WorldWideScience

Sample records for brake linings

  1. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    Arnab Ganguly; Raji George

    2008-02-01

    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 wear and shows good temperature stability.

  2. 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.

  3. REPORT on the TRUCK BRAKE LINING WORKSHOP and FLEET OPERATORS' SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.

    2003-02-03

    The report summarizes what transpired during brake linings-related workshop held at the Fall 2003 meeting of the Technology and Maintenance Council (TMC) in Charlotte, NC. The title of the workshop was ''Developing a Useful Friction Material Rating System''. It was organized by a team consisting of Peter Blau (Oak Ridge National Laboratory), Jim Britell (National Highway Traffic Safety Administration), and Jim Lawrence (Motor and Equipment Manufacturers Association). The workshop was held under the auspices of TMC Task Force S6 (Chassis), chaired by Joseph Stianche (Sanderson Farms, Inc.). Six invited speakers during the morning session provided varied perspectives on testing and rating aftermarket automotive and truck brake linings. They were: James R. Clark, Chief Engineer, Foundation Brakes and Wheel Equipment, Dana Corporation, Spicer Heavy Axle and Brake Division; Charles W. Greening, Jr, President, Greening Test Labs; Tim Duncan, General Manager, Link Testing Services;Dennis J. McNichol, President, Dennis NationaLease; Jim Fajerski, Business Manager, OE Sales and Applications Engineering, Federal Mogul Corporation; and Peter J. Blau, Senior Materials Development Engineer, Oak Ridge National Laboratory. The afternoon break-out sessions addressed nine questions concerning such issues as: ''Should the federal government regulate aftermarket lining quality?''; ''How many operators use RP 628, and if so, what's good or bad about it?''; and ''Would there be any value to you of a vocation-specific rating system?'' The opinions of each discussion group, consisting of 7-9 participants, were reported and consolidated in summary findings on each question. Some questions produced a greater degree of agreement than others. In general, the industry seems eager for more information that would allow those who are responsible for maintaining truck brakes to make better, more informed choices

  4. The Tribological Efficiency and the Mechanism of Action of Nano-Porous Composition Base Brake Lining Materials

    Science.gov (United States)

    Kutelia, E. R.; Gventsadze, D. I.; Eristavil, B. G.; Maisuradze, N. I.; Tsurtsumia, O. O.; Gventsadze, L. D.; Olofsson, U.; Wahlström, J.; Olander, L.

    2011-12-01

    Based on the comparative analysis of the experimental values determined for the tribological parameters for the three novel nano-porous composition base and two conventional brake lining materials while friction with the grey cast iron disc, it was shown the considerable high tribological efficiency of the novel nano-porous composition base lining materials in comparison with the conventional (from EU and USA market) brake lining materials. The explanation is given to the action mechanism of nano-porous composition base brake lining material and its tribological efficiency basing on the "triple phase" tribo-pair model.

  5. Integration of Gas Nitrocarburising and Oxidising in a Mass Production Line for Brake Pistons

    Institute of Scientific and Technical Information of China (English)

    Gero Walkowiak; Dieter M(u)ller; Uwe Zeibig

    2004-01-01

    The combination of wear- and corrosion resistance is a demand to a multitude of automotive parts. Several metallic coatings as hard/soft chromium or electroless nickel have been the conventional surface protection e.g. on parts as brake pistons and shock absorber or gas spring piston rods. The Corr-I-Dur(R) process - a special gasnitrocarburising and oxidising technology - has a huge potential not only in substituting those coatings but also in delivering surfaces with higher quality.The benefits of the replacement of soft chromium with Corr-I-Dur(R) and the implementation of the process in the customers production line with an annual capacity of 17 million brake pistons is described in this presentation. Starting with the demands on wear- and corrosion resistance the way of process development and the design of applicative equipment is shown. The result is a tailor-made surface solution with superior quality for deep drawn brake pistons. Two main disadvantagesoutgassing of the chromium layer and reduced corrosion resistance on the inner diameter - are eliminated by the replacement with Corr-I-Dur(R). The process-sure achievement of enhanced corrosion resistance, uniform layer thickness, negligible distortion as well as environmental and economical advantages make Corr-I-Dur(R) an excellence choice for this application.

  6. 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…

  7. Metal emissions from brake linings and tires: case studies of Stockholm, Sweden 1995/1998 and 2005.

    Science.gov (United States)

    Hjortenkrans, David S T; Bergbäck, Bo G; Häggerud, Agneta V

    2007-08-01

    Road traffic has been highlighted as a major source of metal emissions in urban areas. Brake linings and tires are known emission sources of particulate matter to air; the aim of the current study was to follow the development of metal emissions from these sources over the period 1995/ 1998-2005, and to compare the emitted metal quantities to other metal emission sources. Stockholm, Sweden was chosen as a study site. The calculations were based on material metal concentrations, traffic volume, particle emission factors, and vehicle sales figures. The results for metal emissions from brake linings/tire tread rubber in 2005 were as follows: Cd 0.061/0.47 kg/year, Cu 3800/5.3 kg/year, Pb 35/3.7 kg/year, Sb 710/0.54 kg/year, and Zn 1000/4200 kg/ year. The calculated Cu and Zn emissions from brake linings were unchanged in 2005 compared to 1998, indicating that brake linings still remain one of the main emission sources for these metals. Further, brake linings are a source of antimony. In contrast, Pb and Cd emissions have decreased to one tenth compared to 1998. The results also showed that tires still are one of the main sources of Zn and Cd emissions in the city.

  8. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Science.gov (United States)

    2010-10-01

    ... (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.47 Brake actuators... steering axle of a truck, truck-tractor or bus shall not be less than 4.8 mm (3/16 inch) at the shoe...

  9. Asbestos fibres in the lungs of an American mechanic who drilled, riveted, and ground brake linings: a case report and discussion.

    Science.gov (United States)

    Finkelstein, Murray M

    2015-05-01

    In North America and Europe, the use of asbestos in friction products was discontinued before the end of the 20th century. In the developing world, the use of asbestos-containing friction products continues. In 2010, Cely-Garcia and colleagues (Cely-Garcia et al., 2012) sampled three brake repair shops located in Bogota, Colombia. Both asbestos and non-asbestos containing brake linings were sold separately or attached to a shoe. When brake linings are sold separated from the shoe, they must be manipulated to attach them to the shoe before installation. The process starts with the removal of the old brake shoe from the vehicle's brake drum. If the existing brake shoe is to be reused, the old lining needs to be removed and the old shoe must be ground to prepare it for a new lining. Riveting requires drilling holes in the linings and shoes and before installing rivets, the lining must be countersunk. The borders of the lining are bevelled. On some occasions, the entire exposed surface of the lining is ground to make it thinner. Once attached to the shoe, the edges of brake linings may extend beyond the shoe. In this case, it is necessary to cut or grind the edges to match the lining to the shoe before bevelling or grinding. The authors reported that 'the sampling results indicate that the brake mechanics sampled are exposed to extremely high asbestos concentrations (i.e. based on transmission electron microscopy counts), suggesting that this occupational group could be at excess risk of asbestos-related diseases'.

  10. 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.

  11. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY...-second of an inch over the fastener, or one-sixteenth of an inch over the brake shoe on bonded linings or... surface. Drum brake linings shall be securely attached to brake shoes. Disc brake pads shall be...

  12. 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.

  13. 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

  14. Bicycle Braking System

    OpenAIRE

    Brady, Noel

    2001-01-01

    A bicycle braking system for permitting controlled rotation and continuous power to the wheels of a bicycle during braking of the bicycle to enhance control of the bicycle during braking includes a cylindrical brake pad that is spring loaded within angled slots in a casing. The brake pad is positioned proximate the rim of a wheel and a cable assembly is coupled to the brake pad for urging the brake pad towards an end of the angled slots and against the rim of the wheel to slow rotation of the...

  15. Simulation analysis for effect of pad lining arc on disc brake squeal%摩擦衬片包角对盘式制动器尖叫影响的仿真分析

    Institute of Scientific and Technical Information of China (English)

    张立军; 陈前银; 刁坤; 孟德建; 余卓平

    2016-01-01

    摩擦衬片包角对制动尖叫具有重要影响。针对某通风盘式制动器,建立有限元复模态模型并通过尖叫台架试验进行了正确性验证。基于该模型针对5种包角水平的摩擦衬片,通过仿真计算分析其对制动尖叫倾向性的影响,并从制动块自由模态特性、盘块间接触压力分布、不稳定模态频率及模态耦合特性角度解释了不同摩擦衬片包角对制动尖叫的影响机制。分析表明:摩擦衬片包角的改变会同时引起制动块结构特性变化和接触压力分布的变化,进而引起不稳定模态数量、频率和模态耦合特性的改变。%Lining arc of brake pad has a very important effect on disc brake squeal.A finite element complex analysis model of a ventilated disc brake was established and validated through a bench test of brake squeal.Based on this model,the influence of pad lining arc on brake squeal trend was investigated using simulation of disc brakes with pads of five lining arcs.At the same time,the influence mechanism was studied from view points of natural vibration characteristics of brake pad,pressure distribution between pad and disc,instable modal frequencies and modal coupling. It was shown that the structural characteristics and pressure distribution variations due to pad lining arc variations can cause the change of instable modes,modal frequencies and modal coupling.

  16. 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... straight air brake 30-50 (7) Self-lapping portion for electro-pneumatic brake (minimum full application... 49 Transportation 4 2010-10-01 2010-10-01 false General requirements for all train brake...

  17. Magnetic braking in ultracompact binaries

    CERN Document Server

    Farmer, Alison

    2010-01-01

    Angular momentum loss in ultracompact binaries, such as the AM Canum Venaticorum stars, is usually assumed to be due entirely to gravitational radiation. Motivated by the outflows observed in ultracompact binaries, we investigate whether magnetically coupled winds could in fact lead to substantial additional angular momentum losses. We remark that the scaling relations often invoked for the relative importance of gravitational and magnetic braking do not apply, and instead use simple non-empirical expressions for the braking rates. In order to remove significant angular momentum, the wind must be tied to field lines anchored in one of the binary's component stars; uncertainties remain as to the driving mechanism for such a wind. In the case of white dwarf accretors, we find that magnetic braking can potentially remove angular momentum on comparable or even shorter timescales than gravitational waves over a large range in orbital period. We present such a solution for the 17-minute binary AM CVn itself which a...

  18. 复合式制动气室性能在线检测系统设计%Disquisition of Performance On-line Detection System for Brake Chamber

    Institute of Scientific and Technical Information of China (English)

    刘宁霞; 罗哉

    2012-01-01

    设计并实现复合式制动气室性能在线检测系统,弥补国内对复合式制动气室性能在线检测研究存在的不足.引入伺服加载机构,突破以往检测中推杆行程限位装置加载速度不可控的局限,实现限位装置的加载速度精确可调;应用高速数据采集卡和计算机控制技术,提高系统的采集速度和测量精度.可对多类型的复合式制动气室驻车制动腔静特性、行车制动腔静特性、开始释放压力等性能进行在线测试和分析.通过试验分析表明检测系统能真实准确的对复合式制动气室的性能进行在线检测,检测周期小于2min/个,其测量精度达到实际应用的要求,并采用R&R法客观的分析检测系统,已达到新设备的验收条件.%The on-line detection system for brake chamber was designed and realized, which made up for the domestic deficiency of on-line detection research for brake chamber. Servo-loading mechanism was introduced in the design of test system to break through the limitation of which previous test can not control the load speed of brake chamber and to achieve load speed precisely and adjustably. Using high-Speed data collection card and computer control technology to improve the sampling speed and the measuring accuracy of the system. It can test as well as analysis the static characteristic of parking brake chamber, static characteristic of service brake chamber and hold-off pressure on-line. Through the test and analysis shows that, the detection system can true accurate the performance of complex braking gas chamber by on-line detection, which the period less than 2 min, the measuring precision has met the practical requirement. Using the R&R method to objectively analysis the detection system, has reached the conditions of the new equipment successfully.

  19. 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.

  20. Safety Braking System

    Directory of Open Access Journals (Sweden)

    Joseph Charles

    2016-10-01

    Full Text Available Now a day's accidents due to brake failure are increasing in a high margin, so safety has acquired a greater priority. In order to control this sudden brake failures we have modified the conventional braking systems in automobiles by adding an extra safety brake to the engine shaft. The idea of the work is to improve the safety parameters regarding the brakes. Engagement of the secondary brake without the assistance of driver is an advantage for this system. As it would make the vehicle to stop without any lag. A Hall effect sensor is used to detect the motion of wheel by noting the magnetic field. The signals given out from the sensor directs the microcontroller to operate the relay and hence to actuate the solenoid and thereby actuating the secondary brake.

  1. Muzzle brakes and their performance

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal

    1958-01-01

    Full Text Available A criteria for the usefulness of a muzzle brake on any equipment is discussed and applied to existing weapons. Efficiencies of the existing muzzle brakes are also calculated. Design considerations for a muzzle brake are summarized.

  2. Study on the braking dyna mics and wheel/rail wear for the heavy haul trucks on ramp lines%重载货车坡道制动动力学及轮轨磨耗研究

    Institute of Scientific and Technical Information of China (English)

    李亨利; 李芾; 付茂海; 王璞

    2014-01-01

    Based on the multi-body dynamic method,a 10,000 tons train dynamic model includes one compli-cated car model with cross-braced bogie or radial bogie,and other 101 simple car models with only the longitu-dinal DOF (Degree of freedom)on the Da-Qin heavy haul lines were established.The coupler forces,buffer damping and braking air wave characteristics,were take into consideration.The vehicle dynamics,safety and wheel/rail wear of different type bogies were investigated when the train brakes on ramp lines.The results show that since the braking forces and brake shoe forces change wheel-rail relationship and creep,the wheel-rail wear is more severe on ramp lines,while the radial bogie on the whole can improve the running safety and wear.%运用多体动力学方法,建立了包括1辆详细车辆动力学模型,101辆仅考虑纵向自由度简化车辆模型的大秦重载铁路万t列车模型,模型包含车钩力、缓冲器阻抗特性、制动空气波传递,以及装配侧架交叉支撑转向架和径向转向架等因素。在此基础上,分析列车坡道制动的车辆动力学行为、运行安全性,以及制动力对不同转向架的影响。研究结果表明:制动力和闸瓦力改变了轮轨接触和蠕滑关系,线路坡道越大,轮轨磨耗越剧烈,但径向转向架可提高列车运行安全性,降低轮轨磨耗。

  3. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

    ... (ii) Allow the pilot(s) to override the system by use of manual braking. (d) Parking brake. The airplane must have a parking brake control that, when selected on, will, without further attention, prevent... be indication in the cockpit when the parking brake is not fully released. (e) Antiskid system. If...

  4. 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

  5. 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.

  6. The application of Lean Production by brake production line%制动器生产线精益生产的应用

    Institute of Scientific and Technical Information of China (English)

    吴军万

    2013-01-01

    This article introduced the assembly process of brake, combined with the operation, and used the theory by Lean Production as practical guidance, to achieve the largest production capacity with minimal staff.%  简要介绍了制动器的装配工艺流程,并结合实际操作,利用精益生产的理论作为实际指导,实现以最少的人力投入,获得最大的产能。

  7. 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.

  8. 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.

  9. 49 CFR 393.52 - Brake performance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Brake performance. 393.52 Section 393.52... NECESSARY FOR SAFE OPERATION Brakes § 393.52 Brake performance. (a) Upon application of its service brakes... braking force is measured by a performance-based brake tester which meets the requirements of...

  10. Research of Motorcycle Braking Parameters

    Directory of Open Access Journals (Sweden)

    Loreta Levulytė

    2016-12-01

    Full Text Available From a technical point of view, in dangerous or emergency situation is very important motorcycle driver reaction and vehicle braking time. Motor-cycle deceleration parameters depend not only on the motorcycle brake system, but also on the driving experience. A significant influence on decel-eration the motorcycle has aerodynamic parameters, pavement type and condition, as well as the technical condition of the motocycle, shock absorb-ers, tire type and their technical condition. This article provides an analysis of the motorcycle longitudinal deceleration, braking modes of the mo-torcycle on a dry asphalt road surface. Motorcycle stopping – deceleration – acceleration efficiency issue, stopping in different modes. First ana-lyzed the dynamics of a motorcycle deceleration braking only the front wheel, then braked front and rear wheels and complex – then braked the front and rear wheels at the same time. The goal of experimental study is to determine the influence of braking modes intense fir motorcycle brak-ing deceleration when braking on dry road pavement, at three different braking modes, and set the braking path of change. Motorcycle decelera-tion in the longitudinal direction is an important parameter for analysis traffic accidents, for accident reconstruction process and the examination of motorcyclists technical possibility to avoid an accident.

  11. Heat distribution in disc brake

    Science.gov (United States)

    Klimenda, Frantisek; Soukup, Josef; Kampo, Jan

    2016-06-01

    This article is deals by the thermal analysis of the disc brake with floating caliper. The issue is solved by numerically. The half 2D model is used for solution in program ADINA 8.8. Two brake discs without the ventilation are solved. One disc is made from cast iron and the second is made from stainless steel. Both materials are an isotropic. By acting the pressure force on the brake pads will be pressing the pads to the brake disc. Speed will be reduced (slowing down). On the contact surface generates the heat, which the disc and pads heats. In the next part of article is comparison the maximum temperature at the time of braking. The temperatures of both materials for brake disc (gray cast iron, stainless steel) are compares. The heat flux during braking for the both materials is shown.

  12. 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.

  13. A Predictive Distribution Model for Cooperative Braking System of an Electric Vehicle

    OpenAIRE

    Hongqiang Guo; Hongwen He; Xuelian Xiao

    2014-01-01

    A predictive distribution model for a series cooperative braking system of an electric vehicle is proposed, which can solve the real-time problem of the optimum braking force distribution. To get the predictive distribution model, firstly three disciplines of the maximum regenerative energy recovery capability, the maximum generating efficiency and the optimum braking stability are considered, then an off-line process optimization stream is designed, particularly the optimal Latin hypercube d...

  14. Brake Pedal Displacement Measuring System based on Machine Vision

    Directory of Open Access Journals (Sweden)

    Chang Wang

    2013-10-01

    Full Text Available Displacement of brake pedal was an important characteristic of driving behavior. This paper proposed a displacement measure algorithm based on machine vision. Image of brake pedal was captured by camera from left side, and images were processed in industry computer. Firstly, average smooth algorithm and wavelet transform algorithm were used to smooth the original image consecutively. Then, edge extracting method which combined Roberts’s operator with wavelet analysis was used to identify the edge of brake pedal. At last, least square method was adopted to recognize the characteristic line of brake pedal’s displacement. The experimental results demonstrated that the proposed method takes the advantages of Roberts’s operator and wavelet transform, it can obtain better measurement result as well as linear displacement sensors

  15. 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

  16. An analysis of braking measures

    NARCIS (Netherlands)

    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.

  17. 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...

  18. Fireproof Brake Hydraulic System.

    Science.gov (United States)

    1981-09-01

    bulk modulus and density are the same (see Table 2). AO-2 is the base stock fluid for AO-8 which is a blend of AO-2 and a viscosity index (VI) improver...RADIANS LI+ BRAK .. .... " 17 . 3000 4 BRAKE .~1~~ 4~~I 4 4 4- 4 .! L 3 00 00i- FTLB 0 ’ 25 00 +--- + + i DISPCE EN FiueE4 raeSse taiiy tndr ytm...VA LVE ... it .. . . .. . F... .. igur E. 8 Brak Syste Stability...... .. .. .. .. Tw-FuRRSstNTer Daming Amit 327. .. .. .. .... APPENDIX F

  19. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  20. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... by testing or previous service. (h) Hand brakes and parking brakes. (1) Except for a locomotive that..., and except for MU locomotives, all locomotives shall be equipped with a hand or parking brake that can... locomotives, on locomotives so equipped, the hand or parking brake as well as its parts and connections...

  1. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... thermal damage to wheels or discs. (f) The brake system design shall allow a disabled train's pneumatic... 49 Transportation 4 2010-10-01 2010-10-01 false Brake system. 238.431 Section 238.431... Equipment § 238.431 Brake system. (a) A passenger train's brake system shall be capable of stopping...

  2. 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.

  3. 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.

  4. 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.

  5. ANALYSIS OF FAILURE MECHANISM IN MULTIPLE DISC WET BRAKES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    By the numberical calculation of dynamic lining pressure distributions,temperature fields and thermal stress fields of steel plates,a method using nonlinear finite element techniques to analyze failure mechanism of a multiple disc wet brake is detailed ,and some measures for combatting these failures are provided.

  6. The Electronic Wedge Brake - EWB

    Energy Technology Data Exchange (ETDEWEB)

    Ho, L.M.; Roberts, R.P.; Hartmann, H.; Gombert, B. [Siemens VDO Automotive (Germany)

    2006-07-01

    Future driver assistance systems will not only monitor the current traffic situation, but actively assist the driver in the day to day driving routines and as well in emergency situations. Autonomous intervention in the vehicle behavior will help to keep the vehicle under control, even in hazardous situations. A fast and smart braking system is one of the basics for the next generation of driver assistance systems. Siemens VDO sees its electronic wedge brake (EWB) brake-by-wire technology as the answer to future vehicle chassis safety, weight, reliability and space requirements. Particularly in the automobile sector, there is an increasing trend towards replacing existing hydraulic or pneumatic brake systems with drive 'by-wire' solutions. While mechatronics, i.e. intelligent, controllable electromechanical actuators, are already in use in many automotive and non automotive areas, there are particularly strict requirements for purely electromechanical braking systems which require complex development processes. These are highly safety critical systems, which must provide both excellent control quality and sophisticated fail-safe behavior. The challenge is to achieve a high power density in the wheel brake actuators. (orig.)

  7. 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.

  8. Magnetic Braking Revisited

    CERN Document Server

    Taam, R E

    2003-01-01

    We present a description for the angular momentum loss rate due to magnetic braking for late type stars taking into account recent observational data on the relationship between stellar activity and rotation. The analysis is based on an idealized two component coronal model subject to constraints imposed on the variation of the coronal gas density with rotation period inferred from the observed variation of X-ray luminosity, L_x, with rotation rate, Omega, (L_x \\propto Omega^2) for single rotating dwarfs. An application of the model to high rotation rates leads to a gradual turnover of the X-ray luminosity which is similar to the saturation recently observed in rapidly rotating dwarfs. The resulting angular momentum loss rate, \\dot J, depends on Omega in the form \\dot J \\propto Omega^beta where beta ~ 3 for slow rotators and ~ 1.3 for fast rotators. The relation at high rotation rates significantly differs from the power law exponent for slowly rotating stars, depressing the angular momentum loss rate without...

  9. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    Science.gov (United States)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  10. A New Model of Stopping Sight Distance of Curve Braking Based on Vehicle Dynamics

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2016-01-01

    Full Text Available Compared with straight-line braking, cornering brake has longer braking distance and poorer stability. Therefore, drivers are more prone to making mistakes. The braking process and the dynamics of vehicles in emergency situations on curves were analyzed. A biaxial four-wheel vehicle was simplified to a single model. Considering the braking process, dynamics, force distribution, and stability, a stopping sight distance of the curve braking calculation model was built. Then a driver-vehicle-road simulation platform was built using multibody dynamic software. The vehicle test of brake-in-turn was realized in this platform. The comparison of experimental and calculated values verified the reliability of the computational model. Eventually, the experimental values and calculated values were compared with the stopping sight distance recommended by the Highway Route Design Specification (JTGD20-2006; the current specification of stopping sight distance does not apply to cornering brake sight distance requirements. In this paper, the general values and limits of the curve stopping sight distance are presented.

  11. 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.

  12. 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...

  13. 30 CFR 56.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment with... stop under normal operating conditions. Parking or emergency (secondary) brakes are not to be actuated... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Brakes. 56.14101 Section 56.14101...

  14. 49 CFR 236.712 - Brake pipe.

    Science.gov (United States)

    2010-10-01

    ...-pneumatic brake equipment on each vehicle of the train. ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake pipe. 236.712 Section 236.712 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.712 Brake pipe. A...

  15. Mountain Braking Test Venue Study

    Science.gov (United States)

    2013-12-12

    resistance, and engine braking. The following equation shows this relationship: PB = W ∙ V ∙ ϴ - PA – PRR – PE. (1) The engine braking power...vehicle rolling resistance is due to tires and can be characterized as: PRR = CRR ∙ W ∙ V ∙ CT / 375 (HP), (3) where CRR is the tire-road interface...resistance is proportional to tire load results in the following equation: PRR = (0.0002455 ∙ V2 + 1.784 ∙ V) ∙ W/80,000 (HP). (4) The power absorbed

  16. Braking performance of aircraft tires

    Science.gov (United States)

    Agrawal, Satish K.

    This paper brings under one cover the subject of aircraft braking performance and a variety of related phenomena that lead to aircraft hydroplaning, overruns, and loss of directional control. Complex processes involving tire deformation, tire slipping, and fluid pressures in the tire-runway contact area develop the friction forces for retarding the aircraft; this paper describes the physics of these processes. The paper reviews the past and present research efforts and concludes that the most effective way to combat the hazards associated with aircraft landings and takeoffs on contaminated runways is by measuring and displaying in realtime the braking performance parameters in the aircraft cockpit.

  17. The design of brake fatigue testing system

    OpenAIRE

    2015-01-01

    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 automa...

