surface roughness and G ratio are also presented and discussed. They confirm the excellent machining capacity of the CBN wheel, with stable behavior in cutting force and roughness results during the tests. The G ratio values are in agreement with the results found by other researchers.

  7. ITALIMPIANTI designs bucket wheel reclaimer and stacker for North Pulau Laut Terminal

    Landi, M.; Cugnach, P. (ITALIMPIANTI, Genoa (Italy))

    Briefly describes the bucket wheel reclaimer and boom stacker, designed by ITALIMPIANTI and supplied by Noyes Clough of Australia to the coal transhipment terminal at the north end of the island of Pulau Laut, South Kalimantan. 1 tab., 2 photos

  8. THE PROSPECTS OF SOLVING THE ISSUES OF IMPROVING THE OPERATIONAL SAFETY OF RAILWAY WHEELS AND TYRES

    I. O. Vakulenko

    2009-01-01

    Full Text Available The conditions of improving the operational safety of rail wheels and tread bends are determined on the basis ofinvestigation of the structure change in carbon steel after different thermomechanical treatments.

  9. Application of rare- earth and nano elements on diamond cup wheels

    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.

  10. Adaptive Noise Cancellation Method Used for Wheel Speed Signal of Integrate ABS/ASR System

    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.

  11. Experimental studies on resulting bucket wheel load in hard and brittle soil

    Hitzschke, K.; Hubrich, F. (Technische Universitaet, Dresden (German Democratic Republic))

    1990-06-01

    Evaluates cutting experiments carried out by a 1:10 model of a SRs 2,000 bucket wheel excavator of the TAKRAF manufacturer aimed at measuring real load on the bucket wheel, regarded as more accurate than using model tests with single cutting buckets. A scheme of the model bucket wheel and its boom is demonstrated. Measuring devices for bucket wheel load are pointed out. Weak sand concrete was used for cutting experiments. The analysis focuses on tangential, lateral and normal forces as well as on angles of pressure. A cutting force model is further established. A comparison is made between measured and calculated load in tangential and normal direction. It is concluded that the established cutting force model was improved during cutting tests and should be further developed. 10 refs.

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

    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.

  13. Dynamic Measurement for the Diameter of A Train Wheel Based on Structured-Light Vision

    Gong, Zheng; Sun, Junhua; Zhang, Guangjun

    2016-01-01

    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. PMID:27104543

  14. Modeling of heat transfer in the cooling wheel in the melt-spinning process

    B. Karpe

    2011-05-01

    Full Text Available Purpose: In the case of continuous casting of metal ribbons with the melt-spinning process on the industrial scale, larger quantity of melt could lead to a slow excessive warming of the chilling wheel, which would further lead to solidification of a ribbon at non-uniform conditions and increased wearing of the wheel. Primary goal of our work was to determine to what extent the release of heat during contact of the melt/ribbon on the circumferential surface of the chilling wheel affect its surface temperature rise, and inversely how much elevated temperature of the chill wheel surface affects on metal ribbon cooling rate and its solidification velocity.Design/methodology/approach: On the basis of developed mathematical model, a computer program was made and used for analyses of heat transfer in the melt-spinning process.Findings: The calculations show that contact resistance between metal melt and chilling wheel has a great influence on melt/ribbon cooling and chill wheel heating rate, and must not be neglected in numerical calculations, even if its value is very low. In the case of continuous casting, significant “long term” surface temperature increase may take place, if the wheel is not internally cooled. But inner cooling is effective only if wheel casing thickness is properly chosen.Research limitations/implications: Influence of process parameters and chill wheel cooling mode on cooling and solidifying rate over ribbon thickness are outlined.Practical implications: Directions for the chill wheel cooling system design are indicated.Originality/value: New method for determining contact resistance through variable heat transfer coefficient is introduced which takes into account physical properties of the casting material, process parameters and contact time/length between metal melt/ribbon and substrate and enables cooling rate prediction before the experiment execution. In the case of continuous casting, heat balance of the melt

  15. An interactive game-based shoulder wheel system for rehabilitation

    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

  16. Wheel-Based Ice Sensors for Road Vehicles

    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

  17. The development of a frameless glass door made for wheel loaders

    Hult, Josefin

    2014-01-01

    This thesis performed on master level covers an assignment given by the cab division at Volvo Construction Equipment (Eskilstuna, Sweden). The thesis has been carried out by Josefin Hult during the period 2014-01-23 to 2014-05-30 at Mälardalen University. Volvo Construction Equipment manufactures products including wheel loaders, backhoe loaders and articulated haulers. The assignment involves developing the standard door for larger wheel loaders. The current door has a welded frame surroundi...

