WorldWideScience

Sample records for braking he-strong cp

  1. Comparison of friction and wear performances of brake materials containing different amounts of ZrSiO4 dry sliding against SiCp reinforced Al matrix composites

    International Nuclear Information System (INIS)

    Zhang Shaoyang; Wang Fuping

    2007-01-01

    Low friction levels for brake materials dry sliding against Al matrix composites (Al-MMCs) were observed. Al matrix composites reinforced with 30 vol.% SiC p (34 μm) were used first to fabricate a new brake drum in place of the conventional cast iron brake drum for a Chase Machine. Experimental studies on the brake materials differing in amounts of zirconium silicate (0 wt%, 4 wt%, 8 wt%, and 12 wt% ZrSiO 4 ) dry sliding against the Al-MMCs drum were performed on the Chase Machine in order to examine their effects on friction and wear performances. The test procedures include friction fade and recovery, load and speed sensitivities at 177 deg. C and 316 deg. C, and wear. Experimental results show that the brake material containing 8 wt% ZrSiO 4 had the best wear resistance and higher friction level. The brake material containing 12 wt% ZrSiO 4 had the highest friction level, but wear increased rapidly. The deterioration of the latter wear suggests that this brake material is unreliable in commercial applications

  2. Fundamental parameters of He-weak and He-strong stars

    Science.gov (United States)

    Cidale, L. S.; Arias, M. L.; Torres, A. F.; Zorec, J.; Frémat, Y.; Cruzado, A.

    2007-06-01

    Context: He-weak and He-strong stars are chemically peculiar AB objects whose He lines are anomalously weak or strong for their MK spectral type. The determination of fundamental parameters for these stars is often more complex than for normal stars due to their abundance anomalies. Aims: We discuss the determination of fundamental parameters: effective temperature, surface gravity, and visual and bolometric absolute magnitudes of He-weak and He-strong stars. We compare our values with those derived independently from methods based on photometry and model fitting. Methods: We carried out low resolution spectroscopic observations in the wavelength range 3400-4700 Å of 20 He-weak and 8 He-strong stars to determine their fundamental parameters by means of the Divan-Chalonge-Barbier (BCD) spectrophotometric system. This system is based on the measurement of the continuum energy distribution around the Balmer discontinuity (BD). For a few He-weak stars we also estimate the effective temperatures and the angular diameters by integrating absolute fluxes observed over a wide spectral range. Non-LTE model calculations are carried out to study the influence of the He/H abundance ratio on the emergent radiation of He-strong stars and on their T_eff determination. Results: We find that the effective temperatures, surface gravities and bolometric absolute magnitudes of He-weak stars estimated with the BCD system and the integrated flux method are in good agreement between each other, and they also agree with previous determinations based on several different methods. The mean discrepancy between the visual absolute magnitudes derived using the hipparcos parallaxes and the BCD values is on average ±0.3 mag for He-weak stars, while it is ±0.5 mag for He-strong stars. For He-strong stars, we note that the BCD calibration, based on stars in the solar environment, leads to overestimated values of T_eff. By means of model atmosphere calculations with enhanced He/H abundance ratios

  3. Gravity brake

    Science.gov (United States)

    Lujan, Richard E.

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  4. Better Brakes

    Science.gov (United States)

    1976-01-01

    Through continuing studies on high-temperature space materials useful for better brake linings, Bendix Corporation worked with Ames Research Center to develop a novel composite. This team worked to fabricate several combinations of composite materials and evaluated results. The one selected increases wear rates and lowers costs. It exhibits constant coefficient of friction at temperatures as high as 650 degrees Fahrenheit, a region where conventional brake linings fade markedly. Other suitable markets include brakes for trucks and industrial equipment such as overhead cranes and hoists. Afterwards brake linings could find successful application in passenger cars.

  5. Braking system

    Science.gov (United States)

    Norgren, D.U.

    1982-09-23

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  6. Sprag solenoid brake

    Science.gov (United States)

    Dane, P. H.

    1972-01-01

    Operation of solenoid braking mechanism is discussed. Illustrations of construction of the brake are provided. Device is used for braking low or medium speed shaft rotations and produces approximately ten times braking torque of similar solenoid brakes.

  7. Magnetostrictive Brake

    Science.gov (United States)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

    A magnetostrictive brake has been designed as a more energy-efficient alternative to a magnetic fail-safe brake in a robot. (In the specific application, failsafe signifies that the brake is normally engaged; that is, power must be supplied to allow free rotation.) The magnetic failsafe brake must be supplied with about 8 W of electric power to initiate and maintain disengagement. In contrast, the magnetostrictive brake, which would have about the same dimensions and the same torque rating as those of the magnetic fail-safe brake, would demand only about 2 W of power for disengagement. The brake (see figure) would include a stationary base plate and a hub mounted on the base plate. Two solenoid assemblies would be mounted in diametrically opposed recesses in the hub. The cores of the solenoids would be made of the magnetostrictive alloy Terfenol-D or equivalent. The rotating part of the brake would be a ring-and spring- disk subassembly. By means of leaf springs not shown in the figure, this subassembly would be coupled with the shaft that the brake is meant to restrain. With no power supplied to the solenoids, a permanent magnet would pull axially on a stepped disk and on a shelf in the hub, causing the ring to be squeezed axially between the stepped disk and the hub. The friction associated with this axial squeeze would effect the braking action. Supplying electric power to the solenoids would cause the magnetostrictive cylinders to push radially inward against a set of wedges that would be in axial contact with the stepped disk. The wedges would convert the radial magnetostrictive strain to a multiplied axial displacement of the stepped disk. This axial displacement would be just large enough to lift the stepped disk, against the permanent magnetic force, out of contact with the ring. The ring would then be free to turn because it would no longer be squeezed axially between the stepped disk and the hub.

  8. BRAKE DEVICE

    Science.gov (United States)

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  9. Automotive Brake Systems.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This correspondence course, orginally developed for the Marine Corps, is designed to provide mechanics with an understanding of the basic operations of automotive brake systems on military vehicles. The course contains four study units covering hydraulic brakes, air brakes, power brakes, and auxiliary brake systems. A troubleshooting guide for…

  10. Emergency braking : research summary.

    NARCIS (Netherlands)

    Schlösser, L.H.M.

    1976-01-01

    This report deals with an investigation concerning braking capacity of trucks if somewhere a failure occurs in the normal service brake. Purpose of research was to get an insight in various secondary braking systems for trucks. It is shown that with almost all of the secondary braking system it was

  11. CP violation

    CERN Document Server

    1989-01-01

    Contents: CP Phenomenology: Introduction to CP Violation (C Jarlskog); CP-Violation in the K 0 -K 0 -System (K Kleinknecht); The Quark Mixing Matrix, Charm Decays and B Decays (S Stone); The Question of CP Noninvariance - As Seen through the Eyes of Neutral Beauty (I I Bigi et al.); In Search of CP Noninvariance in Heavy Quark Systems (L-L Chau); CP Violation at High Energy e + e - Colliders (J Bernabéu & M B Gavela); CP Violation in the Standard Model with Four Families (A Datta & E A Paschos); CP Effects When Neutrinos are their Own Antiparticles (B Kayser); On Spontaneous CP Violation Trigg

  12. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system, and...

  13. Antiskid braking system

    Science.gov (United States)

    Pazdera, J. S.

    1974-01-01

    Published report describes analytical development and simulation of braking system. System prevents wheels from skidding when brakes are applied, significantly reducing stopping distance. Report also presents computer simulation study on system as applied to aircraft.

  14. Deployable Brake for Spacecraft

    Science.gov (United States)

    Rausch, J. R.; Maloney, J. W.

    1987-01-01

    Aerodynamic shield that could be opened and closed proposed. Report presents concepts for deployable aerodynamic brake. Brake used by spacecraft returning from high orbit to low orbit around Earth. Spacecraft makes grazing passes through atmosphere to slow down by drag of brake. Brake flexible shield made of woven metal or ceramic withstanding high temperatures created by air friction. Stored until needed, then deployed by set of struts.

  15. Roller Locking Brake

    Science.gov (United States)

    Vranish, John M.

    1993-01-01

    Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

  16. Brake Fundamentals. Automotive Articulation Project.

    Science.gov (United States)

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  17. Reel safety brake

    Science.gov (United States)

    Carle, C. E. (Inventor)

    1976-01-01

    A braking apparatus is described for a tape transport device having two stacked coaxial reels and feelers mounted in proximity to the reels for sensing the tape being wound on each reel. A device is mounted in proximity to adjacent central hubs of the reels to a simultaneously, frictionally engage both hubs and brake both reels. A mechanical actuator is coupled to both feelers and to the brake device. The brake means comprises a pair of rubber shoulders that extend in opposite directions relative to a common axis, and turns about the axis in response to either of the feelers.

  18. An antilock molecular braking system.

    Science.gov (United States)

    Sun, Wei-Ting; Huang, Shou-Ling; Yao, Hsuan-Hsiao; Chen, I-Chia; Lin, Ying-Chih; Yang, Jye-Shane

    2012-08-17

    A light-driven molecular brake displaying an antilock function is constructed by introducing a nonradiative photoinduced electron transfer (PET) decay channel to compete with the trans (brake-off) → cis (brake-on) photoisomerization. A fast release of the brake can be achieved by deactivating the PET process through addition of protons. The cycle of irradiation-protonation-irradiation-deprotonation conducts the brake function and mimics the antilock braking system (ABS) of vehicles.

  19. Brake for rollable platform

    Science.gov (United States)

    Morris, A. L.

    1974-01-01

    Frame-mounted brake is independent of wheels and consists of simple lever-actuated foot. Brake makes good contact with surface even though foot pad is at higher or lower level than wheels, this is particularly important when a rollable platform is used on irregular surface.

  20. Magnetorheological suspension electromagnetic brake

    International Nuclear Information System (INIS)

    Bica, Ioan

    2004-01-01

    The magnetorheological suspension (MRS) brake is of the monoblock type. The main part of the electromagnetic brake is an electromagnet, between whose poles two MRS disks are placed. For distances between disks of 0.65x10 -3 m±10%, revolutions of the electric motor, coupled to the electromagnetic brake, ranging between 200 and 1600 rev/min and braking powers of up to 85 W, there are no differences in revolutions between the disks of the electromagnetic brake. For fixed revolutions of the electric motor, the revolution of the parallel disk can be modified continuously by means of the intensity of the magnetic field. In all cases, the quantity of MRS is of 0.35x10 -3 kg

  1. CP violation

    CERN Multimedia

    CERN. Geneva

    1999-01-01

    In the first two lectures, CP violation in the K system is pedagogically reviewed: its manifestations in the neutral K meson systems, in rare K meson decays and in decays of charged K mesons, and results from classical and current experiments, are discussed. In the third lecture, CP Violation in the B system and the forthcoming experimental tests will be discussed.

  2. CP violation

    Indian Academy of Sciences (India)

    We have just entered a period during which we expect considerable progress toward understanding CP violation. Here we review what we have learnt so far, and what is to be expected in the near future. To do this we cover the foundation of CP violation at a level which can be understood by physicists who are not working ...

  3. WIND BRAKING OF MAGNETARS

    International Nuclear Information System (INIS)

    Tong, H.; Xu, R. X.; Qiao, G. J.; Song, L. M.

    2013-01-01

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L x rot may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  4. CP violation

    International Nuclear Information System (INIS)

    Gronau, M.

    1995-01-01

    We review the present status of the Standard Model of CP violation, which is based on a complex phase in the Cabibbo-Kobayashi-Maskawa (CKM) matrix. So far CP violation has been observed only in K 0 -K 0 mixing, consistent with a sizable phase. The implications of future CP nonconserving measusrements in K and B decays are discussed within the model. Direct CP violation in K→2π may be observed in the near future, however this would not be a powerful test of the model. B decays provide a wide variety of CP asymmetry measurements, which can serve as precise tests of the Standard Model in cases where the asymmetry is cleanly related to phases of CKM matrix elements. Some of the most promising cases are discussed. ((orig.))

  5. Improved Electromagnetic Brake

    Science.gov (United States)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may

  6. On friction braking demand with regenerative braking

    NARCIS (Netherlands)

    Walker, A.M.; Lampérth, M.U.; Wilkins, S.

    2002-01-01

    Developments in Hybrid Electric and pure Electric Vehicles are intended to improve the operational efficiency of road vehicles. Regenerative braking, which has long been established in rail vehicles, is integral to efficiency improvement, with up to 30% of overall traction energy demand satisfied by

  7. Vehicle brake testing system

    Science.gov (United States)

    Stevens, Samuel S [Harriman, TN; Hodgson, Jeffrey W [Lenoir City, TN

    2002-11-19

    This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

  8. Braking System for Wind Turbines

    Science.gov (United States)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  9. CP violation

    International Nuclear Information System (INIS)

    Gilman, F.J.

    1989-12-01

    Predictions for CP violation in the three generation Standard Model are reviewed based on what is known about the Cabibbo-Kobayashi-Maskawa matrix. Application to the K and B meson systems are emphasized. 43 refs., 13 figs

  10. CP violation

    International Nuclear Information System (INIS)

    Quinn, H.

    1995-12-01

    In this talk the author briefly reviews the cosmological importance of CP violation and the status of calculations of baryogenisis in the context of the Standard Model. The author then turns to a discussion of Standard Model Predictions for CP violation in B decays, stressing the importance of multiple measurements to overconstrain the model parameters and thus search for indications of beyond-Standard-Model physics

  11. Load proportional safety brake

    Science.gov (United States)

    Cacciola, M. J.

    1979-01-01

    This brake is a self-energizing mechanical friction brake and is intended for use in a rotary drive system. It incorporates a torque sensor which cuts power to the power unit on any overload condition. The brake is capable of driving against an opposing load or driving, paying-out, an aiding load in either direction of rotation. The brake also acts as a no-back device when torque is applied to the output shaft. The advantages of using this type of device are: (1) low frictional drag when driving; (2) smooth paying-out of an aiding load with no runaway danger; (3) energy absorption proportional to load; (4) no-back activates within a few degrees of output shaft rotation and resets automatically; and (5) built-in overload protection.

  12. Development of hydraulic brake actuator for active brake control; Active brake seigyoyo yuatsu booster no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Y; Hattori, M. Sugisawa, M.; Nishii, M [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    Recently, application of active brake control systems of the vehicle are increasing. (Vehicle stability control, Panic brake assist ) We have developed a new hydraulic brake actuator for active brake control systems. New hydraulic brake actuator is composed of the three parts. (Hydraulic booster unit, Power supply unit, Control valve unit) This report describes the construction of the new hydraulic booster unit. 2 refs., 10 figs.

  13. Unidirectional high gain brake stop

    Science.gov (United States)

    Lang, David J. (Inventor)

    1987-01-01

    This invention relates to a unidirectional high gain brake arrangement that includes in combination a shaft mounted for rotation within a housing. The shaft is rotatable in either direction. A brake is selectively releasably coupled to the housing and to the shaft. The brake has a first member. An intermittent motion device is respectively coupled through the first member to the housing and through a one-way clutch to the shaft. The brake also has a second member that is mechanically coupled to the first brake member and to the housing. The intermittent motion device causes the brake to be activated by movement imparted to the first brake member after a preset number of revolutions of the shaft in one direction. The brake is released by rotation of the shaft in an opposite direction whereby torque transmitted through the one-way clutch to the first brake member is removed.

  14. Research on Braking Stability of Electro-mechanical Hybrid Braking System in Electric Vehicles

    OpenAIRE

    Ji, Fenzhu; Tian, Mi

    2010-01-01

    For the electro-mechanical hybrid braking system, which is composed of electric brake and general friction brake, the models of electric braking force, total braking force and the utilization adhesion coefficient for front and rear axles were established based on the analysis of braking torque distribution. The variation relationship between electric braking force and friction braking force in different braking intensity was calculated and analyzed with the paralleled-hybridized braking contr...

  15. Braking System Modeling and Brake Temperature Response to Repeated Cycle

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2014-12-01

    Full Text Available Braking safety is crucial while driving the passenger or commercial vehicles. Large amount of kinetic energy is absorbed by four brakes fitted in the vehicle. If the braking system fails to work, road accident could happen and may result in death. This research aims to model braking system together with vehicle in Matlab/Simulink software and measure actual brake temperature. First, brake characteristic and vehicle dynamic model were generated to estimate friction force and dissipated heat. Next, Arduino based prototype brake temperature monitoring was developed and tested on the road. From the experiment, it was found that brake temperature tends to increase steadily in long repeated deceleration and acceleration cycle.

  16. Development of mechanical brake assist; Mechanical brake assist no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, M; Shingyoji, S; Nakamura, I; Tagawa, T; Saito, Y; Ishihara, T; Kobayashi, S; Yoshida, M [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    We have recognized that there are drivers who cannot apply strong brake pedal force , in spite of the necessity of hard braking in emergencies. We have developed a `mechanical brake assist system` which assists drivers appropriately, according to the drivers` characteristics based on studying the characteristic`s of conditions of drivers applying the brake pedal force in emergency conditions. 2 refs., 7 figs., 1 tab.

  17. CP Violation

    International Nuclear Information System (INIS)

    Aleksan, R.

    1993-06-01

    The violation of the CP symmetry is a phenomenon, the origin of which is not yet well established and deserves a particular attention since it may be a fundamental property of Nature with very important consequences for the evolution of the universe. We propose in these lectures to have an overview of this phenomenon as we understand it so far. To this end, and after introducing the discrete space-time symmetries, we discuss the observation of the violation of the CP symmetry in the neutral kaon decays. We then derive the general formalism for any neutral system made of a particle and its antiparticle and discuss how CP violation is introduced. We show how this phenomenon is generated in the Standard Model of the electroweak interactions and what are the predictions that can be made. In particular we shall concentrate on the expected effects in the decays of mesons involving the b quark. We review the various possibilities for observing these effects, calculate their magnitudes and show how the consistency of the theory can be tested. Finally, we outline the experimental prospects for studying CP non conservation at an asymmetric B Factory to either verify the Standard Model mechanism or provide evidence for new physics. (author)

  18. Development of brake assist system. Summary of hydraulic brake assist system; Brake assist system no kaihatsu. Ekiatsushiki brake assist system no gaiyo

    Energy Technology Data Exchange (ETDEWEB)

    Hara, M; Ota, M; Shimizu, S [Toyota, Motor Corp., Aichi (Japan)

    1997-10-01

    We have already developed vacuum-booster-type Brake Assist System that supplies additional braking power when panic braking is recognized. We are convinced that the expansion of Brake Assist System will become more important issue in the future. Therefore we have developed hydraulic Brake Assist System with increasing its controllability and reducing its discomfort. This system have a brake pressure sensor to detect emergency braking operation and an antilock device to supply additional braking power. 8 refs., 11 figs.

  19. Safety brake for tape reels

    Science.gov (United States)

    Carle, C. E.

    1977-01-01

    All-mechanical device senses end of tape and stops reel, even in event of electronic system failure. Assembly includes stop to prevent brake from overriding tape. Recentering mechanism returns brake to neutral position after torque is removed from reels.

  20. Cooperative Control of Regenerative Braking and Antilock Braking for a Hybrid Electric Vehicle

    OpenAIRE

    Yin, Guodong; Jin, XianJian

    2013-01-01

    A new cooperative braking control strategy (CBCS) is proposed for a parallel hybrid electric vehicle (HEV) with both a regenerative braking system and an antilock braking system (ABS) to achieve improved braking performance and energy regeneration. The braking system of the vehicle is based on a new method of HEV braking torque distribution that makes the antilock braking system work together with the regenerative braking system harmoniously. In the cooperative braking control strategy, a sli...

  1. Development of combined brake system on front and rear brakes for scooter; Scooter yo zenkorin rendo brake system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Y; Itabashi, T; Shinohara, S; Honda, Y [Honda R and D Co. Ltd., Tokyo (Japan)

    1997-10-01

    Scooters need appropriate front and rear wheel braking power distribution and each of front and rear brakes have been operated using right and left levers. This time, a low cost brakes with cable type combined brake system for small size scooter and a brakes with hydraulic type combined brake system for middle size scooter have been developed to obtain appropriate front and rear wheel braking power distribution. Both systems use convenient left lever to operate. 3 refs., 9 figs., 1 tab.

  2. Deployable Engine Air Brake

    Science.gov (United States)

    2014-01-01

    On approach, next-generation aircraft are likely to have airframe noise levels that are comparable to or in excess of engine noise. ATA Engineering, Inc. (ATA) is developing a novel quiet engine air brake (EAB), a device that generates "equivalent drag" within the engine through stream thrust reduction by creating a swirling outflow in the turbofan exhaust nozzle. Two Phase II projects were conducted to mature this technology: (1) a concept development program (CDP) and (2) a system development program (SDP).

  3. Tether Deployer And Brake

    Science.gov (United States)

    Carroll, Joseph A.; Alexander, Charles M.

    1993-01-01

    Design concept promises speed, control, and reliability. Scheme for deploying tether provides for fast, free, and snagless payout and fast, dependable braking. Developed for small, expendable tethers in outer space, scheme also useful in laying transoceanic cables, deploying guidance wires to torpedoes and missiles, paying out rescue lines from ship to ship via rockets, deploying antenna wires, releasing communication and power cables to sonobuoys and expendable bathythermographs, and in reeling out lines from fishing rods.

  4. Sprag solenoid brake. [development and operations of electrically controlled brake

    Science.gov (United States)

    Dane, D. H. (Inventor)

    1974-01-01

    The development and characteristics of an electrically operated brake are discussed. The action of the brake depends on energizing a solenoid which causes internally spaced sprockets to contact the inner surface of the housing. A spring forces the control member to move to the braking position when the electrical function is interrupted. A diagram of the device is provided and detailed operating principles are explained.

  5. Hydraulic brake-system for a bicycle

    NARCIS (Netherlands)

    Van Frankenhuyzen, J.

    2007-01-01

    The invention relates to a hydraulic brake system for a bicycle which may or may not be provided with an auxiliary motor, comprising a brake disc and brake claws cooperating with the brake disc, as well as fluid-containing channels (4,6) that extend between an operating organ (1) and the brake

  6. 49 CFR 393.52 - Brake performance.

    Science.gov (United States)

    2010-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... specifications for performance-based brake testers for commercial motor vehicles, where braking force is the sum of the braking force at each wheel of the vehicle or vehicle combination as a percentage of gross...

  7. CP violation with an unbroken CP transformation

    Energy Technology Data Exchange (ETDEWEB)

    Ratz, Michael [Department of Physics and Astronomy, University of California,Irvine, California 92697-4575 (United States); Trautner, Andreas [Bethe Center for Theoretical Physics und Physikalisches Institut der Universität Bonn,Nussallee 12, 53115 Bonn (Germany)

    2017-02-21

    A CP conserving SU(3) gauge theory is spontaneously broken to T{sub 7} by the vacuum expectation value (VEV) of a 15-plet. Even though the SU(3)-CP transformation is not broken by the VEV, the theory exhibits physical CP violation in the broken phase. This is because the SU(3)-CP transformation corresponds to the unique order-two outer automorphism of T{sub 7}, which is not a physical CP transformation for the T{sub 7} states, and there is no other possible CP transformation. We explicitly demonstrate that CP is violated by calculating a CP odd decay asymmetry in the broken phase. This scenario provides us with a natural protection for topological vacuum terms, ensuring that θ G{sub μν}G̃{sup μν} is absent even though CP is violated for the physical states of the model.

  8. Combined hydraulic and regenerative braking system

    Science.gov (United States)

    Venkataperumal, R.R.; Mericle, G.E.

    1979-08-09

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  9. Clutches and brakes design and selection

    CERN Document Server

    Orthwein, William C

    2004-01-01

    FRICTION MATERIALSFriction CodeWearBrake FadeFriction MaterialsNotationReferencesBAND BRAKESDerivation of EquationsApplicationLever-Actuated Band Brake: Backstop DesignExample: Design of a BackstopNotationFormula CollectionReferencesEXTERNALLY AND INTERNALLY PIVOTED SHOE BRAKESPivoted External Drum BrakesPivoted Internal Drum BrakesDesign of Dual-Anchor Twin-Shoe Drum BrakesDual-Anchor Twin-Shoe Drum Brake Design ExamplesDesign of Single-Anchor Twin-Shoe Drum BrakesSingle-Anchor Twin-Shoe Drum Brake Design Exam

  10. Emergency Brake for Tracked Vehicles

    Science.gov (United States)

    Green, G. L.; Hooper, S. L.

    1986-01-01

    Caliper brake automatically stops tracked vehicle as vehicle nears end of travel. Bar on vehicle, traveling to right, dislodges block between brake pads. Pads then press against bar, slowing vehicle by friction. Emergencybraking system suitable for elevators, amusement rides and machine tools.

  11. Brakes Specialist. Teacher Edition. Automotive Service Series.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains teacher's materials for a course on becoming an automotive brakes specialist, based on the National Institute of Automotive Service Excellence task lists. The course consists of three instructional units: service brake hydraulic system and wheel bearings, service drum brakes, and service disc brakes. Depending on the…

  12. Adjustable Tooling for Bending Brake

    Science.gov (United States)

    Ellis, J. M.

    1986-01-01

    Deep metal boxes and other parts easily fabricated. Adjustable tooling jig for bending brake accommodates spacing blocks and either standard male press-brake die or bar die. Holds spacer blocks, press-brake die, bar window die, or combination of three. Typical bending operations include bending of cut metal sheet into box and bending of metal strip into bracket with multiple inward 90 degree bends. By increasing free space available for bending sheet-metal parts jig makes it easier to fabricate such items as deep metal boxes or brackets with right-angle bends.

  13. Thermal Characterisation of Brake Pads

    DEFF Research Database (Denmark)

    Ramousse, Séverine; Høj, Jakob Weiland; Sørensen, O. T.

    2001-01-01

    The chemical-physical decomposition processes that occur in a brake pad heated to 1000degreesC have been studied. This temperature can be reached when a brake pad is applied. Thermogravimetry and differential thermal analysis were used in combination with evolved gas analysis, and image analysis...... using a scanning electron microscope.A brake pad is essentially a mixture of iron, carbon and binder. Combined techniques have been used, because of chemical reaction overlap, to determine how and at what temperature the binder decomposes, the coal and graphite combust and the iron oxidises.This work...

  14. Transient switching control strategy from regenerative braking to anti-lock braking with a semi-brake-by-wire system

    Science.gov (United States)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Liu, Yahui; Song, Jian; Ran, Xu

    2016-02-01

    Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV.

  15. Intelligent Braking System using the IR Sensor

    OpenAIRE

    Gajanan Koli

    2017-01-01

    Most of the accidents in four wheeled vehicles occur because of failure of braking systems. Manual method of applying brakes is always dangerous as it leads to accidents. Unconsciousness of driver, failure in the linkages of braking systems, road conditions, uncontrollable speed of the vehicle and manual operation of braking systems are the reasons of accidents. It is necessary to control brakes automatically through electronics devices to minimize the accident problems. In this research pape...

  16. Single acting translational/rotational brake

    Science.gov (United States)

    Allred, Johnny W. (Inventor); Fleck, Jr., Vincent J. (Inventor)

    1996-01-01

    A brake system is provided that applies braking forces on surfaces in both the translational and rotational directions using a single acting self-contained actuator that travels with the translational mechanism. The brake engages a mechanical lock and creates a frictional force on the translational structure preventing translation while simultaneously creating a frictional torque that prevents rotation of the vertical support. The system may include serrations on the braking surfaces to provide increased braking forces.

  17. Brake Stops Both Rotation And Translation

    Science.gov (United States)

    Allred, Johnny W.; Fleck, Vincent J., Jr.

    1995-01-01

    Combination of braking and positioning mechanisms allows both rotation and translation before brake engaged. Designed for use in positioning model airplane in wind tunnel. Modified version used to position camera on tripod. Brake fast and convenient to use; contains single actuator energizing braking actions against both rotation and translation. Braking actuator electric, but pneumatic actuator could be used instead. Compact and lightweight, applies locking forces close to load, and presents minimal cross section to airflow.

  18. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Brake Systems.

    Science.gov (United States)

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers theory, operation, and repair of drum brakes, disc brakes, and brake system components. The course is comprised of six units: (1) Fundamentals of Brake Systems, (2) Master Cylinder, (3) Drum Brakes, (4) Disc Brakes, (5) Power Brakes, and (6)…

  19. An analysis of braking measures

    OpenAIRE

    De Groot, S.; De Winter, J.C.F.; Wieringa, P.A.; Mulder, M.

    2010-01-01

    Braking to a full stop at a prescribed target position is a driving manoeuvre regularly used in experiments to investigate driving behaviour or to test vehicle acceleration feedback systems in simulators. Many different performance measures have been reported in the literature for analysing braking. These may or may not be useful to analyse the stopping manoeuvre, because a number of potential problems exist: 1) the scores on a measure may be insufficiently reliable, 2) the measure may be inv...

  20. Slowly braked, rotating neutron stars

    Science.gov (United States)

    Sato, H.

    1975-01-01

    A slowly braked, rotating neutron star is believed to be a star which rapidly rotates, has no nebula, is nonpulsing, and has a long initial braking time of ten thousand to a million years because of a low magnetic field. Such an object might be observable as an extended weak source of infrared or radio wave radiation due to the scattering of low-frequency strong-wave photons by accelerated electrons. If these objects exist abundantly in the Galaxy, they would act as sources of relatively low-energy cosmic rays. Pulsars (rapidly braked neutron stars) are shown to have difficulties in providing an adequate amount of cosmic-ray matter, making these new sources seem necessary. The possibility that the acceleration mechanism around a slowly braked star may be not a direct acceleration by the strong wave but an acceleration due to plasma turbulence excited by the strong wave is briefly explored. It is shown that white dwarfs may also be slowly braked stars with braking times longer than 3.15 million years.

  1. Brake Performance Analysis of ABS for Eddy Current and Electrohydraulic Hybrid Brake System

    OpenAIRE

    Ren He; Xuejun Liu; Cunxiang Liu

    2013-01-01

    This paper introduces an eddy current and electro-hydraulic hybrid brake system to solve problems such as wear, thermal failure, and slow response of traditional vehicle brake system. Mathematical model was built to calculate the torque of the eddy current brake system and hydraulic brake system and analyze the braking force distribution between two types of brake systems. A fuzzy controller on personal computer based on LabVIEW and Matlab was designed and a set of hardware in the loop system...

  2. Thermal analysis on motorcycle disc brake geometry

    Science.gov (United States)

    W. M. Zurin W., S.; Talib, R. J.; Ismail, N. I.

    2017-08-01

    Braking is a phase of slowing and stop the movement of motorcycle. During braking, the frictional heat was generated and the energy was ideally should be faster dissipated to surrounding to prevent the built up of the excessive temperature which may lead to brake fluid vaporization, thermoelastic deformation at the contact surface, material degradation and failure. In this paper, solid and ventilated type of motorcycle disc brake are being analyse using Computational Fluid Dynamic (CFD) software. The main focus of the analysis is the thermal behaviour during braking for solid and ventilated disc brake. A comparison between both geometries is being discussed to determine the better braking performance in term of temperature distribution. It is found that ventilated disc brake is having better braking performance in terms of heat transfer compare to solid disc.

  3. Performance requirements for locomotive braking systems

    CSIR Research Space (South Africa)

    Vermaak, P

    2000-02-01

    Full Text Available operated “Neutral Brake”. This brake may become active immediately or after a certain time delay when the controller is placed in the neutral position or moved into the neutral position by the “dead-man’s device”. Because this brake will interfere... in testing emergency brake systems due to the inherent braking action of the service brakes and/or locomotive controllers; • Potential problems limitations to braking effort associated with the prime movers and/or hydraulic systems on hydrostatically...

  4. Brake Performance Analysis of ABS for Eddy Current and Electrohydraulic Hybrid Brake System

    Directory of Open Access Journals (Sweden)

    Ren He

    2013-01-01

    Full Text Available This paper introduces an eddy current and electro-hydraulic hybrid brake system to solve problems such as wear, thermal failure, and slow response of traditional vehicle brake system. Mathematical model was built to calculate the torque of the eddy current brake system and hydraulic brake system and analyze the braking force distribution between two types of brake systems. A fuzzy controller on personal computer based on LabVIEW and Matlab was designed and a set of hardware in the loop system was constructed to validate and analyze the performance of the hybrid brake system. Through lots of experiments on dry and wet asphalt roads, the hybrid brake system achieves perfect performance on the experimental bench, the hybrid system reduces abrasion and temperature of the brake disk, response speed is enhanced obviously, fuzzy controller keeps high utilization coefficient due to the optimal slip ratio regulation, and the total brake time has a smaller decrease than traditional hydraulic brake system.

  5. Giant CP stars

    International Nuclear Information System (INIS)

    Loden, L.O.; Sundman, A.

    1989-01-01

    This study is part of an investigation of the possibility of using chemically peculiar (CP) stars to map local galactic structure. Correct luminosities of these stars are therefore crucial. CP stars are generally regarded as main-sequence or near-main-sequence objects. However, some CP stars have been classified as giants. A selection of stars, classified in literature as CP giants, are compared to normal stars in the same effective temperature interval and to ordinary 'non giant' CP stars. There is no clear confirmation of a higher luminosity for 'CP giants', than for CP stars in general. In addition, CP characteristics seem to be individual properties not repeated in a component star or other cluster members. (author). 50 refs., 5 tabs., 3 figs

  6. The design of brake fatigue testing system

    Directory of Open Access Journals (Sweden)

    Huang, Xiaoya

    2015-01-01

    Full Text Available Brake is used to reduce the operating speed of the machinery equipment or to make it stop. It is essential for vehicles, climbing machines and many fixed equipment in their safety work. Brake tester is an experimental apparatus to measure and analyse the braking performance. Based on the PLC technology and for the purpose of testing brake shoe friction material’s life, this paper designed a virtual brake test platform. In it, inverter were used to control the motor, so that it can load automatically and ensure brake drum constant speed output; what is more, closed loop control system were used to control the brake shoe, so that the cylinder pressure keeps stable in the process of dynamic braking.

  7. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

    ...) Equipped with brake indicators as defined in § 238.5, designed so that the pressure sensor is placed in a... alcohol or other chemicals into the air brake system of passenger equipment is prohibited. (f) The...

  8. CP Violation course

    CERN Multimedia

    CERN. Geneva HR-RFA

    2006-01-01

    The lecture introduces the concepts and phenomena of matter-antimatter symmetry violation, so-called "CP" violation. The lecture is organized in four courses, the first being devoted to a historical overview and an introduction into fundamental discrete symmetries. The second course introduces the most compelling CP-violating phenomena, and presents the first experimental discovery of CP violation in the neutral kaon system. The third course discusses how CP violation is beautifully incorporated into the Standard Model of particle interactions, and how modern B-meson "factories" provide precise tests of this picture. Finally, the fourth and last course introduces CP violation and the genesis of our matter world.

  9. THE STUDY OF BRAKE EFFECTIVENESS HOPPER SYSTEM WITH SEPARATE BRAKING TRUCKS

    Directory of Open Access Journals (Sweden)

    O. Je. Nishhenko

    2009-06-01

    Full Text Available The results of tests of the hopper brake systems for the pellets having typical system and separate braking per each bogie are presented. It is shown that the brake system with separate braking has several advantages as compared to the typical one.

  10. Biodegradability of unused lubricating brake fluids in fresh and ...

    African Journals Online (AJOL)

    The biodegradability of four unused lubricating brake fluids (Total brake fluid, Allied brake fluid, Oando brake fluid and Ate brake fluid) was carried out in fresh and marine water obtained from Isiokpo stream and Bonny river of the Niger Delta, South South Nigeria. Biodegradability, of the brake fluids were obtained after a 56 ...

  11. Brakes, brake control and driver assistance systems function, regulation and components

    CERN Document Server

    2014-01-01

    Braking systems have been continuously developed and improved throughout the last years. Major milestones were the introduction of antilock braking system (ABS) and electronic stability program. This reference book provides a detailed description of braking components and how they interact in electronic braking systems. Contents Motor vehicle safety.- Basic principles of vehicle dynamics.- Car braking systems.- Car braking-system components.- Wheel brakes.- Antilock breaking systems.- Traction control system.- Electronic stability program.- Automatic brake functions.- Hydraulic modulator.- Sensors for brake control.- Sensotronic brake control.- Active steering.- Occupant protection systems.- Driver assistance systems.- Adaptive cruise control.- Parking systems.- Instrumentation.- Orientation methods.- Navigation systems.- Workshop technology. The target groups Motor-vehicle technicians in education and vocational training Master-mechanics and technicians in garage-workshops Teachers and lecturers in vocation...

  12. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

    .... (e) The following requirements apply to blended braking systems: (1) Loss of power or failure of the... adhesion control system designed to automatically adjust the braking force on each wheel to prevent sliding during braking. In the event of a failure of this system to prevent wheel slide within preset parameters...

  13. The dynamics of antilock brake systems

    Science.gov (United States)

    Denny, Mark

    2005-11-01

    The nonlinear dynamics of automobile braking are investigated. Nonlinearity arises because of the manner in which the friction coefficient between vehicle tyres and road surface depends upon vehicle speed and wheel angular speed. We show how antilock brake systems approach optimum braking performance.

  14. 49 CFR 236.712 - Brake pipe.

    Science.gov (United States)

    2010-10-01

    ... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.712 Brake pipe. A pipe running from the engineman's brake valve through the train, used for the transmission of air under... 49 Transportation 4 2010-10-01 2010-10-01 false Brake pipe. 236.712 Section 236.712 Transportation...

  15. 49 CFR 229.46 - Brakes: General.

    Science.gov (United States)

    2010-10-01

    ... regulating all pressures, including but not limited to the automatic and independent brake valves, operate as intended and that the water and oil have been drained from the air brake system. ... 49 Transportation 4 2010-10-01 2010-10-01 false Brakes: General. 229.46 Section 229.46...

  16. Brake wear warning device: A concept

    Science.gov (United States)

    Hawkins, S. F.

    1973-01-01

    Heat-insulated wire is introduced through brake shoe and partially into brake lining. Wire is connected to positive terminal and light bulb. When brakes wear to critical point, contact between wire and wheel drum grounds circuit and turns on warning light.

  17. Friction brake cushions acceleration and vibration loads

    Science.gov (United States)

    Fraser, G. F.; Zawadski, G. Z.

    1966-01-01

    Friction brake cushions an object in a vehicle from axially applied vibration and steady-state acceleration forces. The brake incorporates a doubly tapered piston that applies a controlled radial force to friction brake segments bearing against the walls of a cylinder.

  18. Compact, Lightweight Servo-Controllable Brakes

    Science.gov (United States)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  19. Sensotronic brake control. Braking with maximum efficiency; Die Sensotronic Brake Control. Bremsen auf hoechstem Niveau

    Energy Technology Data Exchange (ETDEWEB)

    Fischle, G.; Stoll, U.; Hinrichs, W.

    2002-05-01

    Sensotronic Brake Control (SBC) celebrated its world premiere when it was introduced into standard production along with the new SL in October 2001. This innovative brake system is also fitted as standard in the new E-Class. The design of the system components is identical to those used in the SL-Class. The software control parameters have been adapted to the conditions in the new saloon. (orig.) [German] Die Sensotronic Brake Control (SBC) wurde als Weltneuheit mit dem neuen SL im Oktober 2001 in Serie gebracht. Dieses innovative Bremssystem gehoert ebenfalls zur Serienausstattung der neuen E-Klasse. Die Systemkomponenten sind baugleich mit denen der SL-Klasse. Die Regelparameter der Software sind an die Verhaeltnisse der Limousine angepasst. (orig.)

  20. Electronic brakes. From ABS to brake-by-wire. 2. ed.; Elektronische Bremssysteme. Vom ABS zum Brake-by-Wire

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, H.R.

    2003-07-01

    The book reports trends in vehicle brakes from 1968 to 1998. This was the age of the electronic revolution. The book presents conventional brakes, antiblocking systems (ABS), antislip systems (ASS), brake assistants (BAS), dynamic control systems, and brake-by-wire systems. [German] Das Buch berichtet ueber Entwicklungen an Fahrzeugbremsanlagen in der Zeitspanne von 1968 bis etwa 1998. Diese Zeit war gepraegt vom Vordringen der Elektronik in die Bremsen, was fuer Hersteller und Kunden eine Revolution bedeutete. Behandelt sind: (a) Konventionelle Bremsanlagen, (b) Antiblockiersysteme (ABS), (c) Anti-Schlupf-regelungen (ASR), (d) Bremsassistenten (BAS), (e) Fahrdynamikregelungen (FDR, ESP), (f) Brake-by-Wire (orig.)