  18. TWO DESIGNS OF THE ELECTROMECHANICAL BRAKE EMBEDDED INTO AN ASYNCHRONOUS MOTOR

    Directory of Open Access Journals (Sweden)

    V. V. Solencov

    2016-01-01

    Full Text Available The significance of the braking devices is increasing due to the intensification of manufacturing, increase in the moving masses, speeds of movement and frequency of braking. During a short time period the braking device needs to convert a significant amount of mechanical energy into heat energy and transfer it into the environment without compromising the operability of both devices and machines in general. For electric actuators braking a normally closed mechanical brake is frequently used. When disconnecting the motor from the network the brake friction surfaces are closed and prevent rotation, and when the motor is switched on, they are opens under the action of the electromagnet, electro-hydraulic pusher, special electric motor, mechanical or pneumatic device. In the case of joint implementation of the asynchronous motor and the mechanical brake, the drive of quick stop is more compact and convenient. Such devices are further called asynchronous motors with electromechanical braking systems henceforth. The large number of requirements as well as different conditions of operation cause a large variety of designs of such motors. One of the major shortcomings of the functioning of well-known design is the periodic wear of the friction linings and the need for frequent replacement of them. The solution to this problem is the use of asynchronous motor with recessed combo braking device. However, for some mechanisms that do not require a smooth stop of the motor shaft and that have a speed of rotation of the motor shaft less than 1500 rpm, more simple and cheap solution would be the use of an electromechanical braking device with an air gap compensation. Due to wear of the friction linings the air gap of the electromagnet increases. Due to the compensation of the air gap of the electromagnet these devices make it possible to rub the material of the friction lining longer. The current designs of the electromechanical braking device with

  19. 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.

  20. Toxic effects of brake wear particles on epithelial lung cells in vitro

    Directory of Open Access Journals (Sweden)

    Perrenoud Alain

    2009-11-01

    Full Text Available Abstract Background Fine particulate matter originating from traffic correlates with increased morbidity and mortality. An important source of traffic particles is brake wear of cars which contributes up to 20% of the total traffic emissions. The aim of this study was to evaluate potential toxicological effects of human epithelial lung cells exposed to freshly generated brake wear particles. Results An exposure box was mounted around a car's braking system. Lung cells cultured at the air-liquid interface were then exposed to particles emitted from two typical braking behaviours („full stop“ and „normal deceleration“. The particle size distribution as well as the brake emission components like metals and carbons was measured on-line, and the particles deposited on grids for transmission electron microscopy were counted. The tight junction arrangement was observed by laser scanning microscopy. Cellular responses were assessed by measurement of lactate dehydrogenase (cytotoxicity, by investigating the production of reactive oxidative species and the release of the pro-inflammatory mediator interleukin-8. The tight junction protein occludin density decreased significantly (p Conclusion These findings suggest that the metals on brake wear particles damage tight junctions with a mechanism involving oxidative stress. Brake wear particles also increase pro-inflammatory responses. However, this might be due to another mechanism than via oxidative stress.

  1. 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.

  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. Brake Fluid Compatibility Studies with Advanced Brake Systems

    Science.gov (United States)

    2016-01-16

    identified as silane based compounds. Therefore, we can eliminate brake fluid polymerization as a possible cause since no siloxane based polymers were...cm-1 indicate presence of O-H peak corresponding UNCLASSIFIED DRAFT UNCLASSIFIED 21 to water ; 1631.50 cm-1 indicate presence of C=C peak...measurements are usually made using an auxiliary liquid with a known density. In this case, water is used as the auxiliary liquid. The weight of the o

  4. 49 CFR 393.49 - Control valves for brakes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Control valves for brakes. 393.49 Section 393.49... NECESSARY FOR SAFE OPERATION Brakes § 393.49 Control valves for brakes. (a) General rule. Except as provided..., which is equipped with power brakes, must have the braking system so arranged that one application...

  5. 49 CFR 393.41 - Parking brake system.

    Science.gov (United States)

    2010-10-01

    ... 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...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  6. 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...

  7. Contribution of MoS{sub 2} additives to the microstructure and properties of PM copper based brake material

    Energy Technology Data Exchange (ETDEWEB)

    Uzunsoy, Deniz; Kelesoglu, Erguen; Erarslan, Yaman [Yildiz Technical Univ. (Turkey). Metallurgical and Materials Engineering Dept.

    2009-07-01

    The effect of a MoS{sub 2} additive on the microstructural evolution and properties of copper based brake linings has been investigated in this study. It was found that the quantity of additive as well as sintering cycle has significant effect on the density and hardness values of the produced material. The microstructure of designed brake lining materials showed that copper based matrix was surrounded by MoS{sub 2} particles. The microstructural investigation also proved that the lower boiling point elements such as Pb in the as-supplied powder vaporise during sintering from the structure, and this result in an increase in the porosity amount by lowering the overall density of brake linings. The Vickers hardness of brake linings decreased with the addition of molybdenum disulphide particles. MoS{sub 2} addition reduces wear rate of samples due to the solid lubrication effect. (orig.)

  8. 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.

  9. Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xiu; GAO Hong-xia; WEI Xiu-lan

    2004-01-01

    The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min, the coefficient of friction decreased rapidly. When the brake speed is 3000r/min, the material's wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to abradant and oxidation wear.

  10. CFD Analysis Of Straight Ventilated Disc Brake

    Directory of Open Access Journals (Sweden)

    Nikhil K

    2016-05-01

    Full Text Available Brakes are the key pieces of a vehicle that plays an active role in safety and performance of the system. The study of aerodynamic cooling of a disc brake in real working condition of vehicle is important in present situations. Brake discs get very hot quickly, so it should be dissipated properly through different modes of heat transfer. Contributions of these heat transfer modes are different in different type of problems. The cooling transfer rates are different in vane surface and frictional surface of a disc brake. Also the temperature varies in each small interval of braking time. So a transient problem simulation is important to study the cooling of a disc brake when a vehicle decelerates from a particular speed. ANSYS CFX tool is used for the simulation of this transient problem.

  11. 制动盘模态分析及其在生产线检测系统上的应用%Modal Analysis of Brake Disc and Its Application to Production-line Inspection System

    Institute of Scientific and Technical Information of China (English)

    褚志刚; 叶方标; 蒋忠翰; 张昌福; 周亚男

    2014-01-01

    为确定制动盘固有频率的容差范围,首先对其进行了试验模态分析和有限元模态分析,二者固有频率的误差小于2%,各对应阶次模态振型一致。在此基础上,利用有限元概率设计方法对影响制动盘固有频率的各结构设计变量进行了灵敏度分析,计算了制动盘固有频率的变化范围。结果表明,制动盘盘体直径、散热辐条宽度与高度、盘体内圈厚度、盘体外圈长度与厚度和沟槽深度等尺寸对低阶固有频率具有显著影响。表明有限元概率设计技术为在线检测系统各阶固有频率容差的设定提供了有效手段。%For determining the tolerance ranges of the natural frequencies of brake disc, firstly both experi-mental modal analysis and finite element modal analysis are conducted with relative errors of natural frequency re-sults less than 2% and the mode shapes of each corresponding order well coincide. On this basis, the sensitivities of natural frequency to the structural design variables of brake disc are analyzed by using finite element probability de-sign method with the natural frequency ranges of brake disc calculated. The results show that the disc diameter, the width and height of ventilated blades, the thickness of inner disc, the length and thickness of outer disc, and the groove depth have significant effects on lower-order natural frequencies. The finite element probability design tech-nique provides an effective means for the setting of tolerances of natural frequencies in online inspection system.

  12. An Experimental Analysis of Brake Efficiency Using four Fluids in a Disc Brake System

    Directory of Open Access Journals (Sweden)

    Seth Daniel Oduro

    2013-02-01

    Full Text Available The paper studies disc brake failure in Mini-buses using an experimental analysis to test the maximum braking force when different brake fluids such as clean, less dirty, dirty and soapy water solution were used in the braking system. The experimental results clearly showed that the soap solution appears to be the best fluid as far as low viscosity and stability of viscosity with increase in temperature are concerned. However, the soap solution is not compatible with other fluid which makes it difficult to be substitute as a clean brake fluid. The result of the Thepra Universal Brake Testing Equipment used for the braking efficiency test indicated that a pedal brake of 117 kN produce a brake force of 0.96 kN for clean brake fluid, 0.91 kN for the less dirty, 0.85 kN for dirty and 1.44 kN for soap solution. The value of 1.44 kN which was achieved when the soap solution was used indicated a positive braking force and the indicating that soap solution could be used to produce a high pedal force within a very short time (about 10-30 min and can therefore be used only in case of emergency. The brake efficiency test indicated that under hot conditions the braking efficiency is reduced and the presence of air in the system renders the braking ineffective because higher pedal force was needed to be able to produce a significant braking force which is noted for causing brake failure.

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

    Science.gov (United States)

    2008-05-20

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

  14. 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…

  15. BRAKE TEST OF SiCp/A356 BRAKE DISK AND INTERPRETATION OF EXPERIMENTAL RESULTS

    Institute of Scientific and Technical Information of China (English)

    YANG Zhiyong; HAN Jianmin; LI Weijing; WANG Jinhua

    2007-01-01

    Material properties are obvious different between aluminum matrix composites and iron and steel materials. After the brake disk braked at the same speed, the average temperature of the aluminum brake disk is 1.5 times as high as one of iron and steel brake disk, the thermal expansion value of the aluminum brake disk is 2 times as big as one of iron and steel brake disk. Mechanical property of the material decreases with the temperature increasing generally during braking, on the other hand, the big thermal stress in the brake disk happens because the material expansion is constrained. Firstly, the reasons of the thermal stress generation and the fracture failure of brake disks during braking are analyzed qualitatively by virtue of three-bar stress frame and sandwich deformation principles in physic, and then the five constraints which cause the thermal stress are summarized. On the base of the experimental results on the 1:1 emergency brake test, the thermal stress and temperature fields are simulated; The behavior of the fracture failure is interpreted semi-quantitatively by finite element analysis. There is the coincident forecast for the fraction position in term of the two methods. In the end, in the light of the analysis and calculation results, it is the general principles observed by the structure design and assembly of the brake disk that are summarized.

  16. Verification of pneumatic railway brake models

    Science.gov (United States)

    Piechowiak, Tadeusz

    2010-03-01

    The article presents a survey of diverse methods for validation of pneumatic train brake modelling. Various experimental measurements of railway pneumatic brakes were made chiefly on a test stand at Poznań University of Technology; other test stands and some results have been taken from the literature. The measurements, some of them unconventional, were performed on separate pneumatic elements, brake devices, the brake pipe and fragments thereof. Mechanical devices were also included. The experimental measurement results were used for the verification of numerical models and for the determination of parameters. The latter was partially performed using an optimisation method.

  17. Analysis and Design of Circular Plate MR Fluids Brake

    Institute of Scientific and Technical Information of China (English)

    Yang Yan; Lin Chang-Hua; Li Hui; Zhou Jing

    2004-01-01

    A magnetorheological (MR) fluids brake is a device to achieve brake by shear force of MR fluids. A MR rotary brake has the property that its braking torque changes quickly in response to an external magnetic field. In this study, the design method of the circular plate MR fluids brake is investigated theoretically. The equation of the torque transmitted by the MR fluids in the brake is derived to provide the theoretical foundation in the design of the brake. Based on this equation, after mathematically manipulated, the calculations of the volume, thickness and width of the MR fluids within the circular plate MR fluids brake are yield.

  18. Research on Heat-Mechanical Coupling of Ventilated Disc Brakes under the Condition of Emergency Braking

    Science.gov (United States)

    Tan, Xuelong; Zhang, Jian; Tang, Wenxian; Zhang, Yang

    Taking the ventilated disc brake in some company as research object, and using UG to build 3D models of brake disc and pad, and making use of ABAQUS/Standard to set up two parts' finite element model, via the decelerated motion of actual simulation brake disc, which gets ventilated disc brake in the case of emergency breaking in time and space distribution of conditions of temperature and stress field, summarizes the distribution of temperature field and stress field, proves complex coupling between temperature, stress, and supplies the direct basis for brake's fatigue life analysis.

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

    Directory of Open Access Journals (Sweden)

    Guoshun Wang

    2013-01-01

    Full Text Available 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 position of the friction block of the brake pad. Structure optimization was conducted on brake pads composed of 5 or 7 circular friction blocks. The result shows that, with the same overall contact area of friction pair, an appropriate brake pad structure can make the friction energy distribute evenly and therefore lowers peak temperature and stress of the brake disc. Compared with a brake pad of 7 friction blocks, an optimized brake pad of 5 friction blocks lowered the peak temperature of the corresponding brake disc by 4.9% and reduced the highest stress by 10.7%.

  20. Effect of surface texture and working gap on the braking performance of the magnetorheological fluid brake

    Science.gov (United States)

    Wang, Na; Li, Dong Heng; Li Song, Wan; Chao Xiu, Shi; Zhi Meng, Xiang

    2016-10-01

    In this paper, the effect of the surface textures of braking disc on the braking performance is experimentally investigated under the conditions of different working gaps and applied currents. For this purpose, a new configuration of magnetorheological fluid brake (MRB) with adjustable working gap is developed to improve the manufacturing accuracy and cost, and to reduce the problem of replacing the braking disc. In addition, the braking discs with three types of surface texture are designed and machined. Based on the test bed developed for the proposed MRB, a series of experiments are carried out on the manufactured prototype and the results are presented to obtain the relationship among the surface texture of the braking disc, applied current, working gap and the braking performance. The results show that the braking torque is significantly influenced by the working gap and surface texture of the braking disc, and the maximum braking torque is obtained on the conditions of 0.25 mm working gap and the braking disc with square surface texture.

  1. Electronic Brake-Force Distribution Control Methods of ABS-Equipped Vehicles During Cornering Braking

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-ye; LIU Zhao-du; MA Yue-feng; QI Zhi-quan

    2007-01-01

    Based on the dynamics of ABS-equipped vehicles during cornering braking,the electronic brakeforce distribution (EBD) control methods of ABS-equipped vehicles during cornering braking are proposed.According to the dynamics and the tire model under tire adhesion limit,the stability acceptance criteria of vehicles during cornering braking are proposed.According to the stability acceptance criteria and the ABS control,the EBD control methods of ABS-equipped vehicles during cornering braking are implemented by adjusting the threshold values of tires slip independently.The vehicle states during cornering braking at two typical initial velocities of the vehicle are analyzed by the EBD control methods,whose results indicate the EBD control methods can improve the braking performances of the vehicle during cornering braking comparing with the ABS control.

  2. 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 with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  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 rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  4. Method and apparatus for electromagnetically braking a motor

    Science.gov (United States)

    Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

    2011-01-01

    An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

  5. Research on temperature rise of hoisting machine disk brake

    Institute of Scientific and Technical Information of China (English)

    MA Jun; JANG Hai-bo

    2012-01-01

    A mathematical model and finite element model for analysis of temperature rise of the hoisting machine brake system was constructed,limit conditions were defined,and the law of temperature rise of brake shoes during emergent brake course was analyzed and calculated by using finite element software.By analyzing the calculation results,the law of temperature change of surface of brake disk and shoes during the braking process was found.The law of brake shoes surface temperature distribution and the law of temperature change along with thickness of brake shoes at brake time 0.5 s,1.0 s and 1.5 s was analyzed.A hoisting machine emergent braking test was carried out.Finally,the author concluded that velocity rebound in the process of hoisting machine emergent brake is due to decreased friction coefficient caused by the temperature rise of the brake shoes surface.

  6. Intelligently Controllable Walker with Magnetorheological Fluid Brake

    Science.gov (United States)

    Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

    Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

  7. What brakes the Crab pulsar?

    CERN Document Server

    Čadež, A; Barbieri, C; Calvani, M; Naletto, G; Barbieri, M; Ponikvar, D

    2015-01-01

    Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. From our analysis, we demonstrate that the power law index undergoes "inst...

  8. 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.

  9. An Experimental Analysis of Brake Efficiency Using Four Fluids in a Drum Brake System

    Directory of Open Access Journals (Sweden)

    Prince Owusu-Ansah

    2014-06-01

    Full Text Available This paper studies drum brake failure in Mini-buses using an experimental analysis to test the viscosities and the maximum braking force when different fluids such as clean, less dirty, dirty and soapy water solution were used in the braking system. The effects of each of these fluids when successive increments in pedal force were applied at hot and cold conditions for drum brakes were studied. The results of the Thepra Universal Brake Testing Equipment used for the braking efficiency test indicated that a pedal force of 110 kN produce a brake force of 0.61 kN for clean fluid, 0.56 kN for less dirty, 0.51 kN for dirty and 0.92 kN. The value of 0.92 kN which was achieved when the soapy water solution was used indicated a positive braking force and that soap water solution could be used to produce a high pedal force within a very short time (10-30 min and can therefore be used only in case of emergency. It was observed that the clean brake fluid gave the best braking force followed by the less dirty and finally the dirty brake fluid. In a situation where air has been trapped in the system under hot condition with or without a servo unit, clean brake fluid performed much better at least three times better than the other three fluids. For soap solution, braking was effective only when it was operated at cold condition but less effective when the system was hot. Soap solution is therefore not reliable when used for a very long time but effective only for emergency situations.

  10. Study on Braking Sensation Based on Urban Working Conditions

    Directory of Open Access Journals (Sweden)

    Abi Lanie

    2017-01-01

    Full Text Available In this paper we researched the vehicle braking sense in three aspects of human, vehicle and environment and analysed their impacts on brake feeling. Through the real vehicle test we analysed the relationship among pedal force, pedal travel and deceleration. We used dynamometer test method to study the brake noise question. We designed a fixture which could imitate the suspension and made the test more close to the true level. Moreover we discussed how to establish the evaluation system of vehicle braking condition. Through real vehicle test of braking, we can test and record the brake system parameters in the braking process under urban working conditions. We recorded the brake frequency, the change of brake speed and brake disc temperature. Meanwhile, based on the analysis of braking condition, we put forward the index of brake load to reflect the city’s traffic conditions. Experiment show that the braking condition and brake feel are related, braking condition also provides theoretical support for the design of brake system.

  11. 49 CFR 570.55 - Hydraulic brake system.

    Science.gov (United States)

    2010-10-01

    ... parking brake and turn the ignition to start to verify that the brake system failure indicator lamp is... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles...

  12. 49 CFR 238.317 - Class II brake test.

    Science.gov (United States)

    2010-10-01

    ... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic... 49 Transportation 4 2010-10-01 2010-10-01 false Class II brake test. 238.317 Section 238.317... Requirements for Tier I Passenger Equipment § 238.317 Class II brake test. (a) A Class II brake test shall...

  13. 49 CFR 236.701 - Application, brake; full service.

    Science.gov (United States)

    2010-10-01

    ... developed. As applied to an automatic or electro-pneumatic brake with speed governor control, an application... 49 Transportation 4 2010-10-01 2010-10-01 false Application, brake; full service. 236.701 Section... § 236.701 Application, brake; full service. An application of the brakes resulting from a continuous...

  14. A Predictive Distribution Model for Cooperative Braking System of an Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2014-01-01

    Full Text Available A predictive distribution model for a series cooperative braking system of an electric vehicle is proposed, which can solve the real-time problem of the optimum braking force distribution. To get the predictive distribution model, firstly three disciplines of the maximum regenerative energy recovery capability, the maximum generating efficiency and the optimum braking stability are considered, then an off-line process optimization stream is designed, particularly the optimal Latin hypercube design (Opt LHD method and radial basis function neural network (RBFNN are utilized. In order to decouple the variables between different disciplines, a concurrent subspace design (CSD algorithm is suggested. The established predictive distribution model is verified in a dynamic simulation. The off-line optimization results show that the proposed process optimization stream can improve the regenerative energy recovery efficiency, and optimize the braking stability simultaneously. Further simulation tests demonstrate that the predictive distribution model can achieve high prediction accuracy and is very beneficial for the cooperative braking system.

  15. A Conceptual Design Method of Disc Brake Systems for Reducing Brake Squeal Considering Pressure Distribution Variations

    OpenAIRE

    松島, 徹; 泉井, 一浩; 西脇, 眞二

    2011-01-01

    This paper proposes a design optimization method for disc brake systems that specifically aims to reduce brake squeal, with robustness against changes on contact surface pressure distribution, based on the concept of First Order Analysis. First, a simplified analysis model is constructed in which a pressure distribution parameter is introduced, and the relationships between the occurrence of brake squeal and the characteristics of various components is then clarified, using the simplified mod...

  16. Structure Topology Optimization of Brake Pad in Large- megawatt Wind Turbine Brake Considering Thermal- structural Coupling

    Science.gov (United States)

    Zhang, S. F.; Yin, J.; Liu, Y.; Sha, Z. H.; Ma, F. J.

    2016-11-01

    There always exists severe non-uniform wear of brake pad in large-megawatt wind turbine brake during the braking process, which has the brake pad worn out in advance and even threats the safety production of wind turbine. The root cause of this phenomenon is the non-uniform deformation caused by thermal-structural coupling effect between brake pad and disc while braking under the conditions of both high speed and heavy load. For this problem, mathematical model of thermal-structural coupling analysis is built. Based on the topology optimization method of Solid Isotropic Microstructures with Penalization, SIMP, structure topology optimization of brake pad is developed considering the deformation caused by thermal-structural coupling effect. The objective function is the minimum flexibility, and the structure topology optimization model of brake pad is established after indirect thermal- structural coupling analysis. Compared with the optimization result considering non-thermal- structural coupling, the conspicuous influence of thermal effect on brake pad wear and deformation is proven as well as the rationality of taking thermal-structural coupling effect as optimization condition. Reconstructed model is built according to the result, meanwhile analysis for verification is carried out with the same working condition. This study provides theoretical foundation for the design of high-speed and heavy-load brake pad. The new structure may provide design reference for improving the stress condition between brake pad and disc, enhancing the use ratio of friction material and increasing the working performance of large-megawatt wind turbine brake.

  17. 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.

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

    Science.gov (United States)

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

    2015-06-01

    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.

  19. Hunting Plan Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan provides guidelines for administration of hunting activity and for development, maintenance, and enforcement of regulations and guidelines on Morgan Brake...

  20. Constraining the Braking Indices of Magnetars

    CERN Document Server

    Gao, Z F; Wang, N; Yuan, J P; Peng, Q H; Du, Y J

    2015-01-01

    Due to the lack of long term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index $n$ of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of $n$ of nine magnetars with SNRs, and find that they cluster in a range of $1\\sim$41. Six magnetars have smaller braking indices of $13$ for other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with $13$ within the updated magneto-thermal evolution models. We point out that there could be some connections between the magnetar's anti-glitch event and its braking index, and the magnitude of $n$ should be taken into account when explaining the event. Although the constrained range of the magnetars' braking indices is tentative, our method provides an effective way to constrain the magnetars' braking indices if th...

  1. Preliminary studies concerning the application of different braking arrangements on Italian freight trains

    Science.gov (United States)

    Pugi, Luca; Rindi, Andrea; Ercole, Andrea Giuseppe; Palazzolo, Alessandro; Auciello, Jury; Fioravanti, Duccio; Ignesti, Mirko

    2011-08-01

    Freight wagons are usually equipped with the standard Union Internationale des Chemins de Fer pneumatic brake. On long trains, the propagation of the pneumatic signals along the pipe and different braking/loading conditions may produce delays and/or differences in the application of the braking effort along the train. This phenomenon may cause heavy longitudinal forces exchanged between wagons through buffers and draw gear. In particular, the workgroup n.6 (freight trains composition) of the Italcertifer committee has performed some preliminary studies concerning the application of LL braking operative conditions on freight wagons trains travelling on Italian lines. Partners have cooperated in this workgroup; however, in this paper, the attention is focused on methodologies and results concerning the contribution of University of Florence. The results of this activity, coordinated by RFI-CESIFER have been used to emanate the 20/07 rule of the RFI ('Modifiche alla Prefazione Generale all'Orario di Servizio') which modify the composition criterion rules of freight trains on the Italian Railways in order to introduce and discipline the application of the LL braking operative condition.

  2. Durability investigation on torque control of a magneto-rheological brake: experimental work

    Science.gov (United States)

    Kim, Wan Ho; Park, Jhin Ha; Kim, Gi-Woo; Shin, Cheol Soo; Choi, Seung-Bok

    2017-03-01

    This study experimentally investigates the torque control durability of a disc brake featuring a magneto-rheological (MR) fluid. An appropriate size of MR disc brake is designed based on a mathematical model, and a prototype is manufactured. A small-scale laboratory-scale test bed is then developed using a DC motor, in-line torque sensor, and the MR brake. S45C and S20C steels are inserted into a tapered hole on the surface of the brake disc. After 105 cycles of operation in shear mode, the wear properties of the MR brake are characterized by average surface roughness measurements, scanning electron microscope images, and energy dispersive x-ray spectra. The torque control performances before and after the operation cycles are examined using open-loop control and closed-loop proportional-integral-derivative control. As expected, the control performance degraded after 105 cycles of operation in the open-loop case, but not in the closed-loop case. This aspect is demonstrated by the sinusoidal torque-tacking control performance before and after the operation cycles.

  3. Brake squeal reduction of vehicle disc brake system with interval parameters by uncertain optimization

    Science.gov (United States)

    Lü, Hui; Yu, Dejie

    2014-12-01

    An uncertain optimization method for brake squeal reduction of vehicle disc brake system with interval parameters is presented in this paper. In the proposed method, the parameters of frictional coefficient, material properties and the thicknesses of wearing components are treated as uncertain parameters, which are described as interval variables. Attention is focused on the stability analysis of a brake system in squeal, and the stability of brake system is investigated via the complex eigenvalue analysis (CEA) method. The dominant unstable mode is extracted by performing CEA based on a linear finite element (FE) model, and the negative damping ratio corresponding to the dominant unstable mode is selected as the indicator of instability. The response surface method (RSM) is applied to approximate the implicit relationship between the unstable mode and the system parameters. A reliability-based optimization model for improving the stability of the vehicle disc brake system with interval parameters is constructed based on RSM, interval analysis and reliability analysis. The Genetic Algorithm is used to get the optimal values of design parameters from the optimization model. The stability analysis and optimization of a disc brake system are carried out, and the results show that brake squeal propensity can be reduced by using stiffer back plates. The proposed approach can be used to improve the stability of the vehicle disc brake system with uncertain parameters effectively.