  18. Mathematical Model for the Contact Stress Calculation of Fluoropolymerized Toothed Wheels

    Ion-Cornel Mituletu

    2010-10-01

    Full Text Available In this paper is presented a contact stress calculation algorithm for a new type of cylindrical toothed wheel. This new type consists in the application of a Xylan 1052 fluoropolymer film on the surface of a metal toothed wheel. Due to the fact that the steel strength, in any case is better than the plastic strength, the main issue which appears is at the contact between the two homologous flank surfaces.

  19. Influence of Turbine and Compressor Wheel Mass and Inertia on the Rotor Dynamics of Turbocharger

    J. Knotek

    2016-03-01

    Full Text Available This paper describes the influence of the compressor and turbine wheel mass and inertia change on the turbocharger rotor dynamics. The model of the turbocharger is presented, the hydrodynamic model of the journal bearing is described and assembly of the whole model in MBS is also presented. The article presents various results describing rotor dynamics on which the influence of compressor and turbine wheel mass and inertia change is discussed.

  20. Influence of Turbine and Compressor Wheel Mass and Inertia on the Rotor Dynamics of Turbocharger

    J. Knotek; P. Novotný; O. Maršálek; Raffai, P.; J. Dlugoš

    2016-01-01

    This paper describes the influence of the compressor and turbine wheel mass and inertia change on the turbocharger rotor dynamics. The model of the turbocharger is presented, the hydrodynamic model of the journal bearing is described and assembly of the whole model in MBS is also presented. The article presents various results describing rotor dynamics on which the influence of compressor and turbine wheel mass and inertia change is discussed.

  1. Optimal control of 2-wheeled mobile robot at energy performance index

    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.

  2. Finishing aeronautical planetary herringbone gear wheels in container vibrating smoothing machine

    Michalski, Jacek

    2015-01-01

    The paper presents the technological process of abrasive-chemical machining wheel bearing surface of the cylindrical herringbone gears planetary gear in vibrating container smoothing machine according to Isotropic Finishing ISF® technology of the REM Chemicals Inc. company. Gear wheels are made of stainless Pyrowear 53 and subjected to carburizing, hardening, cold working and low tempering. The change in value of deviation indicators for the kinematic accuracy, smoothness and geometric struct...

  3. Applications of High-Efficiency Abrasive Process with CBN Grinding Wheel

    Yan Zhou; Changhe Li; Yali Hou

    2010-01-01

    High-efficiency abrasive process with CBN grinding wheel is one of the important techniques of advanced manufacture. Combined with raw and finishing machining, it can attain high material removal rate like turning, milling and planning. The difficult-to-grinding materials can also be ground by means of this method with high performance. In the present paper, development status and latest progresses on high-efficiency abrasive machining technologies with CBN grinding wheel relate to high speed...

  4. Terminal Sliding Mode Control of Mobile Wheeled Inverted Pendulum System with Nonlinear Disturbance Observer

    2014-01-01

    A terminal sliding mode controller with nonlinear disturbance observer is investigated to control mobile wheeled inverted pendulum system. In order to eliminate the main drawback of the sliding mode control, “chattering” phenomenon, and for compensation of the model uncertainties and external disturbance, we designed a nonlinear disturbance observer of the mobile wheeled inverted pendulum system. Based on the nonlinear disturbance observer, a terminal sliding mode controller is also proposed....

  5. a Four Wheel Drive System for a Formula Style Electric Racecar

    Aune, Peder August

    2016-01-01

    This is a master thesis detailing the development and design of a four wheel drive transmission system for a formula style race car using four electric motors to achieve asynchronous power output to each wheel. First an in depth analysis was performed in order to identify key system performance parameters. A concept development phase was used to come up with a system layout based on the performance requirements. The transmission system was then designed and calculated using KISSSoft. Topology...

  6. The Simulation of Grinding Wheels and Ground Surface Roughness Based on Virtual Reality Technology

    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 ...