  1. CP violation in B decay

    OpenAIRE

    Yamamoto, Hitoshi

    2001-01-01

    We review the physics of CP violation in B decays. After introducing the CKM matrix and how it causes CP violation, we cover three types of CP violation that can occur in B decays: CP violation in mixing, CP violation by mixing-decay interference, and CP violation in decay.

  2. Cooperative Control of Regenerative Braking and Antilock Braking for a Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Guodong Yin

    2013-01-01

    Full Text Available A new cooperative braking control strategy (CBCS is proposed for a parallel hybrid electric vehicle (HEV with both a regenerative braking system and an antilock braking system (ABS to achieve improved braking performance and energy regeneration. The braking system of the vehicle is based on a new method of HEV braking torque distribution that makes the antilock braking system work together with the regenerative braking system harmoniously. In the cooperative braking control strategy, a sliding mode controller (SMC for ABS is designed to maintain the wheel slip within an optimal range by adjusting the hydraulic braking torque continuously; to reduce the chattering in SMC, a boundary-layer method with moderate tuning of a saturation function is also investigated; based on the wheel slip ratio, battery state of charge (SOC, and the motor speed, a fuzzy logic control strategy (FLC is applied to adjust the regenerative braking torque dynamically. In order to evaluate the performance of the cooperative braking control strategy, the braking system model of a hybrid electric vehicle is built in MATLAB/SIMULINK. It is found from the simulation that the cooperative braking control strategy suggested in this paper provides satisfactory braking performance, passenger comfort, and high regenerative efficiency.

  3. Brake blending strategy for a hybrid vehicle

    Science.gov (United States)

    Boberg, Evan S.

    2000-12-05

    A hybrid electric powertrain system is provided including a transmission for driving a pair of wheels of a vehicle and a heat engine and an electric motor/generator coupled to the transmission. A friction brake system is provided for applying a braking torque to said vehicle. A controller unit generates control signals to the electric motor/generator and the friction brake system for controllably braking the vehicle in response to a drivers brake command. The controller unit determines and amount of regenerative torque available and compares this value to a determined amount of brake torque requested for determining the control signals to the electric motor/generator and the friction brake system.

  4. BASIC STUDY ON TAILORMADE BRAKING SUPPORT SYSTEM

    Directory of Open Access Journals (Sweden)

    Toshiya HIROSE, M.S.

    2004-01-01

    This research reviewed the construction of models of a Tailormade Braking Support System (TBSS for braking to stop vehicles and the evaluation of drivers. As a result, the following conclusions were drawn. (1 Braking factors were found to change in the period from the start of braking to stopping; (2 Changes in braking factors can be logically incorporated into the control elements of braking support system; (3 Readymade Driver Model is effective as a model to be incorporated into the base system of TBSS; (4 Tailormade Driver Model built on Neural Network is effective as a main model to construct TBSS; (5 As for TBSS, both subjective and objective ratings on the timing and magnitude of braking are favorable, and its safety and sense of security are improved.

  5. Phenomenology of CP violation

    International Nuclear Information System (INIS)

    Ecker, G.

    1987-01-01

    A short survey of the theoretical status of CP violation is presented. The Standart Model is confronted with the present experimental situation. Possible future tests of our notions of CP violation are discussed, concentrating on rare K decays. Other promising reactions such as B decays are briefly reviewed. Among alternative models of CP violation, multi-Higgs extensions of the Standart Model, left-right symmetric gauge theories and minimal SUSY models are discussed. Finally, the relevance of generalized CP invariance is emphasized. 64 refs., 7 figs. (Author)

  6. Leptonic CP violation theory

    DEFF Research Database (Denmark)

    Hagedorn, C.

    2017-01-01

    I summarize the status of theoretical predictions for the yet to be measured leptonic CP phases, the Dirac phase δ and the two Majorana phases α and β. I discuss different approaches based on: (a) a flavor symmetry without and with corrections, (b) different types of sum rules and (c) flavor and CP...... symmetries. I show their predictive power with examples. In addition, I present scenarios in which low and high energy CP phases are connected so that predictions for the CP phases α, β and δ become correlated to the sign of the baryon asymmetry YB of the Universe that is generated via leptogenesis....

  7. Is CP violation maximal

    International Nuclear Information System (INIS)

    Gronau, M.

    1984-01-01

    Two ambiguities are noted in the definition of the concept of maximal CP violation. The phase convention ambiguity is overcome by introducing a CP violating phase in the quark mixing matrix U which is invariant under rephasing transformations. The second ambiguity, related to the parametrization of U, is resolved by finding a single empirically viable definition of maximal CP violation when assuming that U does not single out one generation. Considerable improvement in the calculation of nonleptonic weak amplitudes is required to test the conjecture of maximal CP violation. 21 references

  8. Rail Brake System Using a Linear Induction Motor for Dynamic Braking

    Science.gov (United States)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Tanaka, Minoru; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    One type of braking system for railway vehicles is the eddy current brake. Because this type of brake has the problem of rail heating, it has not been used for practical applications in Japan. Therefore, we proposed the use of a linear induction motor (LIM) for dynamic braking in eddy current brake systems. The LIM reduces rail heating and uses an inverter for self excitation. In this paper, we estimated the performance of an LIM from experimental results of a fundamental test machine and confirmed that the LIM generates an approximately constant braking force under constant current excitation. At relatively low frequencies, this braking force remains unaffected by frequency changes. The reduction ratio of rail heating is also approximately proportional to the frequency. We also confirmed that dynamic braking resulting in no electrical output can be used for drive control of the LIM. These characteristics are convenient for the realization of the LIM rail brake system.

  9. Developing of a software for determining advanced brake failures in brakes test bench

    Directory of Open Access Journals (Sweden)

    Hakan Köylü

    2016-08-01

    Full Text Available At present time, the brake test bench conducts the braking and suspension tests of front or rear axles and the test results are evaluated through one axle. The purpose of the brake testing system is to determine braking force and damping coefficient dissymmetry of one axle. Thus, this test system evaluates the performance of service brake, hand brake and suspension systems by considering separately front and rear axle dissymmetry. For this reason, the effects of different braking and damping forces applied by right and left wheels of both axles on braking performance of all vehicle are not determined due to available algorithm of the test bench. Also, the other brake failures are not occurred due to the algorithm of brake test system. In this study, the interface has been developed to determine the other effects of dissymmetry and the other brake failures by using the one axle results of brake test bench. The interface has algorithm computing the parameters according to the interaction between front and rear axles by only using measured test results. Also, it gives the warnings by comparing changes in the parameters with braking performance rules. Braking and suspension tests of three different vehicles have been conducted by using brake test bench to determine the performance of the algorithm. Parameters based on the axle interaction have been calculated by transferring brake test results to the interface and the test results have been evaluated. As a result, the effects of brake and suspension failures on braking performance of both axle and vehicle have been determined thanks to the developed interface.

  10. IDEAL BRAKE FORCE DISTRIBUTION BETWEEN THE AXLES OF THE TWO-AXLE VEHICLE SERVICE BRAKE APPLICATIONS

    Directory of Open Access Journals (Sweden)

    M. Podryhalo

    2015-07-01

    Full Text Available The obtained analytical expressions allow us to evaluate the stability of two-axle vehicles at various slowdowns. An analytical expression for calculating the ideal according to condition stability ensuring of a two-axle vehicle at service brake applications of brake force distribution allows to offer automatic control devices for brake force adjucement. With decellerationg growth of the two-axle vehicle at service braking the braking force acting on the front axle should decrease relative to the brake force on the rear axle.

  11. Space shuttle wheels and brakes

    Science.gov (United States)

    Carsley, R. B.

    1985-01-01

    The Space Shuttle Orbiter wheels were subjected to a combination of tests which are different than any previously conducted in the aerospace industry. The major testing difference is the computer generated dynamic landing profiles used during the certification process which subjected the wheels and tires to simulated landing loading conditions. The orbiter brakes use a unique combination of carbon composite linings and beryllium heat sink to minimize weight. The development of a new lining retention method was necessary in order to withstand the high temperature generated during the braking roll. As with many programs, the volume into which this hardware had to fit was established early in the program, with no provisions made for growth to offset the continuously increasing predicted orbiter landing weight.

  12. Development of Regenerative Braking Co-operative Control System for Automatic Transmission-based Hybrid Electric Vehicle using Electronic Wedge Brake

    OpenAIRE

    Ko, Jiweon; Ko, Sungyeon; Bak, Yongsun; Jang, Mijeong; Yoo, Byoungsoo; Cheon, Jaeseung; Kim, Hyunsoo

    2013-01-01

    This research proposes a regenerative braking co-operative control system for the automatic transmission (AT)-based hybrid electric vehicle (HEV). The brake system of the subject HEV consists of the regenerative braking and the electronic wedge brake (EWB) friction braking for the front wheel, and the hydraulic friction braking for the rear wheel. A regenerative braking co-operative control algorithm is suggested for the regenerative braking and friction braking, which distributes the braking...

  13. 49 CFR 230.77 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall be...

  14. Research of braking peculiarities of used cars

    Directory of Open Access Journals (Sweden)

    V. Mitunevičius

    2002-06-01

    Full Text Available This paper briefly describes some analysis of a car braking process - the peculiarities of car wheel-to-road adhesion, the influence of distribution of braking forces on car stability between front and rear axles. The requirements of EU Directive 71/320/EEC to braking force coefficients of car front and rear axles are exposed. Structural designs of braking systems are analyzed with respect to their meeting the EU standards. Experimental measurements of braking force coefficients for some models of cars which are used in Lithuania, are presented with the analysis how these coefficients meet the EU standards. The analysis of test results, suggestions for the ratio of braking forces of car front and rear axles are presented.

  15. Talking about the Automobile Braking System

    Science.gov (United States)

    Xu, Zhiqiang

    2017-12-01

    With the continuous progress of society, the continuous development of the times, people’s living standards continue to improve, people continue to improve the pursuit. With the rapid development of automobile manufacturing, the car will be all over the tens of thousands of households, the increase in car traffic, a direct result of the incidence of traffic accidents. Brake system is the guarantee of the safety of the car, its technical condition is good or bad, directly affect the operational safety and transportation efficiency, so the brake system is absolutely reliable. The requirements of the car on the braking system is to have a certain braking force to ensure reliable work in all cases, light and flexible operation. Normal braking should be good performance, in addition to a foot sensitive, the emergency brake four rounds can not be too long, not partial, not ring.

  16. Fatal accidental inhalation of brake cleaner aerosols.

    Science.gov (United States)

    Veit, F; Martz, W; Birngruber, C G; Dettmeyer, R B

    2018-04-23

    Brake cleaner liquid is commonly used for cleaning of engines and motor parts. The commercially available products usually contain mainly volatile organic compounds. As a consequence brake cleaner evaporates fast and almost completely from the cleaned surface. This case report presents a fatal accidental inhalation of brake cleaner liquid aerosols due to the attempted cleaning of a boat engine. A 16year old boy was found lifeless in the engine compartment of a boat engine. In close proximity to the body, the police found cleanings wipes soaked with brake cleaner as well as a pump spray bottle filled with brake cleaner. Essentially the autopsy revealed a cerebral oedema with encephalomalacia, no coagulated blood as well as increased blood and tissue fluid content of the lung. Toxicological analysis revealed brake cleaner fluid in the lung, gastric content and heart blood. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Design and Analysis of a Novel Centrifugal Braking Device for a Mechanical Antilock Braking System.

    Science.gov (United States)

    Yang, Cheng-Ping; Yang, Ming-Shien; Liu, Tyng

    2015-06-01

    A new concept for a mechanical antilock braking system (ABS) with a centrifugal braking device (CBD), termed a centrifugal ABS (C-ABS), is presented and developed in this paper. This new CBD functions as a brake in which the output braking torque adjusts itself depending on the speed of the output rotation. First, the structure and mechanical models of the entire braking system are introduced and established. Second, a numerical computer program for simulating the operation of the system is developed. The characteristics of the system can be easily identified and can be designed with better performance by using this program to studying the effects of different design parameters. Finally, the difference in the braking performance between the C-ABS and the braking system with or without a traditional ABS is discussed. The simulation results indicate that the C-ABS can prevent the wheel from locking even if excessive operating force is provided while still maintaining acceptable braking performance.

  18. Impact of Brake Pad Structure on Temperature and Stress Fields of Brake Disc

    OpenAIRE

    Wang, Guoshun; Fu, Rong

    2013-01-01

    Utilizing ABAQUS finite element software, the study established the relationship between a brake pad structure and distributions of temperature and thermal stress on brake disc. By introducing radial structure factor and circular structure factor concepts, the research characterized the effect of friction block radial and circumferential arrangement on temperature field of the brake disc. A method was proposed for improving heat flow distribution of the brake disc through optimizing the posit...

  19. Regenerative braking system of PM synchronous motor

    Science.gov (United States)

    Gao, Qian; Lv, Chengxing; Zhao, Na; Zang, Hechao; Jiang, Huilue; Zhang, Zhaowen; Zhang, Fengli

    2018-04-01

    Permanent-magnet synchronous motor is widely adopted in many fields with the advantage of a high efficiency and a high torque density. Regenerative Braking Systems (RBS) provide an efficient method to assist PMSM system achieve better fuel economy and lowering exhaust emissions. This paper describes the design and testing of the regenerative braking systems of PMSM. The mode of PWM duty has been adjusted to control regenerative braking of PMSM using energy controller for the port-controlled Hamiltonian model. The simulation analysis indicates that a smooth control could be realized and the highest efficiency and the smallest current ripple could be achieved by Regenerative Braking Systems.

  20. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    Science.gov (United States)

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  1. Brake noise measurements on mixed freight trains with composite brake blocks

    NARCIS (Netherlands)

    Jansen, E.H.W.; Dittrich, M.G.; Sikma, E.L.

    2008-01-01

    Brake noise is known to be a major contributor to the total sound emission of railway yards and areas near stations. It has been established that composite brake blocks reduce rolling noise, but it is not known if this is also the case for braking noise. Therefore, in order to investigate this,

  2. CP violation and modular symmetries

    OpenAIRE

    Dent, Thomas

    2001-01-01

    We reconsider the origin of CP violation in fundamental theory. Existing string models of spontaneous CP violation make ambiguous predictions, due to the arbitrariness of CP transformation and the apparent non-invariance of the results under duality. We find an unambiguous modular CP invariance condition, applicable to predictive models of spontaneous CP violation, which circumvents these problems; it strongly constrains CP violation by heterotic string moduli. The dilaton is also evaluated a...

  3. CP violation and modular symmetries

    International Nuclear Information System (INIS)

    Dent, Thomas

    2001-01-01

    We reconsider the origin of CP violation in fundamental theory. Existing string models of spontaneous CP violation make ambiguous predictions, due to the arbitrariness of CP transformation and the apparent noninvariance of the results under duality. We find a modular CP invariance condition, applicable to any predictive model of spontaneous CP violation, which circumvents these problems; it strongly constrains CP violation by heterotic string moduli. The dilaton is also evaluated as a source of CP violation, but is likely experimentally excluded. We consider the prospects for explaining CP violation in strongly coupled strings and brane worlds

  4. Regenerative Braking System for Series Hybrid Electric City Bus

    OpenAIRE

    Zhang, Junzhi; Lu, Xin; Xue, Junliang; Li, Bos

    2008-01-01

    Regenerative Braking Systems (RBS) provide an efficient method to assist hybrid electric buses achieve better fuel economy while lowering exhaust emissions. This paper describes the design and testing of three regenerative braking systems, one of which is a series regenerative braking system and two of which are parallel regenerative braking systems. The existing friction based Adjustable Braking System (ABS) on the bus is integrated with each of the new braking systems in order to ensure bus...

  5. Accelerometer-controlled automatic braking system

    Science.gov (United States)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1973-01-01

    Braking system, which employs angular accelerometer to control wheel braking and results in low level of tire slip, has been developed and tested. Tests indicate that system is feasible for operations on surfaces of different slipperinesses. System restricts tire slip and is capable of adapting to rapidly-changing surface conditions.

  6. THE DEVELOPMENT OF TROLLEYBUS DRIVE BRAKE SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. Safonau

    2011-01-01

    Full Text Available The requirements for trolleybuses brake systems are analyzed. Some results of the studies examined, contemporary trends of developing in this direction are shows. The range of problems whose solution is aimed at creating high-performance brake systems whose increase efficiency and safety of trolleybuses determined.

  7. Feedback brake distribution control for minimum pitch

    Science.gov (United States)

    Tavernini, Davide; Velenis, Efstathios; Longo, Stefano

    2017-06-01

    The distribution of brake forces between front and rear axles of a vehicle is typically specified such that the same level of brake force coefficient is imposed at both front and rear wheels. This condition is known as 'ideal' distribution and it is required to deliver the maximum vehicle deceleration and minimum braking distance. For subcritical braking conditions, the deceleration demand may be delivered by different distributions between front and rear braking forces. In this research we show how to obtain the optimal distribution which minimises the pitch angle of a vehicle and hence enhances driver subjective feel during braking. A vehicle model including suspension geometry features is adopted. The problem of the minimum pitch brake distribution for a varying deceleration level demand is solved by means of a model predictive control (MPC) technique. To address the problem of the undesirable pitch rebound caused by a full-stop of the vehicle, a second controller is designed and implemented independently from the braking distribution in use. An extended Kalman filter is designed for state estimation and implemented in a high fidelity environment together with the MPC strategy. The proposed solution is compared with the reference 'ideal' distribution as well as another previous feed-forward solution.

  8. Air brake-dynamometer accurately measures torque

    Science.gov (United States)

    1965-01-01

    Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

  9. 30 CFR 56.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... which is not originally equipped with brakes unless the manner in which the equipment is being operated...; (2) The performance of the service brakes shall be evaluated according to Table M-1. Table M-1 Gross... values include a one-second operator response time. Table M-2—The Speed of a Vehicle Can be Determined by...

  10. Design of a magnetic braking system

    International Nuclear Information System (INIS)

    Jou, M.; Shiau, J.-K.; Sun, C.-C.

    2006-01-01

    A non-contact method, using magnetic drag force principle, was proposed to design the braking systems to improve the shortcomings of the conventional braking systems. The extensive literature detailing all aspects of the magnetic braking is briefly reviewed, however little of this refers specifically to upright magnetic braking system, which is useful for industries. One of the major issues to design upright magnetic system is to find out the magnetic flux. The changing magnetic flux induces eddy currents in the conductor. These currents dissipate energy in the conductor and generate drag force to slow down the motion. Therefore, a finite element model is developed to analyze the phenomena of magnetic flux density when air gap and materials of track are varied. The verification shows the predicted magnetic flux is within acceptable range with the measured value. The results will facilitate the design of magnetic braking systems

  11. CP violation in gauge theories

    International Nuclear Information System (INIS)

    Escobar, C.O.

    Some aspects of CP violation in gauge theories are reviewed. The topics covered include a discussion of the Kobayashi-Maskawa six-quarks model, models of soft- CP violation (extended Higgs sector), the strong CP problem and finally some speculations relating CP violation and magnetic charges in non-abelian gauge theories. (Author) [pt

  12. New technical solutions of using rolling stock electrodynamical braking

    Directory of Open Access Journals (Sweden)

    Leonas Povilas LINGAITIS

    2009-01-01

    Full Text Available The paper considers some theoretical and practical problems associated with the use of traction motor are operating in the generator mode (in braking. Mathematical and graphical relationships of electrodynamic braking, taking into account the requirements raised to braking systems in rail transport are presented. The latter include discontinuity of braking process, braking force regulation, depending on the locomotive speed, mass, type of railway and other parameters. Schematic diagrams of the locomotive braking and ways of controlling the braking force by varying electric circuit parameters are presented. The authors suggested contact-free regulation method of braking resistor for controlling braking force in rheostatic braking, and resistor parameters regulate with pulse regulation mode by semiconductor devices, such as new electrical components for rolling stock – IGBT transistors operating in the key mode. Presenting energy savings power systems, which are using regenerative braking-returning energy and diesel engine or any form of hybrid traction vehicles systems, circuit diagrams, electrical parameters curves.

  13. CP violation in atoms

    International Nuclear Information System (INIS)

    Barr, S.M.

    1992-01-01

    Electric dipole moments of large atoms are an excellent tool to search for CP violation beyond the Standard Model. These tell us about the electron EDM but also about CP-violating electron-nucleon dimension-6 operators that arise from Higgs-exchange. Rapid strides are being made in searches for atomic EDMs. Limits on the electron EDM approaching the values which would be expected from Higgs-exchange mediated CP violation have been achieved. It is pointed out that in this same kind of model if tan β is large the effects in atoms of the dimension-6 e - n operators may outweigh the effect of the electron EDM. (author) 21 refs

  14. Highlights of CP 2000

    CERN Document Server

    Ellis, John R.

    2001-01-01

    Various developing topics in CP violation are reviewed. There are many theoretical reasons to hope that the CKM paradigm may be incomplete. It is surely too soon to be claiming new physics in \\epsilon^\\prime/\\epsilon or in D^0-\\bar D^0 mixing, but rare K decays offer interesting places to search for new physics. It is probably also premature to see a clash between global CKM fits and current estimates of sin \\beta and \\gamma, where much more precise data will soon be available. There are interesting possibilities to look for CP violation in neutrino oscillations and in Higgs physics. Rapid progress can be expected now that CP violation is moving to the top of the particle physics agenda.

  15. Frictional Performance and Temperature Rise of a Mining Nonasbestos Brake Material during Emergency Braking

    Directory of Open Access Journals (Sweden)

    Jiusheng Bao

    2015-01-01

    Full Text Available By simulating emergency braking conditions of mine hoisters, tribological experiments of a mining nonasbestos brake material sliding on E355CC steel friction disc investigated a pad-on-disc friction tester. It is shown that, under combined influence of braking velocity and pressure, the lubricating film and micro-convex-apices on wear surface would have complex physicochemical reactions which make the instant friction coefficient rise gradually while the instant surface temperature rises first and then falls. With the antifriction effect from lubricating film and the desquamating of composite materials, the mean friction coefficient decreases first, then rises, and decreases again with the increasing of initial braking velocity. And with the existence of micro-convex-apices and variation from increment ratio of load and actual contacting area, it rises first and then falls with the increasing of braking pressure. However, the mean surface temperature rises obviously with the increasing of both initial braking velocity and braking pressure for growth of transformed kinetic energy. It is considered that the friction coefficient cannot be considered as a constant when designing brake devices for mine hoisters. And special attention should be paid to the serious influence of surface temperature on tribological performance of brake material during emergency braking.

  16. Validity of a device designed to measure braking power in bicycle disc brakes.

    Science.gov (United States)

    Miller, Matthew C; Fink, Philip W; Macdermid, Paul William; Perry, Blake G; Stannard, Stephen R

    2017-07-21

    Real-world cycling performance depends not only on exercise capacities, but also on efficiently traversing the bicycle through the terrain. The aim of this study was to determine if it was possible to quantify the braking done by a cyclist in the field. One cyclist performed 408 braking trials (348 on a flat road; 60 on a flat dirt path) over 5 days on a bicycle fitted with brake torque and angular velocity sensors to measure brake power. Based on Newtonian physics, the sum of brake work, aerodynamic drag and rolling resistance was compared with the change in kinetic energy in each braking event. Strong linear relationships between the total energy removed from the bicycle-rider system through braking and the change in kinetic energy were observed on the tar-sealed road (r 2  = 0.989; p brake torque and angular velocity sensors are valid for calculating brake power on the disc brakes of a bicycle in field conditions. Such a device may be useful for investigating cyclists' ability to traverse through various terrains.

  17. Design and analysis of an MR rotary brake for self-regulating braking torques.

    Science.gov (United States)

    Yun, Dongwon; Koo, Jeong-Hoi

    2017-05-01

    This paper presents a novel Magneto-rheological (MR) brake system that can self-regulate the output braking torques. The proposed MR brake can generate a braking torque at a critical rotation speed without an external power source, sensors, or controllers, making it a simple and cost-effective device. The brake system consists of a rotary disk, permanent magnets, springs, and MR fluid. The permanent magnets are attached to the rotary disk via the springs, and they move outward through grooves with two different gap distances along the radial direction of the stator due to the centrifugal force. Thus, the position of the magnets is dependent on the spin speed, and it can determine the magnetic fields applied to MR fluids. Proper design of the stator geometry gives the system unique torque characteristics. To show the performance of an MR brake system, the electromagnetic characteristics of the system are analyzed, and the torques generated by the brake are calculated using the result of the electromagnetic analysis. Using a baseline model, a parametric study is conducted to investigate how the design parameters (geometric shapes and material selection) affect the performance of the brake system. After the simulation study, a prototype brake system is constructed and its performance is experimentally evaluated. The experimental results show that the prototype produced the maximum torque of 1.2 N m at the rotational speed of 100 rpm. The results demonstrate the feasibility of the proposed MR brake as a speed regulator in rotating systems.

  18. Influence of convective cooling on a disc brake temperature distribution during repetitive braking

    International Nuclear Information System (INIS)

    Adamowicz, Adam; Grzes, Piotr

    2011-01-01

    The purpose of this study is to evaluate an impact of convective mode of heat transfer on the thermal behaviour of a disc brake system during repetitive braking process with the constant velocity using fully three-dimensional finite element model. The transient thermal analysis to determine the temperature distributions on the contact surface of a disc brake is performed. The issue of non-uniform frictional heating effects of mutual slipping of a disc over fixed pads is tested using FE models with the several possible to occur in automotive application heat transfer coefficients. To have a possibility of comparison of the temperature distributions of a disc during cyclic brake application, the energy transformed during time of every analyzed case of braking process and the subsequent release periods was equal. The time-stepping procedure is employed to develop moving heat source as the boundary heat flux acting interchangeably with the convective cooling terms. The difficulties accounted for the accurate simulation of heating during spin of the rotor is omitted by the use of the code, which enable shaping curves responsible for the thermal flux entering the disc at subsequent moments of time. The resulting evolution of temperature on the friction surface reveals a wide range of variations, distinguishing periods of heating and cooling states. It has been established, that during single braking the convective cooling has insignificant influence on the temperature distributions of a disc brake, consequently is not able to prevent overheat problem. However the brake release period after the braking operation, when the velocity of the vehicle remains on the same level, results in considerable decrease of temperature. - Highlights: → Convection does not allow to lower temperature of disc during single braking process. → Maximal temperature of disc decreases with number of brake applications. → Temperature at the end of braking increases with number of brake

  19. Topics in CP violation

    International Nuclear Information System (INIS)

    Quinn, H.R.

    1993-02-01

    Given the varied backgrounds of the members of this audience this talk will be a grab bag of topics related to the general theme of CP Violation. I do not have time to dwell in detail on any of them. First, for the astronomers and astrophysicists among you, I want to begin by reviewing the experimental status of evidence for CP violation in particle processes. There is only one system where this has been observed, and that is in the decays of neutral K mesons

  20. Topics in CP violation

    Science.gov (United States)

    Quinn, H. R.

    1993-02-01

    Given the varied backgrounds of the members of this audience this talk will be a grab bag of topics related to the general theme of CP Violation. I do not have time to dwell in detail on any of them. First, for the astronomers and astrophysicists among you, I want to begin by reviewing the experimental status of evidence for CP violation in particle processes. There is only one system where this has been observed, and that is in the decays of neutral K mesons.

  1. Dynamic analysis of three autoventilated disc brakes

    Directory of Open Access Journals (Sweden)

    Ricardo A. García-León

    2017-09-01

    Full Text Available The braking system of a car must meet several requirements, among which safety is the most important. It is also composed of a set of mechanical parts such as springs, different types of materials (Metallic and Non Metallic, gases and liquids. The brakes must work safely and predictably in all circumstances, which means having a stable level of friction, in any condition of temperature, humidity and salinity of the environment. For a correct design and operation of brake discs, it is necessary to consider different aspects, such as geometry, type of material, mechanical strength, maximum temperature, thermal deformation, cracking resistance, among others. Therefore, the main objective of this work is to analyze the dynamics and kinetics of the brake system from the pedal as the beginning of mathematical calculations to simulate the behavior and Analysis of Finite Elements (FEA, with the help of SolidWorks Simulation Software. The results show that the third brake disc works best in relation to the other two discs in their different working conditions such as speed and displacement in braking, concluding that depending on the geometry of the brake and the cooling channels these systems can be optimized that are of great importance for the automotive industry.

  2. Screw-released roller brake

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1999-01-01

    A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

  3. Statistical analysis of brake squeal noise

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.

    2011-06-01

    Despite substantial research efforts applied to the prediction of brake squeal noise since the early 20th century, the mechanisms behind its generation are still not fully understood. Squealing brakes are of significant concern to the automobile industry, mainly because of the costs associated with warranty claims. In order to remedy the problems inherent in designing quieter brakes and, therefore, to understand the mechanisms, a design of experiments study, using a noise dynamometer, was performed by a brake system manufacturer to determine the influence of geometrical parameters (namely, the number and location of slots) of brake pads on brake squeal noise. The experimental results were evaluated with a noise index and ranked for warm and cold brake stops. These data are analysed here using statistical descriptors based on population distributions, and a correlation analysis, to gain greater insight into the functional dependency between the time-averaged friction coefficient as the input and the peak sound pressure level data as the output quantity. The correlation analysis between the time-averaged friction coefficient and peak sound pressure data is performed by applying a semblance analysis and a joint recurrence quantification analysis. Linear measures are compared with complexity measures (nonlinear) based on statistics from the underlying joint recurrence plots. Results show that linear measures cannot be used to rank the noise performance of the four test pad configurations. On the other hand, the ranking of the noise performance of the test pad configurations based on the noise index agrees with that based on nonlinear measures: the higher the nonlinearity between the time-averaged friction coefficient and peak sound pressure, the worse the squeal. These results highlight the nonlinear character of brake squeal and indicate the potential of using nonlinear statistical analysis tools to analyse disc brake squeal.

  4. 49 CFR 393.40 - Required brake systems.

    Science.gov (United States)

    2010-10-01

    ... subpart. (2) Air brake systems. Buses, trucks and truck-tractors equipped with air brake systems and..., and 393.52 of this subpart. (4) Electric brake systems. Motor vehicles equipped with electric brake..., trucks and truck tractors manufactured on or after March 1, 1975, and trailers manufactured on or after...

  5. Model-Based Brake Control including Tyre Behaviour

    NARCIS (Netherlands)

    De Vries, E.J.H.

    2012-01-01

    The objective of the thesis is to develop a method for controlled braking of a vehicle. The brake pedal depression has been considered to be proportional to the intended deceleration. The brake controller is not aimed to replace a cruise control; it will have an anti-lock braking (ABS) function. The

  6. 49 CFR 393.43 - Breakaway and emergency braking.

    Science.gov (United States)

    2010-10-01

    ... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with... brake systems installed on towed vehicles shall be so designed, by the use of “no-bleed-back” relay...

  7. Brakes. Auto Mechanics Curriculum Guide. Module 6. Instructor's Guide.

    Science.gov (United States)

    Allain, Robert

    This module is the sixth of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Eight units cover: introduction to automotive brake systems; disc and drum brake system components and how they operate; properties of brake fluid and procedures for bleeding the brake system; diagnosing and determining needed repairs on…

  8. 49 CFR 393.55 - Antilock brake systems.

    Science.gov (United States)

    2010-10-01

    ... hydraulic braked vehicles. Each hydraulic braked vehicle subject to the requirements of paragraph (a) of...)). (2) Each air braked commercial motor vehicle other than a truck tractor, manufactured on or after... malfunction circuits and signals for air braked vehicles. (1) Each truck tractor manufactured on or after...

  9. Diesel Technology: Brakes. Teacher Edition [and] Student Edition.

    Science.gov (United States)

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

    This document contains teacher and student materials for a course on brakes in the diesel technology curriculum. The course consists of 12 units organized in three sections. The three units of the introductory section cover: (1) brakes; (2) wheel bearings and seals; and (3) antilock brake systems. The second section, Hydraulic Brakes, contains the…

  10. 49 CFR 236.701 - Application, brake; full service.

    Science.gov (United States)

    2010-10-01

    ... a split reduction in brake pipe pressure at a service rate until maximum brake cylinder pressure is developed. As applied to an automatic or electro-pneumatic brake with speed governor control, an application other than emergency which develops the maximum brake cylinder pressure, as determined by the design of...

  11. 49 CFR 393.41 - Parking brake system.

    Science.gov (United States)

    2010-10-01

    ... system shall, at all times, be capable of being applied by either the driver's muscular effort or by... 49 Transportation 5 2010-10-01 2010-10-01 false Parking brake system. 393.41 Section 393.41... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles...

  12. Combined braking system for hybrid vehicle

    Science.gov (United States)

    Kulekina, A. V.; Bakholdin, P. A.; Shchurov, N. I.

    2017-10-01

    The paper presents an analysis of surface vehicle’s existing braking systems. The technical solution and brake-system design were developed for use of regenerative braking energy. A technical parameters comparison of energy storage devices of various types was made. Based on the comparative analysis, it was decided to use supercapacitor because of its applicability for an electric drive intermittent operation. The calculation methods of retarder key components were proposed. Therefrom, it was made a conclusion that rebuild gasoline-electric vehicles are more efficient than gasoline ones.

  13. Beautiful CP violation

    International Nuclear Information System (INIS)

    Dunietz, I.

    1997-01-01

    CP violation is observed to date only in K 0 decays and is parameterizable by a single quantity ε. Because it is one of the least understood phenomena in the Standard Model and holds a clue to baryogenesis, it must be investigated further. Highly specialized searches in K 0 decays are possible. Effects in B decays are much larger. In addition to the traditional B d → J/ψK S , π + π - asymmetries, CP violation could be searched for in already existing inclusive B data samples. The rapid B s --anti B s oscillations cancel in untagged B s data samples, which therefore allow feasibility studies for the observation of CP violation and the extraction of CKM elements with present vertex detectors. The favored method for the extraction of the CKM angle γ is shown to be unfeasible and a solution is presented involving striking direct CP violation in charged B decays. Novel methods for determining the B s mixing parameter Δm are described without the traditional requirement of flavor-specific final states

  14. Performance of an aircraft tire under cyclic braking and of a currently operational antiskid braking system

    Science.gov (United States)

    Tanner, J. A.

    1972-01-01

    An experimental investigation was conducted to study the performance of an aircraft tire under cyclic braking conditions and to study the performance of a currently operational aircraft antiskid braking system. Dry, damp, and flooded runway surface conditions were used in the investigation. The results indicated that under cyclic braking conditions the braking and cornering-force friction coefficients may be influenced by fluctuations in the vertical load, flexibility in the wheel support, and the spring coupling between the wheel and the tire-pavement interface. The cornering capability was shown to be negligible at wheel slip ratios well below a locked-wheel skid under all test surface conditions. The maximum available brake-force friction coefficient was shown to be dependent upon the runway surface condition, upon velocity, and, for wet runways, upon tire differences. Moderate reductions in vertical load and brake system pressure did not significantly affect the overall wet-runway performance of the tire.

  15. Nonlinear Coupling Characteristics Analysis of Integrated System of Electromagnetic Brake and Frictional Brake of Car

    Directory of Open Access Journals (Sweden)

    Ren He

    2015-01-01

    Full Text Available Since theoretical guidance is lacking in the design and control of the integrated system of electromagnetic brake and frictional brake, this paper aims to solve this problem and explores the nonlinear coupling characteristics and dynamic characteristics of the integrated system of electromagnetic brake and frictional brake. This paper uses the power bond graph method to establish nonlinear coupling mathematical model of the integrated system of electromagnetic brake and frictional brake and conducts the contrastive analysis on the dynamic characteristics based on this mathematical model. Meanwhile, the accuracy of the nonlinear coupling mathematical model proposed above is verified on the hardware in the loop simulation platform, and nonlinear coupling characteristics of the integrated system are also analyzed through experiments.

  16. Wheel slip dump valve for railway braking system

    Science.gov (United States)

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

    2017-09-01

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

  17. CP violation in ATLAS

    International Nuclear Information System (INIS)

    Saavedra, A.F.

    1995-01-01

    Full text: In the standard model CP violation is generated by a non trivial complex phase in the CKM matrix. The Standard Model does not predict the elements of the CKM matrix, they need to be experimentally measured. This will show if all the CP violation phenomena can be accounted by the complex phase or there are other contributing mechanisms which lie beyond the scope of Standard Model. It is of interest to overconstraint the so called unitary triangle by measuring each angle (α, β and γ) from the CP asymmetry that occurs in different decay modes. During the initial low luminosity period of the LHC a large effort will be concentrated in studying B physics, especially CP violation in the B 0 - B-bar 0 system, with the ATLAS detector. The features of the detector which are important for CP studies are: sharp trigger from the muon spectrometer (muons will be identify down to p T ≅ 5GeV, be able to distinguish electrons from hadrons (down to p T ≅ 1 GeV) with the Straw Tracker and Transition detector and high resolution of tracks, secondary vertices with the Semiconductor Tracker (resolution of 10-90 μm. For some decays modes ATLAS is expected to obtain larger sample of events than the B-factories that are being proposed. It has been calculated that the systematic error σ sin (2 α) = 0.06 and σ sin ( 2 β) = 0.027 which is comparable with other future experiments

  18. The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

    Directory of Open Access Journals (Sweden)

    Damian HADRYŚ

    2008-01-01

    Full Text Available In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

  19. The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

    OpenAIRE

    Damian HADRYŚ; Tomasz WĘGRZYN; Michał MIROS

    2008-01-01

    In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

  20. Dynamics of braking vehicles: from Coulomb friction to anti-lock braking systems

    International Nuclear Information System (INIS)

    Tavares, J M

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and without sliding. The advantage of using an anti-lock braking system (ABS) is put in evidence, and a quantitative estimate of its efficiency is proposed and discussed

  1. Research of braking process of transport vehicle with hydraulic brake system parameters

    OpenAIRE

    Vladimirov, Oleg

    2005-01-01

    Emergency braking of a vehicle is bound with many factors, such as the behaviour of the driver, the drive of the vehicle braking system, the braking mechanisms, the condition of the tyres, and the properties of the pavement. This process involves all parameters of the system “the driver – the vehicle – the road”. In order to investigate the efficiency of braking process upon specific conditions, it is necessary to examine all physical processes that take place in the vehicle on pressing the b...

  2. Optimal design and selection of magneto-rheological brake types based on braking torque and mass

    International Nuclear Information System (INIS)

    Nguyen, Q H; Lang, V T; Choi, S B

    2015-01-01

    In developing magnetorheological brakes (MRBs), it is well known that the braking torque and the mass of the MRBs are important factors that should be considered in the product’s design. This research focuses on the optimal design of different types of MRBs, from which we identify an optimal selection of MRB types, considering braking torque and mass. In the optimization, common types of MRBs such as disc-type, drum-type, hybrid-type, and T-shape types are considered. The optimization problem is to find an optimal MRB structure that can produce the required braking torque while minimizing its mass. After a brief description of the configuration of the MRBs, the MRBs’ braking torque is derived based on the Herschel-Bulkley rheological model of the magnetorheological fluid. Then, the optimal designs of the MRBs are analyzed. The optimization objective is to minimize the mass of the brake while the braking torque is constrained to be greater than a required value. In addition, the power consumption of the MRBs is also considered as a reference parameter in the optimization. A finite element analysis integrated with an optimization tool is used to obtain optimal solutions for the MRBs. Optimal solutions of MRBs with different required braking torque values are obtained based on the proposed optimization procedure. From the results, we discuss the optimal selection of MRB types, considering braking torque and mass. (technical note)

  3. 14 CFR 29.735 - Brakes.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For... dry, smooth pavement. [Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as amended by Amdt. 29-24, 49 FR...

  4. 14 CFR 27.735 - Brakes.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft... dry, smooth pavement. [Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as amended by Amdt. 27-21, 49 FR...

  5. Plasma brake model for preliminary mission analysis

    Science.gov (United States)

    Orsini, Leonardo; Niccolai, Lorenzo; Mengali, Giovanni; Quarta, Alessandro A.

    2018-03-01

    Plasma brake is an innovative propellantless propulsion system concept that exploits the Coulomb collisions between a charged tether and the ions in the surrounding environment (typically, the ionosphere) to generate an electrostatic force orthogonal to the tether direction. Previous studies on the plasma brake effect have emphasized the existence of a number of different parameters necessary to obtain an accurate description of the propulsive acceleration from a physical viewpoint. The aim of this work is to discuss an analytical model capable of estimating, with the accuracy required by a preliminary mission analysis, the performance of a spacecraft equipped with a plasma brake in a (near-circular) low Earth orbit. The simplified mathematical model is first validated through numerical simulations, and is then used to evaluate the plasma brake performance in some typical mission scenarios, in order to quantify the influence of the system parameters on the mission performance index.