  4. Evaluation of Wear in Aftermarket Brake Pads for Enhancing Braking Performance in a Passenger Vehicle

    Directory of Open Access Journals (Sweden)

    Mohd Zaki Bahrom

    2016-08-01

    Full Text Available Nowadays, due to the high demands from the independence automotive service centers; there are many aftermarket brake pads available at spare parts shops and sold at reasonable prices. Several types of brake pads are available in the market such as semi-metallic and Non-Asbestos brake pads. The purpose of this study is to evaluate the wear of after-market brake pad performance under the normal driving conditions (highway and non-highway. Three types of aftermarket brake pads that mainly used and sold by independent service shop were selected in this study.  The data of the wear in thicknesses losses and weight percentage losses were recorded. The results show that brake pad of non- Asbestos Organic type gives the highest wear loss and create a lot of dust. For semi-metallic brake pad type, the result shows the lowest mass loss. Therefore, it is important to select the suitable type of after-market brake pads in order to get balance between cost and quality.

  5. On the safety of braking mine up-haulage devices

    Energy Technology Data Exchange (ETDEWEB)

    Murzin, V.A.; Samusia, V.I.

    1982-01-01

    Experiments conducted on several mine up-haulage devices to analyze breakdowns due to the operator who quickly turned on the brake showed that sudden braking may really invoke maximum brake application on the machine winding much earlier than preventive braking and may lead to shutdown. It was concluded that in the Safety Regulations or Engineering Regulations that use of the handbrake should be more clearly outlined to preclude breakdown. One method of prevention is to develop and use a diagram showing build-up and magnitude of the braking moment when using the manual brake.

  6. Braking Index of Isolated Pulsars

    CERN Document Server

    Hamil, Oliver Q; Urbanec, Martin; Urbancova, Gabriela

    2016-01-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities $\\Omega$, and their time derivatives that show unambiguously that the pulsars are slowing down. The commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of $\\Omega$. This relation leads to the power law $\\dot{\\Omega}$ = -K $\\Omega^{\\rm n}$ where $n$ is called the braking index. The MDR model predicts $n$ exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of $n$, individually accurate to a few percent or better, in the range 1$ <$ n $ < $ 2.8, which is consistently less than the predictions of the MDR model. In spite of an extensive investigation of various modifications of the MDR model, no satisfactory explanation of observation has been found yet. The aim of this work is t...

  7. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Science.gov (United States)

    2010-10-01

    ... conventional pneumatic brakes shall not move in a freight train operating in ECP brake mode unless it would otherwise have effective and operative brakes if it were part of a conventional pneumatic brake-equipped... pneumatic brakes shall not operate with freight cars equipped with stand-alone ECP brake systems unless:...

  8. HEAT TRANSIENT TRANSFER ANALYSIS OF BRAKE DISC /PAD SYSTEM

    OpenAIRE

    Thuppal Vedanta, Srivatsan; Kora, Naga Vamsi Krishna

    2016-01-01

    Braking is mainly controlled by the engine. Friction between a pair of pads and a rotating disc converts the kinetic energy of the vehicle into heat. High temperatures can be reached in the system which can be detrimental for both, components and passenger safety. Numerical techniques help simulate load cases and compute the temperatures field in brake disc and brake pads. The present work implements a Finite Element (FE) toolbox in Matlab/Simulink able to simulate different braking manoeuvre...

  9. The strength of the hybrid braking calipers analysis

    Institute of Scientific and Technical Information of China (English)

    Li Weitao; Yu Haiqing; Jiang Xiaoyan

    2015-01-01

    The braking system is an important part to ensure the safety of the vehicle, so the strength analysis is essential to the brake caliper. In this article, the forces will be mixed in the caliper brake systems theoretical analysis, and based on the actual working conditions established calipers ABAQUS finite element model to simulate calipers provide a theoretical basis for the structural design of the brake caliper.

  10. A Review of a Study on Disc Brake Noise

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With the development of the automotive industry, disc brake noise has become an issue of growing concern to the automotive industry and customers. In this paper, the types of disc brake noise have been discussed. Ajter that, the theories and models that have been proposed as an explanation of brake squeal are reviewed. On the basis of these theories and models, some example simulations of disc brake squeal which use the Finite Element method and mathematical model have been introduced.

  11. ACTIVE FRONT STEERING DURING BRAKING PROCESS

    Institute of Scientific and Technical Information of China (English)

    CHEN Deling; CHEN Li; YIN Chengliang; ZHANG Yong

    2008-01-01

    An active front steering (AFS) intervention control during braking for vehicle stability is presented. Based on the investigation of AFS mechanism, a simplified model of steering system is established and integrated with vehicle model. Then the AFS control on vehicle handling dynamics during braking is designed. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation. Thereafter, the controller with the feedback of both sideslip and yaw angle is implemented. To evaluate the system control, the proposed AFS controlled vehicle has been tested in the Hardware-in-the-loop-simulation (HILS) system and compared with that of conventional vehicle. Results show that AFS can improve vehicle lateral stability effectively without reducing the braking performance.

  12. Hillside, Morgans Brake, and Mathews Brake National Wildlife Refuges Deer Harvest Records are from 2008 and 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Hillside, Morgans Brake, and Mathews Brake NWRs during the 2008 and 2014 deer seasons. They measure weight, antler size, prevalence of...

  13. Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges in 2001 and 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges conducted from October 2001 to February 2002

  14. Central Mississippi Refuges: Yazoo, Panther Swamp, Hillside, Morgan Brake & Bathews Brake: Annual narrative report: Calendar year 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yazoo, Hillside, Panther Swamp, Morgan Brake, and Mathews Brake NWRs covers refuge activities during 2001. The report begins with a...

  15. 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,...

  16. 49 CFR 393.40 - Required brake systems.

    Science.gov (United States)

    2010-10-01

    ... motor vehicle must meet the applicable service, parking, and emergency brake system requirements....49, and 393.52 of this subpart. (c) Parking brakes. Each commercial motor vehicle must be equipped with a parking brake system that meets the applicable requirements of § 393.41. (d) Emergency...

  17. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Science.gov (United States)

    2010-10-01

    ... that all of the equipment's brake system pneumatic components that contain moving parts and are sealed... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic brake equipment maintenance. 238.309... Maintenance Requirements for Tier I Passenger Equipment § 238.309 Periodic brake equipment maintenance....

  18. 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. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  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...

  20. The braking indices in pulsar emission models

    CERN Document Server

    Wu, F; Gil, J; Gil, Janusz

    2003-01-01

    Using the method proposed in a previous paper, we calculate pulsar braking indices in the models with torque contributions from both inner and outer accelerating regions, assuming that the interaction between them is negligible. We suggest that it is likely that the inverse Compton scattering induced polar vacuum gap and the outer gap coexist in the pulsar magnetosphere. We include the new near threshold vacuum gap models with curvature-radiation and inverse Compton scattering induced cascades, respectively; and find that these models can well reproduce the measured values of the braking indices.

  1. Dynamic Braking System of a Tidal Generator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Wright, Alan; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-08-01

    Renewable energy generation has experienced significant cost reductions during the past decades, and it has become more accepted by the global population. In the beginning, wind generation dominated the development and deployment of renewable energy; however, during recent decades, photovoltaic (PV) generation has grown at a very significant pace due to the tremendous decrease in the cost of PV modules. The focus on renewable energy generation has now expanded to include new types with promising future applications, such as river and tidal generation. The input water flow to these types of resources is more predictable than wind or solar generation. The data used in this paper is representative of a typical river or tidal generator. The analysis is based on a generator with a power rating of 40 kW. The tidal generator under consideration is driven by two sets of helical turbines connected to each side of the generator located in between the turbines. The generator is operated in variable speed, and it is controlled to maximize the energy harvested as well as the operation of the turbine generator. The electrical system consists of a three-phase permanent magnet generator connected to a three-phase passive rectifier. The output of the rectifier is connected to a DC-DC converter to match the rectifier output to the DC bus voltage of the DC-AC inverter. The three-phase inverter is connected to the grid, and it is controlled to provide a good interface with the grid. One important aspect of river and tidal generation is the braking mechanism. In a tidal generator, the braking mechanism is important to avoid a runaway condition in case the connection to the grid is lost when there is a fault in the lines. A runaway condition may lead to an overspeed condition and cause extreme stresses on the turbine blade structure and eventual disintegration of the mechanical structure. In this paper, the concept of the dynamic braking system is developed and investigated for normal

  2. Hillside, Morgan Brake, and Mathews Brake National Wildlife Refuges Reforestation Plan for 1992-1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan addresses the history of reforestation at Hillside National Wildlife Refuge and its two satellite refuges, Morgan Brake National Wildlife Refuge and...

  3. Study on Braking Energy Regeneration System for City Bus

    Institute of Scientific and Technical Information of China (English)

    ZOU Zheng-yao; CHEN Ru-wen; YANG Xue-mei; LIU Gou-bing; JIN Jia-jun

    2011-01-01

    Braking of the urban vehicles of public service wastes a large number of engine energy in the condition of starting and stopping frequently. Aiming at the problem, an electro-mechanical braking energy regeneration system was proposed which adopted a high-speed flywheel and a battery to recover the braking energy and achieve the secondary traction for the auxiliary start function. The system strategy was designed and the braking simulation was processed to validate its feasibility. The experiment results show that the system can effectively recover the braking energy, improve the starting performance of the city bus and it can be applied to the engineering.

  4. BRAKING PROCESS OF ENDURO AND HIGHWAY-TOURIST MOTORBIKES

    Directory of Open Access Journals (Sweden)

    Paweł SKRZYPCZYK

    2015-06-01

    Full Text Available In the event of an emergency, head of the motorcycle has a split second to decide what to do defensive maneuver. The most common choice is the braking maneuver. Starting motorcycle braking is associated with the selection of additional brake, which uses a driver. It is here to choose to use the front brake, rear or both simultaneously. The paper presents the study of the effects of such decision on the braking process. Tests were carried out for enduro and highway-tourist motorbikes.

  5. A HIGH BRAKING INDEX FOR A PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Archibald, R. F.; Ferdman, R. D.; Kaspi, V. M.; Tendulkar, S. P. [Department of Physics and McGill Space Institute, McGill University, 3600 University Street, Montréal, QC H3A 2T8 (Canada); Gotthelf, E. V. [Columbia Astrophysics Laboratory, 550 West 120th Street, New York, NY 10027-6601 (United States); Guillot, S. [Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Harrison, F. A. [Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Pasadena, CA 91125 (United States); Keane, E. F. [SKA Organization, Jodrell Bank Observatory, Cheshire SK11 9DL (United Kingdom); Pivovaroff, M. J. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550-9234 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Tomsick, J. A. [Space Science Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450 (United States)

    2016-03-01

    We present a phase-coherent timing solution for PSR J1640–4631, a young 206 ms pulsar using X-ray timing observations taken with NuSTAR. Over this timing campaign, we have measured the braking index of PSR J1640–4631 to be n = 3.15 ± 0.03. Using a series of simulations, we argue that this unusually high braking index is not due to timing noise, but is intrinsic to the pulsar's spin-down. We cannot, however, rule out contamination due to an unseen glitch recovery, although the recovery timescale would have to be longer than most yet observed. If this braking index is eventually proven to be stable, it demonstrates that pulsar braking indices greater than three are allowed in nature; hence, other physical mechanisms such as mass or magnetic quadrupoles are important in pulsar spin-down. We also present a 3σ upper limit on the pulsed flux at 1.4 GHz of 0.018 mJy.

  6. 30 CFR 57.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment with... surface-operated equipment at underground mines when an MSHA inspector has reasonable cause to...

  7. Massive star models with magnetic braking

    CERN Document Server

    Meynet, Georges; Maeder, Andre

    2010-01-01

    Magnetic fields at the surface of a few early-type stars have been directly detected. These fields have magnitudes between a few hundred G up to a few kG. In one case, evidence of magnetic braking has been found. We investigate the effects of magnetic braking on the evolution of rotating ($\\upsilon_{\\rm ini}$=200 km s$^{-1}$) 10 M$_\\odot$ stellar models at solar metallicity during the main-sequence (MS) phase. The magnetic braking process is included in our stellar models according to the formalism deduced from 2D MHD simulations of magnetic wind confinement by ud-Doula and co-workers. Various assumptions are made regarding both the magnitude of the magnetic field and of the efficiency of the angular momentum transport mechanisms in the stellar interior. When magnetic braking occurs in models with differential rotation, a strong and rapid mixing is obtained at the surface accompanied by a rapid decrease in the surface velocity. Such a process might account for some MS stars showing strong mixing and low surfa...

  8. NAC Off-Vehicle Brake Testing Project

    Science.gov (United States)

    2007-05-01

    Project Officer ( TIPO ) US Army National Automotive Center (NAC) Warren, MI Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden...May 2007 FinalR1 UNCLAS: Dist A. Approved for public release Leo Miller, Technology Insertion Project Officer ( TIPO ) NAC Off-vehicle Brake Testing

  9. Comparative Frictional Analysis of Automobile Drum and Disc Brakes

    Directory of Open Access Journals (Sweden)

    H.P. Khairnar

    2016-03-01

    Full Text Available In the present work, a comparative frictional behaviour of drum brakes and disc brakes in automobiles has been investigated. The influential factors; contact force and friction radius were modeled for the estimation of the friction coefficient for drum as well as disc brakes. The effect of contact force and friction radius is studied with varying conditions of parameters; longitudinal force, caliper force and torque on piston side as well as non-piston side. The numerical results obtained have been compared with the similar obtained from virtual Matlab/Simulink models for drum and disc brakes. The results evidenced that friction radius predominantly affects brake pressure and thus the friction coefficient, also the increase in contact force resulted with decrease in friction coefficient both for drum and disc brakes. Further it has been found that disc brakes exhibit gradual decrease of friction coefficient due to the equitable distribution of braking effort while drum brake presents sudden variations in friction coefficient. It can be revealed that frictional behaviour of disc brake is more consistent than drum brake.

  10. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability wer...

  11. 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.

  12. Design and preliminary validation of a tool for the simulation of train braking performance

    Institute of Scientific and Technical Information of China (English)

    Luca Pugi; Monica Malvezzi; Susanna Papini; Gregorio Vettori

    2013-01-01

    Train braking performance is important for the safety and reliability of railway systems. The availability of a tool that allows evaluating such performance on the basis of the main train features can be useful for train system designers to choose proper dimensions for and optimize train’s subsystems. This paper presents a modular tool for the prediction of train braking performance, with a par-ticular attention to the accurate prediction of stopping distances. The tool takes into account different loading and operating conditions, in order to verify the safety require-ments prescribed by European technical specifications for interoperability of high-speed trains and the corresponding EN regulations. The numerical results given by the tool were verified and validated by comparison with experi-mental data, considering as benchmark case an Ansaldo EMU V250 train-a European high-speed train-currently developed for Belgium and Netherlands high-speed lines, on which technical information and experimental data directly recorded during the preliminary tests were avail-able. An accurate identification of the influence of the braking pad friction factor on braking performances allowed obtaining reliable results.

  13. Tribological properties of nonasbestos brake pad material by using coconut fiber

    Science.gov (United States)

    Craciun, A. L.; Pinca-Bretotean, C.; Utu, D.; Josan, A.

    2017-01-01

    In automotive industry, the brake system is influenced by a large number of variables including geometry of components, materials of brakes, components interaction and many operating condition. Organic fiber reinforced metallic friction composites are increasingly being used in automotive brake shoes, disc and pads, linings, blocks, clutch facings, primarily because of awareness of health hazards of asbestos. Current trend in the research field of automotive industry is to utilization of different wastes as a source of raw materials for composite materials. This will provide more economical benefit and also environmental preservation by utilize the waste of natural fibre In this paper it has performed a tribological study to determine the characteristics of the friction product by using coconut natural fibred reinforced in aluminium composite. In this sense, two different laboratory formulation were prepared with 5% and 10% coconut fibre and other constitutes like binder, friction modifiers, abrasive material and solid lubrificant using powder mettallurgy. These dnew materials for brake pads are tested for tribological behaviour in a standard pin on disc tribometer. To know the wear behavior of composite materials will determine the parameters that characterize there tribological properties.

  14. Personal exposure to asbestos and respiratory health of heavy vehicle brake mechanics.

    Science.gov (United States)

    Cely-García, María Fernanda; Torres-Duque, Carlos A; Durán, Mauricio; Parada, Patricia; Sarmiento, Olga Lucía; Breysse, Patrick N; Ramos-Bonilla, Juan P

    2015-01-01

    Asbestos brake linings and blocks are currently used in heavy vehicle brake repair shops (BRSs) in Bogotá, Colombia. Some brake products are sold detached from their supports and without holes, requiring manipulation before installation. The aim of this study was to assess asbestos exposures and conduct a preliminary evaluation of respiratory health in workers of heavy vehicles in BRSs. To estimate asbestos exposures, personal and area samples were collected in two heavy vehicle BRSs. Each shop was sampled during six consecutive days for the entire work shift. Personal samples were collected on 10 workers including riveters, brake mechanics, and administrative staff. Among workers sampled, riveters had the highest phase contrast microscopy equivalent (PCME) asbestos concentrations, with 8-h time-weighted average (TWA) personal exposures ranging between 0.003 and 0.157 f/cm(3). Respiratory health evaluations were performed on the 10 workers sampled. Three workers (30%) had circumscribed pleural thickening (pleural plaques), with calcifications in two of them. This finding is strongly suggestive of asbestos exposure. The results of this study provide preliminary evidence that workers in heavy vehicle BRSs could be at excessive risk of developing asbestos-related diseases.

  15. 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.

  16. Excitation Method of Linear-Motor-Type Rail Brake without Using Power Sources by Dynamic Braking with Zero Electrical Output

    Science.gov (United States)

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

    The eddy current rail brake is a type of braking system used in railway vehicles. Because of problems such as rail heating and problems associated with ensuring that power is supplied when the feeder malfunctions, this braking system has not been used for practical applications in Japan. Therefore, we proposed the use of linear induction motor (LIM) technology in eddy current rail brake systems. The LIM rail brake driven by dynamic braking can reduce rail heating and generate the energy required for self-excitation. In this paper, we present an excitation system and control method for the LIM rail brake driven by “dynamic braking with zero electrical output”. The proposed system is based on the concept that the LIM rail brake can be energized without using excitation power sources such as a feeder circuit and that high reliability can be realized by providing an independent excitation system. We have studied this system and conducted verification tests using a prototype LIM rail brake on a roller rig. The results show that the system performance is adequate for commercializing the proposed system, in which the LIM rail brake is driven without using any excitation power source.

  17. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability were simulated. It shows that differential brake can amend turning shortage of automobile brake and improve its braking stability, but the effect of automobile mass on its braking stability is great. So the distribution mode of braking force and the effect of mass change should be considered while differential brake is applied.

  18. 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.

  19. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Science.gov (United States)

    2010-10-01

    ... 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... reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The...

  20. 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.

  1. Plasma Braking Due to External Magnetic Perturbations

    Science.gov (United States)

    Frassinetti, L.; Olofsson, Kejo; Brunsell, P. R.; Khan, M. W. M.; Drake, J. R.

    2010-11-01

    The RFP EXTRAP T2R is equipped with a comprehensive active feedback system (128 active saddle coils in the full-coverage array) and active control of both resonant and non-resonant MHD modes has been demonstrated. The feedback algorithms, based on modern control methodology such as reference mode tracking (both amplitude and phase), are a useful tool to improve the ``state of the art'' of the MHD mode control. But this tool can be used also to improve the understanding and the characterization of other phenomena such as the ELM mitigation with a resonant magnetic perturbation or the plasma viscosity. The present work studies plasma and mode braking due to static RMPs. Results show that a static RMP produces a global braking of the flow profile. The study of the effect of RMPs characterized by different helicities will also give information on the plasma viscosity profile. Experimental results are finally compared to theoretical models.

  2. A high performance pneumatic braking system for heavy vehicles

    Science.gov (United States)

    Miller, Jonathan I.; Cebon, David

    2010-12-01

    Current research into reducing actuator delays in pneumatic brake systems is opening the door for advanced anti-lock braking algorithms to be used on heavy goods vehicles. However, these algorithms require the knowledge of variables that are impractical to measure directly. This paper introduces a sliding mode braking force observer to support a sliding mode controller for air-braked heavy vehicles. The performance of the observer is examined through simulations and field testing of an articulated heavy vehicle. The observer operated robustly during single-wheel vehicle simulations, and provided reasonable estimates of surface friction from test data. The effect of brake gain errors on the controller and observer are illustrated, and a recursive least squares estimator is derived for the brake gain. The estimator converged within 0.3 s in simulations and vehicle trials.

  3. Squeal noise in simple numerical brake models

    Science.gov (United States)

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

    2015-09-01

    Since the early 1920s, automotive disc brake squeal has caused warranty issues and customer dissatisfaction. Despite a good deal of progress achieved, predicting brake squeal propensity is as difficult as ever as not all mechanisms and interactions are known owing to their highly fugitive complex nature. In recent years, research has been focused on the prediction of unstable vibration modes by the complex eigenvalue analysis (CEA) for the mode-coupling type of instability. There has been very limited consideration given to the calculation of the acoustic radiation properties due to friction contact between a pad and a rotor. Recent analyses using a forced response analysis with harmonic contact pressure excitation indicates negative dissipated energy at some pad eigenfrequencies predicted to be stable by the CEA. A transient nonlinear time domain analysis with no external excitation indicates that squeal could develop at these eigenfrequencies. Here, the acoustic radiation characteristics of those pad modes are determined by analysing the acoustic power levels and radiation efficiencies of simplified brake models in the form of a pad rubbing on a plate or on a disc using the acoustic boundary element method based on velocities extracted from the forced response analysis. Results show that unstable pad modes trigger unstable disc vibrations resulting in instantaneous mode squeal similar to those observed experimentally. Changes in the radiation efficiency with pressure variations are smaller than those with friction coefficient variations and are caused by the phase difference of the velocities out-of-plane vibration between the pad and the disc.

  4. Investigation of the coatings applied onto brake discs on disc-brake pad pair

    Directory of Open Access Journals (Sweden)

    I. Kiliçaslan

    2009-07-01

    Full Text Available While braking, according to the severity of it, thermal, metallurgical, constructive and tribological occurrences emerge on the brake disc-pad interface. In this study, NiCr was sprayed as bonding layer onto the discs, one ofwhich was coated with Al2O3-TiO2 by plasma spray and the other was coated with NiCr-Cr3C2 by High Velocity Oxygen Fuel (HVOF. In addition, the discs were tested with inertia dynamometer according to SAE’s J2522 testing procedure. The measurements showed that although the pads of the coated discs were exposed to higher braking temperatures, friction coefficient of the disc coated with NiCr- Cr3C2 was obtained 6 % higher compared to the original disc.

  5. 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.

  6. Low-impact friction materials for brake pads

    OpenAIRE

    2016-01-01

    State-of-the-art friction materials for applications in disc brake systems are constituted by composite materials, specifically formulated to ensure proper friction and wear performances, under the sliding contact conditions of braking events. The bases of typical friction compound formulations usually include 10 to 30 different components bonded with a polymeric binder cross-linked in situ. Main requests to be fulfilled during braking are an adequate friction efficiency and enough mechanical...

  7. 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.

  8. Application of eddy current braking for the railway marshaling yard hu mp hu mping speed braking%涡流制动技术在铁路驼峰调节溜放速度的应用研究

    Institute of Scientific and Technical Information of China (English)

    侯忠馨; 王庆贤; 祝曦; 司徒国强

    2015-01-01

    Eddy -current braking is a kind of technology which utilizes electromagnet solenoid coils to generate electromagnetic fields.Rotating conductor cuts magnetic field lines to generate eddy current,and then generate a braking force.Eddy current braking is a new approach to take place of the original reduction gear device which had been used in the railway marshaling yard hump humping speed braking.Considering a low -noise,no me-chanical impact and friction,maintence free,low carbon environmental protection and other factors,eddy current reduction is an ideal new technology for hump humping deceleration and braking.The formulas of disc braking torque of eddy current braking were deduced on the basis of the theory of electromagnetic field.The formulas re-flect the relationship between the different design parameters of disc eddy current braking and can be used for the design and performance analysis of the eddy current braking structure.%涡流制动技术是利用电磁线圈产生电磁场,旋转导体在磁场中切割磁力线产生电涡流,从而产生制动力。所以涡流制动是替代铁路编组场驼峰溜放调速制动原有机械减速装置的新方法。考虑低噪声、无机械撞击与摩擦、免维护、低碳环保等因素,涡流减速是一种理想的驼峰溜放车列减速制动新技术。运用电磁场理论推导出盘形涡流制动装置的制动力矩计算公式,计算公式反映盘形涡流制动器各设计参数之间的相互关系,可用于盘形涡流制动器结构设计和性能分析的参考。

  9. 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.

  10. 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, ...

  11. Light Weight Individually Powered Railway Freight Wagons Modified to Utilize Lost Energy during Braking

    Directory of Open Access Journals (Sweden)

    Gaurab Bhowmick

    2013-10-01

    Full Text Available EMU or the Electric Multiple Units are those type of trains consisting of self-propelled carriages using electricity as the motive power. An EMU requires no separate locomotives, as electric traction motors are incorporated within one or a number of carriages. Generally EMUs are used for passenger train but the same technology can be implemented in freight carriages also. These EMU based freight cars will reduce the line congestion mainly in India due to its rapid acceleration and high speeds.In this study, the purpose of the carriage is to be self-propelled using highly efficient traction motors powering each carriage made of high strength Aluminum having individual and independent wheel set. Also, the wagon will harness the waste braking energy using regenerative braking technique to power the traction motors partially. This study addresses the problem of severe line congestion, unwanted holding of freight trains to make passageway for passenger trains, light weight wagons, harnessing the wastage braking energy which are generally removed as heat. Therefore, study of the methodologies suggested has to be done in order to determine the feasibility and effectiveness of the methods both in terms of technology and financially. To achieve this detailed analysis is carried out to understand the modification of normal freight wagon to self-propelled EMU type wagon.