  7. Durability Characteristics Analysis of Plastic Worm Wheel with Glass Fiber Reinforced Polyamide

    Tae-Il Seo; Jeong-Won Lee; Gun-Hee Kim

    2013-01-01

    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 stud...

  8. Wheelies and Headers, or How to Keep Both Bicycle Wheels on the Ground

    Wehrbein, William M.

    2004-01-01

    A "wheelie" is when a bicycle is ridden with its front wheel lifted from the ground. Riding the bicycle in a way to lift the rear wheel off the ground might lead to the cyclist tumbling over the handlebars, called a "header." Other colorful terms for this situation are "endo" (short for "end-over-end") and "face plant" (for landing face first on the ground). Let's determine the conditions required in order to keep both tires touching the ground at all times.

  9. Comparative Study of Multiple Mode Power Split Transmissions for Wheel Loaders

    Pettersson, Karl; Rydberg, Karl-Erik; Krus, Petter

    2011-01-01

    To increase energy efficiency and lower emissions in construction machines, the use ofhydromechanical power split drive trains shows high potential. The possibility of usingmultiple gear speeds without losing traction force makes the power split architecture especiallysuitable for heavier wheel loaders. This paper analyses two known concepts ofmulti-mode power split transmissions suitable for the wheel loader application and comparesthe solutions based on energy efficiency. The concepts are s...

  10. Simulation of Suspensions, Torsion Bars, and Fifth Wheel for Semitrailers Using Finite Elements

    R. Miralbes; Abad, J.; D. Valladares

    2013-01-01

    The objective of this paper is the simulation of some different types of elements for semitrailers, like the suspension, both mechanical with springs and pneumatic with a spring and diapresses; other parts like the wheels, the torsion bars, the fifth wheel and the suspension of the tractor unit have also been simulated. Then, the numerical simplified FE model of these elements that allows simulating the real behavior of the suspension to apply adequately the boundary conditions of a heavy veh...

  11. Prediction of bead area contact load at the tire-wheel interface using NASTRAN

    Chen, C. H. S.

    1982-01-01

    The theoretical prediction of the bead area contact load at the tire wheel interface using NASTRAN is reported. The application of the linear code to a basically nonlinear problem results in excessive deformation of the structure and the tire-wheel contact conditions become impossible to achieve. A psuedo-nonlinear approach was adopted in which the moduli of the cord reinforced composite are increased so that the computed key deformations matched that of the experiment. Numerical results presented are discussed.

  12. Effect of Vorticity Amplification on Flow Separation from Landing Gear Wheels

    Feltham, Graham; McCarthy, Philip; Ekmekci, Alis

    2014-11-01

    The flow near the stagnation point of landing gear wheels has been previously shown to support a mechanism for inbound streams of weak vorticity to collect, growth, and amplify into large-scale discrete vortex structures. The current experimental study is an extension to investigate the effects of these vortex structures on the separation characteristics of the flow around the outboard sides of the wheels. Experiments were performed in a water channel with qualitative understanding of the flow topology achieved by employing the hydrogen bubble visualization technique and quantitative measurements performed using Particle Image Velocimetry (PIV). The upstream vorticity source is a platinum wire (d = 100 μm) placed 30 mm upstream of the model wheels. The Reynolds number based on wire diameter is 21 and based on wheel diameter (D = 152 mm) is 32,500. The inbound pair of vorticity streams impinged at the wheel surface where maximum vortex growth and amplification occurs as identified by previous experiments. The growth and shedding of the resulting vortical structures is shown to alter the shape and size of the separation bubbles on the outboard sides of the wheels. A vortex identification and tracking method is applied to map the growth and movement of the observed structures.

  13. Amplification of Vorticity Near the Stagnation Point of Landing Gear Wheels

    Feltham, Graham; Ekmekci, Alis

    2013-11-01

    In this experimental investigation, a stream of steady weak vorticity impinging near the stagnation point of a landing gear wheel is shown to grow and amplify into large-scale vortices that coherently shed from the point of generation. To produce the upstream vorticity, a platinum wire of 100 micron diameter, similar to that used in hydrogen bubble visualization technique, is placed upstream of the wheel model. Experiments are conducted in a recirculating water channel. The wheel diameter is D = 152 mm. The Reynolds number based on the wire diameter is 21 and based on the wheel diameter is 32,500. Qualitative understanding of the vorticity amplification and eventual vortex shedding near the stagnation region of the wheel is achieved by employing the hydrogen bubble visualization technique while quantitative insight is collected using Particle Image Velocimetry (PIV). The size and frequency of the shed vortices are found to depend on the wheel geometry as well as the magnitude and impingement point of the inbound vorticity.