  6. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    WINTEC

    Abstract. An asbestos free friction material composite for brake linings is synthesized containing fibrous re- inforcing ... every manufacturer of automotive friction materials uses phenolics as ... The resin binder is a critical compo- nent. The limits ...

  7. Clutches and brakes design and selection

    CERN Document Server

    Orthwein, William C

    2004-01-01

    Conveniently gathering formulas, analytical methods, and graphs for the design and selection of a wide variety of brakes and clutches in the automotive, aircraft, farming, and manufacturing industries, Clutches and Brakes: Design and Selection, Second Edition simplifies calculations, acquaints engineers with an expansive range of application, and assists in the selection of parameters for specific design challenges. Contains an abundance of examples, 550 display equations, and more than 200 figures for clear presentation of various design strategies Thoroughly revised throughout, the second edition offers… Additional chapters on friction drives and fluid clutches and retarders An extended discussion on cone brakes and clutches A simpler formulation of the torque from a centrifugal clutch Updated sections on automatic braking systems An analysis of variable-speed friction drives with clutch capability Analytical and computer-assisted design techniques.

  8. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    Science.gov (United States)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  9. Rotary Speed Sensor for Antilocking Brakes

    Science.gov (United States)

    Berdahl, C. M.

    1986-01-01

    Sensor based on fluidic principles produces negative pressure approximately proportional to rotational speed. Sensor developed as part of antilocking brake system for motorcycles. Uses inlet pressure rather than outlet pressure as braking-control signal, eliminating pressure pulsations caused by pump vanes and ensuring low-noise signal. Sensor is centrifugal air pump turned by one of motorcycle wheels. Air enters pump through orifice plates, and suction taken off through port in pump inlet plenum.

  10. Method and apparatus for wind turbine braking

    Science.gov (United States)

    Barbu, Corneliu [Laguna Hills, CA; Teichmann, Ralph [Nishkayuna, NY; Avagliano, Aaron [Houston, TX; Kammer, Leonardo Cesar [Niskayuna, NY; Pierce, Kirk Gee [Simpsonville, SC; Pesetsky, David Samuel [Greenville, SC; Gauchel, Peter [Muenster, DE

    2009-02-10

    A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

  11. CP violation in K decays

    International Nuclear Information System (INIS)

    Gilman, F.J.

    1989-05-01

    Recent theoretical and experimental progress on the manifestation of CP violation in K decays, and toward understanding whether CP violation originates in a phase, or phases, in the weak mixing matrix of quarks is reviewed. 23 refs., 10 figs

  12. CP violation in B decays

    International Nuclear Information System (INIS)

    Kayser, B.

    1990-01-01

    The study of CP-violating effects in B decays will be a good test of whether CP violation is caused by the known weak interaction. If this is its origin, then large, cleanly-predicted CP-violating effects are expected in certain neutral B decays to hadronic CP eigenstates. The phenomenology of CP violation in the B system is reviewed, and the genesis of these large effects is explained. In this it is shown that large, cleanly-predicted effects are also expected in some decays to states which are not CP eigenstates. The combined study of the latter decays and those to CP eigenstates may make it possible to obtain a statistically-significant CP-violating signal with fewer B mesons that would otherwise be required

  13. Automated visual inspection of brake shoe wear

    Science.gov (United States)

    Lu, Shengfang; Liu, Zhen; Nan, Guo; Zhang, Guangjun

    2015-10-01

    With the rapid development of high-speed railway, the automated fault inspection is necessary to ensure train's operation safety. Visual technology is paid more attention in trouble detection and maintenance. For a linear CCD camera, Image alignment is the first step in fault detection. To increase the speed of image processing, an improved scale invariant feature transform (SIFT) method is presented. The image is divided into multiple levels of different resolution. Then, we do not stop to extract the feature from the lowest resolution to the highest level until we get sufficient SIFT key points. At that level, the image is registered and aligned quickly. In the stage of inspection, we devote our efforts to finding the trouble of brake shoe, which is one of the key components in brake system on electrical multiple units train (EMU). Its pre-warning on wear limitation is very important in fault detection. In this paper, we propose an automatic inspection approach to detect the fault of brake shoe. Firstly, we use multi-resolution pyramid template matching technology to fast locate the brake shoe. Then, we employ Hough transform to detect the circles of bolts in brake region. Due to the rigid characteristic of structure, we can identify whether the brake shoe has a fault. The experiments demonstrate that the way we propose has a good performance, and can meet the need of practical applications.

  14. Status in CP violation

    International Nuclear Information System (INIS)

    Fayard, L.

    1989-11-01

    Twenty-five years after the discovery of CP violation in the neutral Kaon system, we still dont know exactly the origin and the components of that weak non invariance. The two more precise experiments give slightly different answers concerning the direct way of CP violation NA 31 gives ε prime/ε incompatible with the Superweak Model (for which ε prime=0) and in agreement with Standard Model predictions compatible with both. Again, one needs new and precise results in order to conclude about ε prime. E731 and NA31 are actually working on their new data samples. Longer term ideas are also being discussed, looking for new experiments able to give ε prime/ε with a precision. Concerning CPT invariance the situation seems to be more clear

  15. LHCb CP violation

    CERN Document Server

    Vesterinen, Mika

    2016-01-01

    The study of $CP$ violation in the beauty hadron sector is a promising approach to search for the effects of physics beyond the Standard Model. Several recent measurements in this area from the LHCb experiment are reported in these proceedings. These are based on the Run-I dataset of 3~fb$^{-1}$ of data collected at proton-proton centre of mass energies of 7 and 8~TeV.

  16. Regional Courts as Judicial Brakes?

    Directory of Open Access Journals (Sweden)

    Metcalf Katrin Nyman

    2017-12-01

    Full Text Available The article examines how regional integration courts can act as judicial brakes, at a time when “constitutional coups” – leaders staying in power past constitutional time limits or other forms of actions against the spirit if not always the letter of the constitution – are alarmingly common. The article discusses how regional courts can be used to modify or protect national rule of law and the constitutional order from the outside (i.e. from the regional integration aspect and the extent to which this can be valid particularly to promote a uniform interpretation and application of human rights. Although this trend is visible in Europe, it is more striking, because less expected, on other continents, in particular Africa and the Americas, where the developments take place in less than perfect democratic environments. The article contains evidence from cases dealt with in the various regional courts, supporting that a system of political and judicial oversight, especially in regions with weak or fragile democratic systems, can be a useful addition to national judicial or other mechanisms of protection of rule of law and control of the executive. Action by regional courts helps defeat perceptions of majoritarian politics, which in many countries allow for the winner to take all. Under a system of regional oversight, states become aware of the limits they themselves have set and citizens become aware of their possibilities to challenge political power.

  17. Electromagnetic brake/clutch device

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1994-01-01

    An electromagnetic brake/clutch device includes a drive shaft supported by at least one bearing for transmitting torque, a housing, affixed to prevent its rotation, surrounding the drive shaft, and an electromagnetically activated device within the housing to selectively prevent and allow rotation of the drive shaft. The electromagnetically activated device includes a plurality of cammed rollers to prevent counter-clockwise rotation of the drive shaft. The drive shaft includes a circumferential disk and the housing includes a reaction ring for engagement with the plurality of cammed rollers. The plurality of cammed rollers are released from engagement with the circumferential disk and the reaction ring by a plurality of tripping mechanisms within the housing. The tripping action uses the locking force to act as a release force merely by changing the boundary conditions of the roller interface angles. The tripping mechanisms include trippers for disengaging the plurality of cammed rollers and an anvil shaped portion for providing lateral movement of the trippers. The plurality of cammed rollers is preloaded to engagement with the circumferential disk and reaction ring by a spring, and is located with respect to an adjacent tripping mechanism with another spring.

  18. Magnetic braking in galactic flows

    International Nuclear Information System (INIS)

    Sparke, L.S.

    1982-01-01

    The nuclear fireworks of active galaxies are believed to derive their power from the kinetic energy of gas falling onto a massive central objects; mass shed from evolving galactic stars is an obvious source of fuel for this process. But this ejected material shares the galactic rotation, and a centrifugal barrier will prevent it from reaching the nucleus, if its angular momentum is not removed. This paper shows that, if the large-scale galactic magnetic field has a strong enough radial component, magnetic torques can act to spin down the infalling matter. Rotation of the interstellar gas induces a toroidal magnetic field, and Maxwell stresses remove angular momentum from the flow; gas can then fall inward to the galactic center. In this way, the monster in the nucleus can be fed on gas from a galaxy's own stars. The magnetic fields in M87 and NGC 1275, giant elliptical galaxies which are accreting from an intracluster medium, appear to be strong enough to allow magnetic braking

  19. Geometric optimal design of a magneto-rheological brake considering different shapes for the brake envelope

    International Nuclear Information System (INIS)

    Nguyen, Q H; Lang, V T; Nguyen, N D; Choi, S B

    2014-01-01

    When designing a magneto-rheological brake (MRB), it is well known that the shape of the brake envelope significantly affects the performance characteristics of the brake. In this study, different shapes for the MR brake envelope, such as rectangular, polygonal or spline shape, are considered and the most suitable shape identified. MRBs with different envelope shapes are introduced followed by the derivation of the braking torque based on Bingham-plastic behavior of the magneto-rheological fluid (MRF). Optimization of the design of the MRB with different envelope shapes is then done. The optimization problem is to find the optimal value for the significant geometric dimensions of the MRB that can produce a certain required braking torque while the brake mass is minimized. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions for the MRBs. From the results, the most suitable shape for the brake envelope is identified and discussed with the reduction of mass. In addition, the results of the analysis are compared with the experimental results to verify the proposed optimal design characteristics. (paper)

  20. THE INFLUENCE OF BRAKE PADS THERMAL CONDUCTIVITY ON PASSANGER CAR BRAKE SYSTEM EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Predrag D Milenković

    2010-01-01

    Full Text Available In phase of vehicle braking system designing, besides of mechanical characteristics, it is also necessary to take under consideration the system's thermal features. This is because it is not enough just to achieve proper braking power, for the brake system to be effective but equally important thing is the dissipation of heat to the environment. Heat developed in the friction surfaces dissipate into the environment over the disk in one hand and through the brake linings and caliper, in the other. The striving is to make that greatest amount of heat to dissipate not threw the brake pads but threw disc. The experimental researching of heat transfer process taking place at vehicle brakes was made in the R&D Center of "Zastava automobili" car factory in order to increase the efficiency of brake system. The standard laboratory and road test procedures were used, according to factory quality regulations. The modern equipment such as thermo camera, thermo couples, torque transducers, signal amplifiers, optical speed measuring system and laptop computer were used. In this paper will be shown the part of the experimental researching, which refers to the thermal conductivity of brake pad friction linings.

  1. Geometric optimal design of a magneto-rheological brake considering different shapes for the brake envelope

    Science.gov (United States)

    Nguyen, Q. H.; Lang, V. T.; Nguyen, N. D.; Choi, S. B.

    2014-01-01

    When designing a magneto-rheological brake (MRB), it is well known that the shape of the brake envelope significantly affects the performance characteristics of the brake. In this study, different shapes for the MR brake envelope, such as rectangular, polygonal or spline shape, are considered and the most suitable shape identified. MRBs with different envelope shapes are introduced followed by the derivation of the braking torque based on Bingham-plastic behavior of the magneto-rheological fluid (MRF). Optimization of the design of the MRB with different envelope shapes is then done. The optimization problem is to find the optimal value for the significant geometric dimensions of the MRB that can produce a certain required braking torque while the brake mass is minimized. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions for the MRBs. From the results, the most suitable shape for the brake envelope is identified and discussed with the reduction of mass. In addition, the results of the analysis are compared with the experimental results to verify the proposed optimal design characteristics.

  2. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... the drain cocks in the service and supply reservoir on the truck or truck-tractor. Note the pressure.... Close the drain cocks, and, with the trailer(s) uncoupled, check air pressure buildup at the... brakes fully applied. (b) Air brake system hoses, tubes and connections. Air system tubes, hoses and...

  3. Neutrons put the brakes on stress

    International Nuclear Information System (INIS)

    Gill, Katynna

    2006-01-01

    Don't you hate it when you're driving along, put your foot on the brake and feel that juddering feeling through the pedal? It happens when the disc brake rotors become distorted through normal use of the brakes. To the car manufacturing industry it's called r unout , and is a multimillion dollar warranty problem each year. Not to mention a pain for drivers! Dr Maurice Ripley and Dr Oliver Kirstein from the Australian Nuclear Science and Technology Organisation (ANSTO) wanted to figure out whether runout is caused by residual stresses from the manufacturing process or by normal use of the brake, so they decided to test and compare a used and new brake disc. 'To picture what metal looks like at the atomic level, imagine spheres stacked evenly around each other in all three dimensions,' explained Kirstein. T he spheres represent atoms in the metal and the structure is called a metallic lattice.' We're familiar with the idea that metal expands when it gets hot - the atoms get excited with the heat and have the energy to move further away from each other, so spaces between the atoms in the lattice get larger. 'When parts of the metal are heated up and cool down at different rates, you may end up with a distorted lattice with some parts expanded and others not,' explained Kirstein. 'This unevenness in the lattice creates residual stress.' While a bunch of methods were available to test the discs, Kirstein and Ripley picked neutrons from ANSTO's HIFAR (High Flux Australian Reactor) as their tool of choice. 'Neutrons allow us to look at the inside of the metal without damaging it,' said Kirstein. 'They can penetrate through the iron, so we were able to take measurements at a series of points at different depths through the brake disc.' Word around the car industry is that when residual stresses are relaxed through heating of the brake disc during use, the discs could potentially distort, causing the runout and that juddering feeling. But everyone was clueless as to what

  4. ABOUT WAVEFORM OF BRAKING CYLINDER FILLING IN FREIGHT CARS

    Directory of Open Access Journals (Sweden)

    L. V. Ursuliak

    2016-04-01

    Full Text Available Purpose. As part of the scientific paper it is necessary to study the waveform impact of the braking cylinders filling on longitudinal train dynamics at different modes of braking. At this one should estimate the level of maximum longitudinal forces and braking distance size in freight cars of various lengths. Methodology. In this paper we attempt to approximate the actual diagram of braking cylinders filling with rational functions of varying degrees. In selection of coefficients in the required functions the highest values of the longitudinal forces and braking distances were used as controlled parameters. They were compared with similar values obtained as a result of experimental rides. The level of longitudinal forces and braking distances amount were evaluated by means of mathematical modeling of train longitudinal vibrations, caused by different braking modes. Findings. At mathematical modeling was assumed that the train consists of 60 uniform four-axle gondola cars, weight of 80 tons, equipped with air dispenser No. 483 included in the median operation, composite braking blocks, and one locomotive VL-8. Train before braking has been pre-stretched. Various types of pneumatic braking (emergency, full service and adjusting braking of the freight train on the horizontal section of the track were simulated. As the calculation results were obtained values of the longitudinal forces, braking distances amounts and reduction time in speed at various braking modes. Originality. Waveform impact of the braking cylinders filling on the longitudinal forces level and braking distances amount in freight trains were investigated. Also the longitudinal loading of freight trains at various pneumatic braking was investigated. Practical value. Obtained results can be used to assess the level of largest longitudinal forces and braking distances in the freight trains of different lengths by mathematical modeling of different braking modes.

  5. Adaptive controller for regenerative and friction braking system

    Science.gov (United States)

    Davis, Roy I.

    1990-01-01

    A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

  6. Recent studies of tire braking performance. [for aircraft

    Science.gov (United States)

    Mccarty, J. L.; Leland, T. J. W.

    1973-01-01

    The results from recent studies of some factors affecting tire braking and cornering performance are presented together with a discussion of the possible application of these results to the design of aircraft braking systems. The first part of the paper is concerned with steady-state braking, that is, results from tests conducted at a constant slip ratio or steering angle or both. The second part deals with cyclic braking tests, both single cycle, where brakes are applied at a constant rate until wheel lockup is achieved, and rapid cycling of the brakes under control of a currently operational antiskid system.

  7. Backup Mechanical Brake System of the Wind Turbine

    Science.gov (United States)

    Sirotkin, E. A.; Solomin, E. V.; Gandzha, S. A.; Kirpichnikova, I. M.

    2018-01-01

    Paper clarifies the necessity of the emergency mechanical brake systems usage for wind turbines. We made a deep analysis of the wind turbine braking methods available on the market, identifying their strengths and weaknesses. The electromechanical braking appeared the most technically reasonable and economically attractive. We described the developed combined electromechanical brake system for vertical axis wind turbine driven from electric drive with variable torque enough to brake over the turbine even on the storm wind speed up to 45 m/s. The progress was made due to the development of specific kinematic brake system diagram and intelligent control system managed by special operation algorithm.

  8. Brake force estimation for electromechanical vehicle brakes; Bremskraft-Rekonstruktion fuer elektromechanische Fahrzeugbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R. [Continental Teves (Germany)

    1999-06-01

    Due to the increasing safety and comfort demands of the customer, the functionality of modern brake systems has grown continuously in the last years. However, implementation of the extended functionality in conventional brake hydraulics makes active electronic intervention necessary and therefore requires a lot of technical effort. In recent years the automotive supplier industry has started to develop brake systems which have electromechanical brake actuators generating the brake forces at the individual wheels. Electromechanically actuated wheel brakes need to be operated in a closed control loop. This paper introduces a new method to reconstruct the needed feedback value brake force from easy to measure signals. (orig.) [Deutsch] Aufgrund des gestiegenen Sicherheits- und Komfortbewusstseins der Fahrzeugkaeufer ist die Funktionsvielfalt moderner Bremssysteme in den letzten Jahren staendig gewachsen. Die Umsetzung der erweiterten Funktionalitaet mittels konventioneller Bremsenhydraulik ist jedoch durch den elektronischen, aktiven Eingriff sehr aufwendig. In den letzten Jahren hat daher die Automobilzulieferindustrie begonnen, Bremssysteme zu entwickeln, bei denen die Bremskraft an den einzelnen Raedern von elektromechanischen Bremsaktuatoren aufgebracht wird. Elektromechanisch betaetigte Radbremsen muessen im geschlossenen Regelkreis betrieben werden. Der vorliegende Beitrag, der im Rahmen einer Forschungskooperation zwischen Continental Teves und dem Institut fuer Automatisierungstechnik der TU Darmstadt entstand stellt ein Verfahren vor, mit dem die dafuer benoetigte Rueckfuehrungsgroesse `Bremskraft` aus einfach messbaren Signalen rekonstruiert werden kann. (orig.)

  9. Analyzing Track Responses to Train Braking

    DEFF Research Database (Denmark)

    Bose, Tulika; Levenberg, Eyal; Zania, Varvara

    2018-01-01

    The objective of this study was to suggest a response analysis framework for railway tracks that are subjected to braking. An analytical formulation was developed, in which the rail–track system was modeled as an infinite beam supported by an orthogonal Winkler foundation consisting of linear...... a response analysis framework for railway tracks that are subjected to braking. An analytical formulation was developed, in which the rail–track system was modeled as an infinite beam supported by an orthogonal Winkler foundation consisting of linear springs in perpendicular directions. The spring constants...... springs in perpendicular directions. The spring constants were varied over a wide range in order to represent different track types. Braking loads were simulated as representative sets of vertical and longitudinal forces, either concentrated or distributed. Considering a realistic set of model parameters...

  10. Consideration of materials for aircraft brakes

    Science.gov (United States)

    Peterson, M. B.; Ho, T.-L.

    1974-01-01

    A study has been made of the frictional behavior of several aircraft brake materials using a simple high-temperature Falex-type apparatus. Tests were run at velocities of seven ft/minute; loads to 600 pounds and temperatures to 700 C. The data for these brake materials sliding against a variety of steels and other materials indicate a large reduction in friction due to surface oxidation in the temperature range 250 to 300 C. It also was found that the retention of this oxide was a function of the temperature changes. With increasing temperature the oxide was removed, while with reducing temperature it was retained. Frictional behavior was more characteristic of the steel than the brake material.

  11. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R.

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  12. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ... 10,000 Pounds § 570.59 Service brake system. (a) Service brake performance. Compliance with any one of the following performance criteria will satisfy the requirements of this section. Verify that tire...

  13. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  14. Regenerative Intelligent Brake Control for Electric Motorcycles

    Directory of Open Access Journals (Sweden)

    Juan Jesús Castillo Aguilar

    2017-10-01

    Full Text Available Vehicle models whose propulsion system is based on electric motors are increasing in number within the automobile industry. They will soon become a reliable alternative to vehicles with conventional propulsion systems. The main advantages of this type of vehicles are the non-emission of polluting gases and noise and the effectiveness of electric motors compared to combustion engines. Some of the disadvantages that electric vehicle manufacturers still have to solve are their low autonomy due to inefficient energy storage systems, vehicle cost, which is still too high, and reducing the recharging time. Current regenerative systems in motorcycles are designed with a low fixed maximum regeneration rate in order not to cause the rear wheel to slip when braking with the regenerative brake no matter what the road condition is. These types of systems do not make use of all the available regeneration power, since more importance is placed on safety when braking. An optimized regenerative braking strategy for two-wheeled vehicles is described is this work. This system is designed to recover the maximum energy in braking processes while maintaining the vehicle’s stability. In order to develop the previously described regenerative control, tyre forces, vehicle speed and road adhesion are obtained by means of an estimation algorithm. A based-on-fuzzy-logic algorithm is programmed to carry out an optimized control with this information. This system recuperates maximum braking power without compromising the rear wheel slip and safety. Simulations show that the system optimizes energy regeneration on every surface compared to a constant regeneration strategy.

  15. CP violating scalar Dark Matter

    Science.gov (United States)

    Cordero-Cid, A.; Hernández-Sánchez, J.; Keus, V.; King, S. F.; Moretti, S.; Rojas, D.; Sokołowska, D.

    2016-12-01

    We study an extension of the Standard Model (SM) in which two copies of the SM scalar SU(2) doublet which do not acquire a Vacuum Expectation Value (VEV), and hence are inert, are added to the scalar sector. We allow for CP-violation in the inert sector, where the lightest inert state is protected from decaying to SM particles through the conservation of a Z 2 symmetry. The lightest neutral particle from the inert sector, which has a mixed CP-charge due to CP-violation, is hence a Dark Matter (DM) candidate. We discuss the new regions of DM relic density opened up by CP-violation, and compare our results to the CP-conserving limit and the Inert Doublet Model (IDM). We constrain the parameter space of the CP-violating model using recent results from the Large Hadron Collider (LHC) and DM direct and indirect detection experiments.

  16. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

    ... motorcycle braking regulations from around the world, including the U.S. motorcycle brake systems standard.... Partial Failure Test--Split Service Brake System I. Power-Assisted Braking System Failure Test V. Other... motorcycle brake system technologies. In order to address modern braking technologies, the agency sought to...

  17. REGRESSIVE ANALYSIS OF BRAKING EFFICIENCY OF M1 CATEGORY VEHICLES WITH ANTI-BLOCKING BRAKE SYSTEM

    Directory of Open Access Journals (Sweden)

    О. Sarayev

    2015-07-01

    Full Text Available The problematics of assessing the effectiveness of vehicle braking after road accidentoccurrence is considered. For the first time in relation to the modern models of vehicles equipped with anti-lock brakes there were obtained regression models describing the relationship between the coefficient of traction and a random variable of steady deceleration. This does not contradict the essence of the stochastic physical object, which is the process of vehicle braking, unlike the previously adopted method of formalizing this process, using a deterministic function.

  18. Hydromagnetic rotational braking of magnetic stars

    International Nuclear Information System (INIS)

    Fleck, R.C. Jr.

    1980-01-01

    It is suggested that the magnetic Ap stars can be rotationally decelerated to long periods by the braking action of the associated magnetic field on time scales of order 10 7 --10 10 years depending on whether the star's dipole field is aligned perpendicular or parallel to the rotation axis. Rotation includes a toroidal magnetic field in the plasma surrounding a star, and the accompanying magnetic stresses produce a net torque acting to despin the star. These results indicate that it is not necessary to postulate mass loss or mass accretion for this purely hydromagnetic braking effect

  19. Tire Models for Use in Braking Applications

    OpenAIRE

    Svendenius, Jacob

    2003-01-01

    The tire is a significant part for control of a vehicle. For a well-working brake system the contact properties between the tire and the ground is the limiting factor for a safe braking. To get optimal performance it is important that the system can utilize all friction resources. The brush tire model was a popular method in the 1960's and 1970's before the empirical approaches became dominating. The brush model gives an educational interpretation of the physics behind the tire behavi...

  20. Present status of CP violation

    International Nuclear Information System (INIS)

    Ng, J.N.

    1989-06-01

    A review of the status of CP violation in kaons is given. Status of our knowledge of quark mixing angles in the standard six quark model is presented. The role Β d o - Βd o transition plays in this study is examined. A comparison of the estimates of CP violation effects from models beyond the standard one is given. Other experiments that have the capability of testing different CP violation models are also discussed. (Author) 35 refs., 6 figs., tab

  1. Station Stopping of Freight Trains with Pneumatic Braking

    OpenAIRE

    Yun Bai; Baohua Mao; Tinkin Ho; Yu Feng; Shaokuan Chen

    2014-01-01

    In Chinese mainline railway, freight trains need to stop within passenger stations at times because of the delayed passenger trains. Without any decision-support system, it is very difficult for drivers to stop trains within stations with consistency in one braking action. The reasons are that braking performance of train changes with the conditions of braking equipment and the drivers’ subjective evaluations of track profiles and braking distance are vague and imprecise. This paper presents ...

  2. Combined emergency braking and turning of articulated heavy vehicles

    OpenAIRE

    Morrison, G; Cebon, David

    2017-01-01

    ‘Slip control’ braking has been shown to reduce the emergency stopping distance of an experimental heavy goods vehicle by up to 19%, compared to conventional electronic/anti-lock braking systems (EBS). However, little regard has been given to the impact of slip control braking on the vehicle’s directional dynamics. This paper uses validated computer models to show that slip control could severely degrade directional performance during emergency braking. A modified slip control strategy, ‘atte...

  3. Controlled braking scheme for a wheeled walking aid

    OpenAIRE

    Coyle, Eugene; O'Dwyer, Aidan; Young, Eileen; Sullivan, Kevin; Toner, A.

    2006-01-01

    A wheeled walking aid with an embedded controlled braking system is described. The frame of the prototype is based on combining features of standard available wheeled walking aids. A braking scheme has been designed using hydraulic disc brakes to facilitate accurate and sensitive controlled stopping of the walker by the user, and if called upon, by automatic action. Braking force is modulated via a linear actuating stepping motor. A microcontroller is used for control of both stepper movement...

  4. Numerical simulation of heat transfer process in automotive brakes

    OpenAIRE

    Gonzalo Voltas, David

    2013-01-01

    This master thesis concerns the theoretical investigations of the heat transfer process in automotive brakes. The process of heat generation and heat transfer to ambient air in automotive brake was presented. The two–dimensional, axi-symmetrical model of transient heat conduction for the brake was applied. The relevant boundary conditions, that describe the heat generated in the brake and the heat transferred to ambient air, were used. The unsteady heat conduction problem was solved by the...

  5. 49 CFR 238.313 - Class I brake test.

    Science.gov (United States)

    2010-10-01

    ... intercity passenger train shall receive a Class I brake test once each calendar day that the train is placed...-distance intercity passenger train shall receive a Class I brake test: (1) Prior to the train's departure... shoes or pads are firmly seated against the wheel or disc with the brakes applied; (3) Piston travel is...

  6. 49 CFR 238.319 - Running brake test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received, or...

  7. Development of a Dynamic Engine Brake Model for Control Purposes

    NARCIS (Netherlands)

    Seykens, X.L.J.; Baert, R.S.G.; Willems, F.P.T.; Vink, W.; van den Heuvel, I.T.M.

    2006-01-01

    This paper presents the extension of an existing mean value dynamic engine model with new models for the combination of a compression release brake and an exhaust valve brake. The focus is on the prediction of engine brake torque, exhaust gas temperatures and mass flow rates. The implemented models

  8. Development of a dynamic engine brake model for control purposes

    NARCIS (Netherlands)

    Seykens, X.L.J.; Baert, R.S.G.; Willems, F.P.T.; Vink, W.; van den Heuvel, I.T.M.; Corde, G.

    2007-01-01

    This paper presents the extension of an existing mean value dynamic engine model with new models for the combination of a compression release brake and an exhaust valve brake. The focus is on the prediction of engine brake torque, exhaust gas temperatures and mass flow rates. The implemented models

  9. 30 CFR 75.1404-1 - Braking system.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Braking system. 75.1404-1 Section 75.1404-1... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Hoisting and Mantrips § 75.1404-1 Braking system. A locomotive equipped with a dual braking system will be deemed to satisfy the requirements of § 75.1404 for a...

  10. 30 CFR 77.1401 - Automatic controls and brakes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic controls and brakes. 77.1401 Section... MINES Personnel Hoisting § 77.1401 Automatic controls and brakes. Hoists and elevators shall be equipped with overspeed, overwind, and automatic stop controls and with brakes capable of stopping the elevator...

  11. Physiology and pathophysiology of the ileal brake in humans

    NARCIS (Netherlands)

    Vu, My Kieu

    2007-01-01

    The ileal brake is an intraluminal nutrient-triggered feedback control from the distal to the proximal gut with fat being the most potent trigger. Peptide YY (PYY) is one of the hormonal mediators of the ileal brake. Effects of the fat induced ileal brake on proximal small intestine, postprandial

  12. 49 CFR 393.49 - Control valves for brakes.

    Science.gov (United States)

    2010-10-01

    ... in paragraphs (b) and (c) of this section, every motor vehicle manufactured after June 30, 1953, which is equipped with power brakes, must have the braking system so arranged that one application valve must when activated cause all of the service brakes on the motor vehicle or combination motor vehicle...

  13. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

    ... that utilize an electric signal to communicate a service brake application and only a pneumatic signal... and release of the brakes on the last car in the train; and (6) The communicating signal system is... be used to verify the set and release on cars so equipped. However, the observation of the brake...

  14. An Instructor's Guide for a Program in Brake Services.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The instructor's guide is designed to present an understanding of the automotive hydraulic brake system and to help individuals develop new skills for employment in this specialized field of automotive service. Applicable for secondary or adult education, this guide describes: the brake system, types of brakes, diagnosis and correction of brake…

  15. 14 CFR 27.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 27.493 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 27.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit...

  16. 14 CFR 23.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 23.493 Section 23.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT....493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their...

  17. 14 CFR 29.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 29.493 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 29.493 Braked roll conditions. Under braked roll conditions with the shock absorbers in their static positions— (a) The limit...

  18. 49 CFR 393.48 - Brakes to be operative.

    Science.gov (United States)

    2010-10-01

    ..., snowy, or icy roads. (2) Automatic devices. Automatic devices must not reduce the front-wheel braking force by more than 50 percent of the braking force available when the automatic device is disconnected... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial...

  19. 49 CFR 229.57 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30 percent...

  20. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. [Statutory Provisions] Each locomotive and haulage car used in an... permit automatic brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other...

  1. Cosmological CP Violation

    CERN Document Server

    Tomaschitz, R

    1994-01-01

    Spinor fields are studied in infinite, topologically multiply connected Robertson-Walker cosmologies. Unitary spinor representations for the discrete covering groups of the spacelike slices are constructed. The spectral resolution of Dirac's equation is given in terms of horospherical elementary waves, on which the treatment of spin and energy is based in these cosmologies. The meaning of the energy and the particle-antiparticle concept is explained in the context of this varying cosmic background. Discrete symmetries, in particular inversions of the multiply connected spacelike slices, are studied. The violation of the unitarity of the parity operator, due to self-interference of P-reflected wave packets, is discussed. The violation of the CP and CPT invariance - already on the level of the free Dirac equation on this cosmological background - is pointed out.

  2. Emergency Braking of a Mine Hoist in the Context of the Braking System Selection

    Science.gov (United States)

    Wolny, Stanisław

    2017-03-01

    The paper addresses the selected aspects of the dynamic behaviour of mine hoists during the emergency braking phase. Basing on the model of the hoist and supported by theoretical backgrounds provided by the author (Wolny, 2016), analytical formulas are derived to determine the parameters of the braking system such that during an emergency braking it should guarantee that: - the maximal loading of the hoisting ropes should not exceed the rope breaking force, - deceleration of the conveyances being stopped should not exceed the admissible levels Results of the dynamic analysis of the mine hoist behaviour during an emergency braking phase summarised in this study can be utilised to support the design of conveyance and rope attachments by the fatigue endurance methods, with an aim to adapt it to the specified operational parameters of the hoisting installation (Eurokod 3).

  3. The design of aircraft brake systems, employing cooling to increase brake life

    Science.gov (United States)

    Scaringe, R. P.; Ho, T. L.; Peterson, M. B.

    1975-01-01

    A research program was initiated to determine the feasibility of using cooling to increase brake life. An air cooling scheme was proposed, constructed and tested with various designs. Straight and curved slotting of the friction material was tested. A water cooling technique, similar to the air cooling procedure, was evaluated on a curved slotted rotor. Also investigated was the possibility of using a phase-change material within the rotor to absorb heat during braking. Various phase-changing materials were tabulated and a 50%, (by weight) LiF - BeF2 mixing was chosen. It was shown that corrosion was not a problem with this mixture. A preliminary design was evaluated on an actual brake. Results showed that significant improvements in lowering the surface temperature of the brake occurred when air or water cooling was used in conjunction with curved slotted rotors.

  4. Beryllium in aircraft brakes - a summary

    International Nuclear Information System (INIS)

    Zenczak, S.

    1977-01-01

    Beryllium has been in use in aircraft brakes for ten years. During the original design phases of the several aircraft programs using beryllium a number of problems requiring solution confronted the designers. In actual service the solution to these problems performed much better than had been anticipated. A summary is presented. (author)

  5. Wear determination in braking systems by radioisotopes

    International Nuclear Information System (INIS)

    Spruch, W.

    1979-01-01

    Friction and wear behaviour of friction couples has been tested applying loads and sliding speeds. The determination was carried out by direct measurements of the lining material and by surface activation of the opposite material with protons. The application limits of several braking materials could be determined and compared

  6. Braking Control for Improving Ride Comfort

    Directory of Open Access Journals (Sweden)

    Lee Jonghyup

    2018-01-01

    Full Text Available While many vehicle control systems focus on vehicle safety and vehicle performance at high speeds, most driving conditions are very low risk situations. In such a driving situation, the ride comfort of the vehicle is the most important performance index of the vehicle. Electro mechanical brake (EMB and other brake-by-wire (BBW systems have been actively researched. As a result, braking actuators in vehicles are more freely controllable, and research on improving ride comfort is also possible. In this study, we develop a control algorithm that dramatically improves ride comfort in low risk braking situations. A method for minimizing the inconvenience of a passenger due to a suddenly changing acceleration at the moment when the vehicle is stopped is presented. For this purpose, an acceleration trajectory is generated that minimizes the discomfort index defined by the change in acceleration, jerk. A controller is also designed to track this trajectory. The algorithm that updates the trajectory is designed considering the error due to the phase lag occurring in the controller and the plant. In order to verify the performance of this controller, simulation verification is completed using a car simulator, Carsim. As a result, it is confirmed that the ride comfort is dramatically improved.

  7. Calculations enable optimum design of magnetic brake

    Science.gov (United States)

    Kosmahl, H. G.

    1966-01-01

    Mathematical analysis and computations determine optimum magnetic coil configurations for a magnetic brake which controllably decelerates a free falling load to a soft stop. Calculations on unconventionally wound coils determine the required parameters for the desired deceleration with minimum electrical energy supplied to the stationary coil.

  8. 30 CFR 57.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... which is not originally equipped with brakes unless the manner in which the equipment is being operated... evaluated according to Table M-1. Table M-1 Gross vehicle weight lbs. Equipment Speed, MPH 10 11 12 13 14 15... response time. Table M-2—The Speed of a Vehicle Can Be Determined by Clocking It Through a 100-Foot...

  9. Use of elastomers in regenerative braking systems

    Science.gov (United States)

    The storage of potential energy as strain energy in elastomers was investigated. The evolution of the preferred stressing scheme is described, and test results on full-size elastomeric energy storage units sized for an automotive regenerative braking system application are presented. The need for elastomeric material improvements is also discussed.

  10. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    An asbestos free friction material composite for brake linings is synthesized containing fibrous reinforcing constituents, friction imparting and controlling additives, elastomeric additives, fire retarding components and a thermosetting resin. The composite shows exemplary friction characteristics and has great resistance to ...

  11. Generation of brake squeal. Fundamental vibration in brake system; Entstehungsmechanismus des Bremsenquietschens. Grundschwingung im Bremssystem

    Energy Technology Data Exchange (ETDEWEB)

    Shi Xiaoming; Mitschke, M.

    1997-11-01

    Reducing or preventing brake squealing is a prime goal of brake development. To provide constructional means of doing this the mechanism by which it occurs must first be understood. Research at the Technical University of Braunschweig now offers a plausible explanation. (orig.) [Deutsch] Die Verringerung oder Vermeidung des Bremsenquietschens ist ein wichtiges Ziel der Bremsenentwicklung. Um konstruktiv Abhilfe zu schaffen, muss zunaechst der Entstehungsmechanismus fuer dieses unerwuenschte Geraeusch geklaert werden. Forschung an der Technischen Universitaet Braunschweig ermoeglicht jetzt eine plausible Erklaerung. (orig.)

  12. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    OpenAIRE

    Minh Vu Trieu; Oamen Godwin; Vassiljeva Kristina; Teder Leo

    2016-01-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. Thi...

  13. Study on reduction method of brake squeal; Brake naki teigen shuho ni kansuru kento

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, T; Okada, Y [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    The reduction of brake squeal is an important technological subject in terms of making vehicles quieter. In our research, we carried out a modal analysis from the caliper to the installation bracket during generating brake squeal to identify the places that influence the squeal. Based on this, we studied proposals to reduce the squeal, and have reduced the squeal noise at about 5 kHz as reported in this paper. 1 ref., 12 figs.

  14. Leptogenesis and residual CP symmetry

    International Nuclear Information System (INIS)

    Chen, Peng; Ding, Gui-Jun; King, Stephen F.

    2016-01-01

    We discuss flavour dependent leptogenesis in the framework of lepton flavour models based on discrete flavour and CP symmetries applied to the type-I seesaw model. Working in the flavour basis, we analyse the case of two general residual CP symmetries in the neutrino sector, which corresponds to all possible semi-direct models based on a preserved Z 2 in the neutrino sector, together with a CP symmetry, which constrains the PMNS matrix up to a single free parameter which may be fixed by the reactor angle. We systematically study and classify this case for all possible residual CP symmetries, and show that the R-matrix is tightly constrained up to a single free parameter, with only certain forms being consistent with successful leptogenesis, leading to possible connections between leptogenesis and PMNS parameters. The formalism is completely general in the sense that the two residual CP symmetries could result from any high energy discrete flavour theory which respects any CP symmetry. As a simple example, we apply the formalism to a high energy S 4 flavour symmetry with a generalized CP symmetry, broken to two residual CP symmetries in the neutrino sector, recovering familiar results for PMNS predictions, together with new results for flavour dependent leptogenesis.

  15. Flavour physics and CP violation

    Indian Academy of Sciences (India)

    It is well known that the study of flavour physics and CP violation is very important to critically test the Standard Model and to look for possible signature of new physics beyond it. The observation of CP violation in kaon system in 1964 has ignited a lot of experimental and theoretical efforts to understand its origin and to look ...

  16. Parametric Optimization Design of Brake Block Based on Reverse Engineering

    Directory of Open Access Journals (Sweden)

    Jin Hua-wei

    2017-01-01

    Full Text Available As one of the key part of automotive brake,the performance of brake block has a direct impact on the safety and comfort of cars. Modeling the brake block of disc brake in reverse parameterization by reverse engineering software, analyzing and optimizing the reconstructed model by CAE software. Processing the scanned point cloud by Geomagic Studio and reconstructing the CAD model of the brake block with the parametric surface function of the software, then analyzing and optimizing it by Wrokbench. The example shows that it is quick to reconstruct the CAD model of parts by using reverse parameterization method and reduce part re-design development cycle significantly.