  12. Optical classification for quality and defect analysis of train brakes

    Science.gov (United States)

    Glock, Stefan; Hausmann, Stefan; Gerke, Sebastian; Warok, Alexander; Spiess, Peter; Witte, Stefan; Lohweg, Volker

    2009-06-01

    In this paper we present an optical measurement system approach for quality analysis of brakes which are used in high-speed trains. The brakes consist of the so called brake discs and pads. In a deceleration process the discs will be heated up to 500°C. The quality measure is based on the fact that the heated brake discs should not generate hot spots inside the brake material. Instead, the brake disc should be heated homogeneously by the deceleration. Therefore, it makes sense to analyze the number of hot spots and their relative gradients to create a quality measure for train brakes. In this contribution we present a new approach for a quality measurement system which is based on an image analysis and classification of infra-red based heat images. Brake images which are represented in pseudo-color are first transformed in a linear grayscale space by a hue-saturation-intensity (HSI) space. This transform is necessary for the following gradient analysis which is based on gray scale gradient filters. Furthermore, different features based on Haralick's measures are generated from the gray scale and gradient images. A following Fuzzy-Pattern-Classifier is used for the classification of good and bad brakes. It has to be pointed out that the classifier returns a score value for each brake which is between 0 and 100% good quality. This fact guarantees that not only good and bad bakes can be distinguished, but also their quality can be labeled. The results show that all critical thermal patterns of train brakes can be sensed and verified.

  13. A parametric FE modeling of brake for non-linear analysis

    Directory of Open Access Journals (Sweden)

    Ibrahim Ahmed, Yasser Fatouh, Wael Aly

    2014-01-01

    Full Text Available A parametric modeling of a drum brake based on 3-D Finite Element Methods (FEM for non-contact analysis is presented. Many parameters are examined during this study such as the effect of drum-lining interface stiffness, coefficient of friction, and line pressure on the interface contact. Firstly, the modal analysis of the drum brake is also studied to get the natural frequency and instability of the drum to facilitate transforming the modal elements to non-contact elements. It is shown that the Unsymmetric solver of the modal analysis is efficient enough to solve this linear problem after transforming the non-linear behavior of the contact between the drum and the lining to a linear behavior. A SOLID45 which is a linear element is used in the modal analysis and then transferred to non-linear elements which are Targe170 and Conta173 that represent the drum and lining for contact analysis study. The contact analysis problems are highly non-linear and require significant computer resources to solve it, however, the contact problem give two significant difficulties. Firstly, the region of contact is not known based on the boundary conditions such as line pressure, and drum and friction material specs. Secondly, these contact problems need to take the friction into consideration. Finally, it showed a good distribution of the nodal reaction forces on the slotted lining contact surface and existing of the slot in the middle of the lining can help in wear removal due to the friction between the lining and the drum. Accurate contact stiffness can give a good representation for the pressure distribution between the lining and the drum. However, a full contact of the front part of the slotted lining could occur in case of 20, 40, 60 and 80 bar of piston pressure and a partially contact between the drum and lining can occur in the rear part of the slotted lining.

  14. Quality control of cast brake discs

    Directory of Open Access Journals (Sweden)

    M. Stawarz

    2008-04-01

    Full Text Available The largest industrial application so far have the gray cast irons which are characterized by low tensile and bending strength, while at the same time they have good ultimate comprehensive strength. Additionally, the fatigue strength of gray cast irons is comparatively low and they are only to some extend sensitive for the surface waters effects. Cast iron is the material, which is comparatively easy to be processed, and for this reason – it is not expensive. Brake discs are exploited in particularly hard conditions. They must be resistant both against the thermal fatigue and abrasion wearing (at dry friction as well as against seizing, corrosion and mechanical load [1-3]. The gray cast iron, better than other materials, fulfills all the requirements necessary for making the material for the casts resistant against such tough conditions. This work reflects the researches aiming to define the quality of cast brake discs (ventilated and non-ventilated ones upon a period of their exploitation in real conditions. The following researches were performed: evaluations of the disc surface condition, measurement of disc thickness, examination of run – out flank and metallographic analysis. In order to more detailed recognition of mechanisms and reasons of brake discs wearing in real conditions, one should conduct additional examinations: computer analysis of the microstructure, chemical composition analysis, etc., as well as study of the technology of their production in foundries, where they are manufactured [4]. By obtaining the full set of the mentioned above data one can draw final conclusions and remove causes of possible defects.

  15. 城轨车辆制动控制系统的分析%Analysis of the brake control system for mass transit vehicles

    Institute of Scientific and Technical Information of China (English)

    何宝昌

    2012-01-01

    制动系统是城轨车辆关键系统之一,根据故障导向安全原则,制动系统失效时应有充足的措施确保列车和人员安全。北京地铁四号线车辆的制动控制系统通过G阀和RIO阀,完成列车的保持制动、常用制动、紧急制动、防滑保护等功能,并且将列车制动控制系统接入到TCMS系统中,保证了车辆的安全运营。%Brake system is critical to a mass transit vehicle, and there should be sufficient measures for this system to ensure train and personnel safety whenever it fails according to Failure Guiding & Safety Principle. By means of G valve and RIO valve, the brake control system of vehicles for Beijing Metro Line 4 can perform retaining brake, service brake, emergency brake and antiskid protection, and can connect train brake control system to TCMS system to ensure the safe operation of rail vehicles.

  16. THE THEORETICAL MODEL FOR PREDICTING CIRCULATION VELOCITY OF HYDRAULIC BRAKE

    Institute of Scientific and Technical Information of China (English)

    刘英林; 侯春生

    1997-01-01

    By rational hypothesis of fluid flow pattern, applied the law of conservation of energy and integrated the laboratory test results, finished the prediction by the theoretical model of circulation velocity of hydraulic brake which is important parameter. Thus provide the theoritical basis for hydraulic brake of belt conveyor whose research has just been started.

  17. 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 t

  18. Characterisation of motorcyclist's upper body motion during braking manoeuvre

    NARCIS (Netherlands)

    Ioannis, S.; Kavadarli, G.; Fraga, F.; Rooij, L. van; Schuller, E.; Peldschus, S.

    2010-01-01

    Motorcycle braking experiments with volunteers were performed in lab, to study the body posture and reactions of the motorcyclists during braking with the aim of providing input for human modelling. Human motion capture methods were employed for the kinematics and the recorded data was further analy

  19. Development of a multi-pole magnetorheological brake

    Science.gov (United States)

    Shiao, Yaojung; Nguyen, Quang-Anh

    2013-06-01

    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.

  20. 49 CFR 393.48 - Brakes to be operative.

    Science.gov (United States)

    2010-10-01

    ...) The steering axle of a three-axle dolly which is steered by a co-driver; (5) Loaded house moving... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  1. 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

  2. A Comparative Study on Automotive Brake Testing Standards

    Science.gov (United States)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  3. Parity space-based fault diagnosis of CCBII braking system

    Institute of Scientific and Technical Information of China (English)

    黄志武; 杨迎泽; 王晶; 李赟

    2013-01-01

    Fault diagnosis is a key issue of the CCBII(computer controlled brake II) braking system, because the CCBII braking system is very complicated and nonlinear, which may exhibit isolated and multi-component coupled faults. A parity space-based method was proposed for fault diagnosis of CCBII braking systems. Firstly, the mathematical models were established according to three function modules of CCBII braking systems where the air fluid theory was utilized. Then, parity vector and threshold function were designed for each output of the system so as to identify more system faults. Fault character matrix was built based on the causal relationship between the output and the fault according to the system function and internal structure. Finally, fault detection and isolation can be realized by the comparison of the observed system output and the fault character matrix. Simulation results show that the proposed method is entirely feasible and effective.

  4. 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.

  5. Design optimization of a magnetorheological brake in powered knee orthosis

    Science.gov (United States)

    Ma, Hao; Liao, Wei-Hsin

    2015-04-01

    Magneto-rheological (MR) fluids have been utilized in devices like orthoses and prostheses to generate controllable braking torque. In this paper, a flat shape rotary MR brake is designed for powered knee orthosis to provide adjustable resistance. Multiple disk structure with interior inner coil is adopted in the MR brake configuration. In order to increase the maximal magnetic flux, a novel internal structure design with smooth transition surface is proposed. Based on this design, a parameterized model of the MR brake is built for geometrical optimization. Multiple factors are considered in the optimization objective: braking torque, weight, and, particularly, average power consumption. The optimization is then performed with Finite Element Analysis (FEA), and the optimal design is obtained among the Pareto-optimal set considering the trade-offs in design objectives.

  6. Design and Analysis of Electro-mechanical Hybrid Anti-lock Braking System for Hybrid Electric Vehicle Utilizing Motor Regenerative Braking

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianlong; YIN Chengliang; ZHANG Jianwu

    2009-01-01

    Braking on low adhesion-coefficient roads, hybrid electric vehicle's motor regenerative torque is switched off to safeguard the normal anti-lock braking system (ABS) function. When the ABS control is terminated, the motor regenerative braking is readmitted.Aiming at avoiding permanent cycles from hydraulic anti-lock braking to motor regenerative braking, a novel electro-mechanical hybrid anti-lock braking system using fuzzy logic is designed. Different from the traditional single control structure, this system has a two-layered hierarchical structure. The first layer is responsible for harmonious adjustment or interaction between regenerative system and anti-lock braking system. The second layer is responsible for braking torque distribution and adjustment. The closed-loop simulation model is built. Control strategy and method for coordination between regenerative and anti-lock braking are developed. Simulation braking on low adhesion-coefficient roads with fuzzy logic control and real vehicle braking field test are presented. The results from simulating analysis and experiment show braking performance of the vehicle is perfect, harmonious coordination between regenerative and anti-lock braking function, significant amount of braking energy can be recovered and the proposed control strategy and method are effective.

  7. PROTOBINARY EVOLUTION DRIVEN BY MAGNETIC BRAKING

    Science.gov (United States)

    Zhao, Bo; Li, Z.; Kratter, K. M.

    2014-01-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  8. Simulation study of the plasma brake effect

    CERN Document Server

    Janhunen, Pekka

    2014-01-01

    The plasma brake is a thin negatively biased tether which has been proposed as an efficient concept for deorbiting satellites and debris objects from low Earth orbit. We simulate the interaction with the ionospheric plasma ram flow with the plasma brake tether by a high performance electrostatic particle in cell code to evaluate the thrust. The tether is assumed to be perpendicular to the flow. We perform runs for different tether voltage, magnetic field orientation and plasma ion mass. We show that a simple analytical thrust formula reproduces most of the simulation results well. The interaction with the tether and the plasma flow is laminar when the magnetic field is perpendicular to the tether and the flow. If the magnetic field is parallel to the tether, the behaviour is unstable and thrust is reduced by a modest factor. The case when the magnetic field is aligned with the flow can also be unstable, but does not result in notable thrust reduction. We also fix an error in an earlier reference. According to...

  9. The Calculation and Verification of the High Speed Train Braking Curve%高速列车制动曲线的计算与验证

    Institute of Scientific and Technical Information of China (English)

    张友兵; 张波

    2012-01-01

    分析了列车运行过程中的受力情况,给出了制动过程中减速度的计算方法,并采用正向、反向两种迭代方式计算列车制动曲线,两种方式计算出的制动曲线一致,证明了计算制动曲线的方法是正确的.在反向迭代计算制动曲线时,缩小距离步长,可以提高制动曲线的精确度,选择合适的距离步长,不但能保证精确度,而且可以满足时效性.通过仿真得出,在平直道上,CRH2型高速列车在初始速度为300km/h时,紧急制动距离为2 780m,最大常用制动距离为4 628m,符合国家规定.分析了制动过程中列车减速度与速度的关系.最后,分析了制动初始速度与制动距离的关系,发现制动初始速度越大,制动距离越长,且制动距离非线性增大.%In CTCS-3 train control system, the on-board equipment uses the target distance and continuous speed control mode to control the train. In order to ensure the train safety, the on-board equipment must calculate the braking curve based on the movement authority and adjust the train speed in real time. In this paper, the forces which are applied to the train are analyzed, and the calculation method of deceleration when the train is braking is given. The train braking curves are calculated by using forward and reverse iterative methods. The methods of calculating the train braking curve are proved to be correct. In the process of reversely and iteratively calculating the braking curve,narrowing the distance step can improve the accuracy of the braking curve,selecting the appropriate distance length not only can ensure the accuracy of the braking curve but also can meet the timeliness of calculating the braking curve, and The simulation result proves that the emergency braking distance of CRH2 high-speed trains is 2 780 m,the max normal braking distance is 4 628 m if the initial speed of the train is 300 km/h and the train is running on the flat and straight line. These results comply with the

  10. Antiskid control of railway train braking based on adhesion creep behavior

    Science.gov (United States)

    Zuo, Jianyong; Chen, Zhongkai

    2012-05-01

    In modern trains wheelset skidding leads to the deterioration of braking behavior, the degradation of comfort, as well as a boost in system hazards. Because of the nonlinearity and unknown characteristics of wheelset adhesion, simplifications are widely adopted in the modeling process of conventional antiskid controllers. Therefore, conventional antiskid controllers usually cannot perform satisfactorily. In this paper, systematic computer simulation and field tests for railway antiskid control system are introduced. The operating principal of antiskid control system is explained, which is fundamental to the simulation of antiskid brakes, and the simulation model is introduced, which incorporates both the adhesion creep curve and a pneumatic submodel of antiskid control system. In addition, the characteristics of adhesion curves and the simulation target are also provided. Using DHSplus, the pneumatic submodel is created to analyze the performance of the different control strategies of antiskid valves. Then the system simulation is realized by combining the kinematical characteristics of railway trains and the pneumatic submodel. The simulation is performed iteratively to obtain the optimized design of the antiskid control system. The design result is incorporated in the hardware design of the antiskid control system and is evaluated in the field tests in Shanghai Subway Line 1. Judging by the antiskid efficiency, the antiskid braking performance observed in the field tests shows the superiority of the optimized design. Therefore, the proposed simulation method, especially in view of its ease of application, appears to be a useful one for designing railway antiskid control systems.

  11. The brake-system of the new Mercedes van-generation Sprinter; Die Bremsanlage der neuen Transporter-Generation Sprinter von Mercedes-Benz

    Energy Technology Data Exchange (ETDEWEB)

    Reuter, M.; Spielmann, W.

    1996-01-01

    The new Mercedes-Sprinter is the first van model series in this weight category which is equipped with disc brakes all round and ABS und ABD as standard. A diagonally divided hydraulic brake system with vacuum-controlled power assistance and automatic load-sensitive brake pressure control (ALB) is installed. The wheel brakes used are of a floating caliper type. During the development particular attention was paid to the constant friction coefficient of the brake linings, the `high` speed suitability and the provision of high thermal reserves. This concept offers good prerequisites for adding additional functions such as a brake assistant or a dynamic handling control system. For the first time there was a close cooperation between vehicle manufacturer, suppliers of brakes, linings and components during the development phase. To organise this complex development work a comprehensive specification booklet with detailed specs was drawn up and agreed with all parties involved. The result of the close cooperation is a positive example of the Mercedes-Benz tandem philosophy. (orig.) [Deutsch] Beim neuen Mercedes-Sprinter handelt es sich um die erste Transporter-Baureihe in dieser Gewichtsklasse mit vier Scheibenbremsen und serienmaessigem ABS mit ABD. Zum Einsatz kommt eine diagonal aufgeteilte hydraulische Bremsanlage mit Vakuum-Hilfskraftunterstuetzung und automatisch lastabhaengiger Bremskraftregelung (ALB). Als Radbremsen werden Schwimmsattelbremsen in Faustsattelbauweise verwendet. Besondere Schwerpunkte bei der Entwicklung waren die Reibwertkonstanz der Bremsbelaege, die Tauglichkeit bei hohen Geschwindigkeiten und die Schaffung hoher thermischer Reserven. Mit dieser Konzeption sind gute Voraussetzungen geschaffen, um weitere Zusatzfunktionen wie etwa einen Bremsassistenten oder eine Fahrdynamikregelung einzusetzen. Bei der Entwicklung wurde erstmals eine enge Zusammenarbeit zwischen Fahrzeughersteller, Bremsen-, Belag- und Komponentenlieferanten praktiziert. Zur

  12. 49 CFR 232.211 - Class III brake tests-trainline continuity inspection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class III brake tests-trainline continuity... § 232.211 Class III brake tests-trainline continuity inspection. (a) A Class III brake test shall be... configuration of the train has changed in certain ways. In particular, a Class III brake test shall be...

  13. 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.

  14. Control strategy of disc braking systems for downward belt conveyors

    Institute of Scientific and Technical Information of China (English)

    Hou Youfu; Xie Fangwei; Huang Fei

    2011-01-01

    Reliability of braking systems is a key requirement to ensure the safety of in using downward belt conveyor brakes.By analyzing and comparing three commonly used braking velocity curves,we conclude that the Harrison curve is the best.Given the characteristics of a downward belt conveyor,we studied the control in a closed-loop velocity,a conventional PID method and an optimal PID control method.We used MATLAB/Simulink to simulate the three control methods.Our simulation results show that optimal PID control is especially suitable for disc braking systems.To verify the results from theoretical analysis and simulation,a multifunctional test-bed was developed to simulate the braking process of a disc brake system.Our experimental results demonstrate that the optimal PID control can make the output velocity to follow a preset velocity correctly with only small fluctuations,meeting the requirements of a flexible brake for a belt conveyor.

  15. ED Brake Priority of Emergence Brake and Its Application to LIM Vehicle%紧急制动优先采用电制动在直线电机车辆上的应用

    Institute of Scientific and Technical Information of China (English)

    郑沃奇

    2012-01-01

    According to the abrupt slope of LIM line and the ED brake of LIM vehicle not depending on adhesion, ED brake priority of emergence brake was applied to Guangzhou LIM vehicle. The design and test of the scheme were introduced, which could reduce the vehicle brake distance effectively of rainy condition and ensure operation safety.%针对直线电机线路坡度大以及直线电机车辆电制动不受粘着限制的特点,广州地铁的直线电机车辆应用了紧急制动优先使用电制动的方案.介绍了该方案的设计、试验情况,认为在紧急制动时优先采用电制动,能有效降低车辆在雨天的紧急制动距离,保证行车的安全.

  16. Regenerative braking control strategy in mild hybrid electric vehicles equipped with automatic manual transmission

    Institute of Scientific and Technical Information of China (English)

    QIN Datong; YE Ming; LIU Zhenjun

    2007-01-01

    The actual regenerative braking force of an integrated starter/generator (ISG),which is varied with desired braking deceleration and vehicle speed,is calculated based on an analysis of the required deceleration,maximum braking force of ISG,engine braking force and state of charge (SOC) of battery.Braking force distribution strategies are presented according to the actual regenerative braking force of ISG.To recover the vehicle's kinetic energy maximally,braking shift rules for a mild hybrid electric vehicle (HEV) equipped with automatic manual transmission (AMT) are brought forward and effects of transmission ratios are considered.A test-bed is built up and regenerative braking tests are carried out.The results show that power recovered by the braking shift rules is more than that recovered by the normal braking control rules.

  17. MODIFICATION OF FLAKE REINFORCED FRICTION BRAKE COMPOSITE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to the recent development trend and need of the friction brake material, the flake reinforced friction brake material has been made out by adjusting the recipe and techniques. The two-dimensional flake vermiculite is selected as the reinforced stuffing of the material; the modified resin is used as the basal bed of the material. The tests manifest that the properties of mechanics are high, the friction coefficients are suitable and stable,and especially in high temperatures the wear is low. It is an excellent friction brake material.

  18. A model of heat dissipation for MR based brake

    Energy Technology Data Exchange (ETDEWEB)

    Wiehe, A; Noack, V; Maas, J [Hochschule Ostwestfalen-Lippe - University of Applied Sciences, Control Engineering and Mechatronics, Liebigstrasse 87, D-32657 Lemgo (Germany)], E-mail: ansgar.wiehe@hs-owl.de

    2009-02-01

    In contrast to conventional brakes actuators based on magnetorheological fluids (MRF) offer an advantage in short term, peak load decelerating. The dissipation of a high amount of energy in a short period of time results in a thermal destruction of conventional brakes. Due to the volume based energy dissipation of MR actuators, instead of the surface based energy dissipation of conventional brakes, the rise of temperature and the distribution of energy shows significant advantages. In this paper a design rule for special peak load MR actuators is derived. Furthermore the simplified model, which is the basis of the design rule, is compared to several simulation models, with different levels of detail.

  19. STUDY KOMPARASI LOST FOAM DAN KONVENSIONAL CASTING PRODUK DISC BRAKE

    OpenAIRE

    Yoso, Sumeru; -, Suyitno

    2014-01-01

    Disc brake component is a vital component with gray cast iron base material, it’s also fast lasting wearing part, so it has be replaced often. The disc brake replacement component in a local market is being supplied by the small scale local metal casting industries have the same quality as the genuine part.Disc brake making process is utilizing casting method inserting RCS core between drag and coup, than metal molten poured inside mold. The problem of this method is the product result often ...

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

    OpenAIRE

    Jiankun Peng; Hongwen He; Wei Liu; Hongqiang Guo

    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...

  1. Tuning the Brake While Raising the Stake

    DEFF Research Database (Denmark)

    Meder, David; Haagensen, Brian Numelin; Hulme, Oliver

    2016-01-01

    to stop to bank the current balance. Within each gambling round, the accumulation of gains gradually increased reaction times for "continue" choices, indicating growing uncertainty in the decision to continue. Neural activity evoked by "continue" choices was associated with growing activity...... and connectivity of a cortico-subcortical "braking" network that positively scaled with the accumulated gains, including pre-supplementary motor area (pre-SMA), inferior frontal gyrus, caudate, and subthalamic nucleus (STN). The influence of the STN on continue-evoked activity in the pre-SMA was predicted...... a paradigm where subjects experienced increasing potential rewards coupled with increasing risk, this study addressed two unresolved questions in the field of decision-making: First, we investigated an "inhibitory" network of regions that has so far been investigated with externally cued action inhibition...

  2. Tribomaterial factors in space mechanism brake performance

    Science.gov (United States)

    Hawthorne, H. M.

    1990-01-01

    The asbestos/phenolic pads of Shuttle Remote Manipulator System (SRMS) brakes are unsuitable for use in long life space mechanisms because their friction decreases on extended sliding in high vacuum. Dehydration of the material and accumulation of wear debris in the conforming interface of this tribosystem induces the permanent friction changes. Other polymer and some ceramic based materials exhibit similar frictional torque behavior due to the development of minimal contact patches by the interfacial debris. In contrast, high friction occurs when other ceramics form many small contacts throughout fine debris beds. Generating this latter interfacial structure during run-in ensures that the in-vacuo friction remains stable thereafter. Such materials with low wear rates are potential candidates for friction elements in SSRMS and similar mechanisms.

  3. Linear Control Technique for Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    Chankit Jain

    2014-08-01

    Full Text Available Antilock braking systems are used in modern cars to prevent the wheels from locking after brakes are applied. The dynamics of the controller needed for antilock braking system depends on various factors. The vehicle model often is in nonlinear form. Controller needs to provide a controlled torque necessary to maintain optimum value of the wheel slip ratio. The slip ratio is represented in terms of vehicle speed and wheel rotation. In present work first of all system dynamic equations are explained and a slip ratio is expressed in terms of system variables namely vehicle linear velocity and angular velocity of the wheel. By applying a bias braking force system, response is obtained using Simulink models. Using the linear control strategies like PI-type the effectiveness of maintaining desired slip ratio is tested. It is always observed that a steady state error of 10% occurring in all the control system models.

  4. 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%.

  5. 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.

  6. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc, proposes an SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane mechanism to switch...

  7. Mathews Brake National Wildlife Refuge Public Use Development Plan - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan for Mathews Brake NWR involves setting station public use goals, project a positive attitude, welcome and orient visitors, develop key resources awareness,...

  8. Handy Brake National Wildlife Refuge Habitat Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Handy Brake National Wildlife Refuge Habitat Management Plan provides a long-term vision and specific guidance on managing habitats for the resources of concern...

  9. Fishing Plan for Mathews Brake National Wildlife Refuge - 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal calls for the opening of Mathews Brake NWR to sport fishing. General regulations pertaining to licenses, creel limits, and methods of taking fish will...

  10. Fishery Management Plan for Mathews Brake National Wildlife Refuge - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U.S. Fish and Wildlife Service for Mathew's Brake National Wildlife Refuge. Data was provided by the refuge and area office...

  11. Fishery Management Plan for Morgan Brake National Wildlife Refuge - 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U. S. Fish and Wildlife Service for Morgan Brake National Wildlife Refuge. Data was provided by the Refuge and Area Office...

  12. RELIABILITY OF BRAKE SYSTEMS OF BUSES OF GROUP MAZ

    Directory of Open Access Journals (Sweden)

    A. Bessarab

    2013-01-01

    Full Text Available All over the world safety of maintained vehicles has the major value. For motor vehicles of the Republic of Belarus this problem is also actual. Maintenance of high reliability of brake systems of cars in operation is one of ways of the decision of a problem of increase of traffic safety.The analysis of reliability of brake systems of buses MAZ is carried out following the results of the state maintenance service in 2010 and the analysis of premature returns from routes of movement of buses MAZ-103 and МАZ-104 one of the motor transportation enterprises of a city of Minsk. Principal causes of structural parameters modification of brake pneumatic system of buses, the brake mechanism and elements АBS are considered.

  13. Crayfish survey at Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Crayfish sampling on Morgan Brake NWR for vernal crawfish and other species was done for 3 days at five sites. Data are present on species of crawfish and amphibians...

  14. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc., (ATA) proposes a Phase II SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane...

  15. Morgan Brake National Wildlife Refuge Public Use Development Plan - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan for Morgan Brake NWR involves setting station public use goals, project a positive attitude, welcome and orient visitors, develop key resources awareness,...