  14. Effect of extrusion wheel angular velocity on continuous extrusion forming process of copper concave bus bar

    WU Peng-yue; XIE Shui-sheng; LI Hua-qing; YAN Ming; HUANG Guo-jie; CHENG Lei

    2007-01-01

    The continuous extrusion forming process for producing large section copper concave bus bar under different extrusion wheel angular velocities was studied by three-dimensional finite element technology based on software DEFORM-3D. The rigid-viscoplastic constitutive equation was employed in the model. The numerical simulation results show that the deformation body flow velocity in the die orifice increases gradually with the increase of the extrusion wheel angular velocity. But slippage between the rod and extrusion wheel occurs when the extrusion wheel angular velocity is high. The effective stress near the die orifice enhances gradually with increasing extrusion wheel angular velocity. High stress is concentrated in adjacent regions of the flash gap. The effective strain gradient is greater near the abutment than that near the die orifice. The effective strain of the product increases gradually with increasing extrusion wheel angular velocity. In the deformation process, the deformation body temperature increases remarkably due to friction and deformation. So the cooling is necessary in the region of the die and tools.

  15. Processing parameter optimization for the laser dressing of bronze-bonded diamond wheels

    Deng, H.; Chen, G. Y.; Zhou, C.; Li, S. C.; Zhang, M. J.

    2014-01-01

    In this paper, a pulsed fiber-laser dressing method for bronze-bonded diamond wheels was studied systematically and comprehensively. The mechanisms for the laser dressing of bronze-bonded diamond wheels were theoretically analyzed, and the key processing parameters that determine the results of laser dressing, including the laser power density, pulse overlap ratio, ablation track line overlap ratio, and number of scanning cycles, were proposed for the first time. Further, the effects of these four key parameters on the oxidation-damaged layer of the material surface, the material removal efficiency, the material surface roughness, and the average protrusion height of the diamond grains were explored and summarized through pulsed laser ablation experiments. Under the current experimental conditions, the ideal values of the laser power density, pulse overlap ratio, ablation track line overlap ratio, and number of scanning cycles were determined to be 4.2 × 107 W/cm2, 30%, 30%, and 16, respectively. Pulsed laser dressing experiments were conducted on bronze-bonded diamond wheels using the optimized processing parameters; next, both the normal and tangential grinding forces produced by the dressed grinding wheel were measured while grinding alumina ceramic materials. The results revealed that the normal and tangential grinding forces produced by the laser-dressed grinding wheel during grinding were smaller than those of grinding wheels dressed using the conventional mechanical method, indicating that the pulsed laser dressing technology provides irreplaceable advantages relative to the conventional mechanical dressing method.

  16. Three dimensional, non-linear, finite element analysis of compactable soil interaction with a hyperelastic wheel

    Chiroux, Robert Charles

    The objective of this research was to produce a three dimensional, non-linear, dynamic simulation of the interaction between a hyperelastic wheel rolling over compactable soil. The finite element models developed to produce the simulation utilized the ABAQUS/Explicit computer code. Within the simulation two separate bodies were modeled, the hyperelastic wheel and a compactable soil-bed. Interaction between the bodies was achieved by allowing them to come in contact but not to penetrate the contact surface. The simulation included dynamic loading of a hyperelastic, rubber tire in contact with compactable soil with an applied constant angular velocity or torque, including a tow load, applied to the wheel hub. The constraints on the wheel model produced a straight and curved path. In addition the simulation included a shear limit between the tire and soil allowing for the introduction of slip. Soil properties were simulated using the Drucker-Prager, Cap Plasticity model available within the ABAQUS/Explicit program. Numerical results obtained from the three dimensional model were compared with related experimental data and showed good correlation for similar conditions. Numerical and experimental data compared well for both stress and wheel rut formation depth under a weight of 5.8 kN and a constant angular velocity applied to the wheel hub. The simulation results provided a demonstration of the benefit of three-dimensional simulation in comparison to previous two-dimensional, plane strain simulations.