  17. Influences of braking system faults on the vehicle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Straky, H.; Kochem, M.; Schmitt, J.; Hild, R.; Isermann, R. [Technische Univ., Darmstadt (Germany). Inst. of Automatic Control

    2001-07-01

    From a safety point of view the braking system is, besides the driver, one of the key subsystems in a car. The driver, as an adaptive control system, might not notice small faults in the hydraulic part of the braking system and sooner or later critical braking situations, e.g. due to a brake-circuit failure, may occur. Most of the drivers are not capable to deal with such critical situations. Therefore this paper investigates the influence of faults in the braking system on the dynamic vehicle behavior and the steering inputs of the driver to keep the vehicle on the desired course. (orig.)

  18. Pedestrian injury mitigation by autonomous braking.

    Science.gov (United States)

    Rosén, Erik; Källhammer, Jan-Erik; Eriksson, Dick; Nentwich, Matthias; Fredriksson, Rikard; Smith, Kip

    2010-11-01

    The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness. 2010 Elsevier Ltd. All rights reserved.

  19. Testing New Indirect CP Violation

    International Nuclear Information System (INIS)

    Grossman, Yuval; Nir, Yosef; Perez, Gilad

    2009-01-01

    If new CP violating physics contributes to neutral meson mixing, but its contribution to CP violation in decay amplitudes is negligible, then there is a model independent relation between four (generally independent) observables related to the mixing: the mass splitting (x), the width splitting (y), the CP violation in mixing (1-|q/p|), and the CP violation in the interference of decays with and without mixing (φ). For the four neutral meson systems, this relation can be written in a simple approximate form: ytanφ≅x(1-|q/p|). In the K system, all four observables have been measured and obey the relation to excellent accuracy. For the B s and D systems, new predictions are provided. The success or failure of these relations will probe the physics that is responsible for the CP violation.

  20. CP-violation and instantons

    International Nuclear Information System (INIS)

    Han, C.G.

    1980-01-01

    Effects of Yang-Mills instantons on CP-violating strong interactions are studied. Using simplified models of CP-noninvariant weak interactions, we calculate the induced strong CP-violation. Even in the simple examples studied, the CP-violating phase of a vacuum-to-vacuum transition amplitude differs in general from the phase of the determinant of the quark mass matrix multiplied by the topological charge of the background Yang-Mills field. Then several CP-violating phenomena such as eta → 2π decay and neutron electric dipole moment induced by instantons are studied. The result of our explicit calculation of eta → 2π decay strength verifies the current algebraic method used by Crewther et al. We also present a calculation of the instanton contribution, in the dilute gas approximation for instanton gas, to the electric dipole moment of a free quark without using 't Hooft's effective Lagrangian

  1. Experimental investigation of an accelerometer controlled automatic braking system

    Science.gov (United States)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1972-01-01

    An investigation was made to determine the feasibility of an automatic braking system for arresting the motion of an airplane by sensing and controlling braked wheel decelerations. The system was tested on a rotating drum dynamometer by using an automotive tire, wheel, and disk-brake assembly under conditions which included two tire loadings, wet and dry surfaces, and a range of ground speeds up to 70 knots. The controlling parameters were the rates at which brake pressure was applied and released and the Command Deceleration Level which governed the wheel deceleration by controlling the brake operation. Limited tests were also made with the automatic braking system installed on a ground vehicle in an effort to provide a more realistic proof of its feasibility. The results of this investigation indicate that a braking system which utilizes wheel decelerations as the control variable to restrict tire slip is feasible and capable of adapting to rapidly changing surface conditions.

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

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2016-01-01

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

  3. Modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2016-07-01

    Full Text Available In mixed-mode braking applications, the electric motor / generator (M/G and hydraulic pressure valve are controlled to meet the driver’s braking demand. Controlling these braking elements is achieved by modulating the current generated by the M/G and adjusting the fluid pressure to the wheel brake cylinders. This paper aims to model and design combined regenerative and hydraulic braking systems which, comprise an induction electric machine, inverter, NiMH battery, controller, a pressure source, pressure control unit, and brake calipers. A 15 kW 1500 rpm induction machine equipped with a reduction gear having a gear ratio of 4 is used. A hydraulic brake capable to produce fluid pressure up to 40 bar is used. Direct torque control and pressure control are chosen as the control criteria in the M/G and the hydraulic solenoid valve. The braking demands for the system are derived from the Federal Testing Procedure (FTP drive cycle. Two simulation models have been developed in Matlab®/Simulink® to analyze the performance of the control strategy in each braking system. The developed model is validated through experiment. It is concluded that the control system does introduce torque ripple and pressure oscillation in the braking system, but these effects do not affect vehicle braking performance due to the high frequency nature of pressure fluctuation and the damping effect of the vehicle inertia. Moreover, experiment results prove the effectiveness of the developed model.

  4. Quantification of brake data acquired with a brake power meter during simulated cross-country mountain bike racing.

    Science.gov (United States)

    Miller, Matthew C; Fink, Philip W; Macdermid, Paul W; Stannard, Stephen R

    2018-01-17

    There is currently a dearth of information describing cycling performance outside of propulsive and physiological variables. The aim of the present study was to utilise a brake power meter to quantify braking during a multi-lap cross-country mountain bike time trial and to determine how braking affects performance. A significant negative association was determined between lap time and brake power (800.8 ± 216.4 W, mean ± SD; r = -0.446; p  0.05) which was attributed to decreased brake work (p < 0.05) and brake time (p < 0.05) in both the front and rear brakes by the final lap. A multiple regression model incorporating braking and propulsion was able to explain more of the variance in lap time (r 2  = 0.935) than propulsion alone (r 2  = 0.826). The present study highlights that riders' braking contributes to mountain bike performance. As riders repeat a cross-country mountain bike track, they are able to change braking, which in turn can counterbalance a reduction in power output. Further research is required to understand braking better.

  5. EVALUATION OF RESULTS OF ROAD RESEARCH OF LANOS CAR, EQUIPPED WITH AN ADVANCED HYDRAULIC BRAKE DRIVE

    Directory of Open Access Journals (Sweden)

    I. Nazarov

    2016-12-01

    Full Text Available The results of studies of road emergency braking of the car, the brake system equipped with an improved hydraulic brake actuator according to the patent number 76189 Ukraine are analyzed. This drive provides more efficient emergency braking of cars under operating conditions by of installing in each of the contours of the rear brakes one brake-power, each of which provides distribution of braking forces between the wheels of the corresponding side.

  6. CP-Recursion in Danish

    DEFF Research Database (Denmark)

    Nyvad, Anne Mette; Christensen, Ken Ramshøj; Vikner, Sten

    2017-01-01

    Based on data from extraction, embedded V2, and complementizer stacking, this paper proposes a cP/CP-analysis of CP-recursion in Danish. Because extraction can be shown to be possible from relative clauses, wh-islands, and adverbial clauses, and given that long extraction is successive......-cyclic, an extra specifier position has to be available as an escape hatch. Consequently, such extractions require a CP-recursion analysis, as has been argued for embedded V2 and for complementizer stacking. Given that CP-recursion in embedded V2 clauses does not allow extraction, whereas other types of CP......-recursion do, we suggest that embedded V2 is fundamentally different, in that main clause V2 and embedded V2 involve a CP (“big CP”), whereas all other clausal projections above IP are instances of cP (“little cP”). The topmost “little” c° has an occurrence feature that enables extraction but bars spell...

  7. Is CP a gauge symmetry?

    International Nuclear Information System (INIS)

    Choi, K.; Kaplan, D.B.; Nelson, A.E.

    1993-01-01

    Conventional solutions to the strong CP problem all require the existence of global symmetries. However, quantum gravity may destroy global symmetries, making it hard to understand why the electric dipole moment of the neutron (EDMN) is so small. We suggest here that CP is actually a discrete gauge symmetry, and is therefore not violated by quantum gravity. We show that four-dimensional CP can arise as a discrete gauge symmetry in theories with dimensional compactification, if the original number of Minkowski dimensions equals 8k+1, 8k+2 or 8k+3, and if there are certain restrictions on the gauge group; these conditions are met by superstrings. CP may then be broken spontaneously below 10 9 GeV, explaining the observed CP violation in the kaon system without inducing a large EDMN. We discuss the phenomenology of such models, as well as the peculiar properties of cosmic 'SP strings' which could be produced at the compactification scale. Such strings have the curious property that a particle carried around the string is turned into its CP conjugate. A single CP string renders four-dimensional space-time nonorientable. (orig.)

  8. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Zhibin Song

    2011-09-01

    Full Text Available Regenerative braking is an effective approach for electric vehicles (EVs to extend their driving range. A fuzzy-logic-based regenerative braking strategy (RBS integrated with series regenerative braking is developed in this paper to advance the level of energy-savings. From the viewpoint of securing car stability in braking operations, the braking force distribution between the front and rear wheels so as to accord with the ideal distribution curve are considered to prevent vehicles from experiencing wheel lock and slip phenomena during braking. Then, a fuzzy RBS using the driver’s braking force command, vehicle speed, battery SOC, battery temperature are designed to determine the distribution between friction braking force and regenerative braking force to improve the energy recuperation efficiency. The experimental results on an “LF620” prototype EV validated the feasibility and effectiveness of regenerative braking and showed that the proposed fuzzy RBS was endowed with good control performance. The maximum driving range of LF620 EV was improved by 25.7% compared with non-RBS conditions.

  9. Friction and Braking Application of Unhazardous Palm Slag Brake Pad Composite

    Science.gov (United States)

    Khoni, Norizzahthul Ainaa Abdul; Ruzaidi Ghazali, Che Mohd; Bakri Abdullah, Mohd Mustafa Al

    2018-03-01

    This paper reveals new alternative friction materials for brake pads. Palm slag was studied as new friction materials in brake pads but its much harder made it difficult to be applied. As a way to reduce the hardness, tire dust was including as purpose on stabilizing the hardness of brake pads. The palm slag was sieves to get desired size that is 150 μm, 300 μm and 600 μm. The percentage weight of materials used are 20% graphite, 20% aluminium oxide, 20% steel fiber, 20% polyester resin and another 40% are varied between tire dust and palm slag. All of materials were blend and compress by using hot pressed machine. The composites properties that were examined are density, porosity, hardness, compressive strength, microstructure analysis and wear rate. The composition of 30% palm slag, 10% tire dust and larger size of filler give better result of mechanical properties and less wear rate of brake pads composites. Then, palm slag can be used in producing of non asbestos brake pads.

  10. On the interpretation of pulsar braking indices

    International Nuclear Information System (INIS)

    Blandford, R.D.; Romani, R.W.

    1988-01-01

    Timing observations of the Crab pulsar rotation frequency of sufficient accuracy and duration to allow a 10 per cent estimate of the third frequency derivative have been reported (Lyne et al. 1988. Mon. Not. R. astr. Soc., 233, 667). This measurement is consistent with both non-dipolar electromagnetic models and a secular change in the dipole moment. A more accurate determination may discriminate between these two possibilities. Measurements of braking indices in other young pulsars may reveal similar variations. (author)

  11. Flavour Physics and CP Violation

    CERN Document Server

    Fleischer, Robert

    2006-01-01

    The starting point of these lectures is an introduction to the weak interactions of quarks and the Standard-Model description of CP violation, where the central role is played by the Cabibbo-Kobayashi-Maskawa matrix and the corresponding unitarity triangles. Since the B-meson system will govern the stage of (quark) flavour physics and CP violation in this decade, it will be our main focus. We shall classify B-meson decays, introduce the theoretical tools to deal with them, investigate the requirements for non-vanishing CP-violating asymmetries, and discuss the main strategies to explore CP violation and the preferred avenues for physics beyond the Standard Model to enter. This formalism is then applied to discuss the status of important B-factory benchmark modes, where we focus on puzzling patterns in the data that may indicate new-physics effects, as well as the prospects for B-decay studies at the LHC.

  12. Flavour physics and CP violation

    Indian Academy of Sciences (India)

    status and prospectives of the flavour physics associated with the strange, charm and .... might reveal something completely unexpected. Standard Model weak ..... Thus, in order to have an observable CP violation effect in the SM, the mixing.

  13. Discussion on stochastic braking for a single-rail rope-driven lifter

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-01

    This paper discusses the braking and control of a A-2/73 clip type friction brake system made in FRG - a clamp type brake system made in USSR and an eccentric wheel type brake system made in Poland. Then it analyses a ZGZ auto increasing force type braking system of a single-rail rope driven lifter. The braking principle of the ZGZ system is that the braking blocks insert along the brake base and contact with the ribs of the single-rail. Then the braking would be realized as a function of increasing frictional force.

  14. A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand

    Science.gov (United States)

    Wolff, Andrzej

    2010-01-01

    The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperature distributions in brake rotors (disc and drum brake) of a light truck have been calculated. As a preliminary consistency criterion of the brake thermal state in road and roll-stand braking conditions, a balance of the energy cumulated in the brake rotor has been taken into account. As the most reliable consistency criterion an equality of average temperatures of the friction surface has been assumed. The presented method allows to achieve on a roll-stand the analogical thermal states of automotive brakes, which are observed during braking in road conditions. Basing on this method, it is possible to calculate the braking time and force for a high-speed roll-stand. In contrast to the previous papers of the author, new calculation results have been presented.

  15. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Science.gov (United States)

    2010-10-01

    ... reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... 49 Transportation 4 2010-10-01 2010-10-01 false Train brake tests conducted using yard air. 232... Train brake tests conducted using yard air. (a) When a train air brake system is tested from a yard air...

  16. Elastoplastic finite element analysis for wet multidisc brake during lasting braking

    Directory of Open Access Journals (Sweden)

    Ji Zhanling

    2015-01-01

    Full Text Available Addressed to serious heat degradation problem of the braking continuously performed in the drag brake application for a long time, finite element analysis for bidirectional thermal-structure coupling is adopted to investigate temperature and stress when material properties are temperature-dependent. Based on the constitutive relations of heat transfer and strain-stress, three-dimensional transient finite element equilibrium equations with many kinds of boundary conditions for bidirectional thermal-structure coupling were derived. And it was originally presented that start time, location, severity and evolution laws of plastic deformation were depicted using dimensionless stress distribution contour with the yield limit related to temperature. The change laws of plastic element number and contact area versus braking time were expressed by plasticity ratio and contact ratio curves, respectively. The laws revealed by the numerical calculation results are in accordance with the objective perception and reasoning.

  17. Practical Use of the Braking Attributes Measurements Results

    Directory of Open Access Journals (Sweden)

    Ondruš Ján

    2017-01-01

    Full Text Available This contribution deals with issues of braking the passenger car. The measurement of braking deceleration of the vehicle Kia Cee´d 1,6 16 V was carried out by an optical device Correvit system. The measurement was carried out on the airport of the village of Rosina located close to Zilina. 10 drivers of different age, praxis, and kilometers driven participated in the measurement. The measured process was the vehicle full braking with the service brake of the initial speed of approximately 50 km.h-1. Each of the drivers had 10 attempts. In the closure of this contribution the results of the performed measurements, their evaluation and comparison are presented. Practical result from the contribution is mainly the measurement set of braking deceleration of the respective vehicle during intensive braking.

  18. In-depth analysis of bicycle hydraulic disc brakes

    Science.gov (United States)

    Maier, Oliver; Györfi, Benedikt; Wrede, Jürgen; Arnold, Timo; Moia, Alessandro

    2017-10-01

    Hydraulic Disc Brakes (HDBs) represent the most recent and innovative bicycle braking system. Especially Electric Bicycles (EBs), which are becoming more and more popular, are equipped with this powerful, unaffected by environmental influences, and low-wear type of brakes. As a consequence of the high braking performance, typical bicycle braking errors lead to more serious accidents. This is the starting point for the development of a Braking Dynamics Assistance system (BDA) to prevent front wheel lockup and nose-over (falling over the handlebars). One of the essential prerequisites for the system design is a better understanding of bicycle HDBs' characteristics. A physical simulation model and a test bench have been built for this purpose. The results of the virtual and real experiments conducted show a high correlation and allow valuable insights into HDBs on bicycles, which have not been studied scientifically in any depth so far.

  19. The Friction of Vehicle Brake Tandem Master Cylinder

    International Nuclear Information System (INIS)

    Kao, M J; Chang, H; Tsung, T T; Lin, H M

    2006-01-01

    The behaviour of an elastomeric seal for vehicle brake Tandem master cylinder is measured and analyzed in temperature and brake fluids changed. Working conditions are simulated for different piston rod velocity and cylinder supply pressure, in temperature rising, brakefluid boundary and Nanoaluminum oxide brakefluid oxide brakefluid lubrication. The result shows that Nanoaluminum oxide brakefluid with its ball shape can highly reduce friction coefficient to avoid seal excessive wear and reduce slick slip in brake applications

  20. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    Science.gov (United States)

    Minh, Vu Trieu; Oamen, Godwin; Vassiljeva, Kristina; Teder, Leo

    2016-11-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. This paper provides educational theories and practices on the design of control for system dynamics.

  1. Modeling thermal effects in braking systems of railway vehicles

    Directory of Open Access Journals (Sweden)

    Milošević Miloš S.

    2012-01-01

    Full Text Available The modeling of thermal effects has become increasingly important in product design in different transport means, road vehicles, airplanes, railway vehicles, and so forth. The thermal analysis is a very important stage in the study of braking systems, especially of railway vehicles, where it is necessary to brake huge masses, because the thermal load of a braked railway wheel prevails compared to other types of loads. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of railway wheels. Thus induced thermal loads determine thermomechanical behavior of the structure of railway wheels. In cases of thermal overloads, which mainly occur as a result of long-term braking on down-grade railroads, the generation of stresses and deformations occurs, whose consequences are the appearance of cracks on the rim of a wheel and the final total wheel defect. The importance to precisely determine the temperature distribution caused by the transfer process of the heat generated during braking due to the friction on contact surfaces of the braking system makes it a challenging research task. Therefore, the thermal analysis of a block-braked solid railway wheel of a 444 class locomotive of the national railway operator Serbian Railways is processed in detail in this paper, using analytical and numerical modeling of thermal effects during long-term braking for maintaining a constant speed on a down-grade railroad.

  2. Evaluation of materials and design modifications for aircraft brakes

    Science.gov (United States)

    Ho, T. L.; Kennedy, F. E.; Peterson, M. B.

    1975-01-01

    A test program is described which was carried out to evaluate several proposed design modifications and several high-temperature friction materials for use in aircraft disk brakes. The evaluation program was carried out on a specially built test apparatus utilizing a disk brake and wheel half from a small het aircraft. The apparatus enabled control of brake pressure, velocity, and braking time. Tests were run under both constant and variable velocity conditions and covered a kinetic energy range similar to that encountered in aircraft brake service. The results of the design evaluation program showed that some improvement in brake performance can be realized by making design changes in the components of the brake containing friction material. The materials evaluation showed that two friction materials show potential for use in aircraft disk brakes. One of the materials is a nickel-based sintered composite, while the other is a molybdenum-based material. Both materials show much lower wear rates than conventional copper-based materials and are better able to withstand the high temperatures encountered during braking. Additional materials improvement is necessary since both materials show a significant negative slope of the friction-velocity curve at low velocities.

  3. Measuring $CP$ violation with $\\Delta A_{CP}$ at LHCb

    CERN Document Server

    Pearce, Alex

    2014-01-01

    The control of systematic uncertainties is a key component of many analyses performed at the Large Hadron Collider, and will only become more important as more data are taken during Run II. Many of the CP measurements performed using the LHCb detector have statistical precisions below the per cent level, and so particular care must be taken in this area. One technique for dealing with the various production and detection asymmetries which can mask the physics asymmetry of interest, and increase the measurement’s systematic uncertainty, is $\\Delta A_{CP}$ . The application of $\\Delta A_{CP}$ in three separate LHCb analyses of $D^{0}$ and $\\Lambda_{b}^{0}$ decays will be discussed, along with prospects for applying the technique to $\\Lambda_{c}^{+}$ decays.

  4. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle.

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  5. Optimal design of a novel configuration of MR brake with coils placed on the side housings

    Science.gov (United States)

    Nguyen, Quoc Hung; Nguyen, Ngoc Diep; Choi, Seung-Bok

    2014-03-01

    It is well known that in design of traditional magneto-rheological brake (MRB), coils are placed on the cylindrical housing of the brake. In this study, a new configuration of MR brake with coils placed on the side housings of the brake is proposed and analyzed. After briefly explaining the operating principle of the proposed configuration, the braking torque of the MR brake is analyze based on Bingham-plastic rheological model of MR fluid. The optimization of the proposed and conventional MR brakes is then performed considering maximum braking torque and mass of the brake. Based on the optimal results, a comparison between the proposed MR brakes and the conventional ones is undertaken. In addition, experimental test of the MR brakes is conducted and the results are presented in order to validate the performance characteristics of the proposed MR brake.

  6. CpG + CpNpG Analysis of Protein-Coding Sequences from Tomato

    DEFF Research Database (Denmark)

    Hobolth, Asger; Nielsen, Rasmus; Wang, Ying

    2006-01-01

    We develop codon-based models for simultaneously inferring the mutational effects of CpG and CpNpG methylation in coding regions. In a data set of 369 tomato genes, we show that there is very little effect of CpNpG methylation but a strong effect of CpG methylation affecting almost all genes. We...... further show that the CpNpG and CpG effects are largely uncorrelated. Our results suggest different roles of CpG and CpNpG methylation, with CpNpG methylation possibly playing a specialized role in defense against transposons and RNA viruses....

  7. Safety valve including a hydraulic brake and hydraulic brake that could be fitted into a valve

    International Nuclear Information System (INIS)

    Chabat-Courrede, Jean.

    1981-01-01

    Making of a safety valve that can be fitted to a containment vessel filled with a non compressible fluid, such as the water system of a nuclear power station. It includes a hydraulic brake located between the valve and the elastic means, close to the valve which completely suppresses the high frequency oscillations of the equipment [fr

  8. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    OpenAIRE

    Jian-ping Wen; Chuan-wei Zhang

    2015-01-01

    In order to improve energy utilization rate of battery-powered electric vehicle (EV) using brushless DC machine (BLDCM), the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO) to observe actual braking current and the unknown disturbances of regenerative braking system, ...

  9. Indonesian commercial bus drum brake system temperature model

    International Nuclear Information System (INIS)

    Wibowo, D. B.; Haryanto, I.; Laksono, N. P.

    2016-01-01

    Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

  10. Indonesian commercial bus drum brake system temperature model

    Science.gov (United States)

    Wibowo, D. B.; Haryanto, I.; Laksono, N. P.

    2016-03-01

    Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

  11. Indonesian commercial bus drum brake system temperature model

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo, D. B., E-mail: rmt.bowo@gmail.com; Haryanto, I., E-mail: ismoyo2001@yahoo.de; Laksono, N. P., E-mail: priyolaksono89@gmail.com [Mechanical Engineering Dept., Faculty of Engineering, Diponegoro University (Indonesia)

    2016-03-29

    Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

  12. Finding CP-violating Higgses

    OpenAIRE

    Kalinowski, Jan

    1999-01-01

    In a general two-Higgs-doublet model with CP violation in the Higgs sector, the three neutral physical Higgs bosons have no definite CP properties. A new sum rule relating Yukawa and Higgs-Z couplings implies that a neutral Higgs boson cannot escape detection at an e^+e^- collider if it is kinematically accessible in Z+Higgs, $b\\bar b+$Higgs and $t\\bar t+$Higgs production, irrespective of the mixing angles and the masses of the other neutral Higgs bosons. The implications of the sum rules for...

  13. On the strong CP problem

    Energy Technology Data Exchange (ETDEWEB)

    Dowrick, N.J. (Dept. of Physics, Oxford (United Kingdom)); McDougall, N.A. (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan))

    1992-07-09

    We show that two well-known solutions to the strong CP problem, the axion and a massless quark, may be understood in terms of the mechanism recently proposed by Samuel where long-range interactions between topological charges may be responsible for the removal of CP violation. We explain how the axion and a QCD meson (identified as the {eta}' if all quarks are massless) suppress fluctuations in global topological charge by almost identical dynamical although the masses, couplings and relevant length scales are very different. Furthermore, we elucidate the precise origin of the {eta}' mass. (orig.).

  14. Pentiptycene-derived light-driven molecular brakes: substituent effects of the brake component.

    Science.gov (United States)

    Sun, Wei-Ting; Huang, Yau-Ting; Huang, Guan-Jhih; Lu, Hsiu-Feng; Chao, Ito; Huang, Shou-Ling; Huang, Shing-Jong; Lin, Ying-Chih; Ho, Jinn-Hsuan; Yang, Jye-Shane

    2010-10-11

    Five pentiptycene-derived stilbene systems (1 R; R = H, OM, NO, Pr, and Bu) have been prepared and investigated as light-driven molecular brakes that have different-sized brake components (1 Hbrake component in the trans form ((E)-1 R), which corresponds to the brake-off state. When the brake is turned on by photoisomerization to the cis form ((Z)-1 R), the pentiptycene rotation can be arrested on the NMR spectroscopic timescale at temperatures that depend on the brake component. In the cases of (Z)-1 NO, (Z)-1 Pr, and (Z)-1 Bu, the rotation is nearly blocked (k(rot)=2-6 s(-1)) at 298 K. It is also demonstrated that the rotation is slower in [D(6)]DMSO than in CD(2)Cl(2). A linear relationship between the free energies of the rotational barrier and the steric parameter A values is present only for (Z)-1 H, (Z)-1 OM, and (Z)-1 NO, and it levels off on going from (Z)-1 NO to (Z)-1 Pr and (Z)-1 Bu. DFT calculations provide insights into the substituent effects in the rotational ground and transition states. The molar reversibility of the E-Z photoswitching is up to 46%, and both the E and Z isomers are stable under the irradiation conditions. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. New Structure Design and Simulation of Brake by Wire System Based on Giant-magnetostrictive Material

    Directory of Open Access Journals (Sweden)

    Changbao CHU

    2014-04-01

    Full Text Available Existing electronic mechanical brake by wire system has several disadvantages. For instance, system actuators are complex, response speed slower, larger vibration noise, etc. This paper discusses a new type brake by wire system based on giant-magnetostrictive material. The new type brake by wire system model was set up under Matlab/Simulink software environment. PID control method was used to control the brake by wire system. Simulation results shows that the new type brake by wire system achieves better braking performance compared with hydraulic braking system. This work provides a new idea for researching automobile brake by wire system.

  16. Braking system for use with an arbor of a microscope

    International Nuclear Information System (INIS)

    Norgren, D.U.

    1984-01-01

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location

  17. Development of a multi-pole magnetorheological brake

    International Nuclear Information System (INIS)

    Shiao, Yaojung; Nguyen, Quang-Anh

    2013-01-01

    This paper presents a new approach in the design and optimization of a novel multi-pole magnetorheological (MR) brake that employs magnetic flux more effectively on the surface of the rotor. MR brakes with conventional single ring-type electromagnetic poles have reached the limits of torque enhancement. One major reason is the limitation of the magnetic field strength within the active area of the MR fluid due to the geometric constraints of the coil. The multi-pole MR brake design features multiple electromagnetic poles surrounded by several coils. As a result, the active chaining areas for the MR fluid are greatly increased, and significant brake torque improvement is achieved. The coil structure, as a part of the stator, becomes flexible and customizable in terms of space usage for the winding and bobbin design. In addition, this brake offers extra options in its dimensions for torque enhancement because either the radial or the axial dimensions of the rotor can be increased. Magnetic circuit analysis was conducted to analyze the effects of the design parameters on the field torque. After that, simulations were done to find the optimal design under all major geometric constraints with a given power supply. The results show that the multi-pole MR brake provides a considerable braking torque increase while maintaining a compact and solid design. This is confirmation of its feasibility in actual braking applications. (paper)

  18. The antilock braking system anomaly: a drinking driver problem?

    Science.gov (United States)

    Harless, David W; Hoffer, George E

    2002-05-01

    Antilock braking systems (ABS) have held promise for reducing the incidence of accidents because they reduce stopping times on slippery surfaces and allow drivers to maintain steering control during emergency braking. Farmer et al. (Accident Anal. Prevent. 29 (1997) 745) provide evidence that antilock brakes are beneficial to nonoccupants: a set of 1992 model General Motors vehicles equipped with antilock brakes were involved in significantly fewer fatal crashes in which occupants of other vehicles, pedestrians, or bicyclists were killed. But, perversely, the risk of death for occupants of vehicles equipped with antilock brakes increased significantly after adoption. Farmer (Accident Anal. Prevent. 33 (2001) 361) updates the analysis for 1996- 1998 and finds a significant attenuation in the ABS anomaly. Researchers have put forward two hypotheses to explain this antilock brake anomaly: risk compensation and improper operation of antilock brake-equipped vehicles. We provide strong evidence for the improper operation hypothesis by showing that the antilock brake anomaly is confined largely to drinking drivers. Further, we show that the attenuation phenomenon occurs consistently after the first three to four years of vehicle service.

  19. Braking system for use with an arbor of a microscope

    Science.gov (United States)

    Norgren, Duane U.

    1984-01-01

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  20. Modified hydraulic braking system limits angular deceleration to safe values

    Science.gov (United States)

    Briggs, R. S.; Council, M.; Green, P. M.

    1966-01-01

    Conventional spring actuated, hydraulically released, fail-safe disk braking system is modified to control the angular deceleration of a massive antenna. The hydraulic system provides an immediate preset pressure to the spring-loaded brake shoes and holds it at this value to decelerate the antenna at the desired rate.

  1. Compressed gas system operates semitrailer brakes during winching operation

    Science.gov (United States)

    Tupper, W. E.

    1964-01-01

    To move van-type semi-trailers into and out of confined spaces, an auxiliary braking system is mounted on a standard dolly converter. Compressed nitrogen is used to actuate the brakes which are used in conjunction with a power winch.

  2. Ileal brake activation: macronutrient-specific effects on eating behavior?

    NARCIS (Netherlands)

    Avesaat, van M.; Troost, F.J.; Ripken, D.; Hendriks, H.F.; Masclee, A.A.M.

    2015-01-01

    Background:Activation of the ileal brake, by infusing lipid directly into the distal part of the small intestine, alters gastrointestinal (GI) motility and inhibits food intake. The ileal brake effect on eating behavior of the other macronutrients is currently unknown.Objective:The objective of this

  3. Ileal brake activation: Macronutrient-specific effects on eating behavior?

    NARCIS (Netherlands)

    Avesaat, M. van; Troost, F.J.; Ripken, D.; Hendriks, H.F.; Aam, M.

    2015-01-01

    BACKGROUND: Activation of the ileal brake, by infusing lipid directly into the distal part of the small intestine, alters gastrointestinal (GI) motility and inhibits food intake. The ileal brake effect on eating behavior of the other macronutrients is currently unknown. OBJECTIVE: The objective of

  4. 16 CFR 1512.5 - Requirements for braking system.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for braking system. 1512.5 Section 1512.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT... dimension between the brake hand lever and the handlebars in the plane containing the centerlines of the...

  5. 49 CFR 238.317 - Class II brake test.

    Science.gov (United States)

    2010-10-01

    ....315(a)(1); (3) When previously tested units (i.e., cars that received a Class I brake test within the... hours) are added to the train; (4) When cars or equipment are removed from the train; and (5) When an... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic...

  6. Metal-bending brake facilitates lightweight, close-tolerance fabrication

    Science.gov (United States)

    Ercoline, A. L.; Wilton, K. B.

    1964-01-01

    A lightweight, metal bending brake ensures very accurate bends. Features of the brake that adapt it for making complex reverse bends to close tolerances are a pronounced relief or cutaway of the underside of the bodyplate combined with modification in the leaf design and its suspension.

  7. 14 CFR 25.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 25.493 Section 25.493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.493 Braked roll conditions. (a...

  8. 30 CFR 57.19006 - Automatic hoist braking devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic hoist braking devices. 57.19006 Section 57.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 57.19006 Automatic hoist braking devices. Automatic hoists shall be provided with devices...

  9. 30 CFR 56.19006 - Automatic hoist braking devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic hoist braking devices. 56.19006 Section 56.19006 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Hoisting Hoists § 56.19006 Automatic hoist braking devices. Automatic hoists shall be provided with devices...

  10. IR-camera methods for automotive brake system studies

    Science.gov (United States)

    Dinwiddie, Ralph B.; Lee, Kwangjin

    1998-03-01

    Automotive brake systems are energy conversion devices that convert kinetic energy into heat energy. Several mechanisms, mostly related to noise and vibration problems, can occur during brake operation and are often related to non-uniform temperature distribution on the brake disk. These problems are of significant cost to the industry and are a quality concern to automotive companies and brake system vendors. One such problem is thermo-elastic instabilities in brake system. During the occurrence of these instabilities several localized hot spots will form around the circumferential direction of the brake disk. The temperature distribution and the time dependence of these hot spots, a critical factor in analyzing this problem and in developing a fundamental understanding of this phenomenon, were recorded. Other modes of non-uniform temperature distributions which include hot banding and extreme localized heating were also observed. All of these modes of non-uniform temperature distributions were observed on automotive brake systems using a high speed IR camera operating in snap-shot mode. The camera was synchronized with the rotation of the brake disk so that the time evolution of hot regions could be studied. This paper discusses the experimental approach in detail.

  11. Development of Asbestos - Free Brake Pad Using Bagasse

    Directory of Open Access Journals (Sweden)

    V. S. Aigbodion

    2010-03-01

    Full Text Available Development of asbestos-free brake pad using bagasse was investigated with a view to replace the use of asbestos whose dust is carcinogenic. The bagasse were sieve into sieve grades of 100, 150, 250, 350 and 710µm. the sieve bagasse was used in production of brake pad in ratio of 70%bagasse-30%resin using compression moulding. The properties examined are microstructure analysis, hardness, compressive strength, density, flame resistance, water and oil absorption. The microstructure reveals uniform distribution of resin in the bagasse. The results obtained showed that the finer the sieve size the better the properties. The results obtained in this work were compared with that of commercial brake pad (asbestos based and optimum formulation laboratory brake pad Palm Kernel Shell based (PKS, the results are in close agreement. Hence bagasse can be used in production of asbestos-free brake pad.

  12. CP violation in B decays

    International Nuclear Information System (INIS)

    Quinn, H.R.

    1994-02-01

    She reviews how one can test the Standard Model predictions for CP violation. This test requires sufficient independent measurements to overconstrain the model parameters and thus be sensitive to possible beyond Standard Model contributions. She addresses the challenges for theory as well as for experiment to achieve such a test

  13. CP Violation and B Physics

    International Nuclear Information System (INIS)

    Quinn, Helen R

    2001-01-01

    These lectures provide a basic overview of topics related to the study of CP Violation in B decays. In the first lecture, I review the basics of discrete symmetries in field theories, the quantum mechanics of neutral but flavor-non-trivial mesons, and the classification of three types of CP violation [1]. The actual second lecture which I gave will be separately published as it is my Dirac award lecture and is focused on the separate topic of strong CP Violation. In Lecture 2 here, I cover the Standard Model predictions for neutral B decays, and in particular discuss some channels of interest for CP Violation studies. Lecture 3 reviews the various tools and techniques used to deal with the hadronic physics effects. In Lecture 4, I briefly review the present and planned experiments that can study B decays. I cannot teach all the details of this subject in this short course, so my approach is instead to try to give students a grasp of the relevant concepts and an overview of the available tools. The level of these lectures is introductory. I will provide some references to more detailed treatments and current literature, but this is not a review article so I do not attempt to give complete references to all related literature. By now there are some excellent textbooks that cover this subject in great detail [1]. I refer students to these for more details and for more complete references to the original literature

  14. B physics and CP violation

    International Nuclear Information System (INIS)

    Quinn, H.

    2002-01-01

    These lectures provide a basic overview of topics related to the study of CP Violation in B decays. In the first lecture, I review the basics of discrete symmetries in field theories, the quantum mechanics of neutral but flavor-non-trivial mesons, and the classification of three types of CP violation. The actual second lecture which I gave will be separately published as it is my Dirac award lecture and is focussed on the separate topic of strong CP Violation. In Lecture 2 here, I cover the Standard Model predictions for neutral B decays, and in particular discuss some channels of interest for CP Violation studies. Lecture 3 reviews the various tools and techniques used to deal with the hadronic physics effects. In Lecture 4, I briefly review the present and planned experiments that can study B decays. I cannot teach all the details of this subject in this short course, so my approach is instead to try to give students a grasp of the relevant concepts and an overview of the available tools. The level of these lectures is introductory. I will provide some references to more detailed treatments and current literature, but this is not a review article so I do not attempt to give complete references to all related literature. By now there are some excellent textbooks that cover this subject in great detail. I refer students to these for more details and for more complete references to the original literature. (author)

  15. Flavour Physics and CP Violation

    CERN Document Server

    Fleischer, Robert

    2005-01-01

    The starting point of these lectures is an introduction to the weak interactions of quarks and the Standard-Model description of CP violation, where the key element is the Cabibbo--Kobayashi--Maskawa matrix and the corresponding unitarity triangles. Since the B-meson system will govern the stage of (quark) flavour physics and CP violation in this decade, it will be -- after a brief look at the kaon system -- our main focus. We shall classify B-meson decays, introduce the theoretical tools to deal with them, explore the requirements for non-vanishing CP-violating asymmetries, and discuss B^0_q--B^0_q_bar mixing (q={d,s}). We will then turn to B-factory benchmark modes, discuss the physics potential of B^0_s mesons, which is particularly promising for B-decay experiments at hadron colliders, and emphasize the importance of studies of rare decays, which are absent at the tree level in the Standard Model, complement nicely the studies of CP violation, and provide interesting probes for new physics.

  16. CP violation in neutral B decays to non-CP-eigenstates

    International Nuclear Information System (INIS)

    Kayser, B.

    1992-01-01

    If CP violation comes from complex phases in the quark mixing matrix, then neutral B decays to CP eigenstates will exhibit large, cleanly-predicted CP-violating effects. The authors show that the same is true of neutral B decays to several types of ''near-CP-eigenstates.'' By experimentally studying the latter decays as well as those to the CP eigenstates, one will be able to obtain more definitive information on CP violation from a given number of B mesons

  17. Radial brake assembly for a control rod drive

    International Nuclear Information System (INIS)

    Hekmati, A.; Gibo, E.Y.

    1992-01-01

    This patent describes a brake assembly for a control rod drive for selectively preventing travel of a control rod in a nuclear reactor vessel. It comprises a shaft having a longitudinal centerline axis; means for selectively rotating the shaft in a first direction and in a second direction, opposite to the first direction; a stationary housing having a central aperture receiving the shaft; a frame fixedly joined to the housing and having a guide hole; a rotor disc fixedly connected to the shaft for rotation therewith and having at least one rotor tooth extending radially outwardly from a perimeter thereof, the rotor tooth having a locking surface and an inclined surface extending therefrom in a circumferential direction; a brake member disposed adjacent to the rotor disc perimeter and including a base, at least one braking tooth having a locking surface extending therefrom in a circumferential direction, and a plunger extending radially outwardly from the base and slidably joined to the frame through the guide hole; the rotor tooth and the braking tooth being complementary to each other; and means for selectively positioning the brake member in a deployed position abutting the rotor disc perimeter for allowing the braking tooth locking surface to contact the rotor tooth locking surface for preventing rotation of the shaft in the first direction, and in a retracted position spaced radially away from the rotor disc for allowing the rotor disc and the shaft to rotate without restraint from the brake member, the positioning means including a tubular solenoid fixedly joined to the frame and having a central bore disposed around the brake member plunger and effective for sliding the brake member plunger relative to the frame for positioning the brake member in the deployed and retracted positions

  18. Numerical Investigation of Aerodynamic Braking for a Ground Vehicle

    Science.gov (United States)

    Devanuri, Jaya Krishna

    2018-06-01

    The purpose of this article is to observe the effect of an air brake on the aerodynamics of a ground vehicle and also to study the influence of change in the parameters like the velocity of the vehicle, the angle of inclination, height, and position of the air brake on the aerodynamics of the vehicle body. The test subject used is an Ahmed body which is a generic 3D car body as it retains all the aerodynamic characteristics of a ground vehicle. Numerical investigation has been carried out by RNG k-ɛ turbulence model. Results are presented in terms of streamlines and drag coefficient to understand the influence of pertinent parameters on flow physics. It is found that with the use of an air brake, though the drag coefficient remains more or less constant with velocity, it increases with the increase in height and angle of inclination of the air brake. But the effect of position of air brake on the coefficient of drag is surprising since for certain heights of the air brake the drag coefficient is maximum at the foremost point and as the air brake moves towards the rear it is first observed to decrease and then increase. It is also observed that with the increase in height of the air brake the drag coefficient monotonically decreases as the position of the air brake is moved towards the rear. Taguchi method has been employed with L16 orthogonal array to obtain the optimal configuration for the air brake. For each of the selected parameters, four different levels have been chosen to obtain the maximum drag coefficient value. The study could provide an invaluable database for the optimal design of an airbrake for a ground vehicle.