  16. 提升机闸瓦温度监测系统的研究%Temperature Monitoring System Research of Hoist Brake Shoe

    Institute of Scientific and Technical Information of China (English)

    沙永东; 李晓豁; 康晓敏; 侯静

    2012-01-01

    In order to effectively protect hoist brake shoe' s braking performance,improve the work reliability and service life, establishing temperature monitoring system of hoist brake shoe in braking process.This system consists of detection system and alarm, communication lines,host computer,etc. ,can be for hoist brake shoe online measurement temperature and real--time monitoring,with low energy consumption,small size,reliability and stability,information processing ability and other characteristics. The system for staff to provide effective reference data,can be according to the monitoring results related parameters in the fixed,ensure brake shoe under the premise of performance improved the safety and reliability of the brake system.%为了有效地保护提升机闸瓦的制动性能、提高其工作可靠性和使用寿命,建立了提升机闸瓦在制动过程中的温度监测系统,该系统由检测系统及报警器、通讯线路、上位机等组成,能对提升机闸瓦温度进行在线测量和实时监控,具有能耗低、体积小、可靠性和稳定性好,信息处理能力强等特点,该系统为工作人员提供了有效数据参考,可以根据监测结果及时进行相关参数的修正,在保证闸瓦性能的前提下提高了制动系统的安全可靠性。

  17. AASPT Carbon/Carbon Aircraft Brake Disk Granted MPA

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Xi'an Chaoma Technology Co. Ltd. was issued Parts Manufacturer Approval (PMA) for Carbon/Carbon aircraft brake disk for Airbus 320 series by Civil Aviation Administration of China (CAAC). The company is held by Academy of Aerospace Solid Propulsion Technology (AASPT), a subsidiary of China Aerospace Science and Technology Corporation (CASC). It is the first approval given to a Chinese company to design and produce brakes for main civilian aircraft.

  18. FES-Assisted Walking with Spring Brake Orthosis: Simulation Studies

    OpenAIRE

    R. Jailani; Tokhi, M.O.; Gharooni, S. C.; B.S.K.K Ibrahim

    2011-01-01

    This paper presents a simulation of bipedal locomotion to generate stimulation pulses for activating muscles for paraplegic walking with wheel walker using functional electrical stimulation (FES) with spring brake orthosis (SBO). A new methodology for paraplegic gait, based on exploiting natural dynamics of human gait, is introduced. The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO...

  19. OPTIMAL EMERGENCY VEHICLE BRAKING CONTROL BASED ON DYNAMIC FRICTION MODEL

    Directory of Open Access Journals (Sweden)

    L. Olmos

    2005-04-01

    Full Text Available A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking ofvehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking inminimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem.The final goal of the control is to improve the safety levels in highway transportation.

  20. Brake subharmonic solutions of first order Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper,we mainly use the Galerkin approximation method and the iteration inequalities of the L-Maslov type index theory to study the properties of brake subharmonic solutions for the first order non-autonomous Hamiltonian systems.We prove that when the positive integers j and k satisfy the certain conditions,there exists a jT-periodic nonconstant brake solution zj such that zj and zkj are distinct.

  1. Investigation of aerodynamic braking devices for wind turbine applications

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D.A. [R. Lynette & amp; Associates, Seattle, WA (United States)

    1997-04-01

    This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.

  2. Design and development of coil casing MRF brake system

    Directory of Open Access Journals (Sweden)

    Siti Lydia R.

    2017-01-01

    Full Text Available Nowadays magneto-rheological brakes has been introduce to overcome the drawback of conventional braking such as bulky, leakage and late build up pressure. Magnetic field is a main parameter need to be maximized in order to increase the efficiency of the brake. In MRF brake system the magnetic field directly affected by coil casing shapes. This paper focused on the study of the effect of coil casing shapes to the magnetic field distribution in MR brake. Finite Element Method will be used to analyze the magnetic field distribution produced by the coil. Five coils shape that different angle from 50° to 90° used in this study. As the result magnetic field was change quadratically by increasing the angle size. The best angle is between 60° to 70°. The peak value is at 70°. If more than that the magnetic field will drop. The significant of this study is to get the most efficient angle for the electromagnet casing for the MR brakes.

  3. Infrared characterization of thermal gradients on disc brakes

    Science.gov (United States)

    Panier, Stephane; Dufrenoy, Philippe; Bremond, Pierre

    2003-04-01

    The heat generated in frictional organs like brakes and clutches induces thermal distortions which may lead to localized contact areas and hot spots developments. Hot spots are high thermal gradients on the rubbing surface. They count among the most dangerous phenomena in frictional organs leading to damage, early failure and unacceptable braking performances such as brake fade or undesirable low frequency vibrations called hot judder. In this paper, an experimental study of hot spots occurrence in railway disc brakes is reported on. The aim of this study was to better classify and to explain the thermal gradients appearance on the surface of the disc. Thermograph measurements with an infrared camera have been carried out on the rubbing surface of brake discs on a full-scale test bench. The infrared system was set to take temperature readings in snap shot mode precisely synchronized with the rotation of the disc. Very short integration time allows reducing drastically haziness of thermal images. Based on thermographs, a classification of hot-spots observed in disc brakes is proposed. A detailed investigation of the most damaging thermal gradients, called macroscopic hot spots (MHS) is given. From these experimental researches, a scenario of hot spots occurrence is suggested step by step. Thanks to infrared measurements at high frequency with high resolution, observations give new highlights on the conditions of hot spots appearance. Comparison of the experimental observations with the theoretical approaches is finally discussed.

  4. Sistem Pendingin Paksa Anti Panas Lebih (Over Heating pada Rem Cakram (Disk Brake Kendaraan

    Directory of Open Access Journals (Sweden)

    Joni Dewanto

    2010-01-01

    Full Text Available Until now, the vehicle brakes are not usually equipped with a special cooling system, so that the release of heat into the air occurs naturally. When used continuously, the brakes can suffer damage as a result of the occurrence of over-heating. This condition is potentially causing a fatal accident. Physically, the over-heating often occurs in type disc brake, because the heat transfer surface is less proportionately, especially for high braking loads. This research aims to develop a brake disc with an active cooling system to prevent overheating. The system is applied to a simulated model of disc brakes empirically. The test was conducted at several levels of constant disc speed and breaking force. The results of this research indicate that at various braking load, the development of disc brakes with an active cooling system in the form of water vapor that is sprayed, can control the brake temperature rise and prevent over-heating.

  5. Regenerative Braking Algorithm for an ISG HEV Based on Regenerative Torque Optimization

    Institute of Scientific and Technical Information of China (English)

    XIAO Wen-yong; WANG Feng; ZHUO Bin

    2008-01-01

    A novel regenerative braking algorithm based on regenerative torque optimization with emulate engine compression braking (EECB) was proposed to make effective and maximum use of brake energy in order to improve fuel economy. The actual brake oil pressure of driving wheel which is reduced by the amount of the regenerative braking force is supplied from the electronic hydraulic brake system. Regenerative torque optimization maximizes the actual regenerative power recuperation by energy storage component, and EECB is a useful extended type of regenerative braking. The simulation results show that actual regenerative power recuperation for the novel regenerative braking algorithm is more than using conventional one, and life-span of brake disks is prolonged for the novel algorithm.

  6. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    Science.gov (United States)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  7. 乳胶粒化学改性酚醛树脂合成闸片的制动性能研究%Braking Performance of Hybrid Fibers Reinforced Brake Pad with Latex Particle Modified Phenolic Resin Binder

    Institute of Scientific and Technical Information of China (English)

    王海庆; 吴行阳; 周广荣; 丛培红

    2011-01-01

    A latex particle modified phenolic resin was designed and developed to manufacture organic brake pad for electric power locomotive brake. The braking performance was evaluated on a full - scale test bench at Vehicle Inspection Station of Product Quality Monitoring Center of Railway Ministry, People's Republic of China, according to the Europe standard UIC 541 - 3: 2006 and Standard of China Railway Ministry TB/T 3118 - 2005 ( the central line speed at brake pad was 41.8 m/s at the highest speed of 200 km/h ). The test results indicated that the average dry friction coefficient of the brake pad under different braking speeds ranged from 0.29 to 0.57, the average static friction coefficient was 0.47, and the wear rate of the pad was O. 2 cm3/MJ after 36 times of braking tests. All the above results satisfied the required values of UIC 541 -3: 2006. No bulges, loss of rubbing material, cracks and metal - embedded deposits were observed on the brake pad after the whole tests. FTIR analysis results indicated that chemical structure of the pad was similar to the polymer matrix, and no obvious tribochemical reactions were confirmed. All the results suggest that the new type organic brake pad may realize application for the brake of “Hexie” electric power locomotive.%采用自制的环保型乳胶粒化学改性酚醛树脂为粘结剂制备了和谐号电力机车用轮装式有机合成闸片,参照欧洲标准UIC 541-3:2006和我国铁道部标准TB/T 3118-2005规定的试验程序,在铁道部产品质量监督检验中心机车车辆检验站进行了闸片的制动性能试验(最高速度200 km/h时制动闸片中心线速度为41.8 m/s).试验结果表明该闸片在不同初始速度干燥条件下的平均摩擦系数在0.29~0.57,静摩擦系数平均值为0.47,36闸后的磨损率约为0.2 cm3/MJ,满足UIC 541-3:2006中规定的指标.表面形貌观察发现制动试验后闸片无开裂、掉渣、塌边和皴裂等现象,红外分析发现闸片摩擦

  8. Electro-mechanical Braking Method in Hybrid Electric Vehicles Based on Feedback Control Theory

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; YU Jun-quan; LIU Zheng-yu; CHANG Cheng

    2014-01-01

    In this paper, the hybrid electric vehicle braking process is researched, by using variables consists of HEV speed, motor speed, and state of charge established, functions of mechanical braking force, regenerative braking force and efficiency of energy recovery are constructed, and the control goal is to maximization the energy recovery efficiency. Under the feedback control strategy, with the constrain condition of braking strength and braking stability, combining experiments in ADVISOR, in different experiments of different working conditions, we can see that in UDDS Cycle, the regenerative braking efficiency is the best. What’s more, compared with strategies in ADVISOR, strategy proposed in this paper is obviously better.

  9. 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.

  10. Flow braking and the substorm current wedge

    Science.gov (United States)

    Birn, J.; Hesse, M.; Haerendel, G.; Baumjohann, W.; Shiokawa, K.

    1999-09-01

    Recent models of magnetotail activity have associated the braking of earthward flow with dipolarization and the reduction and diversion of cross-tail current, that is, the signatures of the substorm current wedge. Estimates of the magnitude of the diverted current by Haerendel [1992] and Shiokawa et al. [1997, 1998] tend to be lower than results from computer simulations of magnetotail reconnection and tail collapse [Birn and Hesse, 1996], despite similar underlying models. An analysis of the differences between these estimates on the basis of the simulations gives a more refined picture of the diversion of perpendicular into parallel currents. The inertial currents considered by Haerendel [1992] and Shiokawa et al. [1997] contribute to the initial current reduction and diversion, but the dominant and more permanent contribution stems from the pressure gradient terms, which change in connection with the field collapse and distortion. The major effect results from pressure gradients in the z direction, rather than from the azimuthal gradients [Shiokawa et al., 1998], combined with changes in By and Bx. The reduction of the current density near the equatorial plane is associated with a reduction of the curvature drift which overcompensates changes of the magnetization current and of the gradient B drift current. In contrast to the inertial current effects, the pressure gradient effects persist even after the burst of earthward flow ends.

  11. Squeal analysis of ventilated disc brake using ansys

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Naser, Ahmed; Allam, Essam; Abouel-seoud, Shawki [Automotive and Tractors Engineering Department., Faculty of Engineering, Helwan University, Cairo (Egypt); Ahmed, Ibrahim; Allam, Sabry [Automotive and Tractors Technology Department, Faculty of Industrial Education, Helwan University, Cairo (Egypt)

    2012-07-01

    It is well-known that automobile brakes can generate several kinds of noises. Among them is squeal, a noise in the 1-15 kHz range. It is commonly accepted that brake squeal is initiated by instability due to the friction forces, leading to self excited vibrations. To predict the onset of brake instability, a modal analysis of the prestressed structure can be performed on an improved dynamic finite element model of ventilated disc brake with friction coupling. An unsymmetric stiffness matrix is a result of the friction coupling between the brake pad and disc; this may lead to complex eigenfrequencies. The complex eigenvalue method (Unsymmetric solver) used to analyse mode shapes associated with the predicted natural frequency. Creating the element of Matrix27 between the ventilated disc and pad was very important in studying the squeal of the coupled ventilated disc brake. The results demonstrated that the FEM for the coupled ventilated rotor and pad showed a good interaction between the non-linear contact and the linear modal analysis. Furthermore, the unsymmetric solver showed that the modes of the coupled disc-pad contained two types of mode. The first type was normal mode, which did not contain an imaginary part while the second type was complex mode that contained real and imaginary parts. Moreover, complex eigenvalue analysis predicted always more unstable modes than the number of squeal frequencies that really occur in the brake system. The maximum squeal index was observed at mode 16 and at frequency of 4083 Hz with instability of 480 sec-1. However; the tendency of instability (TOI) for the system at contact stiffness of 1 GN/m was 59 that gave the lowest instability of the system.

  12. Squeal analysis of ventilated disc brake using ansys

    Directory of Open Access Journals (Sweden)

    Ahmed Abdel-Naser, Ibrahim Ahmed, Essam Allam, Sabry Allam, Shawki Abouel-seoud

    2012-01-01

    Full Text Available It is well-known that automobile brakes can generate several kinds of noises. Among them is squeal, a noise in the 1-15 kHz range. It is commonly accepted that brake squeal is initiated by instability due to the friction forces, leading to self excited vibrations. To predict the onset of brake instability, a modal analysis of the prestressed structure can be performed on an improved dynamic finite element model of ventilated disc brake with friction coupling. An unsymmetric stiffness matrix is a result of the friction coupling between the brake pad and disc; this may lead to complex eigenfrequencies. The complex eigenvalue method (Unsymmetric solver used to analyse mode shapes associated with the predicted natural frequency. Creating the element of Matrix27 between the ventilated disc and pad was very important in studying the squeal of the coupled ventilated disc brake. The results demonstrated that the FEM for the coupled ventilated rotor and pad showed a good interaction between the non-linear contact and the linear modal analysis. Furthermore, the unsymmetric solver showed that the modes of the coupled disc-pad contained two types of mode. The first type was normal mode, which did not contain an imaginary part while the second type was complex mode that contained real and imaginary parts. Moreover, complex eigenvalue analysis predicted always more unstable modes than the number of squeal frequencies that really occur in the brake system. The maximum squeal index was observed at mode 16 and at frequency of 4083 Hz with instability of 480 sec-1. However; the tendency of instability (TOI for the system at contact stiffness of 1 GN/m was 59 that gave the lowest instability of the system.

  13. 城市轨道车辆电气制动能量建模及仿真%Model Building and Simulation of the Electric Brake Energy of Urban Rail Vehicle

    Institute of Scientific and Technical Information of China (English)

    师蔚; 方宇

    2011-01-01

    By analyzing conditions that urban rail vehicles in the traction power supply network occur the regenerative braking or resistor braking in electric braking process, and depending on the grouping of vehicles, lines, load, run strategy, operation plans, traction power supply and other basic conditions, based on single vehicle computing model and multi-vehicles power supply network model, electric braking energy distribution model were established and simulation were carried out. Simulation results showed that in the same line and vehicle conditions, the ratio of regenerative braking energy occupying the total braking was 80.1% when vehicle interval was 180 seconds, with the interval increases the ratio decrease. When the interval was 900 seconds the electric braking energy was almost consumed by braking resistor.The braking energy distribution model can provide theoretical support for a variety of urban rail transit braking energy recovery methods, but also offer foundation for selection of braking energy recovery device.%通过分析城轨车辆在电气制动过程中发生再生制动及电阻制动的条件,并且根据车辆的编组、线路、载重、运行策略、运行图、牵引供电等基本因素,在单车牵引计算模型及多车运行的牵引供电网络模型的基础上,建市了城轨车辆电气制动能量分布模型,并进行了实例仿真计算.仿真计算结果表明,在相同的线路及车辆条件下,车辆发车间隔为180 s时,再生制动能量占总电气制动能量的比率为80.1%,随着发车间隔的增大,该比率逐渐减小;当发车间隔在900 s时,电气制动能最绝大多数消耗在制动电阻上.该制动能量分布模型可以为各种城市轨道交通制动能量回收方法提供理论支持,还可以为各种制动能量回收装置提供装置选型等方面的依据.

  14. Piecewise polynomial chaos expansion with an application to brake squeal of a linear brake system

    Science.gov (United States)

    Sarrouy, E.; Dessombz, O.; Sinou, J.-J.

    2013-02-01

    This paper proposes numerical developments based on polynomial chaos (PC) expansions to process stochastic eigenvalue problems efficiently. These developments are applied to the problem of linear stability calculations for a simplified brake system: the stability of a finite element model of a brake is investigated when its friction coefficient or the contact stiffness are modeled as random parameters. Getting rid of the statistical point of view of the PC method but keeping the principle of a polynomial decomposition of eigenvalues and eigenvectors, the stochastic space is decomposed into several elements to realize a low degree piecewise polynomial approximation of these quantities. An approach relying on continuation principles is compared to the classical dichotomy method to build the partition. Moreover, a criterion for testing accuracy of the decomposition over each cell of the partition without requiring evaluation of exact eigenmodes is proposed and implemented. Several random distributions are tested, including a uniform-like law for description of friction coefficient variation. Results are compared to Monte Carlo simulations so as to determine the method accuracy and efficiency. Some general rules relative to the influence of the friction coefficient or the contact stiffness are also inferred from these calculations.

  15. Unusual Braking Indices in Young X-ray Pulsars

    Science.gov (United States)

    Frederic Archibald, Robert; Kaspi, Victoria M.; Beardmore, Andrew P.; Gehrels, Neil; Kennea, Jamie; Gotthelf, Eric V.; Ferdman, Robert; Guillot, Sebastien; Harrison, Fiona; Keane, Evan; Pivovaroff, Michael; Stern, Daniel; Tendulkar, Shriharsh P.; Tomsick, John

    2016-04-01

    Pulsars spin down over time. By measuring braking indices of pulsars, effectively the change in the spin-down rate over time, we can probe the underlying driving engine of the spin-down. For a magnetic dipole in a vacuum, n is predicted to be 3. To date, all measured braking indices are less than 3, which can be explained, e.g. by particle winds, changes in the magnetic field. In all models of braking indices, n should be nearly constant on year time-scales. Here, I will discuss two recent observation results that challenge this model, interestingly both coming from young X-ray pulsars with no detected radio emission. The first, a long-lived decrease in the braking index of PSR J1846-0258 following a burst of magnetar-like activity, and secondly, the first stationary braking index greater than three. Understanding neutron-star spin evolution is key to constraining these objects' long-term energy output and has relevance to topics ranging from pulsar wind nebulae and supernova remnants to core-collapse supernova rates, physics, and expected outcomes.

  16. Hall drift and the braking indices of young pulsars

    CERN Document Server

    Gourgouliatos, K N

    2014-01-01

    Braking index measurements of young radio pulsars are all smaller than the value expected for spin down by magnetic dipole braking. We investigate magnetic field evolution in the neutron star crust due to Hall drift as an explanation for observed braking indices. Using numerical simulations and a semi-analytic model, we show that a $\\approx 10^{14}\\ {\\rm G}$ quadrupolar toroidal field in the neutron star crust at birth leads to growth of the dipole moment at a rate large enough to agree with measured braking indices. A key factor is the density at which the crust yields to magnetic stresses that build up during the evolution, which sets a characteristic minimum Hall timescale. The observed braking indices of pulsars with inferred dipole fields of $\\lesssim 10^{13}\\ {\\rm G}$ can be explained in this picture, although with a significant octupole component needed in some cases. For the stronger field pulsars, those with $B_d\\gtrsim 10^{13}\\ {\\rm G}$, we find that the magnetic stresses in the crust exceed the max...

  17. Prosthetic leg powered by MR brake and SMA wires

    Science.gov (United States)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  18. 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.

  19. Freshwater Fish Survey of Mathews Brake Water Body - 1980 and 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A Freshwater Fish Survey of Mathews Brake water body including land not within Mathews Brake NWR. Methods included Electroshocker, creel census, and seine.

  20. Maslov-type index and brake orbits in nonlinear Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, we study the Maslov-type index theory for linear Hamiltonian systems with brake orbits boundary value conditions and its applications to the existence of multiple brake orbits of nonlinear Hamiltonian systems.

  1. 77 FR 46633 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Science.gov (United States)

    2012-08-06

    ... RIN 2126-AB28 Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits AGENCY... Safety Administration (FMCSA) amends the requirements regarding brake readjustment limits in the Federal Motor Carrier Safety Regulations (FMCSRs). This rule amends the readjustment limits, clarifies...

  2. Thermo-mechanical behaviour of heavy-duty disc brake systems

    OpenAIRE

    Chen, J. P.

    2001-01-01

    In heavy-duty disc brake systems, braking is a transient, non-linear and asymmetrical thermo-mechanical process. Surface cracking, rather than wear, is the major factor limiting the brake disc's life. The disc material (cast-iron), heat transfer boundary conditions and pad-disc frictional reactions are characteristically non-linear and asymmetrical during the friction process. Non-uniform deformation and surface cracks in brake discs result from the accumulation of excess...

  3. 热镀锌张力辊电机气动抱闸系统的改造%Reformation of Pneumatic Brake System in Tension Roller Motor of Hot Dip Galvanized Steel

    Institute of Scientific and Technical Information of China (English)

    岑耀东; 陈林

    2012-01-01

    Against the problem of the tension roller brake system motor's frequent abnormal braking in the production line of hot dip galvanizing, the brake system s working principle and structural characteristics were analyzed. It is found that the main reasons causing this fault is failure of closing switches induction position, which result from the brake head bushings seal leakage. By improving the design and transformation of brake system's structure, the problem of the brake sensor is solved, and the resulting problem of abnormal downtime is avoided as well.%针对热镀锌生产线中张力辊电机抱闸系统频繁出现非正常制动故障的问题,从抱闸系统的工作原理和结构特点方面进行分析,发现抱闸头轴套密封处漏气造成接近开关感应位置失效是此故障的主要原因,采用铁片在外端固定接近开关来代替原来的密封盖后,解决了该故障问题.

  4. 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.

  5. Thermal Modeling of Disc Brake Rotor in Frictional Contact

    Science.gov (United States)

    Ali, Belhocine; Ghazaly, Nouby Mahdi

    2013-01-01

    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 analyze 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. The analysis also gives us, the heat flux distribution for the two discs.

  6. Braking the Gas in the beta Pictoris Disk

    CERN Document Server

    Fern'andez, R; Wu, Y; Brandeker, Alexis; Fern\\'andez, Rodrigo

    2006-01-01

    (Abridged) The main sequence star beta Pictoris hosts the best studied circumstellar disk to date. Nonetheless, a long-standing puzzle has been around since the detection of metallic gas in the disk: radiation pressure from the star should blow the gas away, yet the observed motion is consistent with Keplerian rotation. In this work we search for braking mechanisms that can resolve this discrepancy. We find that all species affected by radiation force are heavily ionized and dynamically coupled into a single fluid by Coulomb collisions, reducing the radiation force on species feeling the strongest acceleration. For a gas of solar composition, the resulting total radiation force still exceeds gravity, while a gas of enhanced carbon abundance could be self-braking. We also explore two other braking agents: collisions with dust grains and neutral gas. Grains surrounding beta Pic are photoelectrically charged to a positive electrostatic potential. If a significant fraction of the grains are carbonaceous (10% in t...

  7. Braking Performance of a Biomimetic Squid-Like Underwater Robot

    Institute of Scientific and Technical Information of China (English)

    Md.Mahbubar Rahman; Sinpei Sugimori; Hiroshi Miki; Risa Yamamoto; Yugo Sanada; Yasuyuki Toda

    2013-01-01

    In this study,the braking performance of the undulating fin propulsion system ofa biomimetic squid-like underwater robot was investigated through free run experiment and simulation of the quasi-steady mathematical model.The quasi-steady equations of motion were solved using the measured and calculated hydrodynamic forces and compared with free-run test results.Various braking strategies were tested and discussed in terms of stopping ability and the forces acting on the stopping stage.The stopping performance of the undulating fin propulsion system tured out to be excellent considering the short stopping time and short stopping distance.This is because of the large negative thrust produced by progressive wave in opposite direction.It was confirmed that the undulating fin propulsion system can effectively perform braking even in complex underwater explorations.

  8. 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.)

  9. Stability Control of Vehicle Emergency Braking with Tire Blowout

    Directory of Open Access Journals (Sweden)

    Qingzhang Chen

    2014-01-01

    Full Text Available 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 a safe speed in an expected trajectory. The simulating test system is also designed, and the testing results show that the vehicle can be quickly stabilized and kept in the original track after tire blowout with the emergency braking system described in the paper.

  10. Dynamics Models of Interacting Torques of Hydrodynamic Retarder Braking Process

    Directory of Open Access Journals (Sweden)

    Wenhao Shen

    2013-01-01

    Full Text Available Hydrodynamic retarder is a kind of assist braking device, which can transfer the vehicle kinetic energy into the heat energy of working medium. There are complicated three-dimensional viscous incompressible turbulent flows in hydrodynamic retarder, so that it is difficult to represent the parameters changing phenomenon and investigate the interactional law. In order to develop a kind of reliable theoretical model for internal flow field, in this study, the dynamics models of interacting torques between impellers and working fluid were constructed based on braking energy transfer principle by using Euler theory to describe the flow state in view of time scale. The model can truly represent the dynamic braking process.

  11. 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.

  12. 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. PMID:26236772

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

    Science.gov (United States)

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

    2016-02-01

    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.

  14. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  15. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Science.gov (United States)

    2010-10-01

    ... cutting out of secondary brake systems; (B) Inoperative or otherwise defective handbrakes or parking... 49 Transportation 4 2010-10-01 2010-10-01 false Movement of passenger equipment with power brake... § 238.15 Movement of passenger equipment with power brake defects. Beginning on January 1, 2002,...

  16. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Science.gov (United States)

    2010-02-03

    ... Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids AGENCY: National Highway Traffic Safety... NPRM proposes to amend FMVSS No. 116, Motor Vehicle Brake Fluids, so that brake fluids would be tested... Date VII. Rulemaking Analyses and Notices VIII. Public Participation I. Background Federal...