  17. Development of Grousers with a Tactile Sensor for Wheels of Lunar Exploration Rovers to Measure Sinkage

    Kojiro Iizuka

    2014-03-01

    Full Text Available This paper presents a grouser developed for the wheels of lunar exploration rovers to measure sinkage. The wheels, which are intended to traverse loose soil such as lunar regolith, contain grousers that transfer thrust to the wheels and thus to the body of the rover. The interaction between the wheel (with grousers and the loose soil can be described using a kinematic model. When traversing loose soil, the wheel sinks into the soil, which necessitates knowledge of the entrance angle needed in order to avoid this problem. If the entrance angle is known, the sinkage can be measured in real time before adverse conditions occur. Because of the importance and usefulness of detecting the entrance angle of the wheel, we herein propose a grouser with an embedded tactile sensor. A strain gauge on the surface of the grousers serves as the tactile sensor. In order to confirm the precision of the proposed grouser, we have performed tests on a rigid surface and loose soil surfaces.

  18. Influence of photoperiod and running wheel access on the entrainment of split circadian rhythms in hamsters

    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.

  19. Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

    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.

  20. Soil Parameter Identification for Wheel-terrain Interaction Dynamics and Traversability Prediction

    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. Design Optimization of Heat Wheels for Energy Recovery in HVAC Systems

    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.

  2. Recognition of diamond grains on surface of fine diamond grinding wheel

    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.

  3. TRACTIVE PERFORMANCE ANALYSIS ON RADIALLY DEPLOYABLE WHEEL CONFIGURATION OF LUNAR ROVER VEHICLE BY DISCRETE ELEMENT METHOD

    LI Wen; GAO Feng; JIA Yang

    2008-01-01

    With the consideration of volume constraint of launch vehicle and trafficability of rover vehicle on lunar regolith terrain, a new design of radially deployable wheel is presented. For the purpose of achieving the meso-mechanics and dynamical behavior of lunar soil particles as well as macro-parameters of tractive performance for radially deployable wheel, the interaction between two types of wheel configurations and lunar soil particles is analyzed by means of discrete element method. The network of contact forces, the displacement vector chart, and the deformation of lunar soil beneath wheels are plotted. The equations of soil thrust, motion resistance, drawbar pull and driven torque are derived in granular scale based on the coordinates transformation and algebraic summation. The calculated results show that there is sufficient traction for both 6-split and 12-split radially deployable wheels with 304 mm outspread diameter to negotiate lunar regolith terrain specified here; the value of drawbar pull enhances with the increase of split number of radially deployable wheel, however, the required driven torque increases simultaneously, therefore, the tractive efficiency decreases.

  4. Design and performance tests of a distributed power-driven wheel loader

    Jin, Xiaolin; Shi, Laide; Bian, Yongming

    2010-03-01

    An improved ZLM15B distributed power-driven wheel loader was designed, whose travel and brake system was accomplished by two permanent magnet synchronous motorized-wheels instead of traditional mechanical components, and whose hydraulic systems such as the working device system and steering system were both actuated by an induction motor. All above systems were flexibly coupled with 3-phase 380VAC electric power with which the diesel engine power is replaced. On the level cement road, traveling, braking, traction and steering tests were carried out separately under non-load and heavy-load conditions. Data show that machine speed is 5 km/h around and travel efficiency of motorized-wheels is above 95%; that machine braking deceleration is between 0.5 and 0.64 m/s2 but efficiency of motorized-wheels is less than 10%; that maximum machine traction is above 2t while efficiency of motorized-wheels is more than 90% and that adaptive differential steering can be smoothly achieved by motorized-wheels.

  5. Grinding performance evaluation of porous composite-bonded CBN wheels for Inconel 718

    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.

  6. Computer Vision Based Method and System for Online Measurement of Geometric Parameters of Train Wheel Sets

    Hong-Jun Yang

    2011-12-01

    Full Text Available Train wheel sets must be periodically inspected for possible or actual premature failures and it is very significant to record the wear history for the full life of utilization of wheel sets. This means that an online measuring system could be of great benefit to overall process control. An online non-contact method for measuring a wheel set’s geometric parameters based on the opto-electronic measuring technique is presented in this paper. A charge coupled device (CCD camera with a selected optical lens and a frame grabber was used to capture the image of the light profile of the wheel set illuminated by a linear laser. The analogue signals of the image were transformed into corresponding digital grey level values. The ‘mapping function method’ is used to transform an image pixel coordinate to a space coordinate. The images of wheel sets were captured when the train passed through the measuring system. The rim inside thickness and flange thickness were measured and analyzed. The spatial resolution of the whole image capturing system is about 0.33 mm. Theoretic and experimental results show that the online measurement system based on computer vision can meet wheel set measurement requirements.