  19. Study on Abrasive Wear of Brake Pad in the Large-megawatt Wind Turbine Brake Based on Deform Software

    Science.gov (United States)

    Zhang, Shengfang; Hao, Qiang; Sha, Zhihua; Yin, Jian; Ma, Fujian; Liu, Yu

    2017-12-01

    For the friction and wear issues of brake pads in the large-megawatt wind turbine brake during braking, this paper established the micro finite element model of abrasive wear by using Deform-2D software. Based on abrasive wear theory and considered the variation of the velocity and load in the micro friction and wear process, the Archard wear calculation model is developed. The influence rules of relative sliding velocity and friction coefficient in the brake pad and disc is analysed. The simulation results showed that as the relative sliding velocity increases, the wear will be more serious, while the larger friction coefficient lowered the contact pressure which released the wear of the brake pad.

  20. EEG potentials predict upcoming emergency brakings during simulated driving

    Science.gov (United States)

    Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

  1. Electronics and braking systems; Elektronik in Bremssystemen

    Energy Technology Data Exchange (ETDEWEB)

    Gaupp, W. [Rheinisch-Westfaelischer Technischer Ueberwachungs-Verein e.V., Essen (Germany). Inst. fuer Fahrzeugtechnik

    2000-02-01

    In addition to the anti-lock braking system ABS, which is now fitted to almost every new passenger car, an increasing number of other control systems which intervene in the vehicle's driving dynamics, such as ASR, DSC or ESP, are being introduced. This article gives an overview of such systems, from their beginnings up to the present-day, and describes future developments. (orig.) [German] Neben das Antiblockiersystem ABS, mit dem heute fast jeder neue Pkw ausgestattet ist, treten zunehmend weitere Regelsysteme, die in die Fahrdynamik des Fahrzeugs eingreifen, wie zum Beispiel ASR, DSC oder ESP. Dieser Beitrag gibt einen Ueberblick von den Anfaengen dieser Systeme bis hin zu zukuenftigen Entwicklungen. (orig.)

  2. Comparisonal Analysis of Manuevering and Braking

    Directory of Open Access Journals (Sweden)

    Artūras Žukas

    2011-04-01

    Full Text Available This article covers the possibility of avoiding a traffic accident considering a car driver who is fallen in a dangerous situation. In such a case, the driver can choose one of the following ways: hard braking or one of the types of maneuvering, including turning off, turning with straightening or changing a line regarding road surface type (dry asphalt, wet asphalt or snowy asphalt. The article also proposes formulas for calculating road distance the car travels till dead stop. Moreover, the tables display theoretical values taking into account various car speeds and road surfaces. The pictures help with determining the most suitable type of action in light of road and weather conditions as well as car speed. The pictures clearly show the dependence of road length on movement speed. At the end of the article, conclusions are proposed.Article in Lithuanian

  3. Flavour physics and CP violation

    CERN Document Server

    Nir, Y.

    2015-05-22

    We explain the many reasons for the interest in flavor physics. We describe flavor physics and the related CP violation within the Standard Model, and explain how the B-factories proved that the Kobayashi-Maskawa mechanism dominates the CP violation that is observed in meson decays. We explain the implications of flavor physics for new physics, with emphasis on the “new physics flavor puzzle”, and present the idea of minimal flavor violation as a possible solution. We explain why the values flavor parameters of the Standard Model are puzzling, present the Froggatt-Nielsen mechanism as a possible solution, and describe how measurements of neutrino parameters are interpreted in the context of this puzzle. We show that the recently discovered Higgs-like boson may provide new opportunities for making progress on the various flavor puzzles.

  4. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2010-03-30

    ... fully develop improved brake systems and also to ensure vehicle control and stability while braking... [Docket No. NHTSA 2009-0175] RIN 2127-AK62 Federal Motor Vehicle Safety Standards; Air Brake Systems... Federal motor vehicle safety standard for air brake systems by requiring substantial improvements in...

  5. 76 FR 55859 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems

    Science.gov (United States)

    2011-09-09

    ... during road tests for the braking system, a vehicle equipped with an interlocking axle system or a front... vehicle braking systems, tire characteristics related to lateral force and longitudinal force generation... stopping distance without activating the ABS system by braking the vehicle so that the brake pressure is...

  6. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Science.gov (United States)

    2010-08-20

    ....121) mandates antilock braking systems (ABS) on all new air-braked vehicles with a GVWR of 10,000...-0116] Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness of Antilock Braking Systems in Heavy Truck Tractors and Trailers AGENCY: National Highway Traffic...

  7. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Science.gov (United States)

    2010-02-03

    ... NHTSA comments S6.2 Wet Equilibrium Boiling Point... Appendix E of SAE J1703 Appendix E of SAE J1703 No.... Definition of ``Brake Fluid'' To apply FMVSS No. 116 to brake fluid that contacts EPDM rubber, we propose to expand the definition of ``brake fluid'' at S4 of the standard to expressly state that ``brake fluid...

  8. Constraints on the CP-Violating MSSM

    CERN Document Server

    Arbey, A; Godbole, R M; Mahmoudi, F

    2016-01-01

    We discuss the prospects for observing CP violation in the MSSM with six CP-violating phases, using a geometric approach to maximise CP-violating observables subject to the experimental upper bounds on electric dipole moments. We consider constraints from Higgs physics, flavour physics, the dark matter relic density and spin-independent scattering cross section with matter.

  9. CP violation without elementary scalar fields

    International Nuclear Information System (INIS)

    Eichten, E.; Lane, K.; Preskill, J.

    1980-04-01

    Dynamically broken gauge theories of electroweak interactions provide a natural mechanism for generating CP violation. Even if all vacuum angles are unobservable, strong CP violation is not automatically avoided. In the absence of strong CP violation, the neutron electric dipole moment is expected to be of order 10 -24 e cm

  10. CP-violations in B decays

    Indian Academy of Sciences (India)

    Recent results on CP-violation measurements in decays from energy asymmetric -factory experiments are reported. Thanks to large accumulated data samples, CP-violations in decays in mixing-decay interference and direct CP-violation are now firmly established. The measurements of three angles of the unitarity ...

  11. ANNIVERSARY: 25 years without CP

    International Nuclear Information System (INIS)

    Riordan, Michael

    1989-01-01

    In 1964 a small group of Princeton University physicists led by Jim Cronin and Val Fitch performed a landmark experiment at Brookhaven. Using a double-arm spectrometer, they showed that long-lived neutral kaons occasionally decayed into a pair of pions - violating the hitherto sacrosanct CP symmetry of combined mirror reflection and particle-antiparticle switching. From May 21-26 scientists gathered at the Chateau de Blois, southwest of Paris, to celebrate the 25th anniversary of this achievement

  12. ANNIVERSARY: 25 years without CP

    Energy Technology Data Exchange (ETDEWEB)

    Riordan, Michael

    1989-07-15

    In 1964 a small group of Princeton University physicists led by Jim Cronin and Val Fitch performed a landmark experiment at Brookhaven. Using a double-arm spectrometer, they showed that long-lived neutral kaons occasionally decayed into a pair of pions - violating the hitherto sacrosanct CP symmetry of combined mirror reflection and particle-antiparticle switching. From May 21-26 scientists gathered at the Chateau de Blois, southwest of Paris, to celebrate the 25th anniversary of this achievement.

  13. New look at CP violation

    International Nuclear Information System (INIS)

    Iqbal, M.J.; Miller, G.A.

    1990-01-01

    The CP-violating (CPV) kaonic matrix elements ε', ImA 0 , and ImA 2 are used to compute CPV observables in baryonic systems. The numerical results for the electric dipole moment and the difference between Λ and bar Λ decay parameters are similar to other approaches that use quark operators. Relations between the neutron electric dipole moment, CPV pion-nucleon coupling constants, and Λ-decay parameters are derived

  14. Cytosine methylation at CpCpG sites triggers accumulation of non-CpG methylation in gene bodies

    OpenAIRE

    Zabet, NR; Catoni, Marco; Prischi, F; Paszkowski, Jerzy Waclaw

    2017-01-01

    Methylation of cytosine is an epigenetic mark involved in the regulation of transcription, usually associated with transcriptional repression. In mammals, methylated cytosines are found predominantly in CpGs but in plants non-CpG methylation (in the CpHpG or CpHpH contexts, where H is A, C or T) is also present and is associated with the transcriptional silencing of transposable elements. In addition, CpG methylation is found in coding regions of active genes. In the absence of the demethylas...

  15. Quark mixing and CP violation

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1992-01-01

    These lectures present a pedagogical introduction to the topics quark mixing and CP violation. They explain how the mixing matrix comes about and reviews the values of constraints for its elements. The second chapter reviews the CP transformation properties of amplitudes and defines the quantities which are measured in the experiments. Then it reviews the theory of CP violation in the standard model. In addition to the phase and the angles introduced through the flavor matrix, numerical predictions also depend (a) on hadronic matrix elements of weak current operators and (b) the short distance expansion of effective Hamiltonians computed by methods of Quantum Chromodynamics (QCD). I also review these topics and present predictions for (ε'/ε) which are shown to be consistent with the experiments. Last but not least, the article is divided into sections which are as self-contained as possible. The article assumes a general knowledge of the electroweak theory. For guidance, the interested reader will find a table of contents at the end of the text. (author). 29 refs, 5 figs, 1 tab

  16. CP violation experiment at Fermilab

    International Nuclear Information System (INIS)

    Hsiung, Yee B.

    1990-07-01

    The E731 experiment at Fermilab has searched for ''direct'' CP violation in K 0 → ππ, which is parametrized by var-epsilon '/var-epsilon. For the first time, in 20% of the data set, all four modes of the K L,S → π + π - (π 0 π 0 ) were collected simultaneously, providing a great check on the systematic uncertainty. The result is Re(var-epsilon '/var-epsilon) = -0.0004 ± 0.0014 (stat) ± 0.0006(syst), which provides no evidence for ''direct'' CP violation. The CPT symmetry has also been tested by measuring the phase difference Δφ = φ 00 - φ ± between the two CP violating parameters η 00 and η ± . We fine Δφ = -0.3 degrees ± 2.4 degree(stat) ± 1.2 degree(syst). Using this together with the world average φ ± , we fine that the phase of the K 0 -bar K 0 mixing parameter var-epsilon is 44.5 degree ± 1.5 degree. Both of these results agree well with the predictions of CPT symmetry. 17 refs., 10 figs

  17. Scania RBS brake system; Das Bremssystem EBS von Scania

    Energy Technology Data Exchange (ETDEWEB)

    Winterhagen, J.

    1996-09-01

    Scania claims to be the first producer of industrial vehicles to market an electronic braking system (EBS) combined with disc brakes for all axles. The new braking systems for long-distance trailers were presented for the first time at the IAA, Hanover, in September 1996. (orig.) [Deutsch] Scania ist nach eigenen Angaben der erste Lkw-Hersteller, der eine elektronisch geregelte Bremsanlage (EBS) in Kombination mit Scheibenbremsen an allen Achsen auf den Markt bringt. Der Oeffentlichkeit stellt Scania das neue Bremssystem fuer die Fernverkehrs-Zugmaschinen der Baureihe 4 zum ersten Mal auf der IAA in Hannover im September 1996 vor. (orig.)

  18. Residual stresses in a cast iron automotive brake disc rotor

    International Nuclear Information System (INIS)

    Ripley, Maurice I.; Kirstein, Oliver

    2006-01-01

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed

  19. Brake lock mechanism for the two axis pointing system

    Science.gov (United States)

    Posey, Alan; Clark, Mike; Mignosa, Larry

    1991-01-01

    Six months prior to shipment of the Broadband X-ray Telescope to the Kennedy Space Center for flight aboard the Space Shuttle Columbia, a major system failure occurred. During modal survey testing of the telescope's gimbal pointing system, the roll axis brake unexpectedly released. Low level vibration and static preloads present during the modal survey were within the expected flight environment. Brake release during shuttle liftoff or ascent was an unacceptable risk to mission success; thus, a Brake Lock Mechanism (BLM) was developed.

  20. Pre-Extreme Automotive Anti-Lock Brake Systems

    Directory of Open Access Journals (Sweden)

    V. G. Ivanov

    2004-01-01

    Full Text Available Designing of systems ensuring active safety of automobiles with intellectual functions requires usage of new control principles for wheel and automobile operation. One of such principles is a preextreme control strategy. Its aim is to ensure wheel work in pre-extreme, stable area of «tire grip coefficient wheel slip coefficient» dependence. The simplest realization of pre-extreme control in automotive anti-lock brake systems consists in the threshold and gradient algorithms. A comparative analysis of these algorithms which has been made on simulation results of bus braking with various anti-lock brake systems has revealed their high efficiency.

  1. Gravitational waves from pulsars with measured braking index

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Jose C.N. de; Coelho, Jaziel G.; Costa, Cesar A. [Instituto Nacional de Pesquisas Espaciais, Divisao de Astrofisica, Sao Jose dos Campos, SP (Brazil)

    2016-09-15

    We study the putative emission of gravitational waves (GWs) in particular for pulsars with measured braking index. We show that the appropriate combination of both GW emission and magnetic dipole brakes can naturally explain the measured braking index, when the surface magnetic field and the angle between the magnetic dipole and rotation axes are time dependent. Then we discuss the detectability of these very pulsars by aLIGO and the Einstein Telescope. We call attention to the realistic possibility that aLIGO can detect the GWs generated by at least some of these pulsars, such as Vela, for example. (orig.)

  2. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Jian-ping Wen

    2015-01-01

    Full Text Available In order to improve energy utilization rate of battery-powered electric vehicle (EV using brushless DC machine (BLDCM, the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO to observe actual braking current and the unknown disturbances of regenerative braking system, the autodisturbances rejection controller (ADRC for controlling the braking current is developed. Experimental results show that the proposed method gives better recovery efficiency and is robust to disturbances.

  3. Behavior of aircraft antiskid braking systems on dry and wet runway surfaces: Hydromechanically controlled system

    Science.gov (United States)

    Tanner, J. A.; Stubbs, S. M.; Smith, E. G.

    1981-01-01

    The investigation utilized one main gear wheel, brake, and tire assembly of a McDonnell Douglas DC-9 series 10 airplane. The landing-gear strut was replaced by a dynamometer. During maximum braking, average braking behavior indexes based upon brake pressure, brake torque, and drag-force friction coefficient developed by the antiskid system were generally higher on dry surfaces than on wet surfaces. The three braking behavior indexes gave similar results but should not be used interchangeably as a measure of the braking of this antiskid sytem. During the transition from a dry to a flooded surface under heavy braking, the wheel entered into a deep skid but the antiskid system reacted quickly by reducing brake pressure and performed normally during the remainder of the run on the flooded surface. The brake-pressure recovery following transition from a flooded to a dry surface was shown to be a function of the antiskid modulating orifice.

  4. Some ideas for learning CP-theories

    OpenAIRE

    Fierens, Daan

    2008-01-01

    Causal Probabilistic logic (CP-logic) is a language for describing complex probabilistic processes. In this talk we consider the problem of learning CP-theories from data. We briefly discuss three possible approaches. First, we review the existing algorithm by Meert et al. Second, we show how simple CP-theories can be learned by using the learning algorithm for Logical Bayesian Networks and converting the result into a CP-theory. Third, we argue that for learning more complex CP-theories, an ...

  5. B decays and models for CP violation

    International Nuclear Information System (INIS)

    He, X.

    1996-01-01

    The decay modes B to ππ, ψK S , K - D, πK, and ηK are promising channels to study the unitarity triangle of the CP-violating Cabibbo-Kobayashi-Maskawa (CKM) matrix. In this paper I study the consequences of these measurements in the Weinberg model. I show that using the same set of measurements, the following different mechanisms for CP violation can be distinguished: (1) CP is violated in the CKM sector only; (2) CP is violated spontaneously in the Higgs sector only; and (3) CP is violated in both the CKM and Higgs sectors. copyright 1996 The American Physical Society

  6. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    OpenAIRE

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking s...

  7. Torque Coordination Control during Braking Mode Switch for a Plug-in Hybrid Electric Vehicle

    OpenAIRE

    Yang Yang; Chao Wang; Quanrang Zhang; Xiaolong He

    2017-01-01

    Hybrid vehicles usually have several braking systems, and braking mode switches are significant events during braking. It is difficult to coordinate torque fluctuations caused by mode switches because the dynamic characteristics of braking systems are different. In this study, a new type of plug-in hybrid vehicle is taken as the research object, and braking mode switches are divided into two types. The control strategy of type one is achieved by controlling the change rates of clutch hold-dow...

  8. Enhanced Regenerative Braking Strategies for Electric Vehicles: Dynamic Performance and Potential Analysis

    OpenAIRE

    Boyi Xiao; Huazhong Lu; Hailin Wang; Jiageng Ruan; Nong Zhang

    2017-01-01

    A regenerative braking system and hydraulic braking system are used in conjunction in the majority of electric vehicles worldwide. We propose a new regenerative braking distribution strategy that is based on multi-input fuzzy control logic while considering the influences of the battery’s state of charge, the brake strength and the motor speed. To verify the braking performance and recovery economy, this strategy was applied to a battery electric vehicle model and compared with two other impr...

  9. The intelligent brake: SBS brakes safely and comfortably in all situations; Die intelligente Bremse: SBS verzoegert stets sicher und komfortabel

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-07-01

    The Vision SLR study demonstrates the technology with which DaimlerChrysler vehicles will be equipped in the next century. The car that won the Gran Turismo incorporates the Sensortronic Brake System (SBS), an electrohydraulic braking system for optimum safety and comfort even in critical situations. [German] Die Fahrzeugstudie Vision SLR demonstriert eindrucksvoll die Technik, mit der DaimlerChrysler Fahrzeuge des kommenden Jahrhunderts ausstatten wird. Eine Besonderheit des Gran Turismo-Silberpfeils: das Sensortronic Brake System (SBS), ein elektrohydraulisches Bremssystem, das auch in kritischen Situationen optimale Fahrsicherheit und Komfort bietet. (orig.)

  10. V2 and cP/CP

    DEFF Research Database (Denmark)

    Vikner, Sten; Christensen, Ken Ramshøj; Nyvad, Anne Mette

    2017-01-01

    As in Nyvad et al. (2017), we will explore a particular derivation of (embedded) V2, in terms of a cP/CP-distinction, which may be seen as a version of the CP-recursion analysis (de Haan & Weerman 1986; Vikner 1995 and many others). e idea is that because embedded V2 clauses do not allow extraction......, whereas other types of CP-recursion clauses do (Christensen et al. 2013a; 2013b; Christensen & Nyvad 2014), CP-recursion in embedded V2 is assumed to be fundamentally di erent from other kinds of CP-recursion, in that main clause V2 and embedded V2 involve a CP (“big CP”), whereas other clausal...... projections above IP are instances of cP (“little cP”)....

  11. CP invariance: a point of view

    International Nuclear Information System (INIS)

    Mohan, Gyan

    1983-01-01

    That the longlived component L of K 0 has both CP = +1 and CP = -1 modes of decay is often cited as evidence of violation of CP invariance. The careful ones find the compelling evidence to be the non-dilution of the regeneration interference pattern when the incident K 0 beam is mixed even substantially with anti-K 0 . However the two phenomena comprehensively imply that L has a CP = +1 component Lsub(+) and CP = -1 component Lsub(-) and that the longlived component of both K 0 and anti-K 0 are one and the same L. This does not demand abandoning CP invariance. It does imply that anti-K 0 is not the CP conjugate of K 0 . (author)

  12. Experimental investigation of disc brakes for formula Bharat

    Science.gov (United States)

    Misra, Sheelam; Chandra, Sharad; Bagwadi, Ashutosh

    2018-05-01

    we have made the brake assembly for Formula Student India in which we gathered the information about the force distribution in Master Cylinder, Assembly of Master Cylinder, Disc Brakes, Pedal Assembly has been gathered from various sources in which we come to know about that Vertical Master Cylinder is much better than the Horizontal Master Cylinder because of which we are able to reduce the weight of the Formula Student Car which ultimately affects the performance of the car. In other words, we have considered the various environmental conditions in which this braking system. The dimensions for the Disc Brake rotor is considered according to the space constraints and the material is finalized according to the hunch of calculations and the environmental conditions.

  13. Numerical Modeling of Disc Brake System in Frictional Contact

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2014-03-01

    Full Text Available Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyse the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor by holding account certain parameters such as; the material used, the geometric design of the disc and the mode of braking. The analysis also gives us, the heat flux distribution for the two discs.

  14. Implementation Of Fuzzy Automated Brake Controller Using TSK Algorithm

    Science.gov (United States)

    Mittal, Ruchi; Kaur, Magandeep

    2010-11-01

    In this paper an application of Fuzzy Logic for Automatic Braking system is proposed. Anti-blocking system (ABS) brake controllers pose unique challenges to the designer: a) For optimal performance, the controller must operate at an unstable equilibrium point, b) Depending on road conditions, the maximum braking torque may vary over a wide range, c) The tire slippage measurement signal, crucial for controller performance, is both highly uncertain and noisy. A digital controller design was chosen which combines a fuzzy logic element and a decision logic network. The controller identifies the current road condition and generates a command braking pressure signal Depending upon the speed and distance of train. This paper describes design criteria, and the decision and rule structure of the control system. The simulation results present the system's performance depending upon the varying speed and distance of the train.

  15. Driver Behavioral Changes through Interactions with an Automatic Brake System for Collision Avoidance

    Science.gov (United States)

    Itoh, Makoto; Fujiwara, Yusuke; Inagaki, Toshiyuki

    This paper discusses driver's behavioral changes as a result of driver's use of an automatic brake system for preventing a rear-end collision from occurring. Three types of automatic brake systems are investigated in this study. Type 1 brake system applies a strong automatic brake when a collision is very imminent. Type 2 brake system initiates brake operation softly when a rear-end crash may be anticipated. Types 1 and 2 are for avoidance of a collision. Type 3 brake system, on the other hand, applies a strong automatic brake to reduce the damage when a collision can not be avoided. An experiment was conducted with a driving simulator in order to analyze the driver's possible behavioral changes. The results showed that the time headway (THW) during car following phase was reduced by use of an automatic brake system of any type. The inverse of time to collision (TTC), which is an index of the driver's brake timing, increased by use of Type 1 brake system when the deceleration rate of the lead vehicle was relatively low. However, the brake timing did not change when the drivers used Type 2 or 3 brake system. As a whole, dangerous behavioral changes, such as overreliance on a brake system, were not observed for either type of brake system.

  16. A study on properties of a cone-type brake for motor vehicle winch

    Directory of Open Access Journals (Sweden)

    Dongxu Li

    2016-05-01

    Full Text Available The brake of winch is to prevent the occurrence of reverse slipping at working time. Based on the analysis of two types of brake, this article establishes the relationship model of the brake force and the angle of the screw thread on the brake shaft and builds the model of the relationship of the brake force and the height of the cone and found that the brake force is the largest when the angle of the screw is 45°. Also found that the brake force increases with the increase in the load, and the brake force is positively related to the height of the cone. Two brake mechanisms are manufactured and arranged in the same winch to conduct the experimental performance comparison. The experimental results show that the temperature of the winch with cone brake finally reaches about 60°C, which is 33% lower than the 90°C of the disk brake, and the no-load current of the cone brake winch is under 60 A, while in the disk brake winch it is over 90 A after 7 min, which consumes 33% energy than cone brake. The cone brake can reduce the occurrence of harmful friction and enhance the efficiency of winch and is able to solve the winch safety problem caused by nylon cable damage because of the heat accumulation.

  17. Research study on antiskid braking systems for the space shuttle

    Science.gov (United States)

    Auselmi, J. A.; Weinberg, L. W.; Yurczyk, R. F.; Nelson, W. G.

    1973-01-01

    A research project to investigate antiskid braking systems for the space shuttle vehicle was conducted. System from the Concorde, Boeing 747, Boeing 737, and Lockheed L-1011 were investigated. The characteristics of the Boeing 737 system which caused it to be selected are described. Other subjects which were investigated are: (1) trade studies of brake control concepts, (2) redundancy requirements trade study, (3) laboratory evaluation of antiskid systems, and (4) space shuttle hardware criteria.

  18. Stability Control of Vehicle Emergency Braking with Tire Blowout

    OpenAIRE

    Chen, Qingzhang; Liu, Youhua; Li, Xuezhi

    2014-01-01

    For the stability control and slowing down the vehicle to a safe speed after tire failure, an emergency automatic braking system with independent intellectual property is developed. After the system has received a signal of tire blowout, the automatic braking mode of the vehicle is determined according to the position of the failure tire and the motion state of vehicle, and a control strategy for resisting tire blowout additional yaw torque and deceleration is designed to slow down vehicle to...

  19. Study on real-time elevator brake failure predictive system

    Science.gov (United States)

    Guo, Jun; Fan, Jinwei

    2013-10-01

    This paper presented a real-time failure predictive system of the elevator brake. Through inspecting the running state of the coil by a high precision long range laser triangulation non-contact measurement sensor, the displacement curve of the coil is gathered without interfering the original system. By analyzing the displacement data using the diagnostic algorithm, the hidden danger of the brake system can be discovered in time and thus avoid the according accident.

  20. Braking and cornering studies on an air cushion landing system

    Science.gov (United States)

    Daugherty, R. H.

    1983-01-01

    An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

  1. Development of automobile brake lining using pulverized cow hooves

    Directory of Open Access Journals (Sweden)

    Katsina C. BALA

    2016-06-01

    Full Text Available Asbestos has been used for so long as automobile brake lining material because of its good physical and chemical properties. However, due to the health hazard associated with its handling, it has lost favour and several alternative materials are being increasingly used. Asbestos-free brake lining was developed in this work using pulverized cow hooves along with epoxy resin, barium sulphate, graphite and aluminium oxide. This was with a view to exploiting the characteristics of cow hooves, which are largely discarded as waste materials to replace asbestos which has been found to be carcinogenic. Samples of brake linings were produced using compressive moulding in which the physical and mechanical properties of the samples were studied. The results obtained showed that proper bonding was achieved as the percentage by weight of epoxy resin increased and percentage by weight of pulverized cow hooves decreased. The hardness, compressive strength, coefficient of friction, water and oil absorption, relative density and wear rate of the brake linings were determined and compared with existing brake lining properties. The result indicates that pulverized cow hooves can be used as brake lining material for automobiles.

  2. Braking distance algorithm for autonomous cars using road surface recognition

    Science.gov (United States)

    Kavitha, C.; Ashok, B.; Nanthagopal, K.; Desai, Rohan; Rastogi, Nisha; Shetty, Siddhanth

    2017-11-01

    India is yet to accept semi/fully - autonomous cars and one of the reasons, was loss of control on bad roads. For a better handling on these roads we require advanced braking and that can be done by adapting electronics into the conventional type of braking. In Recent years, the automation in braking system led us to various benefits like traction control system, anti-lock braking system etc. This research work describes and experiments the method for recognizing road surface profile and calculating braking distance. An ultra-sonic surface recognition sensor, mounted underneath the car will send a high frequency wave on to the road surface, which is received by a receiver with in the sensor, it calculates the time taken for the wave to rebound and thus calculates the distance from the point where sensor is mounted. A displacement graph will be plotted based on the output of the sensor. A relationship can be derived between the displacement plot and roughness index through which the friction coefficient can be derived in Matlab for continuous calculation throughout the distance travelled. Since it is a non-contact type of profiling, it is non-destructive. The friction coefficient values received in real-time is used to calculate optimum braking distance. This system, when installed on normal cars can also be used to create a database of road surfaces, especially in cities, which can be shared with other cars. This will help in navigation as well as making the cars more efficient.

  3. Flavor Physics & CP Violation 2015

    Science.gov (United States)

    "Flavor Physics & CP violation 2015" (FPCP 2015) was held in Nagoya, Japan, at Nagoya University, from May 25 to May 29 2015. This is the 13th meeting of the series of annual conferences started in Philadelphia, PA, USA in 2002. The aim of the conference is to review developments in flavor physics and CP violation, in both theory and experiment, exploiting the potential to study new physics at the LHC and future facilities. The topics include CP violation, rare decays, CKM elements with heavy quark decays, flavor phenomena in charged leptons and neutrinos, and also interplay between flavor and LHC high Pt physics. The FPCP2015 conference had more than 140 participants, including researchers from abroad and many young researchers (postdocs and students). The conference consisted of plenary talks and poster presentations. The plenary talks include 2 overview talks, 48 review talks, and 2 talks for outlook in theories and experiments, given by world leading researchers. There was also a special lecture by Prof. Makoto Kobayashi, one of the Nobel laureates in 2008. The poster session had 41 contributions. Many young researchers presented their works. These proceedings contain written documents for these plenary and poster presentations. The full scientific program and presentation materials can be found at http://fpcp2015.hepl.phys.nagoya-u.ac.jp/. We would like to thank the International Advisory Committee for their invaluable assistance in coordinating the scientific program and in helping to identifying many speakers. Thanks are also due to the Local Organizing Committee for tireless efforts for smooth running of the conference and very enjoyable social activities. We also thank the financial supports provided by Japanese Scociety for the Promotion of Science (JSPS) unfer the Grant-in-Aid for Scientific Research (S) "Probing New Physics with Tau-Lepton" (No. 26220706), by Nagoya University under the Program for Promoting the Enhancement of Research Universities, and

  4. Experience on CP1 turbines

    International Nuclear Information System (INIS)

    Moinaud, C.

    1984-01-01

    Analysis of the experience acquired on the behaviour of the turbine itself, excluding alternators, superheaters... of the nuclear power plants of the French program contract CP1 (Fessenhein prototype): method of anomaly process (assumption, scenarios, calculations and hierarchy of the assumptions), study of the accidents on the shutdown valves and control valves (HP admission devices), on the LP admission devices, on the HP module (leakage at the parting line, bolt and screw accidents), on the LP module (diaphragm, diapragm support erosion, rotor anomaly, blade anomaly with rupture of the wire bracing), behaviour of the shafting and of the pillars (radial and axial floating) and at last global behaviour of the group [fr

  5. Development of aircraft brake materials. [evaluation of metal and ceramic materials in sliding tests simulation of aircraft braking

    Science.gov (United States)

    Ho, T. L.; Peterson, M. B.

    1974-01-01

    The requirements of brake materials were outlined and a survey made to select materials to meet the needs of high temperature brakes. A number of metals and ceramic materials were selected and evaluated in sliding tests which simulated aircraft braking. Nickel, molybdenum tungsten, Zr02, high temperature cements and carbons were tested. Additives were then incorporated into these materials to optimize their wear or strength behavior with particular emphasis on nickel and molybdenum base materials and a high temperature potassium silicate cement. Optimum materials were developed which improved wear behavior over conventional brake materials in the simulated test. The best materials are a nickel, aluminum oxide, lead tungstate composition containing graphite or molybdenum disulphite; a molybdenum base material containing LPA100 (an intermetallic compound of cobalt, molybdenum, and silicon); and a carbon material (P5).

  6. Thermal measurement of brake pad lining surfaces during the braking process

    Science.gov (United States)

    Piątkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Małachowski, Jerzy; Mazurkiewicz, Łukasz

    2012-06-01

    This paper presents the test campaign concept and definition and the analysis of the recorded measurements. One of the most important systems in cars and trucks are brakes. The braking temperature on a lining surface can rise above 500°C. This shows how linings requirements are so strict and, what is more, continuously rising. Besides experimental tests, very supportive method for investigating processes which occur on the brake pad linings are numerical analyses. Experimental tests were conducted on the test machine called IL-68. The main component of IL-68 is so called frictional unit, which consists of: rotational head, which convey a shaft torque and where counter samples are placed and translational head, where samples of coatings are placed and pressed against counter samples. Due to the high rotational speeds and thus the rapid changes in temperature field, the infrared camera was used for testing. The paper presents results of analysis registered thermograms during the tests with different conditions. Furthermore, based on this testing machine, the numerical model was developed. In order to avoid resource demanding analyses only the frictional unit (described above) was taken into consideration. Firstly the geometrical model was performed thanks to CAD techniques, which in the next stage was a base for developing the finite element model. Material properties and boundary conditions exactly correspond to experimental tests. Computations were performed using a dynamic LS-Dyna code where heat generation was estimated assuming full (100%) conversion of mechanical work done by friction forces. Paper presents the results of dynamic thermomechanical analysis too and these results were compared with laboratory tests.

  7. Predict optimize the friction characteristics of brake pads; Brake pad no masatsu tokusei no yosoku to saitekika

    Energy Technology Data Exchange (ETDEWEB)

    Saotome, H [Nissin Kogyo Co., Tokyo (Japan); Kato, T [The University of Tokyo, Tokyo (Japan)

    1997-10-01

    The effect of the friction and the wear properties of brake pads were experimentally studied using a test rig of scale of 1/10 of the system used in a commercial car. The experimental data were investigated by the Multiple Regression Analysis and the Neural Network, and the effects of volume % of components on the friction and the wear properties were predicted. In addition the components of brake pads are optimized by Genetic Algorithms. 8 refs., 9 figs., 4 tabs.

  8. Reconstruction of braking force in vehicles with electromechanically actuated wheel brakes; Rekonstruktion der Bremskraft bei Fahrzeugen mit elektromechanisch betaetigten Radbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R.

    1999-07-01

    Modern braking systems have a variety of functions, but implementation of the enhanced functionality with conventional hydraulic systems is difficult because of electronic actuation. The car industry therefore is working on new braking systems in which the braking force is generated individually on the wheels by means of electromechanical actuators. Owing to their nonlinear characteristics and variable braking efficiency, electromechanically actuated wheel brakes must be operated in a closed control loop. The author presents a low-cost method for reconstruction of the braking force which is required for efficient control. [German] Aufgrund des gestiegenen Sicherheits- und Komfortbewusstseins der Fahrzeugkaeufer ist die Funktionsvielfalt moderner Bremssysteme in den letzten Jahren staendig gewachsen. Die Umsetzung der erweiterten Funktionalitaet mittels konventioneller Bremsenhydraulik ist jedoch durch den elektronischen Eingriff sehr aufwendig. - Von der Automobilzulieferindustrie werden daher neuartige Bremssysteme entwickelt, bei denen die Bremskraft an den einzelnen Raedern von elektromechanischen Bremsaktuatoren aufgebracht wird. - Elektromechanisch betaetigte Radbremsen muessen aufgrund ihres nichtlinearen Verhaltens und des veraenderlichen Wirkungsgrades im geschlossenen Regelkreis betrieben werden. In dieser Arbeit wird erstmals ein Verfahren vorgestellt, mit dem die fuer die Regelung benoetigte Rueckfuehrungsgroesse Bremskraft kostenguenstig rekonstruiert werden kann. (orig.)

  9. Airborne asbestos concentrations associated with heavy equipment brake removal.

    Science.gov (United States)

    Madl, A K; Gaffney, S H; Balzer, J L; Paustenbach, D J

    2009-11-01

    Asbestos-containing brake linings were used in heavy-duty construction equipment such as tractors, backhoes, and bulldozers prior to the 1980s. While several published studies have evaluated exposures to mechanics during brake repair work, most have focused on automobiles and light trucks, not on heavy agricultural or construction vehicles. The purpose of this study is to characterize the airborne concentration of asbestos to workers and bystanders from brake wear debris during brake removal from 12 loader/backhoes and tractors manufactured between 1960 and 1980. Asbestos content in brake lining (average 20% chrysotile by polarized light microscopy) and brake wear debris [average 0.49% chrysotile by transmission electron microscopy (TEM)] was also quantified. Breathing zone samples on the lapel of mechanics (n = 44) and area samples at bystander (n = 34), remote (n = 22), and ambient (n = 12) locations were collected during 12 brake changes and analyzed using phase contrast microscopy (PCM) [National Institute for Occupational Safety and Health (NIOSH) 7400] and TEM (NIOSH 7402). In addition, the fiber distribution by size and morphology was evaluated according to the International Organization for Standardization method for asbestos. Applying the ratio of asbestos fibers:total fibers (including non-asbestos) as determined by TEM to the PCM results, the average airborne chrysotile concentrations (PCM equivalent) were 0.024 f/cc for the mechanic and 0.009 f/cc for persons standing 1.2-3.1 m from the activity during the period of exposure ( approximately 0.5 to 1 h). Considering the time involved in the activity, and assuming three brake jobs per shift, these results would convert to an average 8-h time-weighted average of 0.009 f/cc for a mechanic and 0.006 f/cc for a bystander. The results indicate that (i) the airborne concentrations for worker and bystander samples were significantly less than the current occupational exposure limit of 0.1 f/cc; (ii

  10. Possible Evolution of the Pulsar Braking Index from Larger than Three to About One

    International Nuclear Information System (INIS)

    Tong, H.; Kou, F. F.

    2017-01-01

    The coupled evolution of pulsar rotation and inclination angle in the wind braking model is calculated. The oblique pulsar tends to align. The pulsar alignment affects its spin-down behavior. As a pulsar evolves from the magneto-dipole radiation dominated case to the particle wind dominated case, the braking index first increases and then decreases. In the early time, the braking index may be larger than three. During the following long time, the braking index is always smaller than three. The minimum braking index is about one. This can explain the existence of a high braking index larger than three and a low braking index simultaneously. The pulsar braking index is expected to evolve from larger than three to about one. The general trend is for the pulsar braking index to evolve from the Crab-like case to the Vela-like case.

  11. Development of nondestructive system for detecting the cracks in KTX brake disk using Rayleigh wave

    International Nuclear Information System (INIS)

    Kim, Min Soo; Lee, Ho Yong; Yeom, Yun Taek; Park, Jin Hyun; Song, Sung Jing; Kim, Hak Joon; Kwon, Sung Duck

    2017-01-01

    Recently, KTX (Korean Train Express) train stoppage accidents were mainly caused by malfunctioning equipment, aging and cracking of railway vehicles, crack breakages of brake disks, and breakages of brake disks. Breakage of brake disk can cause large-scale casualties such as high-speed collision and concern about derailment by hitting lower axle and wheel. Therefore, in this study, a brake disk with solid and ventilation type, which is the brake disk of a KTX train was modeled, and a dynamometer system was constructed to operate the disk. A Rayleigh wave was used to inspect the surface of the brake disk. An ultrasonic inspection module was developed for the brake disk by using a local immersion method due to the difficulty involved in ultrasonic inspection using an existing immersion method. In addition, the surface defects of the brake disk were evaluated using a dynamometer mock-up system and an ultrasonic inspection module of the brake disk

  12. Possible Evolution of the Pulsar Braking Index from Larger than Three to About One

    Energy Technology Data Exchange (ETDEWEB)

    Tong, H. [School of Physics and Electronic Engineering, Guangzhou University, 510006 Guangzhou (China); Kou, F. F., E-mail: htong_2005@163.com [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang 830011 (China)

    2017-03-10

    The coupled evolution of pulsar rotation and inclination angle in the wind braking model is calculated. The oblique pulsar tends to align. The pulsar alignment affects its spin-down behavior. As a pulsar evolves from the magneto-dipole radiation dominated case to the particle wind dominated case, the braking index first increases and then decreases. In the early time, the braking index may be larger than three. During the following long time, the braking index is always smaller than three. The minimum braking index is about one. This can explain the existence of a high braking index larger than three and a low braking index simultaneously. The pulsar braking index is expected to evolve from larger than three to about one. The general trend is for the pulsar braking index to evolve from the Crab-like case to the Vela-like case.

  13. Torque Coordination Control during Braking Mode Switch for a Plug-in Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-10-01

    Full Text Available Hybrid vehicles usually have several braking systems, and braking mode switches are significant events during braking. It is difficult to coordinate torque fluctuations caused by mode switches because the dynamic characteristics of braking systems are different. In this study, a new type of plug-in hybrid vehicle is taken as the research object, and braking mode switches are divided into two types. The control strategy of type one is achieved by controlling the change rates of clutch hold-down and motor braking forces. The control strategy of type two is achieved by simultaneously changing the target braking torque during different mode switch stages and controlling the motor to participate in active coordination control. Finally, the torque coordination control strategy is modeled in MATLAB/Simulink, and the results show that the proposed control strategy has a good effect in reducing the braking torque fluctuation and vehicle shocks during braking mode switches.