  17. 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...

  18. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    Science.gov (United States)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-01-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in…

  19. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

    .... George Soodoo, Division Chief, Vehicle Dynamics (NVS-122), Office of Crash Avoidance Standards (Email... technologies would help prevent the introduction of unsafe motorcycle brake systems on the road. Moreover... the proper grade of brake fluid. If the service brake system is a split hydraulic type, a...

  20. EFFECT OF GENDER DIFFERENCE ON BRAKE REACTION TIME

    Directory of Open Access Journals (Sweden)

    Ashok

    2016-02-01

    Full Text Available BACKGROUND OF THE STUDY Reaction time is the time taken to respond to a stimulus or change in the environment. It is a method to assess the time taken from the perception of a stimulus followed by mental processing for a motor response. Reaction time in various day to day activities as in driving a car is very important. Brake reaction time (BRT is the time taken for the driver to respond to visualize an object and to press the brake pedal. It is affected by many features like age, gender, neuromuscular disorders. OBJECTIVE OF THE STUDY Study has been undertaken to compare the BRT in male and female drivers and to analyze the effect of sex difference on Brake reaction time. MATERIALS & METHODS Male and female subjects between the age group of 25 – 35 years with driving license were included. Study is conducted in a stationary car. An in-house built; braking timer is fixed to the electric circuit of the braking system in the car. This device is wirelessly connected to the reaction time software installed in the laptop. The subject is instructed to press the brake pedal when the light changed from red to green in the laptop screen. 5 readings are taken and the mean BRT is recorded. STATISTICAL ANALYSIS & RESULTS Statistical analysis done with unpaired student t test indicates that the BRT was more in the females than the males and was statistically significant (p value - 0007. CONCLUSION Gender difference has a significant effect on BRT and reaction time in female is longer than for the males.

  1. RELIABILITY OF BRAKE SYSTEMS OF BUSES OF GROUP MAZ

    OpenAIRE

    A. Bessarab

    2013-01-01

    All over the world safety of maintained vehicles has the major value. For motor vehicles of the Republic of Belarus this problem is also actual. Maintenance of high reliability of brake systems of cars in operation is one of ways of the decision of a problem of increase of traffic safety.The analysis of reliability of brake systems of buses MAZ is carried out following the results of the state maintenance service in 2010 and the analysis of premature returns from routes of movement of buses M...

  2. Mechanical braking system for the pulsed power supply system of ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Käsemann, C.-P., E-mail: c.p.kaesemann@ipp.mpg.de [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Huart, M. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Michel Huart Personal Coaching and Consulting, Georgenschwaigstraße 23 RG, 80807 München (Germany); Stobbe, F.; Goldstein, I.; Sigalov, A. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Sachs, E. [Siemens AG, Industrial Automation Systems, Gleiwitzer Straße 555, 90475 Nürnberg (Germany); Perk, E. [Piper Test and Measurement Ltd., The Barn, Bilsington, Ashford, Kent TN25 7JT, England (United Kingdom)

    2013-10-15

    Highlights: ► Compact and innovative solution for dumping of large kinetic energy. ► Small mass of energy converter at the shaft due to circulating storage medium. ► Design of the active parts ensures flat torque/power characteristics. ► Also suitable for spending a great part of operating life in “Freewheeling” mode. -- Abstract: A few years ago, IPP reviewed the safety of the ASDEX Upgrade pulsed power supply system. Two critical sub-systems had been identified: The (electrical) braking system for the flywheel generators and the oil lubrication system for the shaft bearings. A simultaneous failure of these two systems may lead to severe damages and could have consequences for the safety of operating personnel. Therefore a second, independent braking possibility for every generator was stipulated. Especially the challenges adapting a dynamometer, originally designed for motor test benches, towards a plant safety system for generator EZ4 will be described in the paper. Further on, the paper will present the problems, implementing such a system into an existing installation, including the calculation of the required supporting structure, balancing of the extended shaft line and required water cooling and control. Finally it will report on the performance achieved during operation.

  3. Failure analysis of energy storage spring in automobile composite brake chamber

    Science.gov (United States)

    Luo, Zai; Wei, Qing; Hu, Xiaofeng

    2015-02-01

    This paper set energy storage spring of parking brake cavity, part of automobile composite brake chamber, as the research object. And constructed the fault tree model of energy storage spring which caused parking brake failure based on the fault tree analysis method. Next, the parking brake failure model of energy storage spring was established by analyzing the working principle of composite brake chamber. Finally, the data of working load and the push rod stroke measured by comprehensive test-bed valve was used to validate the failure model above. The experimental result shows that the failure model can distinguish whether the energy storage spring is faulted.

  4. Asynchronous Electric Motor with Built-in Combined Braking Device Based on Electro-Mechanical Brake and Electro-Magnetic Clutch

    OpenAIRE

    V. V. Solenkov; Brel, V. V.

    2011-01-01

    The paper shows advantages and disadvantages of the known designs of asynchronous motors with electro-mechanical braking device. A new developed and studied asynchronous motor design with built-in combined braking device based on an electro-mechanical brake and an electro-magnetic clutch is given in the paper. The paper describes its advantages and prospects of its usage for electric drives operating in intermittent cycle.

  5. Design of Braking Caliper's Braking Torque in Hydraulic Disc Braking System%液压盘式刹车系统制动钳制动力矩的设计

    Institute of Scientific and Technical Information of China (English)

    高燕; 宋胜涛; 王跃军; 韩美香; 郭太清

    2012-01-01

    针对目前液压盘式刹车系统刹车力矩小,刹车性能不稳定等现状,基于老算法对制动转矩的计算原理设计了一种新算法,对制动钳的工作制动转矩,紧急制动转矩及驻车制动转矩,冗余安全设计等进行了计算.为提高液压盘式刹车系统的设计效率和安全系数,该算法从制动钳的工作原理出发,通过对制动钳的制动结构进行分析,以下放到井中的最重套管柱所形成的静制动转矩作为盘刹系统能满足的最小工作制动转矩为依据,通过验证计算结果,保障了液压盘式刹车系统的安全性和有效性.%The current braking torque of the hydraulic disc braking system is small and braking performance is instable.A new algorithm was designed based on the braking torque's calculation of the old algorithm.The work braking torque, emergency braking torque, park braking torque and the redundant safety design were calculated in this new algorithm.To improve the design efficiency and safety coefficient of the hydraulic disc braking system, the algorithm based on the working principle of the braking caliper, through the braking structure analysis of the braking caliper, according to the static braking torque formed by the heaviest casing string that put into the well could be taken as the minimum working braking torque which the disc braking system could meet.The safety and effectiveness of the hydraulic disc braking system are safeguarded through the authentication and calculation of the result.

  6. Coaxial magnetic brakes using single-domain YBCO

    Energy Technology Data Exchange (ETDEWEB)

    Putman, P.T. [Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77204 (United States)], E-mail: pputman@uh.edu; Salama, K. [Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77204 (United States)

    2008-06-15

    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.

  7. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Science.gov (United States)

    2010-10-01

    ... identifiable stripes of at least one-sixteenth of an inch in width, placed on opposite sides of the brake hose... a twisted orientation in either side of the vehicle, need not meet the requirements of S5.2.1. S5.2... assemblies with end fittings that do not permit entry of the gauge (e.g., restrictive orifice or...

  8. CFD Analysis of Automotive Ventilated Disc Brake Rotor

    Directory of Open Access Journals (Sweden)

    Amol V. More

    2014-04-01

    Full Text Available Disc brakes work on the principle of friction by converting kinetic energy into heat energy. The key objective of a disc brake rotor is to accumulate this heat energy and dissipate it immediately. The effect of rotational speed on the aero-thermal performance is assessed. The rotor speed is observed to have substantial effect on the rotor performance. The heat dissipation and thermal performance of ventilated brake discs intensely be influenced by the aerodynamic characteristics of the air flow through the rotor passages. In order to investigate the aero-thermal performance of the ventilated disc brake at several altered driving speeds of the vehicle, the simulations were carried out at 3 different rotational speeds of 44rad/s 88 rad/s and 120 rad/s. The semi-automatic geometric model is created using the package Solid Works and the mesh for the model is done using ICEM CFD and the Post processing of the results is done using FLUENT-14.5.The results are discussed and presented in detail.

  9. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

    ... first morning departure of each commuter or short-distance intercity passenger train, unless all of the... repeated at the first passenger terminal if the train remains on a source of compressed air and: (1) The... that utilize an electric signal to communicate a service brake application and only a pneumatic...

  10. 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 coil...

  11. 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....

  12. Chinese Enterprises Slams the Brakes on Acquisition of Overseas Mines

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>On June 25,China Mining Association revealed that,as of the middle of June,Chinese enterprises slammed the brakes on acquisition of overseas mines.There are only 53 overseas mine acquisition cases so far this year,

  13. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    Science.gov (United States)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-12-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in obtaining their estimates of these quantities before and after watching a video recording of a car braking from various initial speeds to a complete stop and subsequent application of mathematical statistics to the obtained sets of students' answers. The results revealed that the difference between the value of the car braking distance estimated before watching the video and the real value of this distance was not caused by a random error but by a systematic error which was due to the incorrect students' conceptions about the car braking process. Watching the video significantly improved the students' estimates of the car braking distance, and we show that in this case, the difference between the estimated value and the real value of the car braking distance was due only to a random error, i.e. the students' conceptions about the car braking process were corrected. Some of the students subsequently performed video analysis of the braking processes of cars of various brands and under various conditions by means of Tracker that gave them exact knowledge of the physical quantities, which characterize a motor vehicle braking. Interviewing some of these students brought very positive reactions to this novel method of learning.

  14. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics

    OpenAIRE

    Dong-Chan Lee; Chul-Goo Kang

    2015-01-01

    A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installat...

  15. 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.

  16. Thermo-Mechanical Simulation of Brake Disc Frictional Character by Moment of Inertia

    Directory of Open Access Journals (Sweden)

    Fei Gao

    2014-01-01

    Full Text Available The distribution of temperatures gradient and thermal stress of brake disc has been simulated by FEM code to make brake disc thermal stress more homogenously. In this study, using moment of inertia to simulate the realistic brake process instead of theoretically predefines the train deceleration rate, nonlinear deceleration rate and thermo-mechanical behavior has been revealed. The FEM models build upon LS-DYNA® thermo-mechanical code and contact algorithm. Non-uniform temperature alone disc radial direction was caused by severe friction in short time and the low heat transfer coefficient of its material. Parametric analysis for disc brakes have been carried out by comparison of grouped brake applications conform to UIC code, the main factor cause the high temperature gradient and thermal stress of brake disc is brake force and its initial speed.

  17. A low cost, light weight cenosphere–aluminium composite for brake disc application

    Indian Academy of Sciences (India)

    V Saravanan; P R Thyla; S R Balakrishnan

    2016-02-01

    The commonly used composite material for brake rotor consists of silicon carbide (SiC) or aluminium oxide (Al$_2$O$_3$) particles which are more expensive. The weight of conventionally used composite is more compared to base alloy. The aim of this paper is to develop a light weight material for brake disc applications thereby substituting base alloy and conventional composite. This analysis led to 10 vol% cenosphere reinforced aluminium alloy (AA) 6063 composite as the most appropriate material for brake disc. To ensure the manufacturability of composite, composite brake rotor was casted using the sand casting technique and was machined to achieve the final component. Thermal capability of brake disc was ensured by studying temperature variation through vehicle testing procedure of disc brake. Cost reduction is one of the important benefit acquired using cenosphere reinforced composite. This was ensured by cost estimation and analysis. The cost estimated to manufacture the AA6063 brake disc was compared with composite cost.

  18. Synthesis and Characterization of Antifriction Magnetorheological Fluids for Brake

    Directory of Open Access Journals (Sweden)

    Chiranjit Sarkar

    2013-07-01

    Full Text Available Magnetorheological (MR fluids are smart materials with shear strength ranging between zero to 100 kPa under the influence of magnetic field. The present paper discusses the synthesis of MR fluid and its application in brake. In MR brake, gap between stator and rotor is filled with low (off-state viscosity MR fluid. On the application of magnetic field, MR fluid changes its state from liquid to semi-solid by aligning magnetic particles in chains. Due to such chaining action, yield strength of fluid increases, friction between stator and rotor increases and fulfils the braking function. The strength of magnetic particle is a function of relative speed between stator and rotor, applied magnetic field, and volume percentage of magnetic particle. In this study antifriction (off-state and strong chain (on-state CI based MR fluid has been prepared by mixing oleic acid as antifriction additives and tetramethylammonium hydroxide as surfactant to reduce the agglomeration of the MR fluid. Yield strengths of the synthesized MR fluid in on-state and off-state have been compared with commercially available MRF 241ES fluid. A flywheel based MR brake experimental setup has been developed to analyze the performance of designed and developed MR brake.Results show that synthesized MR fluid is stronger and faster in response compared to MRF 241ES fluid.Defence Science Journal, 2013, 63(4, pp.408-412, DOI:http://dx.doi.org/10.14429/dsj.63.2633

  19. Guidelines for numerical vibration and acoustic analysis of disc brake squeal using simple models of brake systems

    Science.gov (United States)

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

    2013-04-01

    Brake squeal has become of increasing concern to the automotive industry but guidelines on how to confidently predict squeal propensity are yet to be established. While it is standard practice to use the complex eigenvalue analysis to predict unstable vibration modes, there have been few attempts to calculate their acoustic radiation. Here guidelines are developed for numerical vibration and acoustic analysis of brake squeal using models of simplified brake systems with friction contact by considering (1) the selection of appropriate elements, contact and mesh; (2) the extraction of surface velocities via forced response; and (3) the calculation of the acoustic response itself. Results indicate that quadratic tetrahedral elements offer the best option for meshing more realistic geometry. A mesh has to be sufficiently fine especially in the contact region to predict mesh-independent unstable vibration modes. Regarding the vibration response, only the direct, steady-state method with a pressurised pad and finite sliding formulation (allowing contact separation) should be used. Comparison of different numerical methods suggest that a obroadband fast multi-pole boundary element method with the Burton-Miller formulation would efficiently solve the acoustic radiation of a full brake system. Results also suggest that a pad lift-off can amplify the acoustic radiation similar to a horn effect. A horn effect is also observed for chamfered pads which are used in practice to reduce the number and strength of unstable vibration modes. These results highlight the importance of optimising the pad shape to reduce acoustic radiation of unstable vibration modes.

  20. Collapse of Magnetized Singular Isothermal Toroids: II. Rotation and Magnetic Braking

    CERN Document Server

    Allen, A; Shu, F H

    2003-01-01

    We study numerically the collapse of rotating, magnetized molecular cloud cores, focusing on rotation and magnetic braking during the main accretion phase of isolated star formation. Motivated by previous numerical work and analytic considerations, we idealize the pre-collapse core as a magnetized singular isothermal toroid, with a constant rotational speed everywhere. The collapse starts from the center, and propagates outwards in an inside-out fashion, satisfying exact self-similarity in space and time. For rotation rates and field strengths typical of dense low-mass cores, the main feature remains the flattening of the mass distribution along field lines -- the formation of a pseudodisk, as in the nonrotating cases. The density distribution of the pseudodisk is little affected by rotation. On the other hand, the rotation rate is strongly modified by pseudodisk formation. Most of the centrally accreted material reaches the vicinity of the protostar through the pseudodisk. The specific angular momentum can b...

  1. Climate Based Performance of Carbon-Carbon Disc Brake for High Speed Aircraft Braking System

    Directory of Open Access Journals (Sweden)

    R. M. Mohanty

    2013-09-01

    Full Text Available Carbon composite brake discs are lighter, economical, and have excellent high energy friction characteristics. These have twice thermal capability compared to steel, remain unaffected by thermal shocks and mechanical fatigue. These are highly useful in emergency breaking situations. Prior to this work, two dimensional (2D reinforced carbon composite laminates were prepared through pitch impregnation process. In an effort to protect the exposed non frictional surface from high temperature service degradations, multilayered ceramic coating systems were developed on 2D composite. Oxidation studies have been carried out on these systems viz., C-SiC, C-SiC-MoSi2-Al2O3 and C-SiC-B4C. These were performed both in dynamic and static conditions up to 1200 °C in 60 per cent humid climate. The hardness, surface topography, developed phases and integrity of layers on the samples at various stages of the experiment have been characterized and analyzed. It was observed that C-SiC-B4C system performs well in the oxidizing environment.Defence Science Journal, 2013, 63(5, pp.531-538, DOI:http://dx.doi.org/10.14429/dsj.63.3932

  2. 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

  3. INFLUENCE OF THE TIME OF DISINHIBITION TO TRANSIENTS AND WEAR OF THE FRICTION LININGS IN AN ASYNCHRONOUS MOTOR

    Directory of Open Access Journals (Sweden)

    V. V. Solencov

    2016-01-01

    Full Text Available Time and the stopping distance of the electric drive with frequent starting-and-braking modes that contain embedded asynchronous motor with a recessed combined braking device depend on the moment of an electromagnet disinhibition. At the same time other important criteria are taken into the account, i.e. wear resistance of the brake device and the smoothness of the deceleration of the electric drive. In general such an asynchronous motor contains asynchronous engine with squirrel-cage rotor, electromechanical normally-closed brake, electromagnetical slip clutch and control circuit. The mechanical characteristics of the deceleration of asynchronous motor with recessed combined brake device at different moments of an electromagnet disinhibition are presented. The mathematical model is featured and the transients in such a motor are presented. Formation models for computer research were carried out in the Fortran 2008 programming language. Calculation of the system of differential equations was fulfilled by the Runge – Kutta method. The deceleration of the electromechanical brake at various speeds caused different time values and stopping distances. The plots of stopping distance and the braking time at various moments of an electromagnet disinhibition are demonstrated. The optimum moment of switching on an electromechanical brake, providing small stopping distance and the braking time is the time when the speed wвкл = 0,6–0,8 of the nominal. In this case the acceptable number of brake applications for friction linings (compared with mechanical braking will increase by 1.6–2.8 times. The pilot study confirmed the validity of the obtained mathematical models and discovered patterns.

  4. Study on the dynamic characteristics of a high frequency brake based on giant magnetostrictive material

    Science.gov (United States)

    Xu, Ai Qun

    2016-06-01

    In order to meet the requirements of rapid and smooth braking, high-frequency braking using a giant magnetostrictive actuator is proposed, which can solve the problems in hydraulic braking, such as, it leaks easily, catches fire easily, is difficult to find failures, high cost on maintenance and repairing, etc. The main factors affecting the force of a high-frequency braking actuator are emphatically analyzed, the brakes dynamic model is established and a performance testing device for high frequency braking is constructed based on LabVIEW. The output force of the actuator increases with the excitation current of the driving coil increasing, and the increased multiple of the output force is greater than that of the excitation current; the range of the actuator force amplitude is 121.63 N ∼ 158.14 N, which changes little, while excitation frequency changes between 200 Hz ∼ 1000 Hz. In a minor range of pre-stress, the output force decreases with an increase in the axial pre-stress of the giant magnetostrictive rod, but is not obvious. It is known by finite element simulation analysis that high-frequency braking shortens the braking displacement and time effectively, which proves the feasibility and effectiveness of high frequency braking. Theoretical analysis and experimental results indicate that the output force of the actuator changes at the same frequency with excitation current; it is controllable and its mechanical properties meet the requirements of high frequency braking.

  5. 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.

  6. Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

    CERN Document Server

    Wurster, James; Bate, Matthew R

    2015-01-01

    We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating the effects of ambipolar diffusion, Ohmic resistivity and the Hall effect alongside a self-consistent calculation of the ionisation chemistry assuming 0.1 micron grains. When including only ambipolar diffusion or Ohmic resistivity, discs do not form in the presence of strong magnetic fields, similar to the cases using ideal MHD. With the Hall effect included, disc formation depends on the direction of the magnetic field with respect to the rotation vector of the gas cloud. When the vectors are aligned, strong magnetic braking occurs and no disc is formed. When the vectors are anti-aligned, a disc with radius of 13AU ca...

  7. Tearing mode velocity braking due to resonant magnetic perturbations

    Science.gov (United States)

    Frassinetti, L.; Menmuir, S.; Olofsson, K. E. J.; Brunsell, P. R.; Drake, J. R.

    2012-10-01

    The effect of resonant magnetic perturbations (RMPs) on the tearing mode (TM) velocity is studied in EXTRAP T2R. Experimental results show that the RMP produces TM braking until a new steady velocity or wall locking is reached. The braking is initially localized at the TM resonance and then spreads to the other TMs and to the rest of the plasma producing a global velocity reduction via the viscous torque. The process has been used to experimentally estimate the kinematic viscosity profile, in the range 2-40 m2 s-1, and the electromagnetic torque produced by the RMP, which is strongly localized at the TM resonance. Experimental results are then compared with a theoretical model which gives a reasonable qualitative explanation of the entire process.

  8. Analysis of natural frequency variability of a brake component

    Science.gov (United States)

    Gallina, A.; Lisowski, W.; Pichler, L.; Stachowski, A.; Uhl, T.

    2012-10-01

    The manufacture of automotive disc brake calipers is subjected to many inherent variabilities resulting in product variability. In particular, the dispersion of natural frequency values is a primary issue in the context of vehicle comfort. This paper aims to quantify natural frequency variability and search for its causes. Extensive experimental tests and numerical simulations, described in the paper, point out the fundamental role of mold wear and assembling process in this variability.

  9. Nonlinear transient and chaotic interactions in disc brake squeal

    Science.gov (United States)

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

    2015-04-01

    In automotive disc-brake squeal, most numerical studies have been focussed on the prediction of unstable vibration modes in the frequency domain using the complex eigenvalue analysis. However, the magnitude of the positive real part of a complex eigenvalue is an unreliable indicator of squeal occurrence. Although nonlinearities have been shown to play a significant role in brake squeal, transient nonlinear time domain analyses have rarely been applied owing to high computational costs. Here the complex eigenvalue analysis, the direct steady-state analysis and the transient nonlinear time domain analysis are applied to an isotropic pad-on-disc finite element model representing a simple model of a brake system. While in this investigation, in-plane pad-mode instabilities are not detected by the complex eigenvalue analysis, the dissipated energy obtained by the direct steady-state analysis of the model subjected to harmonic contact pressure excitation is negative at frequencies of pad modes, indicating a potential for instabilities. Transient nonlinear time domain analysis of the pad and disc dynamics reveal that in-plane pad vibrations excite a dominant out-of-plane disc mode. For intermittently chaotic pad motion, the disc dynamics is quasi-periodic; and for chaotic motion of the pad, a toroidal attractor is found for the disc's out-of-plane motion. Nonlinear interactions between the pad and the disc highlight that different parts in a brake system display different dynamic behaviour and need to be analysed separately. The type II intermittency route to chaos could be the cause for the experimentally observed instantaneous mode squeal.

  10. Subway Train Braking System: A Fuzzy Based Hardware Approach

    Directory of Open Access Journals (Sweden)

    Mamun B.I. Reaz

    2011-01-01

    Full Text Available Problem statement: Automated subway train-braking system require perfection, efficiency and fast response. In order to cope with this concerns, an appropriate algorithm need to be developed which need to be implemented in hardware for faster response. Approach: In this research, the FPGA realization of fuzzy based subway train braking system has been presented on an Alter FLEX10K device to provide an accurate and increased speed of convergence of the network. The fuzzy based subway train braking system is comprised of fusilier, inference, rule selector and defuzzifier modules. Sixteen rules are identified for the rule selector module. After determining the membership functions and its fuzzy variables, the Max-Min Composition method and Madman-Min implication operator are used for the inference module and the Centre of Gravity method is used for the defuzzification module. Each module is modeled individually using behavioral VHDL. The layers are then connected using structural VHDL. Two 8-bit and one 8-bit unsigned digital signals are used for input and output respectively. Six ROMs are defined in order to decrease the chances of processing and increasing the throughput of the system. Results: Functional simulations were commenced to verify the functionality of the individual modules and the system as well. We have validated the hardware implementation of the proposed approach through comparison, verification and analysis. The design has utilized 2372 units of LC with a system frequency of 139.8MHz. Conclusion: In this research, the FPGA realization of fuzzy brake system of subway train has been successfully implemented with minimum usage of logic cells. The validation study with C model shows that the hardware model is appropriate and the hardware approach shows faster and accurate response with full automatic control.

  11. Adaptive Brake By Wire: From Human Factors to Adaptive Implementation

    OpenAIRE

    Spadoni, Andrea

    2013-01-01

    The introduction of the Brake By Wire is replacing the traditional mechanical control systems with ECUs and it is raising the need to reproduce feelings of eliminated static mechanical components (i.e. hydraulic fluids, pumps and cylinders). Thanks to electromechanical actuators and human-machine interfaces (i.e. active pedal) it is possible to reproduce such feelings and, therefore, arbitrarily change their features. In this way it will be possible to customize the pedal feelings and the veh...

  12. Slide Mode Control for Integrated Electric Parking Brake System

    OpenAIRE

    Bin Wang; Xuexun Guo; Chengcai Zhang; Zhe Xiong; Huan Xia; Jie Zhang

    2013-01-01

    The emerging integrated electric parking brake (IEPB) system is introduced and studied. Through analyzing the various working stages, the stages switched IEPB system models are given with the consideration of the friction and system idle inertia. The sliding mode control (SMC) method is adopted to control the clamping force by the widely used motor angle and clamping force relationship method. Based on the characteristics of the state equations, two sliding surfaces are built to control the m...

  13. 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.

  14. An Investigation into Regenerative Braking Control Strategy for Hybrid Electric Vehicle

    Institute of Scientific and Technical Information of China (English)

    PENG Dong; YIN Cheng-liang; ZHANG Jian-wu

    2005-01-01

    Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is added by electric motor, the braking torque distribution between front and rear axles should be changed and the control logic of anti-lock braking system (ABS) ought to be adjusted according to the regenerative braking torque. This paper put forward a braking control strategy for hybrid electric vehicle; the control strategy is implemented with eight DOFs (Degree-of-Freedom) nonlinear vehicle forward simulation model which is built under the environment of Matlab/Simulink. Based on target wheel slip ratio, a fuzzy logic approach was applied to maintain the optimal target slip ratio so that best compromise between hydraulic torque and regenerative torque can be obtained for the vehicle.