  7. Road Identification for Anti-Lock Brake Systems Equipped with Only Wheel Speed Sensors

    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.``

  8. A Vehicle Maneuver by Using Two Mobile Robots Grasping Single Wheel

    Yonezawa, Naoaki; Kashiwazaki, Koshi; Kosuge, Kazuhiro; Hirata, Yasuhisa; Sugahara, Yusuke; Endo, Mitsuru; Kanbayashi, Takashi; Suzuki, Koki; Murakami, Kazunori; Nakamura, Kenichi; Nakanishi, Masaki

    In this article, a new car transportation system which consists of two MRWheels (a Mobile Robot for a Wheel) is proposed. The system grasps only two front wheels of a front-wheel-drive vehicle and positions it. Therefore, it is possible that the system make smaller than the previous car transportation systems using multiple robots. However, the system has nonholonomic constraints because rear wheels of the vehicle are not lifted by the system. And it is necessary to transport vehicles that the system lifting front wheels knows their rear wheels' position. Therefore, to transport the vehicle, a motion control algorithm for the system and a vehicle's wheelbase estimate algorithm by mechanical interaction are proposed. First, a motion control algorithm based on the chained system is illustrated. Next, the system is applied Impedance Control to achieve the passive motion along its nonholonomic constraints when it doesn't know the vehicle's size. After that, the wheelbase estimate algorithm based on Impedance Control and its convergence are described. Finally, through preliminary experiments, the concept of the system is illustrated and the effectiveness of proposed algorithm is confirmed.

  9. Prototyping of the ILC Baseline Positron Target

    Gronberg, J; Brooksby, C; Piggott, T; Abbott, R; Javedani, J; Cook, E

    2012-02-29

    The ILC positron system uses novel helical undulators to create a powerful photon beam from the main electron beam. This beam is passed through a titanium target to convert it into electron-positron pairs. The target is constructed as a 1 m diameter wheel spinning at 2000 RPM to smear the 1 ms ILC pulse train over 10 cm. A pulsed flux concentrating magnet is used to increase the positron capture efficiency. It is cooled to liquid nitrogen temperatures to maximize the flatness of the magnetic field over the 1 ms ILC pulse train. We report on prototyping effort on this system.

  10. Flank crack detection in locomotive wheels with NDE techniques

    Laczynski, Marie; Jayaraman, Subash B.; Halter, Ryan; Tittmann, Bernhard R.

    2001-08-01

    There is a need to analyze locomotive wheels for flank cracks in a non-destructive manner in order to prevent catastrophic failures. Flaw, shape, and size are desired parameters in establishing the quality of commercial tires. A variety of defects such as voids, inclusions, surface and internal cracks, or the like, must be discerned in order to prevent failure. This paper exhibits and compares the benefits of a number of different techniques used for flaw detection. Non-destructive evaluation techniques used consist of a magnetic particle, dye penetrant, eddy current, electro-magnetic acoustic transducer (EMAT), and longitudinal and shear wave ultrasonic inspection. The techniques vary in their ability to ascertain the flaw characteristics. Surface, sub-surface, and internal defects were visualized using the various methodologies. Magnetic particle, dye penetrant, and eddy current inspection techniques are viable methods for looking at surface flaws. Depending on the penetration depth, sub- surface flaws were also detectable via these methods. EMAT and ultrasonic transducer methods can be used to find surface, subsurface, and internal flaws based on the configuration utilized.

  11. Cassini Thruster Calibration Algorithm Using Reaction Wheel Biasing Data

    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.