  14. CFD Modeling and Simulation of Aeorodynamic Cooling of Automotive Brake Rotor

    Science.gov (United States)

    Belhocien, Ali; Omar, Wan Zaidi Wan

    Braking system is one of the important control systems of an automotive. For many years, the disc brakes have been used in automobiles for the safe retarding of the vehicles. During the braking enormous amount of heat will be generated and for effective braking sufficient heat dissipation is essential. The thermal performance of disc brake depends upon the characteristics of the airflow around the brake rotor and hence the aerodynamics is an important in the region of brake components. A CFD analysis is carried out on the braking system as a case study to make out the behavior of airflow distribution around the disc brake components using ANSYS CFX software. We are interested in the determination of the heat transfer coefficient (HTC) on each surface of a ventilated disc rotor varying with time in a transient state using CFD analysis, and then imported the surface film condition data into a corresponding FEM model for disc temperature analysis.

  15. Development of nondestructive system for detecting the cracks in KTX brake disk using Rayleigh wave

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Soo; Lee, Ho Yong [Korea Railroad Research Institute, Uiwang (Korea, Republic of); Yeom, Yun Taek; Park, Jin Hyun; Song, Sung Jing; Kim, Hak Joon [Dept. of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Kwon, Sung Duck [Dept. of Physics, Andong National University, Andong (Korea, Republic of)

    2017-02-15

    Recently, KTX (Korean Train Express) train stoppage accidents were mainly caused by malfunctioning equipment, aging and cracking of railway vehicles, crack breakages of brake disks, and breakages of brake disks. Breakage of brake disk can cause large-scale casualties such as high-speed collision and concern about derailment by hitting lower axle and wheel. Therefore, in this study, a brake disk with solid and ventilation type, which is the brake disk of a KTX train was modeled, and a dynamometer system was constructed to operate the disk. A Rayleigh wave was used to inspect the surface of the brake disk. An ultrasonic inspection module was developed for the brake disk by using a local immersion method due to the difficulty involved in ultrasonic inspection using an existing immersion method. In addition, the surface defects of the brake disk were evaluated using a dynamometer mock-up system and an ultrasonic inspection module of the brake disk.

  16. B decays and models for CP violation

    International Nuclear Information System (INIS)

    He, Xiao Gang

    1995-12-01

    The decay modes B to π π,υK S , K - D, πK and ηK are promising channels to study the unitarity triangle of the CP violating Cabibbo-Kobayashi-Maskawa (CKM) matrix. The consequences of these measurements in the Weinberg model are discussed. It is shown that measurements of CP violation in B decay can be used to distinguish Standard Model from Weinberg model and that the following different mechanisms for CP violation can be distinguished: 1) CP is violated in the CKM sector only; 2) CP is violated spontaneously in the Higgs sector only; and 3) CP is violated in both the CKM and Higgs sectors. 27 refs., 4 figs

  17. Exploring CP Violation in the MSSM

    CERN Document Server

    Arbey, A.; Godbole, R.M.; Mahmoudi, F.

    2015-01-01

    We explore the prospects for observing CP violation in the minimal supersymmetric extension of the Standard Model (MSSM) with six CP-violating parameters, three gaugino mass phases and three phases in trilinear soft supersymmetry-breaking parameters, using the CPsuperH code combined with a geometric approach to maximize CP-violating observables subject to the experimental upper bounds on electric dipole moments. We also implement CP-conserving constraints from Higgs physics, flavour physics and the upper limits on the cosmological dark matter density and spin-independent scattering. We study possible values of observables within the constrained MSSM (CMSSM), the non-universal Higgs model (NUHM), the CPX scenario and a variant of the phenomenological MSSM (pMSSM). We find values of the CP-violating asymmetry A_CP in b -> s gamma decay that may be as large as 3%, so future measurements of A_CP may provide independent information about CP violation in the MSSM. We find that CP-violating MSSM contributions to the...

  18. Superweak-like models of CP violation

    International Nuclear Information System (INIS)

    Lavoura, L.

    1992-01-01

    I put forward a two-Higgs-doublet model in which CP violation is mediated only by the neutral Higgs bosons, via the mechanism of scalar-pseudoscalar mixing. In this model there is no CP violation in the exchange of either W bosons or of charged Higgs bosons. The model is therefore an approximate realization of the superweak theory of CP violation. It has only two basic CP-violating quantities. I point out that other models of this kind, but with more than two Higgs doublets, may also be built

  19. Optimal design for slip deceleration control in anti-lock braking system

    Science.gov (United States)

    Mishra, Sheelam; Kumar, Pankaj; Rahman, Mohd. Saifur

    2018-05-01

    ABS (Anti-lock Braking System) is the most advanced braking system implemented in modern cars to avoid the slipping or skidding of the vehicle on the road. Moreover, it reduces the stopping distance of the vehicle because it avoids the locking of the wheel during braking. It enables the driver to steer the vehicle during braking. But every system has its downsides and likewise ABS too, it is not efficient during normal braking or snowy conditions. Our aim is to overcome these downsides and optimize Anti-lock Braking System to make it even better.

  20. An integrated control strategy for the composite braking system of an electric vehicle with independently driven axles

    Science.gov (United States)

    Sun, Fengchun; Liu, Wei; He, Hongwen; Guo, Hongqiang

    2016-08-01

    For an electric vehicle with independently driven axles, an integrated braking control strategy was proposed to coordinate the regenerative braking and the hydraulic braking. The integrated strategy includes three modes, namely the hybrid composite mode, the parallel composite mode and the pure hydraulic mode. For the hybrid composite mode and the parallel composite mode, the coefficients of distributing the braking force between the hydraulic braking and the two motors' regenerative braking were optimised offline, and the response surfaces related to the driving state parameters were established. Meanwhile, the six-sigma method was applied to deal with the uncertainty problems for reliability. Additionally, the pure hydraulic mode is activated to ensure the braking safety and stability when the predictive failure of the response surfaces occurs. Experimental results under given braking conditions showed that the braking requirements could be well met with high braking stability and energy regeneration rate, and the reliability of the braking strategy was guaranteed on general braking conditions.

  1. Charging valve of the full hydraulic braking system

    Directory of Open Access Journals (Sweden)

    Jinshi Chen

    2016-03-01

    Full Text Available It is known that the full hydraulic braking system has excellent braking performance. As the key component of the full hydraulic braking system, the parameters of the accumulator charging valve have a significant effect on the braking performance. In this article, the key parameters of the charging valve are analyzed through the static theoretical and an Advanced Modeling Environment for performing Simulation of engineering systems (AMESim simulation model of the dual-circuit accumulator charging valve is established based on the real structure parameters first. Second, according to the results of the dynamic simulation, the dynamic characteristics of the charging pressure, the flow rate, and the frequency of the charging valve are studied. The key parameters affecting the serial production are proposed and some technical advices for improving the performance of the full hydraulic system are provided. Finally, the theoretical analysis is validated by the simulation results. The comparison between the simulation results and the experimental results indicates that the simulated AMESim model of the charging valve is accurate and credible with the error rate inside 0.5% compared with the experimental result. Hence, the performance of the charging valve meets the request of the full hydraulic braking system exactly.

  2. Simulation and Robust Contol of Antilock Braking System ABS

    Directory of Open Access Journals (Sweden)

    David Jordan DELICHRISTOV

    2009-06-01

    Full Text Available This paper deals with simulation and robust control of Antilock Braking System ABS. The briefly are described the main parts of ABS hydraulic system and control algorithm of ABS. Hydraulic system described here is BOSCH ABS 5.x series. The goal of ABS system is vehicle stability and vehicle steering response when braking. If during the braking occurred slip at one or more wheels from any reason, ABS evaluates this by “brake slip” controller. At this moment ABS is trying to use maximal limits of adhesion between tire and road. It means that is necessary control the differences between braking torque and friction torque , which reacts to the wheel via friction reaction tire-road surface. This is realized through the solenoid valves, which are controls (triggered by on the base of PID controller described further in chapter 4. Presented concept is more or less standard for most of the existing ABS systems. The issue should be applied concept of robust ABS control algorithm, which is specific for every type of ABS.

  3. Optimal design of an automotive magnetorheological brake considering geometric dimensions and zero-field friction heat

    International Nuclear Information System (INIS)

    Nguyen, Q H; Choi, S B

    2010-01-01

    This paper presents an optimal design of a magnetorheological (MR) brake for a middle-sized passenger car which can replace a conventional hydraulic disc-type brake. In the optimization, the required braking torque, the temperature due to zero-field friction of MR fluid, the mass of the brake system and all significant geometric dimensions are considered. After describing the configuration, the braking torque of the proposed MR brake is derived on the basis of the field-dependent Bingham and Herschel–Bulkley rheological model of the MR fluid. The optimal design of the MR brake is then analyzed taking into account available space, mass, braking torque and steady heat generated by zero-field friction torque of the MR brake. The optimization procedure based on the finite element analysis integrated with an optimization tool is proposed to obtain optimal geometric dimensions of the MR brake. Based on the proposed procedure, optimal solutions of single and multiple disc-type MR brakes featuring different types of MR fluid are achieved. From the results, the most effective MR brake for the middle-sized passenger car is identified and some discussions on the performance improvement of the optimized MR brake are described

  4. Study on Two-segment Electric-mechanical Composite Braking Strategy of Tracked Vehicle Hybrid Transmission System

    OpenAIRE

    Ma, Tian; Gai, Jiangtao; Ma, Xiaofeng

    2010-01-01

    In order to lighten abrasion of braking system of hybrid electric tracked vehicle, according to characteristic of hybrid electric transmission, electric-mechanical composite braking method was proposed. By means of analyzing performance of electric braking and mechanical braking and three-segment composite braking strategy, two-segment electric-mechanical composite braking strategy was put forward in this paper. Simulation results of Matlab/Simulink indicated that the two-segment electric-mec...

  5. Performance Evaluation of an Anti-Lock Braking System for Electric Vehicles with a Fuzzy Sliding Mode Controller

    OpenAIRE

    Jingang Guo; Xiaoping Jian; Guangyu Lin

    2014-01-01

    Traditional friction braking torque and motor braking torque can be used in braking for electric vehicles (EVs). A sliding mode controller (SMC) based on the exponential reaching law for the anti-lock braking system (ABS) is developed to maintain the optimal slip value. Parameter optimizing is applied to the reaching law by fuzzy logic control (FLC). A regenerative braking algorithm, in which the motor torque is taken full advantage of, is adopted to distribute the braking force between the m...

  6. LHCb : Measuring $CP$ violation with $\\Delta A_{CP}$ at LHCb

    CERN Multimedia

    Pearce, A

    2014-01-01

    Measurements are presented of direct $CP$ violation in $D^{0}$ meson decays in LHCb, using the $\\Delta A_{CP}$ technique, and a proposal is outlined to make similar measurements in the decays of the charmed baryon $\\Lambda_{c}^{+}$. The motivations for use of the $\\Delta A_{CP}$ method are discussed, along with the current results and future prospects.

  7. Registration of 'CP 09-2392' Sugarcane

    Science.gov (United States)

    CP 09-2392’ (Reg. No.____; PI _____) sugarcane, a complex hybrid of Saccharum spp, was developed through cooperative research conducted by the USDA-ARS, the University of Florida, and the Florida Sugar Cane League, Inc., and was released to growers in June 2016. ‘CP 09-2392’ was selected from a cro...

  8. Spontaneous CP violation on the lattice

    CERN Document Server

    Laine, Mikko

    2000-01-01

    At finite temperatures around the electroweak phase transition, the thermodynamics of the MSSM can be described by a three-dimensional two Higgs doublet effective theory. This effective theory has a phase where CP is spontaneously violated. We study spontaneous CP violation with non-perturbative lattice simulations, and analyse whether one could end up in this phase for any physical MSSM parameter values.

  9. Contact Thermal Analysis and Wear Simulation of a Brake Block

    Directory of Open Access Journals (Sweden)

    Nándor Békési

    2013-01-01

    Full Text Available The present paper describes an experimental test and a coupled contact-thermal-wear analysis of a railway wheel/brake block system through the braking process. During the test, the friction, the generated heat, and the wear were evaluated. It was found that the contact between the brake block and the wheel occurs in relatively small and slowly moving hot spots, caused by the wear and the thermal effects. A coupled simulation method was developed including numerical frictional contact, transient thermal and incremental wear calculations. In the 3D simulation, the effects of the friction, the thermal expansion, the wear, and the temperature-dependent material properties were also considered. A good agreement was found between the results of the test and the calculations, both for the thermal and wear results. The proposed method is suitable for modelling the slowly oscillating wear caused by the thermal expansions in the contact area.

  10. Product and process innovation of grey cast iron brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Schorn, M. [Brembo S.P.A. (Italy)

    2006-07-01

    The brake disc out of grey cast iron often seems to be playing the role of the ''underdog'' in the technical examinations of the entire brake system. This is also reflected by the 25 year history of the {mu}-club. In a total of 93 presentations in those 25 years, only 3 were related to the topic of grey cast iron discs. This is not a correct relation to the importance of this component within the brake system. The disc, although per definition with a lower specific load than the pad, has the major task to store and dissipate the heat in which the kinetic energy of the vehicle is transformed. The disc also has a significant effect on NVH behaviour, particularly in the low frequency range. It also has a permanent fight with its weight as an unsprung mass. (orig.)

  11. Steering redundancy for self-driving vehicles using differential braking

    Science.gov (United States)

    Jonasson, M.; Thor, M.

    2018-05-01

    This paper describes how differential braking can be used to turn a vehicle in the context of providing fail-operational control for self-driving vehicles. Two vehicle models are developed with differential input. The models are used to explain the bounds of curvature that differential braking provides and they are then validated with measurements in a test vehicle. Particular focus is paid on wheel suspension effects that significantly influence the obtained curvature. The vehicle behaviour and its limitations due to wheel suspension effects are, owing to the vehicle models, defined and explained. Finally, a model-based controller is developed to control the vehicle curvature during a fault by differential braking. The controller is designed to compensate for wheel angle disturbance that is likely to occur during the control event.

  12. Effect of the crone suspension control system on braking

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, X.; Oustaloup, A. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique; Nouillant, C. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique]|[DRIA-PSA Peugeot Citroen, Velizy - Villacoublay (France)

    2001-07-01

    Semi-active or active suspensions not only increase driving comfort, but also permit the control system to be switched over if required in order to improve the transmission of forces at the points of contact between tire and road surface by minimizing the dynamic wheel loads. It may also be possible to use these systems to control wheel load distribution and, thus, influence braking or steering performance by changing the distribution of normal forces between the front and rear axles. This article examines the effect of the CRONE suspension control system on braking. The central idea is to use continuously variable dampers and fast load levelling devices to distribute the normal forces of tire between the front and rear axles. The basis principle is explained using known dynamic properties of active suspension, vehicles and tires. The effect of active suspension on vehicle response during braking is then evaluated using computer simulations from a two-wheel vehicle model. (orig.)

  13. Molecular brake pad hypothesis: pulling off the brakes for emotional memory.

    Science.gov (United States)

    Vogel-Ciernia, Annie; Wood, Marcelo A

    2012-01-01

    Under basal conditions histone deacetylases(HDACs) and their associated co-repressor complexes serve as molecular 'brake pads' to prevent the gene expression required for long-term memory formation. Following a learning event, HDACs and their co-repressor complexes are removed from a subset of specific gene promoters, allowing the histone acetylation and active gene expression required for long-term memory formation.Inhibition of HDACs increases histone acetylation,extends gene expression profiles, and allows for the formation of persistent long-term memories for training events that are otherwise forgotten. We propose that emotionally salient experiences have utilized this system to form strong and persistent memories for behaviorally significant events. Consequently, the presence or absence of HDACs at a selection of specific gene promoters could serve as a critical barrier for permitting the formation of long-term memories.

  14. Molecular brake pad hypothesis: pulling off the brakes for emotional memory

    Science.gov (United States)

    Vogel-Ciernia, Annie

    2015-01-01

    Under basal conditions histone deacetylases (HDACs) and their associated co-repressor complexes serve as molecular ‘brake pads’ to prevent the gene expression required for long-term memory formation. Following a learning event, HDACs and their co-repressor complexes are removed from a subset of specific gene promoters, allowing the histone acetylation and active gene expression required for long-term memory formation. Inhibition of HDACs increases histone acetylation, extends gene expression profiles, and allows for the formation of persistent long-term memories for training events that are otherwise forgotten. We propose that emotionally salient experiences have utilized this system to form strong and persistent memories for behaviorally significant events. Consequently, the presence or absence of HDACs at a selection of specific gene promoters could serve as a critical barrier for permitting the formation of long-term memories. PMID:23096102

  15. The comparison of antioxidative and hepatoprotective activities of Codonopsis pilosula polysaccharide (CP) and sulfated CP.

    Science.gov (United States)

    Liu, Cui; Chen, Jin; Li, Entao; Fan, Qiang; Wang, Deyun; Li, Peng; Li, Xiuping; Chen, Xingying; Qiu, Shulei; Gao, Zhenzhen; Li, Hongquan; Hu, Yuanliang

    2015-02-01

    Codonopsis pilosula polysaccharide (CP) was extracted, purified and modified by chlorosulfonic acid-pyridine method to obtain a sulfated CP (sCP). Their antioxidative activities in vitro were compared through the free radical-scavenging test. The results demonstrated that the scavenging capabilities of sCP were significantly stronger than those of CP. In vivo test, the mice hepatic injury model was prepared by BCG/LPS method, then administrated respectively with sCP and CP at three dosages, the biochemical indexes in serum, antioxidative indexes in liver homogenate and histopathological change in liver of the mice were compared. The results showed that in high (200mg/kg) and middle (150mg/kg) dosages of sCP groups, the contents of ALT, AST and TNF-α in serum and MDA in liver homogenate were significantly lower than those in the model group and numerically lower than those in the CP groups, the activities of SOD and GSH-Px in liver homogenate were significantly higher than those in the model group and numerically higher than those in the CP groups. In the model group there were obvious pathological changes in the liver, while in the sCP groups were near normal. These results indicate that sCP and CP possess antioxidative activity in vitro and in vivo, the activity of sCP is stronger than that of CP and sulfation modification can enhance the antioxidative and hepatoprotective activities of Codonopsis pilosula polysaccharide. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Research on motor braking-based DYC strategy for distributed electric vehicle

    Science.gov (United States)

    Zhang, Jingming; Liao, Weijie; Chen, Lei; Cui, Shumei

    2017-08-01

    In order to bring into full play the advantages of motor braking and enhance the handling stability of distributed electric vehicle, a motor braking-based direct yaw moment control (DYC) strategy was proposed. This strategy could identify whether a vehicle has under-steered or overs-steered, to calculate the direct yaw moment required for vehicle steering correction by taking the corrected yaw velocity deviation and slip-angle deviation as control variables, and exert motor braking moment on the target wheels to perform correction in the manner of differential braking. For validation of the results, a combined simulation platform was set up finally to simulate the motor braking control strategy proposed. As shown by the results, the motor braking-based DYC strategy timely adjusted the motor braking moment and hydraulic braking moment on the target wheels, and corrected the steering deviation and sideslip of the vehicle in unstable state, improving the handling stability.

  17. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R.

    1994-01-01

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

  18. Optimal design of a magneto-rheological brake absorber for torsional vibration control

    International Nuclear Information System (INIS)

    Nguyen, Q H; Choi, S B

    2012-01-01

    This research presents an optimal design of a magneto-rheological (MR) brake absorber for torsional vibration control of a rotating shaft. Firstly, the configuration of an MR brake absorber for torsional vibration control of a rotating shaft system is proposed. Then, the braking torque of the MR brake is derived based on the Bingham plastic model of the MR fluid. By assuming that the behaviour of the MR brake absorber is similar to that of a dry friction torsional damper, the optimal braking torque to control the torsional vibration is determined and validated by simulation. The optimal design problem of the MR brake absorber is then developed and a procedure to solve the optimal problem is proposed. Based on the proposed optimal design procedure, the optimal design of a specific rotating shaft system is performed. Vibration control performance of the shaft system employing the optimized MR brake absorber is then investigated through simulation and discussion on the results is given. (paper)

  19. A low cost, light weight cenosphere–aluminium composite for brake ...

    Indian Academy of Sciences (India)

    2. Literature review. Disc brake is often used in automobile transmission system to halt a vehicle. .... components such as brake disc, jet turbines, engines, power plants, etc. ... This section presents an infrared (IR)-based wireless temperature ...

  20. USING COUPLING WEIGHTS AND RATIONAL DISTRIBUTION OF BRAKE FORCES BETWEEN THE AXLES OF WHEELED VEHICLES

    Directory of Open Access Journals (Sweden)

    M. Kholodov

    2011-01-01

    Full Text Available The dependence of the coefficient of coupling weight-axle vehicles under braking and a ra-tional distribution coefficient of braking force to the front axle on the condition of maximum coupling weight.

  1. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1994-10-25

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control. 123 figs.

  2. Development of a Cooperative Braking System for Front-Wheel Drive Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Di Zhao

    2018-02-01

    Full Text Available Most electric vehicles adopt cooperative braking systems that can blend friction braking torque with regenerative braking torque to achieve higher energy efficiency while maintaining a certain braking performance and driving safety. This paper presented a new cooperative regenerative braking system that contained a fully-decoupled hydraulic braking mechanism based on a modified electric stability control system. The pressure control algorithm and brake force distribution strategy were also discussed. Dynamic models of a front wheel drive electric car equipped with this system and a simulation platform with a driver model and driving cycles were established. Tests to evaluate the braking performance and energy regeneration were simulated and analyzed on this platform and the simulation results showed the feasibility and effectiveness of this system.

  3. Industrial heat treatment of R-HPDC A356 automotive brake callipers [Conference paper

    CSIR Research Space (South Africa)

    Chauke, L

    2012-10-01

    Full Text Available brake callipers to the automotive industry. This research studied A356 brake callipers heat treated on the industrial scale with particular emphasis on the resulting microstructure, hardness and tensile properties. The eutectic Si...

  4. Optimal design of a magneto-rheological brake absorber for torsional vibration control

    Science.gov (United States)

    Nguyen, Q. H.; Choi, S. B.

    2012-02-01

    This research presents an optimal design of a magneto-rheological (MR) brake absorber for torsional vibration control of a rotating shaft. Firstly, the configuration of an MR brake absorber for torsional vibration control of a rotating shaft system is proposed. Then, the braking torque of the MR brake is derived based on the Bingham plastic model of the MR fluid. By assuming that the behaviour of the MR brake absorber is similar to that of a dry friction torsional damper, the optimal braking torque to control the torsional vibration is determined and validated by simulation. The optimal design problem of the MR brake absorber is then developed and a procedure to solve the optimal problem is proposed. Based on the proposed optimal design procedure, the optimal design of a specific rotating shaft system is performed. Vibration control performance of the shaft system employing the optimized MR brake absorber is then investigated through simulation and discussion on the results is given.

  5. CP nonconservation in dynamically broken gauge theories

    International Nuclear Information System (INIS)

    Lane, K.

    1981-01-01

    The recent proposal of Eichten, Lane, and Preskill for CP nonconservation in electroweak gauge theories with dynamical symmetry breaking is reviewed. Through the alignment of the vacuum with the explicit chiral symmetry breaking Hamiltonian, these theories provide a natural way to understand the dynamical origin of CP nonconservation. Special attention is paid to the problem of strong CP violation. Even through all vacuum angles are zero, this problem is not automatically avoided. In the absence of strong CP violation, the neutron electric dipole moment is expected to be 10 -24 -10 -26 e-cm. A new class of models is proposed in which both strong CP violation and large /ΔS/ = 2 effects may be avoided. In these models, /ΔC/ = 2 processes such as D/sup o/ D/sup -o/ mixing may be large enough to observe

  6. CP violation and the top quark

    International Nuclear Information System (INIS)

    Atwood, D.

    1994-02-01

    We consider signals of CP violation in semi-leptonic decay of the top quark. We show that the transverse polarization asymmetries of the τ-lepton in the decay t → brv is extremely sensitive CP violation. As an illustration we consider CP phases arising from the charged Higgs exchange in the Weinberg three Higgs doublet model. Qualitatively, the polarization asymmetries are enhanced over rate or energy asymmetries by a factor of O(m t /m r ) ∼ 100 with a corresponding increase in sensitivity to CP violating parameters. We also examine τ polarization in b decays via b → cvr and find that may also be very effective in constraining CP violating effects such as those that arise from an extended Higgs sector

  7. Theory prospective on leptonic CP violation

    International Nuclear Information System (INIS)

    Petcov, S.T.

    2016-01-01

    The phenomenology of 3-neutrino mixing, the current status of our knowledge about the 3-neutrino mixing parameters, including the absolute neutrino mass scale, and of the Dirac and Majorana CP violation in the lepton sector are reviewed. The problems of CP violation in neutrino oscillations and of determining the nature – Dirac or Majorana – of massive neutrinos are discussed. The seesaw mechanism of neutrino mass generation and the related leptogenesis scenario of generation of the baryon asymmetry of the Universe are considered. The results showing that the CP violation necessary for the generation of the baryon asymmetry of the Universe in leptogenesis can be due exclusively to the Dirac and/or Majorana CP-violating phase(s) in the neutrino mixing matrix U are briefly reviewed. The discrete symmetry approach to understanding the observed pattern of neutrino mixing and the related predictions for the leptonic Dirac CP violation are also reviewed.

  8. NUMERICAL THERMAL ANALYSIS OF A CAR BRAKING SYSTEM

    Directory of Open Access Journals (Sweden)

    Patryk Różyło

    2017-06-01

    Full Text Available The study involved performing a numerical thermal analysis of selected components in a car braking system. The primary goal of the study was to determine the regions which are the most susceptible to variations in temperature, and to determine the degree of thermal impact upon them. The analysis was performed using the Abaqus environment. The examined components of the braking system were made of materials reflecting the mechanical properties of the real subassemblies. The FEM analysis enabled determination of the distribution of temperature in the system with respect to the properties of the investigated materials and applied boundary conditions.

  9. Non-resonant magnetic braking on JET and TEXTOR

    DEFF Research Database (Denmark)

    Sun, Y.; Liang, Y.; Shaing, K.C.

    2012-01-01

    The non-resonant magnetic braking effect induced by a non-axisymmetric magnetic perturbation is investigated on JET and TEXTOR. The collisionality dependence of the torque induced by the n = 1, where n is the toroidal mode number, magnetic perturbation generated by the error field correction coils...... in the 1/ν regime. The strongest NTV torque on JET is also located near the plasma core. The magnitude of the NTV torque strongly depends on the plasma response, which is also discussed in this paper. There is no obvious braking effect with n = 2 magnetic perturbation generated by the dynamic ergodic...

  10. Hydraulic braking system for loads subjected to impacts and vibrations

    International Nuclear Information System (INIS)

    1980-01-01

    This invention concerns a hydraulic braking system for loads subjected to impacts and vibrations. These double acting telescopic type hydraulic braking systems possess significant drawbacks linked to possibly important hydraulic leaks due to (a) the use of many dynamic seals in such appliances and (b) the effects of the environment of the system on these seals, particularly when employed in nuclear power stations where the seals reach significant temperatures and are subjected to radiation. Under this invention a remedy is suggested to such drawbacks by integrating means to offset automatically the leaks and the accumulation of hydraulic fluid expansions, as well as facilities to show if such leaks have occurred [fr

  11. Tribo-performance evaluation of ecofriendly brake friction composite materials

    Science.gov (United States)

    Kumar, Naresh; Singh, Tej; Grewal, G. S.

    2018-05-01

    This paper presents the potential of natural fibre in brake friction materials. Natural fibre filled ecofriendly brake friction materials were developed without Kevlar fibre evaluated for tribo-performance on a chase friction testing machine following SAE J 661a standard. Experimental results indicated that natural fibre enhances the fade performance, but depresses the friction and wear performance, whereas Kevlar fibre improves the friction, wear and recovery performance but depresses the fade performance. Also the results revealed that with the increase in natural fibre content, the friction and fade performances enhanced.

  12. Sliding bifurcations and chaos induced by dry friction in a braking system

    International Nuclear Information System (INIS)

    Yang, F.H.; Zhang, W.; Wang, J.

    2009-01-01

    In this paper, non-smooth bifurcations and chaotic dynamics are investigated for a braking system. A three-degree-of-freedom model is considered to capture the complicated nonlinear characteristics, in particular, non-smooth bifurcations in the braking system. The stick-slip transition is analyzed for the braking system. From the results of numerical simulation, it is observed that there also exist the grazing-sliding bifurcation and stick-slip chaos in the braking system.

  13. Usage of aids monitoring in automatic braking systems of modern cars

    OpenAIRE

    Dembitskyi V.; Mazylyuk P.; Sitovskyi O.

    2016-01-01

    Increased safety can be carried out at the expense the installation on vehicles of automatic braking systems, that monitor the traffic situation and the actions of the driver. In this paper considered the advantages and disadvantages of automatic braking systems, were analyzed modern tracking tools that are used in automatic braking systems. Based on the statistical data on accidents, are set the main dangers, that the automatic braking system will be reduced. In order to ensure the acc...

  14. Industrial research on the quality of brake shoes meant for rolling stock

    Science.gov (United States)

    Popa, E.; Pascu, L.; Socalici, A.; Lascufoni, A.

    2016-02-01

    Brake shoes wear appears as a normal exploitation process and depends both on the braking force and on the material the shoe is made of. Brake shoes are made of molded sulfurous cast iron. The industrial research and experiments aim at determining the specific characteristics of the phosphorous cast iron (chemical and structural homogeneity, hardness) and their optimization in view of improving the quality of the brake shoes meant for the rolling stock

  15. 78 FR 44189 - Petition for Modification of Single Car Air Brake Test Procedures

    Science.gov (United States)

    2013-07-23

    ... brake pipe exhaust. Sec. 3.12.5: Added time and pressure criteria. Sec. 3.13: Added criteria for brake... brake pipes. Also, the choke in the 3/8- inch cock valve changed from 0.266 (17/64 ) to 0.313 (5/16 ), increasing the discharge rate to ensure emergency application on cars with long brake pipes. Sec. Sec. 2.2.4...

  16. Deviation from bimaximal mixing and leptonic CP phases in S4 family symmetry and generalized CP

    International Nuclear Information System (INIS)

    Li, Cai-Chang; Ding, Gui-Jun

    2015-01-01

    The lepton flavor mixing matrix having one row or one column in common with the bimaximal mixing up to permutations is still compatible with the present neutrino oscillation data. We provide a thorough exploration of generating such a mixing matrix from S 4 family symmetry and generalized CP symmetry H CP . Supposing that S 4 ⋊H CP is broken down to Z 2 ST 2 SU ×H CP ν in the neutrino sector and Z 4 TST 2 U ⋊H CP l in the charged lepton sector, one column of the PMNS matrix would be of the form (1/2,1/√2,1/2) T up to permutations, both Dirac CP phase and Majorana CP phases are trivial to accommodate the observed lepton mixing angles. The phenomenological implications of the remnant symmetry K 4 (TST 2 ,T 2 U) ×H CP ν in the neutrino sector and Z 2 SU ×H CP l in the charged lepton sector are studied. One row of PMNS matrix is determined to be (1/2,1/2,−i/√2), and all the three leptonic CP phases can only be trivial to fit the measured values of the mixing angles. Two models based on S 4 family symmetry and generalized CP are constructed to implement these model independent predictions enforced by remnant symmetry. The correct mass hierarchy among the charged leptons is achieved. The vacuum alignment and higher order corrections are discussed.

  17. CP violations in the Universe

    Science.gov (United States)

    Auriemma, Giulio

    2003-12-01

    The origin of the asymmetry between matter and antimatter that is evident in our part of the Universe is one of the open questions in cosmology, because the CPT symmetry between matter and antimatter seems to be absolutely conserved at microscopic level. We repeat here the classical proofs which exclude the viability of a Universe baryon symmetric on the average, or the observed asymmetry as an initial conditions. The current understanding is that the asymmetry should have been dynamically generated before nucleosynthesis, by B, C, and CP violating processes, acting out of thermodynamical equilibrium, as suggested by Sakharov in the 70's. The physical realizations of these conditions would be possible, in principle, also in the framework of the Standard Model of elementary particles, but the present limits on the mass of the higgs particle exclude this possibility. Finally we present the model of baryogenesis through leptogenesis, which is allowed by a minimal extension of the Standard Model, which has the appeal of being testable in future long-baseline neutrino oscillation experiments.

  18. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Science.gov (United States)

    2010-10-01

    ... brakes; (C) Piston travel that is in excess of the Class I brake test limits required in § 238.313 but... where the necessary repairs can be made. (3) Commuter, short-distance intercity, and short-distance Tier... brakes. Commuter, short-distance intercity, and short-distance Tier II passenger trains which develop...

  19. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Science.gov (United States)

    2010-10-01

    ... (ECP) Braking Systems § 232.609 Handling of defective equipment with ECP brake systems. (a) Ninety-five... systems. 232.609 Section 232.609 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT...

  20. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Jiankun Peng

    2015-01-01

    Full Text Available This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  1. Modification of General Research Corporation (GRC) Dynatup 8200 Drop Tower Rebounding Brake System

    Science.gov (United States)

    2016-08-01

    Rebounding Brake System by David Gray, Robert Kaste, and Bradley Lawrence Approved for public release; distribution is...Research Laboratory Modification of General Research Corporation (GRC) Dynatup 8200 Drop Tower Rebounding Brake System by David Gray and...Research Corporation (GRC) Dynatup 8200 Drop Tower Rebounding Brake System 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  2. 49 CFR 214.529 - In-service failure of primary braking system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway maintenance...

  3. Investigation of Product Performance of Al-Metal Matrix Composites Brake Disc using Finite Element Analysis

    International Nuclear Information System (INIS)

    Fatchurrohman, N; Marini, C D; Suraya, S; Iqbal, AKM Asif

    2016-01-01

    The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc. (paper)

  4. 30 CFR 75.1403-2 - Criteria-Hoists transporting materials; brakes.

    Science.gov (United States)

    2010-07-01

    ... Mantrips § 75.1403-2 Criteria—Hoists transporting materials; brakes. Hoists and elevators used to transport materials should be equipped with brakes capable of stopping and holding the fully loaded platform, cage... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Criteria-Hoists transporting materials; brakes...

  5. A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops

    Science.gov (United States)

    Barthlome, D. E.

    1975-01-01

    Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

  6. Design, Modeling And Control Of Steering And Braking For An Urban Electric Vehicle

    OpenAIRE

    Maciua, Dragos

    1996-01-01

    This report describes research which involved the design modification, modeling and control of automatic steering and braking systems for an urban electric vehicle. The vehicle is equipped with four-wheel independent drive, four-wheel independent braking and four-wheel steering. Control algorithms were developed for steering and braking. Simulation results show the feasibility of the algorithms.

  7. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved. PMID:26236772

  8. Vehicle State Estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

    NARCIS (Netherlands)

    Jansen, S.T.H.; van Boekel, J.J.P.; Iersel, van S.S.; Besselink, I.J.M.; Nijmeijer, H.

    2013-01-01

    The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the electric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

  9. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2013-02-11

    ... initial speeds, vehicle manufacturers will need to develop unique or complicated braking systems to comply... [Docket No. NHTSA-2013-0011] RIN 2127-AL11 Federal Motor Vehicle Safety Standards; Air Brake Systems... rule that amended the Federal motor vehicle safety standard for air brake systems by requiring...

  10. 76 FR 9717 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Science.gov (United States)

    2011-02-22

    ...\\ Radlinski & Associates, Inc. Vehicle Systems Consultants (May 2003). ``Braking Performance of Saddlemount... of the last vehicle tends to lock up under heavy braking, and submitted test results supporting this... vehicle tends to lock up under heavy braking, potentially increasing stopping distance. Stopping distances...

  11. Vehicle state estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

    NARCIS (Netherlands)

    Jansen, S.T.H.; Boekel, J.J.P. van; Iersel, S.S. van; Besselink, I.J.M.; Nijmeijer, H.

    2013-01-01

    The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the elctric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

  12. 76 FR 56318 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Science.gov (United States)

    2011-09-13

    ... because the lightly loaded axle of the last vehicle tends to lock up under heavy braking. DATES: The final... antilock braking systems. ACC Automobile Carriers Conference. ATA American Trucking Associations. ATC ATC... heavy braking, potentially increasing stopping distance. Stopping distances are specified in the vehicle...

  13. ESTIMATION OF DRIVER’S POWER EXPENSES OF CAR BRAKE MANAGEMENT

    Directory of Open Access Journals (Sweden)

    A. Turenko

    2010-01-01

    Full Text Available The estimation method of driver’s power expenses for the brake management is offered. The estimation method takes into account power expenses at driving in action of the brake system and power expenses at holding the pressed brake pedal

  14. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Science.gov (United States)

    2010-10-01

    ... per minute. (ii) Air Flow Method Test. When a locomotive is equipped with a 26-L brake valve or equivalent pressure maintaining locomotive brake valve, a railroad may use the Air Flow Method Test as an... air flow shall not exceed 60 cubic feet per minute (CFM). (i) Leakage Test. The brake pipe leakage...

  15. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ... brake actuating forces in response to signals from one or more sensed wheels. Initial brake temperature means the average temperature of the service brakes on the hottest axle of the vehicle 0.2 mi before any... procedures and in the sequence set forth in S7. Each school bus with a GVWR greater than 10,000 pounds must...

  16. Investigations into the Mechanical Properties and Microstructural Behavior of Foreign and Locally Fabricated Brake Disc

    Directory of Open Access Journals (Sweden)

    Basil Olufemi Akinnuli

    2017-11-01

    Full Text Available The present work reports investigations on mechanical and microstructural properties of foreign and locally fabricated brake disc. From safety point of view, brake disc is a crucial component of the braking system. Foreign brake disc (FBD are known for their long life span and better mechanical properties under service condition. However, locally fabricated brake disc (LFBD may possess similar or better mechanical properties than the foreign one. Therefore, the need to investigate their mechanical properties in order to determine which brake disc has better mechanical properties under the same service condition. It was observed that a high machinability index occurs in the locally fabricated brake disc as compared with the foreign brake disc, noticeable in the softness and weak graphite flakes formation in the matrix. Higher resistance to indentation was noticeable in the foreign brake disc as compared to the locally fabricated disc. The locally fabricated brake disc however, witnesses about 22% reduction in toughness compared to the foreign brake disc. An offshoot from this research will enhance the choice of material selection in the manufacturing of brake disc and assurance of locally made spare parts at affordable prices, and the provision of employment opportunities by establishing spare-parts production and allied industries

  17. Auto Mechanics I. Learning Activity Packets (LAPs). Section E--Brakes.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) that outline the study activities for the "brakes" instructional area for an Auto Mechanics I course. The two LAPs cover the following topics: brake systems and power disc brakes. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included…

  18. 49 CFR 232.103 - General requirements for all train brake systems.

    Science.gov (United States)

    2010-10-01

    ... pneumatic technology, the integrity of the train line shall be monitored by the brake control system. (c) A... travel exceeds: (1) 10 1/2 inches for cars equipped with nominal 12-inch stroke brake cylinders; or (2) The piston travel limits indicated on the stencil, sticker, or badge plate for the brake cylinder with...

  19. 76 FR 7623 - Parts and Accessories Necessary for Safe Operation; Brakes; Application for Exemption From...

    Science.gov (United States)

    2011-02-10

    ... potential significant market penetration in commercial trailers equipped with electric brakes. Consequently... current definition of a surge brake. DATES: Comments must be received on or before March 14, 2011... originally submitted, and suggested that the definition of surge brakes may someday require modification. For...

  20. 49 CFR 232.503 - Process to introduce new brake system technology.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Process to introduce new brake system technology... Technology § 232.503 Process to introduce new brake system technology. (a) Pursuant to the procedures... brake system technology, prior to implementing the plan. (b) Each railroad shall complete a pre-revenue...

  1. Driver braking behavior analysis to improve autonomous emergency braking systems in typical Chinese vehicle-bicycle conflicts.

    Science.gov (United States)

    Duan, Jingliang; Li, Renjie; Hou, Lian; Wang, Wenjun; Li, Guofa; Li, Shengbo Eben; Cheng, Bo; Gao, Hongbo

    2017-11-01

    Bicycling is one of the fundamental modes of transportation especially in developing countries. Because of the lack of effective protection for bicyclists, vehicle-bicycle (V-B) accident has become a primary contributor to traffic fatalities. Although AEB (Autonomous Emergency Braking) systems have been developed to avoid or mitigate collisions, they need to be further adapted in various conflict situations. This paper analyzes the driver's braking behavior in typical V-B conflicts of China to improve the performance of Bicyclist-AEB systems. Naturalistic driving data were collected, from which the top three scenarios of V-B accidents in China were extracted, including SCR (a bicycle crossing the road from right while a car is driving straight), SCL (a bicycle crossing the road from left while a car is driving straight) and SSR (a bicycle swerving in front of the car from right while a car is driving straight). For safety and data reliability, a driving simulator was employed to reconstruct these three scenarios and some 25 licensed drivers were recruited for braking behavior analysis. Results revealed that driver's braking behavior was significantly influenced by V-B conflict types. Pre-decelerating behaviors were found in SCL and SSR conflicts, whereas in SCR the subjects were less vigilant. The brake reaction time and brake severity in lateral V-B conflicts (SCR and SCL) was shorter and higher than that in longitudinal conflicts (SSR). The findings improve their applications in the Bicyclist-AEB and test protocol enactment to enhance the performance of Bicyclist-AEB systems in mixed traffic situations especially for developing countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. The structure of completely positive matrices according to their CP-rank and CP-plus-rank

    NARCIS (Netherlands)

    Dickinson, Peter James Clair; Bomze, Immanuel M.; Still, Georg J.