  15. Design and analysis of the hybrid excitation rail eddy brake system of high-speed trains

    Institute of Scientific and Technical Information of China (English)

    Ji-en MA; Bin ZHANG; Xiao-yan HUANG; You-tong FANG; Wen-ping CAO

    2011-01-01

    Compared to the current eddy braking patterns using a single magnetic source,hybrid excitation rail eddy brakes have many advantages,such as controllability,energy saving,and various operating models.Considering the large braking power consumption of the high-speed train,a hybrid excitation rail eddy brake system,which is based on the principle of electromagnetic field,is proposed to fulfill the needs of safety and reliability.Then the working processes of the mechanical lifting system and electromagnetic system are demonstrated.With the electromagnetic system analyzed using the finite element method,the factors such as speed,air gap,and exciting current have influences on the braking force and attractive force.At last,the structure optimization of the brake system is discussed.

  16. 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.

  17. Optimal design of a new multipole bilayer magnetorheological brake

    Science.gov (United States)

    Shiao, Yaojung; Ngoc, Nguyen Anh; Lai, Chien-Hung

    2016-11-01

    This article presents a new high-torque multipole bilayer magneto-rheological brake (MRB). This MRB has a unique structural design with multiple electromagnetic poles and multiple media layers of magnetorheological fluid (MRF). The MRB has two rotors located on the outer and inner sides of a six-pole stator, and therefore, it can provide higher torque and a larger torque-to-volume ratio (TVR) than conventional single- or multipole single-layer MRBs can. Moreover, the problem of potential MRF leakage is solved by using cylindrical separator rings around the stator. In this study, first, the structure of the proposed MRB is introduced. An analog magnetic circuit was built for the MRB to investigate the effects of the MRB parameters on the magnetic field intensity of the MRF layers. In addition, a 3D electromagnetic model of the MRB was developed to simulate and examine the magnetic flux intensity and corresponding braking torque. An approximate optimization method was then applied to obtain the optimal geometric dimensions for the major dimensional parameters of the MRB. The MRB was manufactured and tested to validate its torque and dynamic characteristics. The results showed that the proposed MRB exhibited great enhancement of the braking torque and TVR.

  18. Effects of Magnetic Braking and Tidal Friction on Hot Jupiters

    CERN Document Server

    Barker, A J

    2009-01-01

    Tidal friction is thought to be important in determining the long-term spin-orbit evolution of short-period extrasolar planetary systems. Using a simple model of the orbit-averaged effects of tidal friction Eggleton, Kiseleva & Hut (1998), we analyse the effects of the inclusion of stellar magnetic braking on the evolution of such systems. A phase-plane analysis of a simplified system of equations, including only the stellar tide together with a model of the braking torque proposed by Verbunt & Zwaan (1981), is presented. The inclusion of stellar magnetic braking is found to be extremely important in determining the secular evolution of such systems, and its neglect results in a very different orbital history. We then show the results of numerical integrations of the full tidal evolution equations, using the misaligned spin and orbit of the XO-3 system as an example, to study the accuracy of simple timescale estimates of tidal evolution. We find that it is essential to consider coupled evolution of th...

  19. 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.

  20. Thermo-Mechanical Simulation of Brake Disc Frictional Character by Moment of Inertia

    OpenAIRE

    Fei Gao

    2014-01-01

    The distribution of temperatures gradient and thermal stress of brake disc has been simulated by FEM code to make brake disc thermal stress more homogenously. In this study, using moment of inertia to simulate the realistic brake process instead of theoretically predefines the train deceleration rate, nonlinear deceleration rate and thermo-mechanical behavior has been revealed. The FEM models build upon LS-DYNA® thermo-mechanical code and contact algorithm. Non-uniform temperature alone disc ...

  1. Development of electronic diagnostic system for improving the diagnosis reliability of passenger car brakes

    OpenAIRE

    2016-01-01

    The mathematical model that allows determining the pressure in the brake cylinder, distributor chambers and auxiliary reservoir of the car depending on the absolute pressure changes in the air flow through the throttle openings for a scheduled time is developed in the paper for diagnosing the parameters of the brake system of the individual car or train. It is embedded in the hardware-software system algorithm. This allows simulating the operation of the serviceable brake equipment and provid...

  2. An approach of inertia compensation based on electromagnetic induction in brake test

    Directory of Open Access Journals (Sweden)

    Xiaowen Li

    2016-04-01

    Full Text Available This paper briefly introduced the operational principle of the brake test bench, and points out the shortcomings when controlling the current of brake test, which means the reference measuring data is instantaneous. Aimed at this deficiency, a current control model based on electromagnetic induction and DC voltage is proposed. On the principle of electromagnetic induction, continuous data and automatic processes are realized. It significantly minimized errors owing to instantaneous data, and maximized the accuracy of the brake test.

  3. Development of Parking Brake Component : Product Development and Mechanical Design Process

    OpenAIRE

    Rintamäki, Julia

    2013-01-01

    This report represents the bachelor thesis examination by Julia Kastehelmi Rintamäki. The examination has been performed during spring semester 2013 at Volvo Construction Equipment in Eskilstuna. This report, Development of parking brake component, describes the product development process of the parking brake component for articulated hauler, wheel loader and grader. Volvo CE has problems with the parking brake switch that exist today on articulated hauler, wheel loader and grader. The purpo...

  4. A Study on Control Strategy of Regenerative Braking in the Hydraulic Hybrid Vehicle Based on ECE Regulations

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2013-01-01

    Full Text Available This paper establishes a mathematic model of composite braking in the hydraulic hybrid vehicle and analyzes the constraint condition of parallel regenerative braking control algorithm. Based on regenerative braking system character and ECE (Economic Commission of Europe regulations, it introduces the control strategy of regenerative braking in parallel hydraulic hybrid vehicle (PHHV. Finally, the paper establishes the backward simulation model of the hydraulic hybrid vehicle in Matlab/simulink and makes a simulation analysis of the control strategy of regenerative braking. The results show that this strategy can equip the hydraulic hybrid vehicle with strong brake energy recovery power in typical urban drive state.

  5. Analysis of the stability of PTW riders in autonomous braking scenarios.

    Science.gov (United States)

    Symeonidis, Ioannis; Kavadarli, Gueven; Erich, Schuller; Graw, Matthias; Peldschus, Steffen

    2012-11-01

    While fatalities of car occupants in the EU decreased remarkably over the last decade, Powered Two Wheelers (PTWs) fatalities still increase following the increase of PTW ownership. Autonomous braking systems have been implemented in several types of vehicles and are presently addressed by research in the field of PTWs. A major concern in this context is the rider stability. Experiments with volunteers were performed in order to find out whether autonomous braking for PTWs will produce a greater instability of the rider in comparison to manual braking. The PTW's braking conditions were simulated in a laboratory with a motorcycle mock-up mounted on a sled, which was accelerated with an average of 0.35 g. The motion of the rider was captured in autonomous braking scenarios with and without pre-warning as well as in manual braking scenarios. No significant differences between the scenarios were found with respect to maximum forward displacement of the volunteer's torso and head (pautonomous braking at low deceleration will not cause significant instabilities of the rider in comparison to manual braking in idealized laboratory conditions. Based on this, further research into the development and implementation of autonomous braking systems for PTWs, e.g. by extensive riding tests, seems valuable.

  6. Real-Time Dynamic Brake Assessment Proof of Concept Final Report

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-01

    This proof-of-concept research was performed to explore the feasibility of using real-world braking data from commercial motor vehicles to make a diagnosis of brake condition similar to that of the performance-based brake tester (PBBT). This was done by determining the relationship between pressure and brake force (P-BF), compensating for the gross vehicle weight (GVW). The nature of this P-BF relationship (e.g., low braking force for a given brake application pressure) may indicate brake system problems. In order to determine the relationship between brake force and brake application pressure, a few key parameters of duty cycle information were collected. Because braking events are often brief, spanning only a few seconds, a sample rate of 10 Hz was needed. The algorithm under development required brake application pressure and speed (from which deceleration was calculated). Accurate weight estimation was also needed to properly derive the braking force from the deceleration. In order to ensure that braking force was the predominant factor in deceleration for the segments of data used in analysis, the data was screened for grade as well. Also, the analysis needed to be based on pressures above the crack pressure. The crack pressure is the pressure below which the individual brakes are not applied due the nature of the mechanical system. This value, which may vary somewhat from one wheel end to another, is approximately 10 psi. Therefore, only pressures 15 psi and above were used in the analysis. The Department of Energy s Medium Truck Duty Cycle research has indicated that under the real-world circumstances of the test vehicle brake pressures of up to approximately 30 psi can be expected. Several different types of data were collected during the testing task of this project. Constant-pressure stopping tests were conducted at several combinations of brake application pressure (15, 20, 25, and 30 psi), load conditions (moderately and fully laden), and speeds (20 and

  7. 重载列车制动管路对制动性能的影响%Influence of braking pipe on braking performance for heavy haul train

    Institute of Scientific and Technical Information of China (English)

    魏伟; 杜念博

    2011-01-01

    应用流体动力学理论,建立了重载列车制动管路模型与分配阀模型,求解了制动管路和边界点的动力学方程,仿真计算了制动过程中的制动系统性能,分析了列车主管和支管长度对制动系统性能的影响。分析结果表明:当列车主管长度由13.24 m增大为17.24 m时,在常用制动下,列车管路减压时间增大了30.75%,制动缸升压时间增大了20.45%,主管长度对常用制动的影响要强于对紧急制动的影响;当列车支管长度由0.50 m增大到5.00 m时,在常用制动下,列车管路减压时间增大了6.63%,制动缸升压时间增大了5.22%,支管长度对常用制动和紧急制动影响程度差别不大。列车制动管路长度增大降低了列车制动管路减压速度与制动缸升压速度;列车主管长度对制动性能的影响要明显大于列车支管长度的影响,车辆位置距机车越远影响越明显。%With fluid dynamics theory,the models of braking pipe and distributing valve for heavy haul train were built,the equations of braking pipe and boundary point were solved,the braking system performances in braking process were simulated,and the influence of the lengths of main pipe and branch pipe on the braking performances was analyzed.Analysis result shows that under common braking,when the length of main pipe increases from 13.24 m to 17.24 m,the decompression time of braking pipe increases by 30.75%,and the boost time of braking cylinder increases by 20.45%.The influence of main pipe on common braking is even stronger than that of main pipe on emergency braking.Under common braking,when the length of branch pipe increases from 0.50 m to 5.00 m,the decompression time of braking pipe increases by 6.63%,and the boost time of braking cylinder increases by 5.22%.The influence of branch pipe on common braking is almost same for that of branch pipe on emergency braking.The increase length of braking pipe reduces the decompression speed of braking pipe

  8. A Computational Study on the Use of an Aluminium Metal Matrix Composite and Aramid as Alternative Brake Disc and Brake Pad Material

    Directory of Open Access Journals (Sweden)

    Nosa Idusuyi

    2014-01-01

    Full Text Available A computational model for the heat generation and dissipation in a disk brake during braking and the following release period has been formulated. The model simulates the braking action by investigating the thermal behaviour occurring on the disc and pad surfaces during this period. A comparative study was made between grey cast iron (GCI, asbestos, Aluminium metal matrix composite (AMC, and aramid as brake pad and disc materials. The braking process and following release period were simulated for four material combinations, GCI disc and Asbestos pad, GCI disc and Aramid pad, AMC disc and Asbestos pad, AMC disc and Aramid pad using COMSOL Multiphysics software. The results show similarity in thermal behaviour at the contact surface for the asbestos and aramid brake pad materials with a temperature difference of 1.8 K after 10 seconds. For the brake disc materials, the thermal behaviour was close, with the highest temperature difference being 9.6 K. The GCI had a peak temperature of 489 K at 1.2 seconds and AMC was 465.5 K but cooling to 406.4 K at 10 seconds, while the GCI was 394.7 K.

  9. Control of Braking Noise of A Car Disc Brake%某型轿车盘式制动器制动噪声的控制

    Institute of Scientific and Technical Information of China (English)

    戢何民

    2011-01-01

    Bench test is made to a car diac brake, it is found in this test that braking noise frequency mainly occurs at 3 kHz. With FEA, vibration characteristic analysis is made to brake disc, brake caliper case, caliper bracket and friction pad. Test results indicate that 7-order vibration mode of brake caliper bracket is a major contributor of -braking noise. Structure of brake caliper bracket is modified, and bench test is made to the disc brake with the modified caliper bracket. The results show that cold state braking noise is reduced from 100.5 dB to 73.4 dB, meeting the requirement of noise limit of this vehicle.%对某型轿车盘式制动器进行了台架试验,发现该制动器主要制动噪声频率在3 kHz附近.采用有限元FEA分析手段对制动盘、制动钳壳体、制动钳支架和摩擦片进行了振动特性分析.结果表明,制动钳支架的7阶振动模态是导致制动噪声产生的原因之一.对制动钳支架结构设计进行了改进,并对装有改进后制动钳支架的盘式制动器进行了台架试验.结果表明,制动器冷态制动噪声从100.5 dB下降为73.4 dB,达到了该车型对制动器噪声的限值要求.

  10. Analysis of heat conduction in a drum brake system of the wheeled armored personnel carriers

    Science.gov (United States)

    Puncioiu, A. M.; Truta, M.; Vedinas, I.; Marinescu, M.; Vinturis, V.

    2015-11-01

    This paper is an integrated study performed over the Braking System of the Wheeled Armored Personnel Carriers. It mainly aims to analyze the heat transfer process which is present in almost any industrial and natural process. The vehicle drum brake systems can generate extremely high temperatures under high but short duration braking loads or under relatively light but continuous braking. For the proper conduct of the special vehicles mission in rough terrain, we are talking about, on one hand, the importance of the possibility of immobilization and retaining position and, on the other hand, during the braking process, the importance movement stability and reversibility or reversibility, to an encounter with an obstacle. Heat transfer processes influence the performance of the braking system. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of analyzed vehicle wheels. In the present work a finite element model for the temperature distribution in a brake drum is developed, by employing commercial finite element software, ANSYS. These structural and thermal FEA models will simulate entire braking event. The heat generated during braking causes distortion which modifies thermoelastic contact pressure distribution drum-shoe interface. In order to capture the effect of heat, a transient thermal analysis is performed in order to predict the temperature distribution transitional brake components. Drum brakes are checked both mechanical and thermal. These tests aim to establish their sustainability in terms of wear and the variation coefficient of friction between the friction surfaces with increasing temperature. Modeling using simulation programs led eventually to the establishment of actual thermal load of the mechanism of brake components. It was drawn the efficiency characteristic by plotting the coefficient of effectiveness relative to the coefficient of friction shoe-drum. Thus induced

  11. 时速250km以上高速列车制动模式曲线算法%Braking mode curve arithmetic of high-speed train above 250 km · h-1

    Institute of Scientific and Technical Information of China (English)

    上官伟; 蔡伯根; 王晶晶; 王剑; 王利

    2011-01-01

    The braking system of high-speed train above 250 km ? H-1 was studied, and the running resistance, braking force and braking distance of high-speed train were analyzed. Based on curve theory of target distance mode, the piecewise iteration model of braking mode curve for high-speed train was proposed. With MATLAB/Simulink software, the changes of running resistances on flat-straight line, direct ramp with grade 15%o and direct ramp with grade 25‰ for CRH2-300 type high-speed train were analyzed, and the normal braking curves and emergency braking curves of CRH2-300 type and CRH3 type high-speed trains at initial braking speed 300 km ? H-1 were compared. Calculation result indicates that the emergency braking distance of CRH2-300 type high-speed train is 2 786. 68 m on direct ramp, the emergency braking distance of CRH3 type high-speed train is 3 319. 37 m on direct ramp, and both of them are less than 3 700 m, which is the maximum braking distance of braking requirement. Simulation braking curves almost consistent with actual braking curves, which verifies the validity of piecewise iteration algorithm. 1 tab, 12 figs, 10 refs.%研究了时速250 km以上高速列车制动系统,分析了高速列车的运行阻力、制动力与制动距离.根据目标距离模式曲线理论,建立了高速列车的制动模式曲线分段迭代模型.应用MAT-LAB/Simulink软件,分析了CRH2-300型高速列车在平直道上、15‰与25‰直坡道上的运行阻力的变化,对比了CRH2-300型和CRH3型高速列车在制动初速为300 km·h-1时的常用和紧急制动曲线.计算结果表明:在平直道上,CRH2-300型高速列车紧急制动距离为2 786.68 m,CRH3型高速列车紧急制动距离为3 319.37 m,均满足紧急制动距离小于3 700 m的制动要求;仿真制动曲线和实际制动曲线基本一致,验证了分段迭代算法的有效性.

  12. To a question of an estimation of possibilities and efficiency of various kinds of electric braking of industrial electric locomotives

    OpenAIRE

    Sinchuk, O. N.; Sinchuk, I. O.; Jakimets, S. N.; Kljuchka, A. S.

    2010-01-01

    The analysis of efficiency of the use of different types of the electric braking by the hauling electromechanics of mines electric locomotives is resulted. Efficiency of the electrodynamic braking is led to. The schemotechnycs decisions are resulted.

  13. Energy-Regenerative Braking Control of Electric Vehicles Using Three-Phase Brushless Direct-Current Motors

    OpenAIRE

    Bo Long; Shin Teak Lim; Ji Hyoung Ryu; Kil To Chong

    2013-01-01

    Regenerative braking provides an effective way of extending the driving range of battery powered electric vehicles (EVs). This paper analyzes the equivalent power circuit and operation principles of an EV using regenerative braking control technology. During the braking period, the switching sequence of the power converter is controlled to inverse the output torque of the three-phase brushless direct-current (DC) motor, so that the braking energy can be returned to the battery. Compared with ...

  14. Product Quality Improvement Using FMEA for Electric Parking Brake (EPB)

    Science.gov (United States)

    Dumitrescu, C. D.; Gruber, G. C.; Tişcă, I. A.

    2016-08-01

    One of the most frequently used methods to improve product quality is complex FMEA. (Failure Modes and Effects Analyses). In the literature various FMEA is known, depending on the mode and depending on the targets; we mention here some of these names: Failure Modes and Effects Analysis Process, or analysis Failure Mode and Effects Reported (FMECA). Whatever option is supported by the work team, the goal of the method is the same: optimize product design activities in research, design processes, implementation of manufacturing processes, optimization of mining product to beneficiaries. According to a market survey conducted on parts suppliers to vehicle manufacturers FMEA method is used in 75%. One purpose of the application is that after the research and product development is considered resolved, any errors which may be detected; another purpose of applying the method is initiating appropriate measures to avoid mistakes. Achieving these two goals leads to a high level distribution in applying, to avoid errors already in the design phase of the product, thereby avoiding the emergence and development of additional costs in later stages of product manufacturing. During application of FMEA method using standardized forms; with their help will establish the initial assemblies of product structure, in which all components will be viewed without error. The work is an application of the method FMEA quality components to optimize the structure of the electrical parking brake (Electric Parching Brake - E.P.B). This is a component attached to the roller system which ensures automotive replacement of conventional mechanical parking brake while ensuring its comfort, functionality, durability and saves space in the passenger compartment. The paper describes the levels at which they appealed in applying FMEA, working arrangements in the 4 distinct levels of analysis, and how to determine the number of risk (Risk Priority Number); the analysis of risk factors and established

  15. Evolution of the pulsar inclination angle in the wind braking model

    CERN Document Server

    Kou, F F; Wang, N

    2016-01-01

    In a plasma filled magnetosphere, in addition to providing a torque to brake down the pulsar, the magnetosphere will also generate a torque to align the pulsar magnetic and rotational axes. The evolution of pulsar inclination angle in the wind braking model is calculated. In the wind braking model, the oblique pulsar tends to align. The pulsar alignment will also affect the spin-down behavior. Braking index will increase firstly and then decrease as the pulsar evolving from the magneto-dipole radiation dominated case to the wind braking dominated case. Braking index may be larger than $3$ in the early time. And during the following long time, braking index will be always smaller than $3$. This can explain braking index observations of larger than $3$ and smaller than $3$. Besides, the pulsar will evolve downwards straightly to the death valley after pulsar death in the $P-\\dot{P}$ diagram. This may explain the observed maximum spinning period of pulsars. And the long-term evolution of pulsars in the wind brak...

  16. 30 CFR 75.523-3 - Automatic emergency-parking brakes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic emergency-parking brakes. 75.523-3... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.523-3 Automatic emergency-parking brakes. (a) Except for personnel carriers, rubber-tired,...

  17. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Science.gov (United States)

    2010-10-01

    ... powered by an electric motor drawing current from rechargeable storage batteries, fuel cells, or other... charge batteries and components thereof. Electrically-actuated service brakes means service brakes that... lightly loaded vehicle weight, and, if an EV, with the propulsion batteries at a state of charge of...

  18. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2010-03-30

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK62 Federal Motor Vehicle Safety... that amended the Federal motor vehicle safety standard for air brake systems by requiring substantial... 37122) amending Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to...

  19. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ... Administration 49 CFR Part 571 [Docket No. NHTSA-2009-0175] RIN 2127-AK84 Federal Motor Vehicle Safety Standards... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to require improved...

  20. INVESTIGATION OF ANTILOCK BRAKE SYSTEM EFFECT ON PASSENGER CAR BRAFKING EFFICIENCY

    Directory of Open Access Journals (Sweden)

    I. Davidenko

    2011-01-01

    Full Text Available It has been experimentally proved that in case of emergency braking the constant decelera-tion of passenger cars equipped by antilock brake system exceeds the tabulated statistical data by 7,7–17 % that is recommended to apply at technical expertise at traffic accident causes investigation.

  1. Brake wear from vehicles as an important source of diffuse copper pollution

    NARCIS (Netherlands)

    Hulskotte, J.H.J.; Gon, H.A.C.D. van der; Visschedijk, A.J.H.; Schaap, M.

    2007-01-01

    In this article we show that brake wear from road traffic vehicles is an important source of atmospheric (participate) copper concentrations in Europe. Consequently, brake wear also contributes significantly to deposition fluxes of copper to surface waters. We estimated the copper emission due to br

  2. MAGNETIC BRAKING AND FIELD DISSIPATION IN THE PROTOSTELLAR ACCRETION PHASE

    Directory of Open Access Journals (Sweden)

    D. Galli

    2009-01-01

    Full Text Available We summarize recent theoretical work addressing the role of magnetic elds in the process of star formation. First, we concentrate on the efficiency of magnetic braking during cloud collapse and its consequences on the formation of centrifugally supported disks around young stars. Then, we relate this issue to the well-known magnetic ux problem of star formation, and we show that the introduction of non-ideal MHD e ects is a necessary step toward the development of self-consistent models for the collapse of molecular clouds and the formation and evolution of accretion disks around young stars.

  3. Taking the brakes off proppant-pack conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gulbis, J.; Hawkins, G.; King, M.; Pulsinelli, R.; Brown, E.; Elphick, J.

    1991-01-01

    Fracture stimulation treatments often fail to achieve predicted results because design data have not accounted for the downhole environment. Since 1986, the Dowell Schlumberger fracture conductivity laboratory has been carrying out realistic evaluations of proppants, fracturing fluids and additives. One element of this program has shown that viscous components of the treatment fluid remain in the proppant and significantly block flow of oil and gas. This knowledge has been applied to develop a new way of breaking down flow resistance, taking the brakes off proppant-pack conductivity. 13 figs., 4 ills., 1 tab., 12 refs.

  4. Modal reduction of brake squeal systems using complex interface modes

    Science.gov (United States)

    Besset, S.; Sinou, J.-J.

    2017-02-01

    This paper deals with a new efficient reduction method for predicting the stability analysis of a damped nonlinear brake system subjected to friction-induced vibration. The originality of the present work is to propose a generalized double modal synthesis method that combines a classical modal reduction and a condensation at the frictional interface by computing a reduced complex mode basis. Comparisons with the existing double modal synthesis reduction method are performed. It is demonstrated that the new suggested reduction technique is more efficient. It allows to provide satisfactory results with a small number of interfaces modes.

  5. 考虑CVT效率的混合动力汽车再生制动控制策略%Control Strategy for Regenerative Braking of HEV with Consideration of CVT Efficiency

    Institute of Scientific and Technical Information of China (English)

    秦大同; 陈斌; 杨阳; 邓涛

    2012-01-01

    Based on the analysis of relation of regenerative braking efficiency and motor,battery as well as CVT efficiency,an optimal working line of motor,battery and CVT was obtained and an optimal control strategy of regenerative braking was proposed in which the efficiencies of the motor,battery and CVT are taken into account.The regenerative braking model of HEV was established and the simulation was carried out.The results showed that compared to the current control strategy for regenerative braking of HEV; the proposed control strategy can not only ensured the prerequisite of braking safety, but also further improved the recovery of braking energy.%在分析再生制动系统综合效率与电机、电池、CVT效率之间关系的基础上,获取了电机、电池、CVT联合最佳效率曲线,提出了综合考虑电机、电池、CVT效率的再生制动优化控制策略,进行了CVT混合动力汽车再生制动的建模与仿真分析.结果表明:所提出的再生制动控制策略与现有CVT混合动力汽车再生制动控制策略相比,可在保证整车制动安全的条件下,进一步提高制动能量回收率.