  12. Tethered satellite system control using electromagnetic forces and reaction wheels

    Alandi Hallaj, Mohammad Amin; Assadian, Nima

    2015-12-01

    In this paper a novel non-rotating space tethered configuration is introduced which its relative positions controlled using electromagnetic forces. The attitude dynamics is controlled by three reaction wheels in the body axes. The nonlinear coupled orbital dynamics of a dumbbell tethered satellite formation flight are derived through a constrained Lagrangian approach. These equations are presented in the leader satellite orbital frame. The tether is assumed to be mass-less and straight, and the J2 perturbation is included to the analysis. The forces and the moments of the electromagnetic coils are modeled based on the far-filed model of the magnetic dipoles. A guidance scheme for generating the desired positions as a function of time in Cartesian form is presented. The satellite tethered formation with variable length is controlled utilizing a linear controller. This approach is applied to a specified scenario and it is shown that the nonlinear guidance method and the linear controller can control the nonlinear system of the tethered formation and the results are compared with optimal control approach.

  13. Electron Beam Welding of Gear Wheels by Splitted Beam

    Dřímal, Daniel

    2014-06-01

    This contribution deals with the issue of electron beam welding of high-accurate gear wheels composed of a spur gearing and fluted shaft joined with a face weld for automotive industry. Both parts made of the high-strength low-alloy steel are welded in the condition after final machining and heat treatment, performed by case hardening, whereas it is required that the run-out in the critical point of weldment after welding, i. e. after the final operation, would be 0.04 mm max.. In case of common welding procedure, cracks were formed in the weld, initiated by spiking in the weld root. Crack formation was prevented by the use of an interlocking joint with a rounded recess and suitable welding parameters, eliminating crack initiation by spiking in the weld root. Minimisation of the welding distortions was achieved by the application of tack welding with simultaneous splitting of one beam into two parts in the opposite sections of circumferential face weld attained on the principle of a new system of controlled deflection with digital scanning of the beam. This welding procedure assured that the weldment temperature after welding would not be higher than 400 °C. Thus, this procedure allowed achieving the final run-outs in the critical point of gearwheels within the maximum range up to 0.04 mm, which is acceptable for the given application. Accurate optical measurements did not reveal any changes in the teeth dimensions.

  14. Physiological Evaluation of a Wheeled Assistive Device for Load Carriage.

    Ketko, Itay; Yanovich, Ran; Plotnik, Meir; Gefen, Amit; Heled, Yuval

    2015-11-01

    Carrying heavy weight imposes high physiological strain on the human body, which can adversely affect physical performance. This is especially important for soldiers whose physical performance level may influence mission completion and survival. Recently, wheel-based devices (WBDs), designed to reduce the load on the soldier, have been suggested as a possible solution. Thus, the aim of this study was to evaluate the physiological effects of a proposed WBD prototype. Ten volunteers performed 3 exercise protocols on a treadmill as follows: without carrying any load, with a military backpack, and with the WBD. While using both modalities, they carried 40% of their body weight. Data acquisition included heart rate, body core temperature, oxygen consumption, and subjective comfort. Postural sway was also measured to evaluate the effect of WBD on standing balance. There were no significant differences between the physiological measures while using both modalities. Subjective comfort evaluation showed that the WBD may be more comfortable, yet it raises difficulty in maintaining balance while walking, as can be explained by the postural sway results. We suggest that the similarity in physiological strain while using the WBD was due to reduced walking efficiency in an attempt to maintain balance. It appears that the WBD may have some biomechanical advantages in reducing the subjective pain and pressure at the shoulder region, a matter that should be further examined together with other biomechanical measures. PMID:26506177

  15. TAKRAF bucket wheel excavators for difficult operating conditions

    Harta, H.; Jurisch, H.

    1987-04-01

    Design, performance and technical specifications are explained for bucket wheel excavators, built by TAKRAF Lauchhammerwerk, GDR. The SRs (K) 2000 excavator (capacity 3000 m/sup 3//h, digging height 28 m) has been built since 1972 and operates in Ehkibastuz black coal surface mines at a temperature range of +/- 40 C. A total of nine such excavators are in operation, two more are being built. The SRs 2000 excavator (42 are in operation, 5 more are being built) operates in the Greek Ptolemais brown coal mine with 4000 m/sup 3//h capacity and at 30 m bench height. The SRs 4000 excavator (7600 m/sup 3//h capacity, 36 m digging height) is new and being assembled at Ptolemais and at Kansk-Achinsk. The largest excavation type is the SRs 6300 for 13,000 m/sup 3//h overburden removal. Smaller equipment includes the SRs 400 operating in the Austrian Oberdorf brown coal mine and also in Yugoslavia, among other places, the SRs 700 and the SRs 1500, the latter two being developed for hard, cohesive overburden, 17 to 22 m digging height and with 2400 to 3000 m/sup 3//h capacity. Photographs of excavators operating in various surface mines are provided. 3 refs.