    2015-01-01

    We study the topological properties of the cp-rank operator $\\mathrm{cp}(A)$ and the related cp-plus-rank operator $\\mathrm{cp}^+(A)$ (which is introduced in this paper) in the set $\\mathcal{S}^n$ of symmetric $n\\times n$-matrices. For the set of completely positive matrices, $\\mathcal{CP}^n$, we

  3. Strong CP, flavor, and twisted split fermions

    International Nuclear Information System (INIS)

    Harnik, Roni; Perez, Gilad; Schwartz, Matthew D.; Shirman, Yuri

    2005-01-01

    We present a natural solution to the strong CP problem in the context of split fermions. By assuming CP is spontaneously broken in the bulk, a weak CKM phase is created in the standard model due to a twisting in flavor space of the bulk fermion wavefunctions. But the strong CP phase remains zero, being essentially protected by parity in the bulk and CP on the branes. As always in models of spontaneous CP breaking, radiative corrections to theta bar from the standard model are tiny, but even higher dimension operators are not that dangerous. The twisting phenomenon was recently shown to be generic, and not to interfere with the way that split fermions naturally weaves small numbers into the standard model. It follows that out approach to strong CP is compatible with flavor, and we sketch a comprehensive model. We also look at deconstructed version of this setup which provides a viable 4D model of spontaneous CP breaking which is not in the Nelson-Barr class. (author)

  4. Exploring CP violation in the MSSM.

    Science.gov (United States)

    Arbey, Alexandre; Ellis, John; Godbole, Rohini M; Mahmoudi, Farvah

    We explore the prospects for observing CP violation in the minimal supersymmetric extension of the Standard Model (MSSM) with six CP-violating parameters, three gaugino mass phases and three phases in trilinear soft supersymmetry-breaking parameters, using the CPsuperH code combined with a geometric approach to maximise CP-violating observables subject to the experimental upper bounds on electric dipole moments. We also implement CP-conserving constraints from Higgs physics, flavour physics and the upper limits on the cosmological dark matter density and spin-independent scattering. We study possible values of observables within the constrained MSSM (CMSSM), the non-universal Higgs model (NUHM), the CPX scenario and a variant of the phenomenological MSSM (pMSSM). We find values of the CP-violating asymmetry [Formula: see text] in [Formula: see text] decay that may be as large as 3 %, so future measurements of [Formula: see text] may provide independent information about CP violation in the MSSM. We find that CP-violating MSSM contributions to the [Formula: see text] meson mass mixing term [Formula: see text] are in general below the present upper limit, which is dominated by theoretical uncertainties. If these could be reduced, [Formula: see text] could also provide an interesting and complementary constraint on the six CP-violating MSSM phases, enabling them all to be determined experimentally, in principle. We also find that CP violation in the [Formula: see text] and [Formula: see text] couplings can be quite large, and so may offer interesting prospects for future [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] colliders.

  5. CP -symmetry of order 4 and its consequences

    International Nuclear Information System (INIS)

    Ivanov, Igor P.

    2017-01-01

    Extended Higgs sectors offer rich opportunities for various forms of CP -violation. Here, we describe a new form of CP-conservation and discuss its consequences. We give a concrete example of a three-Higgs-doublet model dubbed CP4-3HDM with a CP -symmetry of order 4 and no other other accidental symmetries. If the vacuum conserves this symmetry, the model is CP -conserving with pairwise mass-degenerate extra neutral Higgs bosons. These fields cannot be classified as CP -even or CP -odd but they can be combined into complex physical fields which are CP -half-odd, that is, they pick up the i factor upon CP transformation. These CP -half-odd scalars can be Yukawa-coupled to the fermion bilinears in a CP -conserving way. We discuss fundamental and phenomenological features of the model, and stress a peculiar clash between the CP -symmetry and any convention for the particle-antiparticle assignment. (paper)

  6. CP violation in the baryon sector

    CERN Document Server

    Smith, Eluned Anne

    2017-01-01

    The study of CP violation in the baryon sector is still a relatively new field and offers the possibility to make many CP measurements which could complement those performed in the meson sector. This is especially true of late given the large number of baryons currently being produced at the LHC. Such measurements could help further over-constrain the CKM unitary triangle, as well as furthering our understand of baryongenesis. These proceedings will give an overview of the current state of the search for CP violation in the baryon sector.

  7. CP violation in CMS expected performance

    CERN Document Server

    Stefanescu, J

    1999-01-01

    The CMS experiment can contribute significantly to the measurement of the CP violation asymmetries. A recent evaluation of the expected precision on the CP violation parameter sin 2 beta in the channel B /sub d//sup 0/ to J/ psi $9 K/sub s//sup 0/ has been performed using a simulation of the CMS tracker including full pattern recognition. CMS has also studied the possibility to observe CP violation in the decay channel B/sub s//sup 0/ to J/ psi phi . The $9 results of these studies are reviewed. (7 refs).

  8. CP Violation in Single Top Quark Production

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Weigang [Michigan State Univ., East Lansing, MI (United States)

    2012-01-01

    We present a search for CP violation in single top quark production with the DØ experiment at the Tevatron proton-antiproton collider. CP violation in the top electroweak interaction results in different single top quark production cross sections for top and antitop quarks. We perform the search in the single top quark final state using 5.4 fb-1 of data, in the s-channel, t-channel, and for both combined. At this time, we do not see an observable CP asymmetry.

  9. Baryogenesis and standard model CP violation

    International Nuclear Information System (INIS)

    Huet, P.

    1994-08-01

    The standard model possesses a natural source of CP violation contained in the phase of the CKM matrix. Whether the latter participated to the making of the matter-antimatter asymmetry of the observable universe is a fundamental question which has been addressed only recently. The generation of a CP observable occurs through interference of quantum paths along which a sequence of flavor mixings and chirality flips take place. The coherence of this phenomenon in the primeval plasma is limited by the fast quark-gluon interactions. At the electroweak era, this phenomenon of decoherence forbids a successful baryogenesis based on the sole CP violation of the CKM matrix

  10. The seesaw path to leptonic CP violation

    Energy Technology Data Exchange (ETDEWEB)

    Caputo, A.; Hernandez, P. [Universidad de Valencia and CSIC, Edificio Institutos Investigacion, Instituto de Fisica Corpuscular, Paterna (Spain); CERN, Theoretical Physics Department, Geneva (Switzerland); Kekic, M.; Salvado, J. [Universidad de Valencia and CSIC, Edificio Institutos Investigacion, Instituto de Fisica Corpuscular, Paterna (Spain); Lopez-Pavon, J. [CERN, Theoretical Physics Department, Geneva (Switzerland)

    2017-04-15

    Future experiments such as SHiP and high-intensity e{sup +}e{sup -} colliders will have a superb sensitivity to heavy Majorana neutrinos with masses below M{sub Z}. We show that the measurement of the mixing to electrons and muons of one such state could establish the existence of CP violating phases in the neutrino mixing matrix, in the context of low-scale seesaw models. We quantify in the minimal model the CP reach of these future experiments, and demonstrate that CP violating phases in the mixing matrix could be established at 5σ CL in a very significant fraction of parameter space. (orig.)

  11. The seesaw path to leptonic CP violation

    CERN Document Server

    Caputo, A.; Kekic, M.; López-Pavón, J.; Salvado, J.

    2017-04-24

    Future experiments such as SHiP and high-intensity $e^+ e^-$ colliders will have a superb sensitivity to heavy Majorana neutrinos with masses below $M_Z$. We show that the measurement of the mixing to electrons and muons of one such state could imply the discovery of leptonic CP violation in the context of seesaw models. We quantify in the minimal model the CP discovery potential of these future experiments, and demonstrate that a 5$\\sigma$ CL discovery of leptonic CP violation would be possible in a very significant fraction of parameter space.

  12. Flavor physics and CP violation

    Science.gov (United States)

    Chang, Paoti; Chen, Kai-Feng; Hou, Wei-Shu

    2017-11-01

    We currently live in the age of the CKM paradigm. The 3 × 3 matrix that links (d , s , b) quarks to (u , c , t) in the charged current weak interaction, being complex and nominally with 18 parameters, can be accounted for by just 3 rotation angles and one CP violating (CPV) phase, with unitarity and the CKM phases triumphantly tested at the B factories. But the CKM picture is unsatisfactory and has too many parameters. The main aim of Flavor Physics and CP violation (FPCP) studies is the pursuit to uncover New Physics beyond the Standard Model (SM). Two highlights of LHC Run 1 period are the CPV phase ϕs of Bs mixing and Bs →μ+μ- decay, which were found to be again consistent with SM, though the saga is yet unfinished. We also saw the emergence of the P5‧ angular variable anomaly in B0 →K∗0μ+μ- decay and R K (∗) anomaly in B →K (∗)μ+μ- to B →K (∗)e+e- rate ratios, and the BaBar anomaly in B →D (∗) τν decays, which suggest possible New Physics in these flavor processes, pointing to extra Z‧, charged Higgs, or leptoquarks. Charmless hadronic, semileptonic, purely leptonic and radiative B decays continue to offer various further windows on New Physics. Away from B physics, the rare K → πνν decays and ε‧ / ε in the kaon sector, μ → e transitions, muon g - 2 and electric dipole moments of the neutron and electron, τ → μγ , μμμ , eee, and a few charm physics probes, offer broadband frontier windows on New Physics. Lastly, flavor changing neutral transitions involving the top quark t and the 125 GeV Higgs boson h, such as t → ch and h → μτ, offer a new window into FPCP, while a new Z‧ related or inspired by the P5‧ anomaly, could show up in analogous top quark processes, perhaps even link with low energy phenomena such as muon g - 2 or rare kaon processes. In particular, we advocate the potential new SM, the two Higgs doublet model without discrete symmetries to control flavor violation, as SM2. As we are

  13. Coaxial magnetic brakes using single-domain YBCO

    International Nuclear Information System (INIS)

    Putman, P.T.; Salama, K.

    2008-01-01

    In coaxial magnetic brakes, the changing field produced by movement of a solenoidal magnet induces a current in the wall of a conductive tube. The interaction of the field and current leads to a repulsive force that slows the motion of the magnet. For brake applications that require high force density, melt-textured YBCO is a clear choice of material for the magnet because it can carry high currents at a given field and temperature, and is inherently capable of operating in persistent current mode. We present calculations of the performance of this type of brake as a function of magnet current density for catch tubes composed of aluminum and titanium. These results are validated with low speed (20 m/s) tests. Calculations indicate that melt-textured magnets can decelerate projectiles with a mass of 1 kg from 2000 m/s to rest in distances on the order of 10 m. This suggests that this type of brake is suitable for use in hypervelocity experiments, which sometimes requires nondestructive deceleration of projectiles for diagnostic purposes

  14. Neural-network hybrid control for antilock braking systems.

    Science.gov (United States)

    Lin, Chih-Min; Hsu, C F

    2003-01-01

    The antilock braking systems are designed to maximize wheel traction by preventing the wheels from locking during braking, while also maintaining adequate vehicle steerability; however, the performance is often degraded under harsh road conditions. In this paper, a hybrid control system with a recurrent neural network (RNN) observer is developed for antilock braking systems. This hybrid control system is comprised of an ideal controller and a compensation controller. The ideal controller, containing an RNN uncertainty observer, is the principal controller; and the compensation controller is a compensator for the difference between the system uncertainty and the estimated uncertainty. Since for dynamic response the RNN has capabilities superior to the feedforward NN, it is utilized for the uncertainty observer. The Taylor linearization technique is employed to increase the learning ability of the RNN. In addition, the on-line parameter adaptation laws are derived based on a Lyapunov function, so the stability of the system can be guaranteed. Simulations are performed to demonstrate the effectiveness of the proposed NN hybrid control system for antilock braking control under various road conditions.

  15. MAGNETIC BRAKING AND PROTOSTELLAR DISK FORMATION: AMBIPOLAR DIFFUSION

    International Nuclear Information System (INIS)

    Mellon, Richard R.; Li Zhiyun

    2009-01-01

    It is established that the formation of rotationally supported disks during the main accretion phase of star formation is suppressed by a moderately strong magnetic field in the ideal MHD limit. Nonideal MHD effects are expected to weaken the magnetic braking, perhaps allowing the disk to reappear. We concentrate on one such effect, ambipolar diffusion, which enables the field lines to slip relative to the bulk neutral matter. We find that the slippage does not sufficiently weaken the braking to allow rotationally supported disks to form for realistic levels of cloud magnetization and cosmic ray ionization rate; in some cases, the magnetic braking is even enhanced. Only in dense cores with both exceptionally weak fields and unreasonably low ionization rate do such disks start to form in our simulations. We conclude that additional processes, such as Ohmic dissipation or Hall effect, are needed to enable disk formation. Alternatively, the disk may form at late times when the massive envelope that anchors the magnetic brake is dissipated, perhaps by a protostellar wind.

  16. 49 CFR 232.109 - Dynamic brake requirements.

    Science.gov (United States)

    2010-10-01

    ... grids on the system; and (2) Display in real-time in the cab of the controlling (lead) locomotive the... received at the grids on the system; and (2) Display either the train deceleration rate or in real-time in... system that includes dynamic brakes shall adopt and comply with written operating rules governing safe...

  17. Reducing braking distance by control of semi-active suspension

    Energy Technology Data Exchange (ETDEWEB)

    Niemz, T.

    2007-07-01

    This thesis presents a control algorithm for semi-active suspensions to reduce the braking distance of passenger cars. Active shock absorbers are controlled and used to influence the vertical dynamics during ABS-controlled full braking. The core of the approach presented in this paper is based on a switching control logic. The control algorithm is implemented in a compact class passenger car. Test drives on a real road, using a braking machine for reproducibility reasons, have been executed. It could be shown that it is possible to reduce the braking distance by affecting on the vertical dynamics of a passenger car in general. This is the first experimental result of this kind published ever. The amount of reduction depends on the height profile of the testing track chosen and on the initial velocity. On a road with an unevenness comparable to the one on a typical German Autobahn an average reduction of 1-2%, compared to the best passive damping, was achieved. (orig.)

  18. Magnetic braking in Solar-type close binaries

    Science.gov (United States)

    Maceroni, C.; Rucinski, S. M.

    In tidally locked binaries the angular momentum loss by magnetic braking affects the orbital period. While this effect is too small to be detected in individual systems, its signature can be seen in shape of the orbital period distribution of suitable samples. As a consequence information on the braking mechanisms can be obtained - at least in principle - from the analysis of the distributions, the main problems being the selection of a large and homogeneous sample of binaries and the appropriate treatment of the observational biases. New large databases of variable stars are becoming available as by-products of microlensing projects, which have the advantage of joining, for the first time, sample richness and homogeneity. We report the main results of the analysis of the eclipsing binaries in OGLE-I catalog, that contains several thousands variables detected in a pencil-beam search volume towards the Baade's Window. By means of an automatic filtering algorithm we extracted a sample of 74 detached, equal-mass, main-sequence binary stars with short orbital periods (i.e., in the range 0.19 braking law. The results suggest an AML braking law very close to the "saturated" one, with a very weak dependence on the period. However we are still far from constraining the precise value of the slope, because of the important role played by the observational bias.

  19. Engineering Design Handbook: Analysis and Design of Automotive Brake Systems.

    Science.gov (United States)

    1976-12-01

    Highway Safety Research institute, Uni- versity of Michigan, September 15, 1972. IF’vn = (I - #)WT’,Kk I1, J. E. Bernard , et al,, A Computer Based...systems involve the reduction in brake line pres- 4. E. L. Cornwell , "Automatic Load-Sensitive Air sure for a given pedal force, the pedal force/de

  20. Smart brake light system would provide more information to drivers

    OpenAIRE

    Trulove, Susan

    2008-01-01

    You are driving in heavy traffic. The brake lights on the car in front of you come on. Is the car slowing or is it going to stop? It slows to 25 mph and the lights go off. You drop back. The car in front of you stops suddenly! You stop just in time. The car behind you collects your rear bumper.

  1. Benchmarking of regenerative braking for a fully electric car

    NARCIS (Netherlands)

    Varocky, B.J.; Nijmeijer, H.; Jansen, S.; Besselink, I.J.M.; Mansvelder, R.; Mansvelders, R.E.

    2011-01-01

    Short range of electric vehicles is one of the stumbling blocks in the way of electric cars to gaining wide user acceptance and becoming a major market player. The possibility to recover vehicle energy otherwise lost as heat during braking is an inherent advantage of a hybrid electric or a fully

  2. Application of numerical modelling in SSM automotive brake calliper castings

    CSIR Research Space (South Africa)

    Jahajeeah, N

    2006-01-01

    Full Text Available Numerical modelling has successfully been used as an efficient tool to convert a gravity cast brake calliper to a thixocasting process. The thixo-modue of Procast has been used for the modelling process to obtain optimum processing parameters...

  3. T-type channels: release a brake, engage a gear

    Czech Academy of Sciences Publication Activity Database

    Weiss, Norbert; Lacinová, L.

    2016-01-01

    Roč. 10, č. 2 (2016), s. 78-80 ISSN 1933-6950 Institutional support: RVO:61388963 Keywords : gating brake * pore opening * Ca(V)3.3 * channel gating * Ca(V)3.1 * low-voltage activated calcium channels Subject RIV: CE - Biochemistry Impact factor: 2.042, year: 2016

  4. A Laboratory Activity on the Eddy Current Brake

    Science.gov (United States)

    Molina-Bolivar, J. A.; Abella-Palacios, A. J.

    2012-01-01

    The aim of this paper is to introduce a simple and low-cost experimental setup that can be used to study the eddy current brake, which considers the motion of a sliding magnet on an inclined conducting plane in terms of basic physical principles. We present a set of quantitative experiments performed to study the influence of the geometrical and…

  5. Brakes Specialist. Teacher Edition. Automotive Service Series. Second Edition.

    Science.gov (United States)

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This curriculum guide for automatic brakes service is one in a series of automotive service speciality publications that is based on the National Institute of Automotive Service Excellence task lists. The curriculum is composed of four units. Each unit of instruction may contain some or all of the following components: objective sheet, suggested…

  6. Can dark matter explain the braking index of neutron stars?

    DEFF Research Database (Denmark)

    Kouvaris, C.; Perez-Garcia, M. A.

    2014-01-01

    We explore a new mechanism of slowing down the rotation of neutron stars via accretion of millicharged dark matter. We find that this mechanism yields pulsar braking indices that can be substantially smaller than the standard n similar to 3 of the magnetic dipole radiation model for millicharged...... dark matter particles that are not excluded by existing experimental constraints thus accommodating existing observations....

  7. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    Science.gov (United States)

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Influences on nonlinear judder vibrations of railway brakes

    Science.gov (United States)

    Heckmann, Andreas; Kurzeck, Bernhard; Carrarini, Antonio; Günther, Frank; Schroeder-Bodenstein, Kaspar

    2010-06-01

    The paper reports on a joined research project of Knorr-Bremse, Siemens Mobility and the Institute of Robotics and Mechatronics. The goal of the project was to analyse the dynamical behaviour of friction brakes for high-speed trains. It was intended to gain insight into possible vibration mechanisms and to assess the potential for lay-out and operation improvements for future light-weight designs. In particular, the frequency range up to 250 Hz has been addressed, since the corresponding excitation is unavoidable at least to some extent and has to be considered when the brake system is designed. The study includes a comprehensive multibody simulation study and its comparison to experimental results at the test rig of Knorr-Bremse in Munich. The simulation model is adapted step by step in order to clearly identify and separate the influences on the dynamical properties of the complete brake system including its mounting. Additionally a minimal model is introduced that demonstrates some characteristics of the brake system. It turned out that the underlying knowledge is essential for the mechanical lay-out, which could be demonstrated by solving a particular vibration problem in an actual high-speed project.

  9. Short term braking capability during power interruptions for integrated matrix converter

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

    attractive. Sinusoidal input currents and bi-directional power flow are other advantages of the matrix converter, but it is less immune to power grid disturbances compared to a standard ASD. In hoisting applications, short-term braking capability during a power outage is needed until the mechanical brake...... engages or to perform more effective a combined braking. This paper proposes a new method to provide short-term braking capability during a power outage for matrix converters. A braking chopper is needed in the clamp circuit, which allows for a drastically reduction of the capacitor size. The power flow...

  10. Fallback level concepts for conventional and by-wire automotive brake systems

    International Nuclear Information System (INIS)

    Retzer, H; Mishra, R; Ball, A; Schmidt, K

    2012-01-01

    Brake-by-wire represents the replacement of traditional brake components such as pumps, hoses, fluids, brake boosters, and master cylinders by electronic sensors and actuators. The different design of these brake concepts poses new challenges for the automotive industry with regard to availability and fallback levels in comparison to standard conventional brake systems. This contribution focuses on the development of appropriate fallback level concepts. Hardware-in-the-loop (HIL) techniques and field trials will be used to investigate the performance and the usability of such systems.

  11. Short term Braking Capability during Power Interruptions for Integrated Matrix Converter-Motor Drives

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2002-01-01

    attractive. Sinusoidal input currents and bi-directional power flow are other advantages of the matrix converter but it is less immune to power grid disturbances compared to a standard ASD. In hoisting applications, short-term braking capability during a power outage is needed until the mechanical brake...... engages or to perform more effective a combined braking.This paper proposes a new method to provide short-term braking capability during a power outage for matrix converters. A braking chopper is needed in the clamp circuit, which allows for a drastically reduction of the capacitor size. The power flow...

  12. Fallback level concepts for conventional and by-wire automotive brake systems

    Science.gov (United States)

    Retzer, H.; Mishra, R.; Ball, A.; Schmidt, K.

    2012-05-01

    Brake-by-wire represents the replacement of traditional brake components such as pumps, hoses, fluids, brake boosters, and master cylinders by electronic sensors and actuators. The different design of these brake concepts poses new challenges for the automotive industry with regard to availability and fallback levels in comparison to standard conventional brake systems. This contribution focuses on the development of appropriate fallback level concepts. Hardware-in-the-loop (HIL) techniques and field trials will be used to investigate the performance and the usability of such systems.

  13. Investigation into the Use of Water Based Brake Fluid for Light Loads

    Directory of Open Access Journals (Sweden)

    W. A. Akpan

    2012-12-01

    Full Text Available This paper addresses the possibility of using water based fluid as a brake fluid for light loads. Characterization of both standard and water based braked fluids formulated was carried out. The properties of the latter were compared with that of a standard commercial brake fluid. The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus of University of Uyo and the braking efficiency obtained attest to its suitability for light loads.

  14. Aspects of soft and spontaneous CP violation

    International Nuclear Information System (INIS)

    Frampton, P.H.; Harada, M.

    1999-01-01

    We study four different models for CP violation: the standard Kobayashi-Maskawa (KM) model, the aspon model of spontaneous breaking, and two models of soft breaking. In all except the standard model, the strong CP problem is addressed and solved. Testable predictions for the area of the unitarity triangle and for (ε ' /ε) K are emphasized. The issue of CP violation may well become the first place where the standard model of particle theory is shown definitively to be deficient. There are two reasons for expecting this to happen: (1) the strong CP problem is still not understood in the unadorned standard model and (2) the KM mechanism, although unquestionably present, may not provide the full explanation of ε K and (ε ' /ε) K . copyright 1999 The American Physical Society

  15. CP violation in B and D decays

    International Nuclear Information System (INIS)

    Bigi, I.I.

    1986-06-01

    Non-leptonic B decays offer the best opportunity to discover the violation of CP invariance outside the neutral K system. Employing the Standard Model one predicts - with reasonable confidence - CP asymmetries of up to 205 (or even more in some cases). The branching ratios for the individual exclusive modes of interest are not expected to exceed the 10 -3 level in most cases; the identification of such decays poses non-trivial problems. It is shown that by summing intelligently over appropriate classes of decays one can greatly enhance statistics without jeopardizing the signal. Data that contain 10 6 produced B mesons would allow meaningful searches for CP violation. It is noted that ''New Physics'' could lead to CP asymmetries in D 0 decays of order 1%. Due to higher branching ratios one can search for such effects in samples of 10 6 produced D mesons. 7 refs

  16. Instantons, CP-violation and axions

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, S. R.

    1980-07-01

    Some specific aspects of the developments in pseudoparticle solutions of Gauge theories are discussed. The general features of the Lagrangian are described. The concepts of instantons, confinement, O-vacua and CP nonconservation are explained.

  17. CP violation in b-hadrons

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00341004

    2016-01-01

    Latest LHCb measurements of $CP$ violation in b-hadrons are presented based on $pp$ collision data collected in 2011 and 2012 at centre-of-mass energies of $\\sqrt{s}=7$ $\\rm TeV$ and $8\\ \\rm TeV$ respectively. The total integrated luminosity collected is 3.0 fb$^{-1}$. Results include recent measurements of $CP$ violation in $B_d$ and $B_s$ mixing, along with those of quantifying the effects of $b\\to c\\bar{c} s$ loop pollution. Standard Model $CP$ violation tests in loop transitions are discussed with results consistent with expectations. New decays of b-baryons are presented and preliminary studies of $CP$ violation are performed.

  18. A definition of maximal CP-violation

    International Nuclear Information System (INIS)

    Roos, M.

    1985-01-01

    The unitary matrix of quark flavour mixing is parametrized in a general way, permitting a mathematically natural definition of maximal CP violation. Present data turn out to violate this definition by 2-3 standard deviations. (orig.)

  19. Theoretical and experimental studies on a magnetorheological brake operating under compression plus shear mode

    International Nuclear Information System (INIS)

    Sarkar, C; Hirani, H

    2013-01-01

    The torque characteristics of magnetorheological brakes, consisting of rotating disks immersed in a MR fluid and enclosed in an electromagnetic casing, are controlled by regulating the yield stress of the MR fluid. An increase in yield stress increases the braking torque, which means that the higher the yield strength of the MR fluid, the better the performance of the MR brake will be. In the present research an application of compressive force on MR fluid has been proposed to increase the torque capacity of MR brakes. The mathematical expressions to estimate the torque values for MR brake, operating under compression plus shear mode accounting Herschel–Bulkley shear thinning model, have been detailed. The required compressive force on MR fluid of the proposed brake has been applied using an electromagnetic actuator. The development of a single-plate MR disk brake and an experimental test rig are described. Experiments have been performed to illustrate braking torque under different control currents (0.0–2.0 A). The torque results have been plotted and compared with theoretical study. Experimental results as well as theoretical calculations indicate that the braking torque of the proposed MR brake is higher than that of the MR brake operating only under shear. (paper)

  20. Braking energy regeneration control of a fuel cell hybrid electric bus

    International Nuclear Information System (INIS)

    Zhang, Junzhi; Lv, Chen; Qiu, Mingzhe; Li, Yutong; Sun, Dongsheng

    2013-01-01

    Highlights: • A braking energy regeneration system has been designed for a fuel cell bus. • Control strategy coordinating energy efficiency and brake safety is proposed. • The system and control strategy proposed are experimentally verified. • Based on test results, energy efficiency of the FCB is improved greatly. - Abstract: This paper presents the braking energy regeneration control of a fuel cell hybrid electric bus. The configuration of the regenerative braking system based on a pneumatic braking system was proposed. To recapture the braking energy and improve the fuel economy, a control strategy coordinating the regenerative brake and the pneumatic brake was designed and applied in the FCHB. Brake safety was also guaranteed by the control strategy when the bus encounters critical driving situations. Fuel economy tests were carried out under China city bus typical driving cycle. And hardware-in-the-loop tests of the brake safety of the FCHB under proposed control strategy were also accomplished. Test results indicate that the present approach provides an improvement in fuel economy of the fuel cell hybrid electric bus and guarantees the brake safety in the meantime

  1. Design, simulation and testing of a novel radial multi-pole multi-layer magnetorheological brake

    Science.gov (United States)

    Wu, Jie; Li, Hua; Jiang, Xuezheng; Yao, Jin

    2018-02-01

    This paper deals with design, simulation and experimental testing of a novel radial multi-pole multi-layer magnetorheological (MR) brake. This MR brake has an innovative structural design with superposition principle of two magnetic fields generated by the inner coils and the outer coils. The MR brake has several media layers of magnetorheological (MR) fluid located between the inner coils and the outer coils, and it can provide higher torque and higher torque density than conventional single-disk or multi-disk or multi-pole single-layer MR brakes can. In this paper, a brief introduction to the structure of the proposed MR brake was given first. Then, theoretical analysis of the magnetic circuit and the braking torque was conducted. In addition, a 3D electromagnetic model of the MR brake was developed to simulate and examine the magnetic flux intensity and corresponding braking torque. A prototype of the brake was fabricated and several tests were carried out to validate its torque capacity. The results show that the proposed MR brake can produce a maximum braking torque of 133 N m and achieve a high torque density of 25.0 kN m-2, a high torque range of 42 and a high torque-to-power ratio of 0.95 N m W-1.

  2. Analysis of downshift’s improvement to energy efficiency of an electric vehicle during regenerative braking

    International Nuclear Information System (INIS)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Song, Jian; He, Kai; Li, Chenfeng

    2016-01-01

    Highlights: • Downshift is effective in improving the energy efficiency of electric vehicles. • Energy improvement of downshift varies with vehicle speed and brake strength. • The designed nonlinear sliding mode observer is accurate in estimating bake torque. • The proposed resembling PWM method is practical to regulate hydraulic pressure. • The effect of downshift on braking safety and comfort can be restrained by control. - Abstract: Downshift during regenerative braking helps to improve the energy efficiency of electric vehicles. Two main problems are involved in the downshift process. One is the determination of optimal downshift point, and the other is the cooperative control of regenerative braking and hydraulic braking. In order to achieve a systemic solution to these problems, a hierarchical control strategy is brought forward for an electric vehicle with a two-speed automated mechanical transmission. For the upper controller, an off-line calculation and on-line look-up table method is adopted to obtain the optimal downshift point, and a series regenerative braking distribution strategy is designed. For the medium controller, a nonlinear sliding mode observer is designed to obtain the actual hydraulic brake torque. For the lower controller, cooperative control of regenerative braking and hydraulic braking is given to ensure brake safety during downshift process, and a resembling pulse width modulation method is proposed to regulated the hydraulic brake torque. Simulation results and hardware-in-loop test show that the proposed algorithm is effective in improving the energy efficiency of electric vehicles.

  3. Enhanced Regenerative Braking Strategies for Electric Vehicles: Dynamic Performance and Potential Analysis

    Directory of Open Access Journals (Sweden)

    Boyi Xiao

    2017-11-01

    Full Text Available A regenerative braking system and hydraulic braking system are used in conjunction in the majority of electric vehicles worldwide. We propose a new regenerative braking distribution strategy that is based on multi-input fuzzy control logic while considering the influences of the battery’s state of charge, the brake strength and the motor speed. To verify the braking performance and recovery economy, this strategy was applied to a battery electric vehicle model and compared with two other improved regenerative braking strategies. The performance simulation was performed using standard driving cycles (NEDC, LA92, and JP1015 and a real-world-based urban cycle in China. The tested braking strategies satisfied the general safety requirements of Europe (as specified in ECE-13H, and the emergency braking scenario and economic potential were tested. The simulation results demonstrated the differences in the braking force distribution performance of these three regenerative braking strategies, the feasibility of the braking methods for the proposed driving cycles and the energy economic potential of the three strategies.

  4. First evidence for direct CP violation

    International Nuclear Information System (INIS)

    Schaffer, A.C.

    1988-06-01

    The double ratio R of the relative decay rates of the short-and long-lived neutral kaons into two charged and two neutral pions was measured to be 0.980 ± 0.004 ± 0.005. The deviation of R from unity implies CP violation in the transition of the CP-odd K 2 into two pions with ε , / ε = (3.3 ± 1.1) X 10 -3

  5. Status of the CP-PACS Project

    International Nuclear Information System (INIS)

    Ukawa, A.

    1995-01-01

    The CP-PACS Project, which started in April 1992, is a five-year plan to develop a massively parallel computer for carrying out research in computational physics with primary emphasis on lattice QCD. This article describes the architectural design of the CP-PACS computer, the entire computing system including the front end and mass storage, and results of benchmarks for the expected performance for lattice QCD applications. ((orig.))

  6. Toimintaterapeuttinen nukkekoti CP-vammaisille lapsille

    OpenAIRE

    Ruotsalainen, Ulla; Tokola, Eveliina

    2009-01-01

    Toiminnallisen opinnäytetyön tarkoitus oli suunnitella ja rakentaa toimintaterapeuttinen nukkekoti CP-vammaisille lapsille. Työn toimeksiantajana oli toimintaterapeutti Päivi Raitanen Terapiapajalta. Työn tavoitteena oli toteuttaa mukana kuljetettava ja lapsen pyörätuolin pöytälevylle sopiva nukkekoti, jolla leikkiminen tukee CP-vammaisen lapsen toimintaterapiaa. Yleisimpiä tavoitteita ovat muun muuassa hienomotoristen taitojen, leikkitaitojen, syy-seuraussuhteiden ja visuaalisen hahmott...

  7. Heavy quarks and CP: Moriond 1985

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1985-03-01

    The presentations at the Fifth Moriond Workshop on Heavy Quarks, Flavor Mixing, and CP Violation (La Plagne, France, January 13-19, 1985) are summarized. The following topics are reviewed. What's New (beyond the top, top quarks, bottom quarks, charm quarks, strange quarks, and others); why is all this being done (strong interactions and hadron structure, and electroweak properties); and what next (facilities and can one see CP violation in the B-anti B system). 64 refs., 10 figs

  8. Penguins and cp violation in β decays

    International Nuclear Information System (INIS)

    He, X.C.

    1996-11-01

    The measurement of the ε-parameter in the K 0 - K-bar 0 meson system is the only direct evidence for CP violation in the laboratory. The Standard Model (SM) of three generations with the source for CP violation arising from the phases in the Cabibbo-Kobayashi-Maskawa (CKM) matrix is consistent with the experiment. An unique feature of this model is that the CKM matrix is a 3 x 3 unitary matrix. (author)

  9. Neutrino mass textures with maximal CP violation

    International Nuclear Information System (INIS)

    Aizawa, Ichiro; Kitabayashi, Teruyuki; Yasue, Masaki

    2005-01-01

    We show three types of neutrino mass textures, which give maximal CP violation as well as maximal atmospheric neutrino mixing. These textures are described by six real mass parameters: one specified by two complex flavor neutrino masses and two constrained ones and the others specified by three complex flavor neutrino masses. In each texture, we calculate mixing angles and masses, which are consistent with observed data, as well as Majorana CP phases

  10. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    International Nuclear Information System (INIS)

    Wibowo,; Zakaria,; Lambang, Lullus; Triyono,; Muhayat, Nurul

    2016-01-01

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  11. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo,, E-mail: wibowo-uns@yahoo.com; Zakaria,, E-mail: zakaaria27@gmail.com; Lambang, Lullus, E-mail: lulus-l@yahoo.com; Triyono,, E-mail: tyon-bila@yahoo.co.id; Muhayat, Nurul, E-mail: nurulmuhayat@ymail.com [Mechanical Engineering Department, Sebelas Maret University, Surakarta 57128 (Indonesia)

    2016-03-29

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  12. Development of Proportional Pressure Control Valve for Hydraulic Braking Actuator of Automobile ABS

    Directory of Open Access Journals (Sweden)

    Che-Pin Chen

    2018-04-01

    Full Text Available This research developed a novel proportional pressure control valve for an automobile hydraulic braking actuator. It also analyzed and simulated solenoid force of the control valves, and the pressure relief capability test of electromagnetic thrust with the proportional valve body. Considering the high controllability and ease of production, the driver of this proportional valve was designed with a small volume and powerful solenoid force to control braking pressure and flow. Since the proportional valve can have closed-loop control, the proportional valve can replace a conventional solenoid valve in current brake actuators. With the proportional valve controlling braking and pressure relief mode, it can narrow the space of hydraulic braking actuator, and precisely control braking force to achieve safety objectives. Finally, the proposed novel proportional pressure control valve of an automobile hydraulic braking actuator was implemented and verified experimentally.

  13. Design and testing of a rotational brake with shear thickening fluids

    Science.gov (United States)

    Tian, Tongfei; Nakano, Masami

    2017-03-01

    A rotational brake working with shear thickening fluid (STF) was designed and tested in this study. With the optimisation in design, most of the STF in the brake can receive the same shear rate when the brake rotates. The parts of this brake were fabricated with a 3D printer and then assembled manually. Three types of STFs with various carrier fluids and different particles were fabricated and tested with a rheometer. Then the brake with each STF was separately tested with the rheometer. The estimated and measured torques as a function of the angular velocity fit each other well. The stability of the rotational STF brake was investigated in repeated tests, which proved the function of the brake for a long time.

  14. Wheel brake with mechatronic parameter value control - investigation of operating behaviour and driver integration problems, with particurticular regard to brake-by-wire systems; Radbremse mit mechatronischer Kennwertregelung - Untersuchung von Betriebsverhalten und Fahreranbindungsproblematik, hinsichtlich Brake-by-Wire-Systemen

    Energy Technology Data Exchange (ETDEWEB)

    Leber, M.

    1998-11-01

    The book presents a new brake system with mechatronically controlled self-energizing and with low energy demand. Potentials and limits of mechatronic parameter value control are pointed out with a view towards future brake-by-wire systems. Measurements on a parameter-controlled duplex drum brake provide information on the response to different disturbances. The possibility of influencing the driver by parameter-controlled wheel brakes were investigated in a novel experimental vehicle with freely programmable brake system parameters, and the main paramters of the driver/brake system interface were identified. The report ends with a few words on adaptive brake systems which can combine optimum driving efficiency with maximum comfort in all possible driving situations. (orig.) [Deutsch] Das vorliegende Buch stellt eine neuartige Fahrzeugbremse mit mechatronisch geregelter Selbstverstaerkung vor, die einen niedrigen Spannenergiebedarf aufweist. Im Hinblick auf zukuenftige Brake-by-Wire-Systeme werden Potentiale, aber auch Grenzen einer mechatronischen Kennwertregelung aufgezeigt. Messungen an einer kennwertgeregelten Duplex-Trommelbremse geben Aufschluss ueber das Betriebsverhalten unter Einfluss verschiedener Stoergroessen. Die Moeglichkeiten einer Fahrerbeeinflussung durch kennwertgeregelte Radbremsen werden mittels eines neuartigen Versuchsfahrzeugs mit frei programmierbaren Bremssystemparametern untersucht. Darueber hinaus wird die Schnittstelle Fahrer/Bremssystem hinsichtlich ihrer bestimmenden Parameter beschrieben. Den Schluss der Arbeit bildet ein Ausblick auf adaptive Bremssysteme mit dem Potential, optimale fahrdynamische Effizienz bei groesstmoeglichem Komfort situationsabhaengig darzustellen. (orig.)

  15. CP and CP-PGN protect mice against MRSA infection by inducing M1 macrophages.

    Science.gov (United States)

    Zhang, Yang; Li, Xiang-Xiang; Ma, Yuan; Xu, Jie; Zhao, Li-Na; Qian, Xue-Feng; Zhang, Xian-Feng; Shi, Jin-Fang; Han, Qing-Zhen

    2017-12-04

    Corynebacterium pyruviciproducens (C. pyruviciproducens, CP), as a newly discovered immunomodulator, has been confirmed to have a stronger immunoregulation than Propionibacterium acnes (P. acnes) of the traditional immune adjuvant, by previous experiments with model antigen ovalbumin and sheep red blood cells. Here, it was designed to assess its ability to resist methicillin-resistant Staphylococcus aureus (MRSA), since MRSA as a vital gram positive pathogen is characterized by high morbidity and mortality. In this report, it was indicated that C. pyruviciproducens and its peptidoglycan (CP-PGN) could help to be against bloodstream infection of MRSA with raised survival rate, decreased bacteria load and alleviated systemic inflammation, and these effects of CP-PGN were more pronounced. However, the whole CP was inclined to prevent localized abdominal infection of MRSA from progressing to a systemic infection. And they showed the potential as a therapeutic drug alone or combined with vancomycin. The diversity of capacity of activating macrophages induced by CP and CP-PGN may result in distinct resistance to MRSA in different infection models. Furthermore, both CP and CP-PGN induced M1 macrophages. In conclusion, CP and its PGN could act as promising immune agents to treat and prevent MRSA infection.

  16. Synthesis and oxidation of CpIrIII compounds: functionalization of a Cp methyl group.

    Science.gov (United States)

    Park-Gehrke, Lisa S; Freudenthal, John; Kaminsky, Werner; Dipasquale, Antonio G; Mayer, James M

    2009-03-21

    [CpIrCl(2)](2) () and new CpIr(III)(L-L)X complexes (L-L = N-O or C-N chelating ligands; X = Cl, I, Me) have been prepared and their reactivity with two-electron chemical oxidants explored. Reaction of with PhI(OAc)(2) in wet solvents yields a new chloro-bridged dimer in which each of the Cp ligands has been singly acetoxylated to form [Cp(OAc)Ir(III)Cl(2)](2) () (Cp(OAc) = eta(5)-C(5)Me(4)CH(2)OAc). Complex and related carboxy- and alkoxy-functionalized Cp(OR) complexes can also be prepared from plus (PhIO)(n) and ROH. [Cp(OAc)Ir(III)Cl(2)](2) () and the methoxy analogue [Cp(OMe)Ir(III)Cl(2)](2) () have been structurally characterized. Treatment of [CpIrCl(2)](2) () with 2-phenylpyridine yields CpIr(III)(ppy)Cl () (ppy = cyclometallated 2-phenylpyridyl) which is readily converted to its iodide and methyl analogues CpIr(III)(ppy)I and CpIr(III)(ppy)Me (). CpIr(III) complexes were also prepared with N-O chelating ligands derived from anthranilic acid (2-aminobenzoic acid) and alpha-aminoisobutyric acid (H(2)NCMe(2)COOH), ligands chosen to be relatively oxidation resistant. These complexes and were reacted with potential two-electron oxidants including PhI(OAc)(2), hexachlorocyclohexadienone (C(6)Cl(6)O), N-fluoro-2,4,6-trimethylpyridinium (Me(3)pyF(+)), [Me(3)O]BF(4) and MeOTf (OTf = triflate, CF(3)SO(3)). Iridium(V) complexes were not observed or implicated in these reactions, despite the similarity of the potential products to known CpIr(V) species. The carbon electrophiles [Me(3)O]BF(4) and MeOTf appear to react preferentially at the N-O ligands, to give methyl esters in some cases. Overall, the results indicate that Cp is not inert under oxidizing conditions and is therefore not a good supporting ligand for oxidizing organometallic complexes.

  17. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

  18. CP and other gauge symmetries in string theory

    International Nuclear Information System (INIS)

    Dine, M.; Leigh, R.G.; MacIntire, D.A.

    1992-01-01

    We argue that CP is a gauge symmetry in string theory. As a consequence, CP cannot be explicitly broken either perturbatively or nonperturbatively; there can be no nonperturbative CP-violating parameters. String theory is thus an example of a theory where all θ angles arise due to spontaneous CP violation, and are in principle calculable

  19. Diagnostics monitor of the braking efficiency in the on board diagnostics system for the motor vehicles

    Science.gov (United States)

    Gajek, Andrzej

    2016-09-01

    The article presents diagnostics monitor for control of the efficiency of brakes in various road conditions in cars equipped with pressure sensor in brake (ESP) system. Now the brake efficiency of the vehicles is estimated periodically in the stand conditions on the base of brake forces measurement or in the road conditions on the base of the brake deceleration. The presented method allows to complete the stand - periodical tests of the brakes by current on board diagnostics system OBD for brakes. First part of the article presents theoretical dependences between deceleration of the vehicle and brake pressure. The influence of the vehicle mass, initial speed of braking, temperature of brakes, aerodynamic drag, rolling resistance, engine resistance, state of the road surface, angle of the road sloping on the deceleration have been analysed. The manner of the appointed of these parameters has been analysed. The results of the initial investigation have been presented. At the end of the article the strategy of the estimation and signalization of the irregular value of the deceleration are presented.

  20. Thermal design of AOTV heatshields for a conical drag brake

    Science.gov (United States)

    Pitts, W. C.; Murbach, M. S.

    1985-01-01

    Results are presented from an on-going study of the thermal performance of thermal protection systems for a conical drag brake type AOTV. Three types of heatshield are considered: rigid ceramic insulation, flexible ceramic blankets, and ceramic cloths. The results for the rigid insulation apply to other types of AOTV as well. Charts are presented in parametric form so that they may be applied to a variety of missions and vehicle configurations. The parameters considered include: braking maneuver heat flux and total heat load, heatshield material and thickness, heatshield thermal mass and conductivity, absorptivity and emissivity of surfaces, thermal mass of support structure, and radiation transmission through thin heatshields. Results of temperature calculations presented show trends with and sensitivities to these parameters. The emphasis is on providing information that will be useful in estimating the minimum required mass of these heatshield materials.

  1. Plasma Jet Braking: Energy Dissipation and Nonadiabatic Electrons

    International Nuclear Information System (INIS)

    Khotyaintsev, Yu. V.; Cully, C. M.; Vaivads, A.; Andre, M.; Owen, C. J.

    2011-01-01

    We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth's magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the electron temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of electrons and isotropization of the electron distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the electron dynamics and thus play an important role in the energy conversion chain during plasma jet braking.

  2. Syntegra: complete integration of traction, bogie and brake systems

    Energy Technology Data Exchange (ETDEWEB)

    Loewenstein, L.; Wangelin, F. von [Siemens AG, Transportation Systems, Erlangen (Germany). Group Technology TS GT; Teichmann, M.; Hoffmann, T. [Siemens TS, Graz (Austria); Joeckel, A. [Siemens Automation and Drives, Nuernberg (Germany)

    2007-07-01

    With Syntegra {sup registered} technology, Siemens has developed an approach to the complete integration of traction, bogie and brake systems, and this has initially been put into practice for metro, underground and S-Bahn (urban regional express) trains. Syntegra constitutes a fundamentally new approach, achieving a greater intensity of integration compared with the types of drive system that have been in use up until now. With Syntegra, the bogie, transmission and brake components are all brought together as part of one and the same system. The integration and, more especially, the technological advances within the three named areas bring about numerous synergies. The new generation of powered bogie features a combination of high efficiency, low dead weight and reduced emissions. A Syntegra drive system achieves a performance which is markedly better than that of conventional systems. (orig.)

  3. Did the CP audits promote the enterprises' CP? A case study in Beijing.

    Science.gov (United States)

    Yu, Gang; Huang, Jun; Chen, Qing

    2002-03-09

    Seven enterprises that have had recent Cleaner Production (CP) audits in Beijing were interviewed to identify whether these enterprises implemented the audit recommendations. If enterprises did implement the recommendations, their reasons and the results were analyzed. Finally, some suggestions on how to promote enterprise-wide CP were given.

  4. Flavor and CP invariant composite Higgs models

    International Nuclear Information System (INIS)

    Redi, Michele; Weiler, Andreas

    2011-09-01

    The flavor protection in composite Higgs models with partial compositeness is known to be insufficient. We explore the possibility to alleviate the tension with CP odd observables by assuming that flavor or CP are symmetries of the composite sector, broken by the coupling to Standard Model fields. One realization is that the composite sector has a flavor symmetry SU(3) or SU(3) U x SU(3) D which allows us to realize Minimal Flavor Violation. We show how to avoid the previously problematic tension between a flavor symmetric composite sector and electro-weak precision tests. Some of the light quarks are substantially or even fully composite with striking signals at the LHC. We discuss the constraints from recent dijet mass measurements and give an outlook on the discovery potential. We also present a different protection mechanism where we separate the generation of flavor hierarchies and the origin of CP violation. This can eliminate or safely reduce unwanted CP violating effects, realizing effectively ''Minimal CP Violation'' and is compatible with a dynamical generation of flavor at low scales. (orig.)

  5. Flavor and CP invariant composite Higgs models

    Energy Technology Data Exchange (ETDEWEB)

    Redi, Michele [CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.; INFN, Firenze (Italy); Weiler, Andreas [CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2011-09-15

    The flavor protection in composite Higgs models with partial compositeness is known to be insufficient. We explore the possibility to alleviate the tension with CP odd observables by assuming that flavor or CP are symmetries of the composite sector, broken by the coupling to Standard Model fields. One realization is that the composite sector has a flavor symmetry SU(3) or SU(3){sub U} x SU(3){sub D} which allows us to realize Minimal Flavor Violation. We show how to avoid the previously problematic tension between a flavor symmetric composite sector and electro-weak precision tests. Some of the light quarks are substantially or even fully composite with striking signals at the LHC. We discuss the constraints from recent dijet mass measurements and give an outlook on the discovery potential. We also present a different protection mechanism where we separate the generation of flavor hierarchies and the origin of CP violation. This can eliminate or safely reduce unwanted CP violating effects, realizing effectively ''Minimal CP Violation'' and is compatible with a dynamical generation of flavor at low scales. (orig.)

  6. 49 CFR 232.305 - Single car air brake tests.

    Science.gov (United States)

    2010-10-01

    ... from a train or when placed on a shop or repair track, as defined in § 232.303(a); (2) A car is on a shop or repair track, as defined in § 232.303(a), for any reason and has not received a single car air... 49 Transportation 4 2010-10-01 2010-10-01 false Single car air brake tests. 232.305 Section 232...

  7. Thulium fiber laser lithotripsy using a muzzle brake fiber tip

    Science.gov (United States)

    Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

    2017-02-01

    The Thulium fiber laser (TFL) is being explored as an alternative to Holmium:YAG laser for lithotripsy. TFL beam profile allows coupling of higher power into smaller fibers than multimode Holmium laser beam, without proximal fiber tip degradation. A smaller fiber provides more space in ureteroscope working channel for increased saline irrigation and allows maximum ureteroscope flexion. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback, but increased retropulsion. In this study, a "fiber muzzle brake" was tested for reducing fiber burnback and stone retropulsion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-OD, 360-μm-ID tube with 275-μm thru hole located 250-μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed, ex vivo. Small stones with a mass of 40 +/- 4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 +/- 4 s (n=10), without distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers. The muzzle brake fiber tip provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

  8. Carbon nanotube torsional springs for regenerative braking systems

    International Nuclear Information System (INIS)

    Liu, Sanwei; Martin, Corbin; Livermore, Carol; Lashmore, David; Schauer, Mark

    2015-01-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg −1   ±  1.2 kJ kg −1 and 3.4 kJ kg −1   ±  0.4 kJ kg −1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg −1 and 0.67 kW kg −1 , respectively, with maximum measured values of up to 4.7 kJ kg −1 and 1.2 kW kg −1 , respectively. A slightly lower energy density of up to 1.2 kJ kg −1 and a 0.29 kW kg −1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism. (paper)

  9. Carbon nanotube torsional springs for regenerative braking systems

    Science.gov (United States)

    Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

    2015-10-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg-1  ±  1.2 kJ kg-1 and 3.4 kJ kg-1  ±  0.4 kJ kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg-1 and 0.67 kW kg-1, respectively, with maximum measured values of up to 4.7 kJ kg-1 and 1.2 kW kg-1, respectively. A slightly lower energy density of up to 1.2 kJ kg-1 and a 0.29 kW kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

  10. CP-even and CP-odd transverse polarization of the electron in muon decay

    International Nuclear Information System (INIS)

    Kuznetsov, A.

    1981-01-01

    A model of the weak interaction which contains intermediate vector bosons of the most general form and which admits CP violation in muon decay is used to calculate the CP-even and CP-odd transverse polarization of the μ-decay electrons with inclusion of radiative corrections. It is shown that these corrections are important only at the beginning of the spectrum, and their contribution reduces the observed effects of the transverse polarization. The transverse polarization grows appreciably at electron energies close to the maximum energy and at small emission angles. It is expedient to search for the CP-even and CP-odd transverse polarization of the electrons at energies E/sub e/ = 0.975E/sup max//sub e/ and emission angles theta = 25--35 0

  11. CP-even and CP-odd transverse polarization of the electron in the muon decay

    International Nuclear Information System (INIS)

    Kuznetsov, A.V.

    1981-01-01

    In the most general weak interaction model with intermediate vector bosons, allowing CP breaking in the muon decay, CP- even and CP-odd transverse polarization of the μ-decay electrons is calculated taking into account the radiative corrections. It is shown that such corrections are essential only at the beginning of the spectrum reducing the observed transverse polarization effects. When the electron energy is close to its maximum and the emission angles are small, the transverse polarization considerably grows. Search for CP-even and CP-odd transverse polarization of the electrons should be carried out at energies Esub(e) approximately equal to O.975 Esub(e)sup(max) and emission angles THETA approximately equal to 25+35 deg [ru

  12. Using robotics in kinematics classes: exploring braking and stopping distances

    Science.gov (United States)

    Brockington, Guilherme; Schivani, Milton; Barscevicius, Cesar; Raquel, Talita; Pietrocola, Maurício

    2018-03-01

    Research in the field of physics teaching has revealed high school students’ difficulties in establishing relations between kinematic equations and real movements. Moreover, there are well-known and significant challenges in their comprehension of graphic language content. Thus, this article explores a didactic activity which utilized robotics in order to investigate significant aspects of kinematics, gathering data and performing analyses and descriptions via graphs and mathematical equations which were indispensable for the analysis of the phenomena in question. Traffic safety appears as a main theme, with particular emphasis on the distinction between braking and stopping distances in harsh conditions, as observed in the robot vehicle’s tires and track. This active-learning investigation allows students to identify significant differences between the average value of the initial empirical braking position and that of the vehicle’s programmed braking position, enabling them to more deeply comprehend the relations between mathematical and graphic representations of this real phenomenon and the phenomenon itself, thereby providing a sense of accuracy to this study.

  13. Stellar rotation, dynamo, electromagnetic braking, age an lithium burning

    International Nuclear Information System (INIS)

    Schatzmann, E.

    1989-01-01

    After an introduction describing the problem and the observational tests of the theory a consistant model of the dynamo mechanism in rotating star is presented. This provides for the electromagnetic braking a law Ω ∼ (1.t/t c har) -3 / 4 , in good agreement with the observations. This rests on the hypothesis that the main contribution to the EM braking is due to the magnetic field present in bipolar magnetic spots at the surface of the stellar disk. The premain sequence EM braking provides an initial angular velocity on arrival on the main sequence which is slightly smaller than the angular velocity when the dynamo turns on. Starting the dynamo takes place when the level at which the (αΩ) dynamo number becomes larger than one drops below the ionization level of hydrogen. Before that time, the surface dynamo mechanism would take place in a region of low ionization, where the magnetic Reynods number is so small that dissipation overtakes the building of the magnetic field. Turbulent mixing with a turbulent diffusion coefficient proportional to Ω 2 provides a consistant picture of the time and mass dependance of the surface abundance of Lithium. When the level of Li-burning is sufficiently far from the bottom of the convective zone an asymptotic value of lithium abundance is reached. This can explain the anomalous Li abundance of pop.II stars. (author). 40 refs

  14. Design and multi-physics optimization of rotary MRF brakes

    Science.gov (United States)

    Topcu, Okan; Taşcıoğlu, Yiğit; Konukseven, Erhan İlhan

    2018-03-01

    Particle swarm optimization (PSO) is a popular method to solve the optimization problems. However, calculations for each particle will be excessive when the number of particles and complexity of the problem increases. As a result, the execution speed will be too slow to achieve the optimized solution. Thus, this paper proposes an automated design and optimization method for rotary MRF brakes and similar multi-physics problems. A modified PSO algorithm is developed for solving multi-physics engineering optimization problems. The difference between the proposed method and the conventional PSO is to split up the original single population into several subpopulations according to the division of labor. The distribution of tasks and the transfer of information to the next party have been inspired by behaviors of a hunting party. Simulation results show that the proposed modified PSO algorithm can overcome the problem of heavy computational burden of multi-physics problems while improving the accuracy. Wire type, MR fluid type, magnetic core material, and ideal current inputs have been determined by the optimization process. To the best of the authors' knowledge, this multi-physics approach is novel for optimizing rotary MRF brakes and the developed PSO algorithm is capable of solving other multi-physics engineering optimization problems. The proposed method has showed both better performance compared to the conventional PSO and also has provided small, lightweight, high impedance rotary MRF brake designs.

  15. The Role of Solid Lubricants for Brake Friction Materials

    Directory of Open Access Journals (Sweden)

    Werner Österle

    2016-02-01

    Full Text Available This review article comprises of three parts. Firstly, reports of brake manufacturers on the beneficial impact of solid lubricants for pad formulations are surveyed. Secondly, since tribofilms were identified to play a crucial role in friction stabilization and wear reduction, the knowledge about tribofilm structures formed during automotive braking was reviewed comprehensively. Finally, a model for simulating the sliding behavior of tribofilms is suggested and a review on modelling efforts with different model structures related to real tribofilms will be presented. Although the variety of friction composites involved in commercial brake systems is very broad, striking similarities were observed in respect to tribofilm nanostructures. Thus, a generalization of the tribofilm nanostructure is suggested and prerequisites for smooth sliding performance and minimal wear rates have been identified. A minimum of 13 vol % of soft inclusions embedded in an iron oxide based tribofilm is crucial for obtaining the desired properties. As long as the solid lubricants or their reaction products are softer than magnetite, the main constituent of the tribofilm, the model predicts smooth sliding and minimum wear.

  16. SPINDOWN OF ISOLATED NEUTRON STARS: GRAVITATIONAL WAVES OR MAGNETIC BRAKING?

    International Nuclear Information System (INIS)

    Staff, Jan E.; Jaikumar, Prashanth; Chan, Vincent; Ouyed, Rachid

    2012-01-01

    We study the spindown of isolated neutron stars from initially rapid rotation rates, driven by two factors: (1) gravitational wave emission due to r-modes and (2) magnetic braking. In the context of isolated neutron stars, we present the first study including self-consistently the magnetic damping of r-modes in the spin evolution. We track the spin evolution employing the RNS code, which accounts for the rotating structure of neutron stars for various equations of state. We find that, despite the strong damping due to the magnetic field, r-modes alter the braking rate from pure magnetic braking for B ≤ 10 13 G. For realistic values of the saturation amplitude α sat , the r-mode can also decrease the time to reach the threshold central density for quark deconfinement. Within a phenomenological model, we assess the gravitational waveform that would result from r-mode-driven spindown of a magnetized neutron star. To contrast with the persistent signal during the spindown phase, we also present a preliminary estimate of the transient gravitational wave signal from an explosive quark-hadron phase transition, which can be a signal for the deconfinement of quarks inside neutron stars.

  17. Neuroendocrine brake for the treatment of morbid obesity. Preliminary report

    Directory of Open Access Journals (Sweden)

    Aureo Ludovico de Paula

    2005-06-01

    Full Text Available Objectives: To demonstrate the preliminary results of a newtechnique named neuroendocrine brake, for surgical treatment ofmorbid obesity. Methods: In November 2003, three patientsunderwent the neuroendocrine brake operation performed by thelaparoscopic approach. The mean age was 46.4 years; all patientswere female. Mean BMI was 42.3 kg/m2. The patients selectedpresented some relative or absolute contraindications to the useof gastrointestinal bypass techniques, including gastric ulcer anda family history of gastric malignancy(1 and chronic anemia (2.All patients had associated diseases, including type II diabetesmellitus (2, hypertension (2, obstructive sleep apnea (1,dyslipidemia (3, cholecystolithiasis (1, gastric ulcer (1 andchronic anemia (2. The laparoscopic technique consisted of anileal interposition at the proximal jejunum and longitudinalgastrectomy. Results: There was no conversion to open surgery orpostoperative complications. Sixteen months later, the meanpercentage of initial body weight loss was 44.6% and the meanBMI was 24.3 kg/m2. Glucose, triglyceride and cholesterol levelswere normalized, and sleep apnea showed remission. Conclusion:In spite of the reduced number of patients and short term followup, the good results suggest that the neuroendocrine brake maybecome an option for surgical treatment of morbid obesity in thenear future.

  18. An evaluation of short-term exposures of brake mechanics to asbestos during automotive and truck brake cleaning and machining activities.

    Science.gov (United States)

    Richter, Richard O; Finley, Brent L; Paustenbach, Dennis J; Williams, Pamela R D; Sheehan, Patrick J

    2009-07-01

    Historically, the greatest contributions to airborne asbestos concentrations during brake repair work were likely due to specific, short-duration, dust-generating activities. In this paper, the available short-term asbestos air sampling data for mechanics collected during the cleaning and machining of vehicle brakes are evaluated to determine their impact on both short-term and daily exposures. The high degree of variability and lack of transparency for most of the short-term samples limit their use in reconstructing past asbestos exposures for brake mechanics. However, the data are useful in evaluating how reducing short-term, dust-generating activities reduced long-term exposures, especially for auto brake mechanics. Using the short-term dose data for grinding brake linings from these same studies, in combination with existing time-weighted average (TWA) data collected in decades after grinding was commonplace in rebuilding brake shoes, an average 8-h TWA of approximately 0.10 f/cc was estimated for auto brake mechanics that performed arc grinding of linings during automobile brake repair (in the 1960s or earlier). In the 1970s and early 1980s, a decline in machining activities led to a decrease in the 8-h TWA to approximately 0.063 f/cc. Improved cleaning methods in the late 1980s further reduced the 8-h TWA for most brake mechanics to about 0.0021 f/cc. It is noteworthy that when compared with the original OSHA excursion level, only 15 of the more than 300 short-term concentrations for brake mechanics measured during the 1970s and 1980s possibly exceeded the standard. Considering exposure duration, none of the short-term exposures were above the current OSHA excursion level.

  19. Lectures on Flavor Physics and CP Violation

    CERN Document Server

    Grinstein, Benjamín

    2016-12-20

    These lectures on flavor physics are an introduction to the subject. First lec- ture: We discuss the meaning of flavor and the importance of flavor physics in restricting extensions of the Standard Model (SM) of Electroweak interactions. We explain the origin of the KM matrix and how its elements are determined. We discuss FCNC and the GIM mechanism, followed by how a principle of Minimal Flavor Violation leads to SM extensions that are safe as far as FCNC are concerned even if the new physics comes in at low, TeVish scales. This is illustrated by the example of B radiative decays ( b → sγ ). Second lecture: We then turn our attention to CP-violation. We start by presenting neutral meson mixing. Then we consider various CP-asymmetries, culminating in the theoretically clean interference between mixing and decay into CP eigenstates.

  20. CP asymmetries in semiinclusive B0 decays

    Energy Technology Data Exchange (ETDEWEB)

    Dunietz, Isard

    1999-02-01

    It was recently pointed out that inclusive B^0(t) decays could show CP violation. The totally inclusive asymmetry is expected to be tiny [O(10^{-3})] because of large cancellations among the asymmetries in the charmless, single charm and double charm final states. Enriching particular final state configurations could significantly increase the CP-asymmetry and observability. Such studies can extract fundamental CKM (Cabibbo-Kobayashi-Maskawa) parameters, and (perhaps) even Delta m(B_s). A superb vertex detector could see CP violation with 10^5 (10^6) flavor-tagged B_s (B_d) mesons within the CKM model. Because the effects could be significantly larger due to new physics, they should be searched for in existing or soon available data samples.

  1. On the measurement of leptonic CP violation

    International Nuclear Information System (INIS)

    Burguet Castell, J.; Gavela, M.B.; Gomez Cadenas, J.J.; Hernandez, P.; Mena, O.

    2001-01-01

    We show that the simultaneous determination of the leptonic CP-odd phase δ and the angle θ 13 from the subleading transitions ν e →ν μ and ν-bar e →ν-bar μ results generically, at fixed neutrino energy and baseline, in two degenerate solutions. In light of this, we refine a previous analysis of the sensitivity to leptonic CP violation at a neutrino factory, in the LMA-MSW scenario, by exploring the full range of δ and θ 13 . Furthermore, we take into account the expected uncertainties on the solar and atmospheric oscillation parameters and in the average Earth matter density along the neutrino path. An intermediate baseline of O(3000) km is still the best option to tackle CP violation, although a combination of two baselines turns out to be very important in resolving degeneracies

  2. The CpG island searcher: a new WWW resource.

    Science.gov (United States)

    Takai, Daiya; Jones, Peter A

    2003-01-01

    Clusters of CpG dinucleotides in GC rich regions of the genome called "CpG islands" frequently occur in the 5' ends of genes. Methylation of CpG islands plays a role in transcriptional silencing in higher organisms in certain situations. We have established a CpG-island-extraction algorithm, which we previously developed [Takai and Jones, 2002], on a web site which has a simple user interface to identify CpG islands from submitted sequences of up to 50kb. The web site determines the locations of CpG islands using parameters (lower limit of %GC, ObsCpG/ExpCpG, length) set by the user, to display the value of parameters on each CpG island, and provides a graphical map of CpG dinucleotide distribution and borders of CpG islands. A command-line version of the CpG islands searcher has also been developed for larger sequences. The CpG Island Searcher was applied to the latest sequence and mapping information of human chromosomes 20, 21 and 22, and a total of 2345 CpG islands were extracted and 534 (23%) of them contained first coding exons and 650 (28%) contained other exons. The CpG Island Searcher is available on the World Wide Web at http://www.cpgislands.com or http://www.uscnorris.com/cpgislands/cpg.cgi.

  3. A possible explanation of the CP puzzle

    International Nuclear Information System (INIS)

    Takhtamyshev, Georgij

    1996-03-01

    The problem of mirror-reflection symmetry (MRS) and time-reversal symmetry (TRS) in our world is discussed. The opinion is expressed, that well-known experiments on parity violation and CP-violation can be treated as signals of some new, yet unknown, level of matter. An hypothesis, which can be used as a base for some future model or theory is formulated. In the framework of this hypothesis, experiments will demonstrate parity violation or CP-violation do not contradict MRS or TRS conservation. (author). 14 refs

  4. CP violation in rare K decays

    International Nuclear Information System (INIS)

    Ecker, G.

    1990-01-01

    The investigation of rare K decays calls for a unified treatment of short- and long-distance aspects as provided by chiral perturbation theory. For the standard model with three generations, the theoretical predictions for signals of CP violation in those decays are reviewed. With direct CP violation as the main target, special emphasis is given to the charge asymmetries in charged K decays and to the especially rare decays K L → π 0 ll-bar. Time dependent rate asymmetries in K 0 decays and the longitudinal muon polarization in K L → μ + μ - are also discussed. 50 refs., 3 figs., 1 tab. (Author)

  5. A Combined Cooperative Braking Model with a Predictive Control Strategy in an Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2013-12-01

    Full Text Available Cooperative braking with regenerative braking and mechanical braking plays an important role in electric vehicles for energy-saving control. Based on the parallel and the series cooperative braking models, a combined model with a predictive control strategy to get a better cooperative braking performance is presented. The balance problem between the maximum regenerative energy recovery efficiency and the optimum braking stability is solved through an off-line process optimization stream with the collaborative optimization algorithm (CO. To carry out the process optimization stream, the optimal Latin hypercube design (Opt LHD is presented to discrete the continuous design space. To solve the poor real-time problem of the optimization, a high-precision predictive model based on the off-line optimization data of the combined model is built, and a predictive control strategy is proposed and verified through simulation. The simulation results demonstrate that the predictive control strategy and the combined model are reasonable and effective.

  6. Mechanism analysis and evaluation methodology of regenerative braking contribution to energy efficiency improvement of electrified vehicles

    International Nuclear Information System (INIS)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Yuan, Ye

    2015-01-01

    Highlights: • The energy flow of an electric vehicle with regenerative brake is analyzed. • Methodology for measuring the regen brake contribution is discussed. • Evaluation parameters of regen brake contribution are proposed. • Vehicle tests are carried out on chassis dynamometer. • Test results verify the evaluation method and parameters proposed. - Abstract: This article discusses the mechanism and evaluation methods of contribution brought by regenerative braking to electric vehicle’s energy efficiency improvement. The energy flow of an electric vehicle considering the braking energy regeneration was analyzed. Then, methodologies for measuring the contribution made by regenerative brake to vehicle energy efficiency improvement were introduced. Based on the energy flow analyzed, two different evaluation parameters were proposed. Vehicle tests were carried out on chassis dynamometer under typical driving cycles with three different control strategies. The experimental results the difference between the proposed two evaluation parameters, and demonstrated the feasibility and effectiveness of the evaluation methodologies proposed

  7. The effects of porosity in friction performance of brake pad using waste tire dust

    Directory of Open Access Journals (Sweden)

    İbrahim Mutlu

    2015-10-01

    Full Text Available Abstract This research is focused on the effect of porosity on the friction-wear properties of automotive brake pads. Waste Tire Dust (WTD was used as a new friction material in brake pads. Newly formulated brake pad materials with five different components have been produced by conventional techniques. In the experimental studies, the change of the friction coefficient, the temperature of the friction surface, the specific wear rate, and the hardness, density and porosity were measured. In addition, the micro-structural characterizations of brake pads are determined using Scanning Electron Microscopy (SEM. The mean coefficient of friction, porosity and specific wear are increased due to a WTD rate increases, on the other hand, hardness and density are decreased. As a result, WTD can be considered as an alternative to revalorize this kind of waste products in the brake pads and the amount of porosity of the brake pad affected the friction coefficient and wear behavior of the pad.

  8. Research on squeal noise of tread brake system in rail freight vehicle

    Science.gov (United States)

    Zhang, Jun; Li, Yong-hua; Fang, Ji; Zhao, Wen-zhong

    2017-07-01

    Brake squeal is a result of a unstable flutter from brake system, it results to the noise pollution in railway side and excessive wear of wheel tread. A finite element model of brake system for rail freight vehicle is set up, the contact and friction between the brake shoe and wheel tread is considered, the complex modals of brake system are calculated, the possibility of happening chatter and squeal noise are analyzed. The results show that the pressure angle or the brake force direction have a important influence on the unstable chatter and squeal noise, the more greater the pressure angle deviates from the wheel center, the more greater the possibility of happening chatter and squeal noise is, and the possibility of happening chatter and squeal noise is also increased along with the addition of friction factor.

  9. The Application of Vibration Accelerations in the Assessment of Average Friction Coefficient of a Railway Brake Disc

    Directory of Open Access Journals (Sweden)

    Sawczuk Wojciech

    2017-06-01

    Full Text Available Due to their wide range of friction characteristics resulting from the application of different friction materials and good heat dissipation conditions, railway disc brakes have long replaced block brakes in many rail vehicles. A block brake still remains in use, however, in low speed cargo trains. The paper presents the assessment of the braking process through the analysis of vibrations generated by the components of the brake system during braking. It presents a possibility of a wider application of vibroacoustic diagnostics (VA, which aside from the assessment of technical conditions (wear of brake pads also enables the determination of the changes of the average friction coefficient as a function of the braking onset speed. Vibration signals of XYZ were measured and analyzed. The analysis of the results has shown that there is a relation between the values of the point measures and the wear of the brake pads.

  10. Anti-lock braking system (ABS) and regenerative braking system (RBS) in hybrid electric vehicle for smart transportation system

    Science.gov (United States)

    Evuri, Geetha Reddy; Rao, G. Srinivasa; Reddy, T. Ramasubba; Reddy, K. Srinivasa

    2018-04-01

    Pulse width modulation (PWM) based (a non-consistent) breaking system is used to keep the wheels from being bolted in the proposed antilock breaking system (ABS). Using this method a better hold of the street by wheels is possible and halting separations likewise diminish essentially particularly on precarious street surfaces like frosty or wet streets. The active vitality of the wheel is by and large lost amid braking as warmth because of grinding among brake cushions. This vitality can be recuperated using regenerative braking systems (RBS). In this strategy, the overabundance vitality is put away incidentally in capacitor banks before it gets changed over to warm vitality and is squandered. This framework delays the battery life by reviving the battery utilizing the put away vitality. Subsequently the mileage of the electric vehicle likewise increments as it can travel more separation in a solitary battery charge. These two techniques together help make electric vehicle vitality productive and more secure and less demanding to utilize subsequently anticipating and diminishing the quantity of mischance's.

  11. Investigation into the use of water based brake fluid for light loads ...

    African Journals Online (AJOL)

    The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus· of University of Uyo and the· braking effiqiency obtained at test to its suitability for light loads. Keywords·: Water-based, Brake fluid properties, Light loads ...

  12. Detection technology research on the one-way clutch of automatic brake adjuster

    Science.gov (United States)

    Jiang, Wensong; Luo, Zai; Lu, Yi

    2013-10-01

    In this article, we provide a new testing method to evaluate the acceptable quality of the one-way clutch of automatic brake adjuster. To analysis the suitable adjusting brake moment which keeps the automatic brake adjuster out of failure, we build a mechanical model of one-way clutch according to the structure and the working principle of one-way clutch. The ranges of adjusting brake moment both clockwise and anti-clockwise can be calculated through the mechanical model of one-way clutch. Its critical moment, as well, are picked up as the ideal values of adjusting brake moment to evaluate the acceptable quality of one-way clutch of automatic brake adjuster. we calculate the ideal values of critical moment depending on the different structure of one-way clutch based on its mechanical model before the adjusting brake moment test begin. In addition, an experimental apparatus, which the uncertainty of measurement is ±0.1Nm, is specially designed to test the adjusting brake moment both clockwise and anti-clockwise. Than we can judge the acceptable quality of one-way clutch of automatic brake adjuster by comparing the test results and the ideal values instead of the EXP. In fact, the evaluation standard of adjusting brake moment applied on the project are still using the EXP provided by manufacturer currently in China, but it would be unavailable when the material of one-way clutch changed. Five kinds of automatic brake adjusters are used in the verification experiment to verify the accuracy of the test method. The experimental results show that the experimental values of adjusting brake moment both clockwise and anti-clockwise are within the ranges of theoretical results. The testing method provided by this article vividly meet the requirements of manufacturer's standard.

  13. Airborne Wear Particles Emissions fromCommercial Disc Brake Materials– Passenger Car Field Test

    OpenAIRE

    Wahlström, Jens; Olofsson, Ulf; Jansson, Anders; Olander, Lars

    2008-01-01

    Most modern passenger cars have disc brakes on the front wheels, which unlike drum brakes are not sealed off to the ambient air. During braking, there is wear to both the rotor and the pads. This wear process generates particles, which may become airborne. In field tests it is difficult to distinguish these particles from others in the surrounding environment. It may be preferable to use laboratory test stands where the cleanness of the surrounding air can be controlled. The validity of these...

  14. Studies on Horizontal Axis Wind Turbine with Passive Teetered Brake & Damper Mechanism

    OpenAIRE

    SHIMIZU, Yukimaru; KAMADA, Yasunari; MAEDA, Takao

    1998-01-01

    In order to improve the reliability of megawatt wind turbines, the passive teetered brake & damper mechanism is applied. Its two unique effects, as its name implies, are braking and damping. The passive brake & damper mechanism is useful for variable speed control of the large wind turbine. It is comprised of teetering and feathering mechanisms. When the wind speed exceeds the rated wind speed, the blade is passively teetered in a downwind direction and, at the same time, a feathering mechani...

  15. Computational Fluid Dynamics (CFD) investigation onto passenger car disk brake design

    International Nuclear Information System (INIS)

    Munisamy, Kannan M; Moorthy, Shangkari K Kanasan

    2013-01-01

    The aim of this study is to investigate the flow and heat transfer in ventilated disc brakes using Computational Fluid Dynamics (CFD). NACA Series blade is designed for ventilated disc brake and the cooling characteristic is compared to the baseline design. The ventilated disc brakes are simulated using commercial CFD software FLUENT TM using simulation configuration that was obtained from experiment data. The NACA Series blade design shows improvements in Nusselt number compared to baseline design.

  16. Computational Fluid Dynamics (CFD) investigation onto passenger car disk brake design

    Science.gov (United States)

    Munisamy, Kannan M.; Kanasan Moorthy, Shangkari K.

    2013-06-01

    The aim of this study is to investigate the flow and heat transfer in ventilated disc brakes using Computational Fluid Dynamics (CFD). NACA Series blade is designed for ventilated disc brake and the cooling characteristic is compared to the baseline design. The ventilated disc brakes are simulated using commercial CFD software FLUENTTM using simulation configuration that was obtained from experiment data. The NACA Series blade design shows improvements in Nusselt number compared to baseline design.

  17. Study on friction behaviour of brake shoe materials for mining hoist

    Science.gov (United States)

    Ungureanu, M.; Ungureanu, N. S.; Crăciun, I.

    2017-02-01

    The friction coefficient in the brake linkages has an important influence on the braking efficiency and safety of machines. The paper presents a method for the study of the friction coefficient of the friction couple brake shoe-drum for mining hoist. In this context, it is interesting to define the friction coefficient, not just according to the materials in contact, but according to the entire ensemble of tribological factors of the friction couple.

  18. The dynamic performance and economic benefit of a blended braking system in a multi-speed battery electric vehicle

    International Nuclear Information System (INIS)

    Ruan, Jiageng; Walker, Paul D.; Watterson, Peter A.; Zhang, Nong

    2016-01-01

    Highlights: • Maximum braking energy recovery potentials of various cycles are reported. • Braking strategies are proposed for performance, comfort and energy recovery. • Braking force distributions and wheel slip ratios of different strategies are demonstrated. • The performance of ‘Eco’ strategy is experimentally validated in HWFET and NEDC. • The economic benefit of energy recovering is summarized, regarding to the fuel and maintenance cost saving. - Abstract: As motor-supplied braking torque is applied to the wheels in an entirely different way to hydraulic friction braking systems and it is usually only connected to one axle complicated effects such as wheel slip and locking, vehicle body bounce and braking distance variation will inevitability impact on the performance and safety of braking. The potential for braking energy recovery in typical driving cycles is presented to show its benefit in this study. A general predictive model is designed to analysis the economic and dynamic performance of blended braking systems, satisfying the relevant regulations/laws and critical limitations. Braking strategies for different purposes are proposed to achieve a balance between braking performance, driving comfort and energy recovery rate. Special measures are taken to avoid any effects of motor failure. All strategies are analyzed in detail for various braking events. Advanced driver assistance systems (ADAS), such as ABS and EBD, are properly integrated to work with the regenerative braking system (RBS) harmoniously. Different switching plans during braking are discussed. The braking energy recovery rates and brake force distribution details for different driving cycles are simulated. Results for two of the cycles in an ‘Eco’ mode are measured on a drive train test rig and found to agree with the simulated results to within approximately 10%. Reliable conclusions can thus be gained on the economic benefit and dynamic braking performance. The

  19. Use of MSC/NASTRAN for the thermal analysis of the Space Shuttle Orbiter braking system

    Science.gov (United States)

    Shu, James; Mccann, David

    1987-01-01

    A description is given of the thermal modeling and analysis effort being conducted to investigate the transient temperature and thermal stress characteristics of the Space Shuttle Orbiter brake components and subsystems. Models are constructed of the brake stator as well as of the entire brake assembly to analyze the temperature distribution and thermal stress during the landing and braking process. These investigations are carried out on a UNIVAC computer system with MSC/NASTRAN Version 63. Analytical results and solution methods are presented and comparisons are made with SINDA results.

  20. WHY DO THE BRAKING INDICES OF PULSARS SPAN A RANGE OF MORE THAN 100 MILLIONS?

    International Nuclear Information System (INIS)

    Zhang Shuangnan; Xie Yi

    2012-01-01

    Here we report that the observed braking indices of the 366 pulsars in the sample of Hobbs et al. range from about –10 8 to about +10 8 and are significantly correlated with their characteristic ages. Using the model of magnetic field evolution we developed previously based on the same data, we derive an analytical expression for the braking index which agrees with all the observed statistical properties of the braking indices of the pulsars in the sample of Hobbs et al. Our model is, however, incompatible with the previous interpretation that magnetic field growth is responsible for the small values of braking indices ( 3 yr. We find that the ''instantaneous'' braking index of a pulsar may be different from the ''averaged'' braking index obtained from fitting the data over a certain time span. The close match between our model-predicted ''instantaneous'' braking indices and the observed ''averaged'' braking indices suggests that the time spans used previously are usually smaller than or comparable to their magnetic field oscillation periods. Our model can be tested with the existing data by calculating the braking index as a function of the time span for each pulsar. In doing so, one can obtain for each pulsar all the parameters in our magnetic field evolution model, and may be able to improve the sensitivity of using pulsars to detect gravitational waves.