  16. Feasibility Study of Two Candidate Reaction Wheel/thruster Hybrid Control Architecture Designs for the Cassini Spacecraft

    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. 汽车轮罩护板选材方案探讨%Discussion of Methods to Select Material for Wheel-house

    贺丽丽; 张娜; 史荣波; 程海勇

    2012-01-01

    简要介绍了四种常用的轮罩护板材料,并从零件重量、吸音降噪效果、使用寿命、精度、成本及模具费用等方面对四种轮罩护板进行了综合比较,同时结合车型档次、目标市场和产量等给出了性价比最佳的五种选材方案.即:对于低档车,产量小或者目标市场为低温市场者用HDPE材料,产量大或者目标市场为非低温市场者用PP+EPDM材料;对于中档车,产量小或者目标市场为低温市场者,前轮用HDPE材料,后轮用PP+PET材料,产量大或者目标市场为非低温市场者,前轮用PP+EPDM材料,后轮用PP+PET材料;高档车则用PP+PET材料.%Four materials of wheel-house which Comprehensive comparison for the four different damping, service life time, dimension tolerance are in common use are introduced in brief. materials are made regarding part weight, noise and tooling cost. Five solutions are recommended based on car category, target market and volume of the model. For low class economical car, HDPE material is suggested for low volume model or low temperature service environment. PP + EPDM material is recommended for high volume model or non low temperature service environment. For middle class car, HDPE material for front wheel and PP + PET material for rear wheel are recommended for low volume model or low temperature environment. PP + EPDM material for front wheel and PP + PET material for rear wheel for high volume model or non low temperature service environment are recommended. For luxury car, PP + PET material is recommended.

  18. Design and Analysis of a Novel Speed-Changing Wheel Hub with an Integrated Electric Motor for Electric Bicycles

    Yi-Chang Wu; Zi-Heng Sun

    2013-01-01

    The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC) hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including...

  19. Theoretical foundations of the automated designing of assembly drawings of rolls of wheel rolling vertical type mills

    Снітко, С. О.; Яковченко, О. В.; Івлєва, Н. І.

    2014-01-01

    Automated designing inker, pressure and conical rolls, as well as centering and driving rollers of modern wheel-rolling mills of vertical type required for the development of new highly effective profile of railway wheels is actual scientific and technical problem. In this paper, first proposed the theoretical foundations of the automated design drawings of rolls of vertical type wheel-rolling mills. The designing of circuits of pressure and inker rolls and calculation values technological ga...

  20. Integration of Heat Treatment in precision forging of gear wheels

    The conventional process chain for the production of gear wheels demands many manufacturing steps. Typically this process chain consists of cutting, heating, forging and deburring. Subsequently, the teeth and the bores of the gears are shaped in a machining process such as milling, slotting and broaching. Afterwards, a heat treatment by case hardening is applied and the gears are finally finished by grinding by grinding. This process chain is often disrupted by storage and transports. Precision forging can significantly reduce this process chain because deburring and machining steps become unnecessary. Additional advantages can be gained if the heat of the precision forging process is used for an integrated heat treatment. Moreover, specific component characteristics can be reached by integrating the heat treatment in connection with an adapted process technology. Hot formed parts are directly hardened by using the forging heat. A new solution for a homogeneous cooling consisting of a two-phase nozzle array will be introduced. The application of this technique allows the hardening of particular component regions according to typical strain profiles of this component. Besides, demands on material properties, an even allowance after the precision forging process has to be maintained. The allowance after the forging process depends on varying alloys and the geometry of the part as well as the forging temperature and related heat loss. The tool must therefore be corrected and adapted accordingly. The new approach for the presented process chain with new tool concepts and an integrated heat treatment using the forging heat will solve many problems. Moreover, dramatic change in the process management is necessary. But on the other hand it offers great potential for cost reduction. Particularly, high-duty automotive components offer a wide application field for the precision forging technology. Advantages like shortened production cycles achieved by eliminating machining