  6. 新型高性能提升机智能电液制动系统的研究%Intelligent Electro-Hydraulic Braking System of New High Performance Hoister

    Institute of Scientific and Technical Information of China (English)

    史世杰; 张根现; 马星河

    2011-01-01

    The high performance intelligent electro-hydraulic hoist braking system further improves the safety of large mine hoist braking performance.Using modern electro-hydraulic control theory,the system is made up of high performance disc brakes,brake on-line monitor system,constant deceleration,hydraulic station,constant deceleration cabinet and the speed measurement equipment.When emergency braking,the system can always brake as the pre-set deceleration speed,not change along with load or working conditionIt not only improves the safety and reliability of mine hoist,but also improves production efficiency.%为进一步提高大型矿井提升机安全制动性能,运用现代电液控制理论,设计了由高性能盘形制动器、制动器在线监控系统、恒减速度液压站、恒减速度电控柜,以及测速装置组成的智能电液制动系统。该系统在紧急制动时,能使制动减速不随负载、工况变化而变化,始终按预先设定的减速度值进行制动,既可提高矿井提升机的安全可靠性,又提高生产效率。

  7. 49 CFR 236.565 - Provision made for preventing operation of pneumatic brake-applying apparatus by double-heading...

    Science.gov (United States)

    2010-10-01

    ... pneumatic brake-applying apparatus by double-heading cock; requirement. 236.565 Section 236.565... preventing operation of pneumatic brake-applying apparatus by double-heading cock; requirement. Where provision is made for preventing the operation of the pneumatic brake-applying appartus of an...

  8. Auxiliary brakes for trucks : research into the behaviour of a tractor-semi-trailer combination during emergency breaking.

    NARCIS (Netherlands)

    Dijks, A. Blijswijk, W.A.M. van Genugten, J. van Meeke, G.J.M. & Schlösser, L.H.M.

    1976-01-01

    The purpose of the research was to obtain an insight into various secondary braking systems for goods vehicles. Practical tests were carried out with a tractor- semi-trailer combination. The performance of various split braking systems as well as spring brake actuators are shown. With nearly all of

  9. Development of brake system of railway vehicles for real-time HILS

    Science.gov (United States)

    Kim, Min-Soo; Park, Joon-Hyuk; Goo, Byeong-Choon

    2007-12-01

    Brake system of railway vehicles has a crucial role for the safety as well as riding quality of passengers. Its core technology for successful development of the brake system is to design of ECU (Electric Control Unit) containing antiskid control, brake blending control, load compensating control, and so on. Each development procedure of ECU involves a verifying test for each step and is completed by an evaluation test of the comprehensive performance verification for the overall systems. The development tool which is applied to this objective is the HILS (Hardware-In-the- Loop-Simulation). In order to design a controller, a good representative model of the system is needed. This paper describes the dynamic modeling of brake system of railway vehicle for HILS and analyzes some dynamic behavior under emergency braking force.

  10. Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

    Science.gov (United States)

    Byrdsong, T. A.

    1973-01-01

    An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

  11. Compositions, Functions, and Testing of Friction Brake Materials and Their Additives

    Energy Technology Data Exchange (ETDEWEB)

    Blau, PJ

    2001-10-22

    The purpose of this report is to present a survey of commercial brake materials and additives, and to indicate their typical properties and functions, especially as regards their use in heavy trucks. Most truck pad and shoe materials described here were designed to wear against cast iron. Brake material test methods are also briefly described. This report does not address issues associated with the fabrication and manufacturing of brake materials. Since there are literally thousands of brake material additives, and their combinations are nearly limitless, it is impractical to list them all here. Rather, an attempt has been made to capture the primary constituents and their functions. An Appendix contains thermo-physical properties of some current and potential brake materials.

  12. Distribution and Dissipation of Braking Power of Wet Multidisc Brake%湿式多片制动器制动能的分配和耗散

    Institute of Scientific and Technical Information of China (English)

    阎清东; 宿新东

    2000-01-01

    研究湿式多片制动器制动过程制动能的分配和耗散,确定制动器的热负荷及摩擦偶件间热流分布的状况. 结合车辆的制动过程提出制动能四次分配的概念,利用有限元法计算制动能的三次、四次分配. 紧急制动中湿式多片制动器制动能的三次、四次分配主要与摩擦偶件的材料有关;持续制动中制动器吸收的能量主要由冷却润滑油带走. 为研究摩擦副的失效及摩擦材料的适用性提供了依据.%To study the distribution and dissipation of braking power of wet multidisc brake and determine thermal load and thermal flux distribution between mated discs, the concept of distributing brake power four times was put forward. The third and the fourth distribution of brake power were calculated by using finite element(FE) software ANSYS. The third and the fourth distribution of wet multidisc brake are mainly related to material characteristics of discs during emergency braking, while most of the braking power is carried off during continuous braking. Basis is provided for further analysis of disc failure and applicability of different friction materials.

  13. Study of heat transfer on front– and back-vented brake discs

    Directory of Open Access Journals (Sweden)

    Supachai Lakkam

    2013-12-01

    Full Text Available A brake disc plays an important role in the automotive industry since it concerns directly with safety. In order to develop proper heat ventilation a wide range of brake discs have been designed. Different types of physical brake disc geometries, as front- and back-vented brake discs, affect the heat ventilation directly. This is a vital factor of the brake’s capability. We recognized the importance of this circumstance and therefore attempted to create a test to investigate the temperature gradient of the brake disc in order to evaluate the coefficients of heat convection. The coefficients were modified by the change of temperature distribution in both brake discs under the forced heat convection in steady state conditions. However, the heat radiation value does not take into account that the heat convection is dominated by the physical geometry of the brake disc. To set up the experimental test for investigating the heat transfer by convection the JASO C406 standard is adopted. The experimental results in terms of heat convection coefficients are used in the numerical simulation via the finite element method in order to study the temperature diffusion and heat ventilation of front and back-vented brake discs. Conse-quently, the experimental results reveal that the overall heat convection coefficients of the front-vented brake disc are higher than these of the back-vented one. In other words the simulation yields that the front-vented brake disc allows stronger heat ventilation than its compared object, leading to larger temperature differences between outboard and inboard rotors, resulting in more thermal stress. This makes it more susceptible to be damaged during operation.

  14. A double modal synthesis approach for brake squeal prediction

    Science.gov (United States)

    Monteil, M.; Besset, S.; Sinou, J.-J.

    2016-03-01

    This paper is devoted to propose a new efficient reduction method for predicting the stability analysis of a brake system subjected to friction-induced vibration. The finite element brake system under study is composed of a disc and a pad. The contact is modeled by introducing contact elements at the friction interface with the classical Coulomb law and a constant friction coefficient. It will be demonstrated that it is possible to build efficient reduced finite element models by developing a reduced model based on a Double Modal Synthesis (i.e. a classical modal reduction via Craig & Bampton plus a condensation at the frictional interface). Special attention is being conducted to validate the convergence of the reduced model especially on the approximation of the unstable modes with respect to real and imaginary parts. This complete numerical strategy based on Double Modal Synthesis allows us to perform relevance squeal prediction of unstable vibration modes. It is demonstrated that the numerical results via the Double Modal Synthesis are in good agreement with those of the classical Craig & Bampton method.

  15. Digital Sliding Mode Control of Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    MITIC, D. B.

    2013-02-01

    Full Text Available The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.

  16. FES-Assisted Walking with Spring Brake Orthosis: Simulation Studies

    Directory of Open Access Journals (Sweden)

    R. Jailani

    2011-01-01

    Full Text Available This paper presents a simulation of bipedal locomotion to generate stimulation pulses for activating muscles for paraplegic walking with wheel walker using functional electrical stimulation (FES with spring brake orthosis (SBO. A new methodology for paraplegic gait, based on exploiting natural dynamics of human gait, is introduced. The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO. This mechanism simplifies the control task and results in smooth motion and more-natural like trajectory produced by the flexion reflex for gait in spinal cord injured subjects. SBO can eliminate reliance on the withdrawal reflex and foot-ground clearance without extra upper body effort. The stored energy in the spring of SBO is used to replace stimulation pulses in knee flexion and reduce total required torque for the paraplegic walking with wheel walker. The study is carried out with a model of humanoid with wheel walker using the Visual Nastran (Vn4D dynamic simulation software. Stimulated muscle model of quadriceps is developed for knee extension. Fuzzy logic control (FLC is developed in Matlab/Simulink to regulate the muscle stimulation pulse-width required to drive FES-assisted walking gait and the computed motion is visualised in graphic animation from Vn4D. The simulation results show that SBO can be successfully used with FES for paraplegic walking with wheel walker with all the advantages discussed over the current hybrid orthoses available.

  17. Structure Analysis at the Micro Iron Pour at Gray Brake

    Directory of Open Access Journals (Sweden)

    Melya D. Sebayang

    2012-01-01

    Full Text Available The use of gray cast iron brake drum as the material is the most appropriate choice, because it has properties which have good heat conductivity, hardness, toughness, good friction properties and the ability to absorb vibration. The purpose of this study to determine the ratio of the microstructure on both original material drum that is new and original drum ex-wear. With the aim of analysis is expected to be used as basis in planning the development of better vehicle brakes. Of all the test results it can be mentioned chemical composition of test results with the main alloying elements, to drum new original: C 4:13%, 2:51% Si, 0.15% S, 0.65% Mn, 0.0054% P, and the original drum ex-wear: C 4:13%, 2:17% Si, 0.15% S, 0.53% Mn, 0.0054% P. So the comparison of properties of the resulting structure after the testing process on each drum is the hardness and resistance to wear and tear on a new original drum better when compared with the original drum ex-wear.

  18. Influence of Optimizing Brake Pads Structure on Brake Disc Temperature and Thermal Stress%优化结构闸片对制动盘温度及热应力的影响

    Institute of Scientific and Technical Information of China (English)

    农万华; 符蓉; 韩晓明

    2012-01-01

    为了研究列车制动产生摩擦热对制动盘的耐热疲劳性能的影响,分析了摩擦热流分布与闸片结构的关系,提出一种优化闸片摩擦块固定位置,达到改善制动盘摩擦热分布的方法,采用有限元软件ABAQUS对优化前后的闸片制动过程进行了数值模拟,结果表明:与闸片优化前相比,闸片优化后制动盘最高温度和热应力分别下降的17%和23%,沿制动盘径向分布更均匀.%In order to study the effects of friction heat generation on thermal fatigue performance of brake disc during train braking, the relationship between friction heat flux distribution and brake pad structure was discussed , and a method of optimizing the brake pad friction blocks to improve the distribution of friction heat on brake disc was proposed. By finite element software ABAQUS, the braking process using the optimized brake pads and non-optimized brake pads was simulated respectively. The results show that the temperature of the optimized brake disc brake pads are decreased and the radial distribution of the thermal stress is more uniform along the brake disc. The results show thai compared with the brake pads before optimization, the highest temperature and thermal stress of the optimized brake discs brake pads are decreased by 17% and 23% respectively.

  19. Optimal design of disc-type magneto-rheological brake for mid-sized motorcycle: experimental evaluation

    Science.gov (United States)

    Sohn, Jung Woo; Jeon, Juncheol; Nguyen, Quoc Hung; Choi, Seung-Bok

    2015-08-01

    In this paper, a disc-type magneto-rheological (MR) brake is designed for a mid-sized motorcycle and its performance is experimentally evaluated. The proposed MR brake consists of an outer housing, a rotating disc immersed in MR fluid, and a copper wire coiled around a bobbin to generate a magnetic field. The structural configuration of the MR brake is first presented with consideration of the installation space for the conventional hydraulic brake of a mid-sized motorcycle. The design parameters of the proposed MR brake are optimized to satisfy design requirements such as the braking torque, total mass of the MR brake, and cruising temperature caused by the magnetic-field friction of the MR fluid. In the optimization procedure, the braking torque is calculated based on the Herschel-Bulkley rheological model, which predicts MR fluid behavior well at high shear rate. An optimization tool based on finite element analysis is used to obtain the optimized dimensions of the MR brake. After manufacturing the MR brake, mechanical performances regarding the response time, braking torque and cruising temperature are experimentally evaluated.

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

    Directory of Open Access Journals (Sweden)

    Jingang Guo

    2014-10-01

    Full Text Available 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 motor braking and the hydraulic braking. Simulations were carried out with Matlab/Simulink. By comparing with a conventional Bang-bang ABS controller, braking stability and passenger comfort is improved with the proposed SMC controller, and the chatting phenomenon is reduced effectively with the parameter optimizing by FLC. With the increasing proportion of the motor braking torque, the tracking of the slip ratio is more rapid and accurate. Furthermore, the braking distance is shortened and the conversion energy is enhanced.

  1. Multi-objective optimization of the control strategy of electric vehicle electro-hydraulic composite braking system with genetic algorithm

    Directory of Open Access Journals (Sweden)

    Zhang Fengjiao

    2015-03-01

    Full Text Available Optimization of the control strategy plays an important role in improving the performance of electric vehicles. In order to improve the braking stability and recover the braking energy, a multi-objective genetic algorithm is applied to optimize the key parameters in the control strategy of electric vehicle electro-hydraulic composite braking system. Various limitations are considered in the optimization process, and the optimization results are verified by a software simulation platform of electric vehicle regenerative braking system in typical brake conditions. The results show that optimization objectives achieved a good astringency, and the optimized control strategy can increase the brake energy recovery effectively under the condition of ensuring the braking stability.

  2. Frictional and heat resistance characteristics of coconut husk particle filled automotive brake pad

    Science.gov (United States)

    Bahari, Shahril Anuar; Chik, Mohd Syahrizul; Kassim, Masitah Abu; Som Said, Che Mohamad; Misnon, Mohd Iqbal; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    The objective of this study was to determine the friction and heat resistance characteristics of automotive brake pad composed with different sizes and percentages of coconut husk particle. The materials used were phenolic resin (phenol formaldehyde) as binder, copper, graphite and brass as friction producer/modifiers, magnesium oxide as abrasive material, steel and barium sulfate as reinforcement while coconut husk particle as filler. To obtain particle, the coconut husk was ground and dried to 3% moisture content. Then the coconut husk particle was screened using 80 mesh (to obtain coarse dust) and 100 mesh (to obtain fine dust). Different percentages of particle, such as 10 and 30% were used in the mixture of brake pad materials. Then the mixture was hot-pressed to produce brake pad. Chase machine was used to determine the friction coefficient in friction resistance testing, while thermogravimetric analyzer (TGA) machine was used to determine the heat decomposition values in heat resistance testing. Results showed that brake pad with 100 mesh and 10% composition of coconut husk particle showed the highest friction coefficient. For heat resistance, brake pad with 100 mesh and 30% composition of coconut husk dust showed the highest decomposition temperature, due to the high percentage of coconut husk particle in the composition, thus increased the thermal stability. As a comparison, brake pad composed with coconut husk particle showed better heat resistance results than commercial brake pad.

  3. A method to model anticipatory postural control in driver braking events.

    Science.gov (United States)

    Östh, Jonas; Eliasson, Erik; Happee, Riender; Brolin, Karin

    2014-09-01

    Human body models (HBMs) for vehicle occupant simulations have recently been extended with active muscles and postural control strategies. Feedback control has been used to model occupant responses to autonomous braking interventions. However, driver postural responses during driver initiated braking differ greatly from autonomous braking. In the present study, an anticipatory postural response was hypothesized, modelled in a whole-body HBM with feedback controlled muscles, and validated using existing volunteer data. The anticipatory response was modelled as a time dependent change in the reference value for the feedback controllers, which generates correcting moments to counteract the braking deceleration. The results showed that, in 11 m/s(2) driver braking simulations, including the anticipatory postural response reduced the peak forward displacement of the head by 100mm, of the shoulder by 30 mm, while the peak head flexion rotation was reduced by 18°. The HBM kinematic response was within a one standard deviation corridor of corresponding test data from volunteers performing maximum braking. It was concluded that the hypothesized anticipatory responses can be modelled by changing the reference positions of the individual joint feedback controllers that regulate muscle activation levels. The addition of anticipatory postural control muscle activations appears to explain the difference in occupant kinematics between driver and autonomous braking. This method of modelling postural reactions can be applied to the simulation of other driver voluntary actions, such as emergency avoidance by steering.

  4. Morphology and properties of periwinkle shell asbestos-free brake pad

    Directory of Open Access Journals (Sweden)

    D.S. Yawas

    2016-01-01

    Full Text Available The development of asbestos-free automotive brake pad using periwinkle shell particles as frictional filler material is presented. This was with a view to exploiting the characteristics of the periwinkle shell, which is largely deposited as a waste, in replacing asbestos which has been found to be carcinogenic. Five sets of brake pads with different sieve size (710–125 μm of periwinkle shell particles with 35% resin were produced using compressive moulding. The physical, mechanical and tribological properties of the periwinkle shell particle-based brake pads were evaluated and compared with the values for the asbestos-based brake pads. The results obtained showed that compressive strength, hardness and density of the developed brake pad samples increased with decreasing the particle size of periwinkle shell from 710 to 125 μm, while the oil soak, water soak and wear rate decreased with decreasing the particle size of periwinkle shell. The results obtained at 125 μm of periwinkle shell particles compared favourably with that of commercial brake pad. The results of this research indicate that periwinkle shell particles can be effectively used as a replacement for asbestos in brake pad manufacture.

  5. Experimental Method for Analyzing Friction Phenomenon Related to Drum Brake Squeal

    Directory of Open Access Journals (Sweden)

    J. GLIŠOVIĆ

    2010-12-01

    Full Text Available Automobile brakes have been intensively developed during past few decades, but the maximum motor’s power, that should amortized in vehicle brakes, has been significantly increased also. Most of the kinetic energy of the moving vehicles is transforming into heat through friction. But the small part of kinetic energy transforms into sound pressure and makes noise. Low frequency squeal of drum brakes is very intense and can lead to customers’ complain. The interaction between the brake system and the vehicle framework and suspension is often very substantial during occurrence of brake noise. Unfortunately, to solve this type of squeal problem is also difficult because of the large number of components involved. The other cause is attributed to self-excited vibration that is induced when the friction material has a negative slope in relation to the relative velocity. This paper illustrates an approach to experimental studies of drum brakes in road conditions in order to monitor changes in the coefficient of friction that can generate drum brake squeal at low frequencies.

  6. Evaluation the course of the vehicle braking process in case of hydraulic circuit malfunction

    Science.gov (United States)

    Szczypiński-Sala, W.; Lubas, J.

    2016-09-01

    In the paper, the results of the research were discussed, the aim of which was the evaluation of the vehicle braking performance efficiency and the course of this process with regard to the dysfunction which may occur in braking hydraulic circuit. As part of the research, on-road tests were conducted. During the research, the delay of the vehicle when braking was measured with the use of the set of sensors placed in the parallel and the perpendicular axis of the vehicle. All the tests were conducted on the same flat section of asphalt road with wet surface. Conditions of diminished tire-to-road adhesion were chosen in order to force the activity of anti-lock braking system. The research was conducted comparatively for the vehicle with acting anti-lock braking system and subsequently for the vehicle without the system. In both cases, there was a subsequent evaluation of the course of braking with efficient braking system and with the dysfunction of hydraulic circuit.

  7. Plugging Braking of Two-PMSM Drive in Subway Applications with Fault-Tolerant Operation

    Directory of Open Access Journals (Sweden)

    Adel A. obed

    2016-06-01

    Full Text Available The Permanent Magnet Synchronous Motor (PMSM is commonly used as traction motors in the electric traction applications such as in subway train. The subway train is better transport vehicle due to its advantages of security, economic, health and friendly with nature. Braking is defined as removal of the kinetic energy stored in moving parts of machine. The plugging braking is the best braking offered and has the shortest time to stop. The subway train is a heavy machine and has a very high moment of inertia requiring a high braking torque to stop. The plugging braking is an effective method to provide a fast stop to the train. In this paper plugging braking system of the PMSM used in the subway train in normal and fault-tolerant operation is made. The model of the PMSM, three-phase Voltage Source Inverter (VSI controlled using Space Vector Pulse Width Modulation technique (SVPWM, Field Oriented Control method (FOC for independent control of two identical PMSMs and fault-tolerant operation is presented. Simulink model of the plugging braking system of PMSM in normal and fault tolerant operation is proposed using Matlab/Simulink software. Simulation results for different cases are given.

  8. Study on Parameter Optimization Design of Drum Brake Based on Hybrid Cellular Multiobjective Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2012-01-01

    Full Text Available In consideration of the significant role the brake plays in ensuring the fast and safe running of vehicles, and since the present parameter optimization design models of brake are far from the practical application, this paper proposes a multiobjective optimization model of drum brake, aiming at maximizing the braking efficiency and minimizing the volume and temperature rise of drum brake. As the commonly used optimization algorithms are of some deficiency, we present a differential evolution cellular multiobjective genetic algorithm (DECell by introducing differential evolution strategy into the canonical cellular genetic algorithm for tackling this problem. For DECell, the gained Pareto front could be as close as possible to the exact Pareto front, and also the diversity of nondominated individuals could be better maintained. The experiments on the test functions reveal that DECell is of good performance in solving high-dimension nonlinear multiobjective problems. And the results of optimizing the new brake model indicate that DECell obviously outperforms the compared popular algorithm NSGA-II concerning the number of obtained brake design parameter sets, the speed, and stability for finding them.

  9. Generation of Nanoparticles from Friction between Railway Brake Disks and Pads.

    Science.gov (United States)

    Namgung, Hyeong-Gyu; Kim, Jong-Bum; Woo, Sang-Hee; Park, Sechan; Kim, Minhae; Kim, Min-Soo; Bae, Gwi-Nam; Park, Duckshin; Kwon, Soon-Bark

    2016-04-01

    In this study, we measured the size distribution of particles ranging in size from 5.6 to 560 nm that were emitted between brake disks and pads under various braking conditions to observe and analyze changes to the resulting particle size distribution over braking time. A peak of 178-275 nm (200 nm peak) was observed in all braking conditions. However, the generation of spherical particles of a 10 nm range was observed only when the disk speed and brake force were above certain levels and intensified only when speed and brake force further increased. The total number concentration of ultrafine particles (no larger than 0.1 μm; PM0.1) generated was found to correlate with disk speed and brake force. Thus, the generation of nanoparticles resulting from disk speed and brake force was attributable primarily to increases in the contact surface temperature. The critical temperature for the generation of nanoparticles of a 10 nm range was found to be about 70 °C, which is the average temperature between the surface and the inside of the disk. If the speed or brake force was higher, that is, the temperature of the contact surface reached a certain level, evaporation and condensation took place. Vapor then left the friction surface, met with the air, and quickly cooled to form nanoparticles through nucleation. When the newly generated particles became highly concentrated, they grew through coagulation to form agglomerates or the vapor condensed directly onto the surface of existing particles of about 200 nm (formed by mechanical friction).

  10. DETERMINATION OF BRAKING OPTIMAL MODE OF CONTROLLED CUT OF DESIGN GROUP

    Directory of Open Access Journals (Sweden)

    A. S. Dorosh

    2015-06-01

    Full Text Available Purpose. The application of automation systems of breaking up process on the gravity hump is the efficiency improvement of their operation, absolute provision of trains breaking up safety demands, as well as improvement of hump staff working conditions. One of the main tasks of the indicated systems is the assurance of cuts reliable separation at all elements of their rolling route to the classification track. This task is a sophisticated optimization problem and has not received a final decision. Therefore, the task of determining the cuts braking mode is quite relevant. The purpose of this research is to find the optimal braking mode of control cut of design group. Methodology. In order to achieve the purpose is offered to use the direct search methods in the work, namely the Box complex method. This method does not require smoothness of the objective function, takes into account its limitations and does not require calculation of the function derivatives, and uses only its value. Findings. Using the Box method was developed iterative procedure for determining the control cut optimal braking mode of design group. The procedure maximizes the smallest controlled time interval in the group. To evaluate the effectiveness of designed procedure the series of simulation experiments of determining the control cut braking mode of design group was performed. The results confirmed the efficiency of the developed optimization procedure. Originality. The author formalized the task of optimizing control cut braking mode of design group, taking into account the cuts separation of design group at all elements (switches, retarders during cuts rolling to the classification track. The problem of determining the optimal control cut braking mode of design group was solved. The developed braking mode ensures cuts reliable separation of the group not only at the switches but at the retarders of brake position. Practical value. The developed procedure can be

  11. Detection of visually unrecognizable braking tracks using Laser-Induced Breakdown Spectroscopy, a feasibility study

    Science.gov (United States)

    Prochazka, David; Bilík, Martin; Prochazková, Petra; Brada, Michal; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

    2016-04-01

    Identification of the position, length and mainly beginning of a braking track has proven to be essential for determination of causes of a road traffic accident. With the introduction of modern safety braking systems and assistance systems such as the Anti-lock Braking System (ABS) or Electronic Stability Control (ESC), the visual identification of braking tracks that has been used up until the present is proving to be rather complicated or even impossible. This paper focuses on identification of braking tracks using a spectrochemical analysis of the road surface. Laser-Induced Breakdown Spectroscopy (LIBS) was selected as a method suitable for fast in-situ element detection. In the course of detailed observations of braking tracks it was determined that they consist of small particles of tire treads that are caught in intrusions in the road surface. As regards detection of the "dust" resulting from wear and tear of tire treads in the environment, organic zinc was selected as the identification element in the past. The content of zinc in tire treads has been seen to differ with regard to various sources and tire types; however, the arithmetic mean and modus of these values are approximately 1% by weight. For in-situ measurements of actual braking tracks a mobile LIBS device equipped with a special module was used. Several measurements were performed for 3 different cars and tire types respectively which slowed down with full braking power. Moreover, the influence of different initial speed, vehicle mass and braking track length on detected signal is discussed here.

  12. The mechanism of changes in the surface layer of grey cast iron automotive brake disc

    OpenAIRE

    Adam Polak; Janusz Grzybek

    2005-01-01

    The aim of the study was to create a model, describing the run of tribological processes in the surface layer of grey cast iron automotive brake discs. Grey cast iron discs mating with non-asbestos organic brake pads were chosen for the investigations, as the most widely used materials in car brakes. Samples for surface analysis were prepared from disc operating in stand and road conditions. Stand tests were pin-on-disc kind. Operating parameters for the stand tests were chosen on the basis o...

  13. Braking indices of pulsars obtained in the presence of an effective force

    CERN Document Server

    Magalhaes, N S; Frajuca, C

    2016-01-01

    Braking indices of pulsars present a scientific challenge as their theoretical calculation is still an open problem. In this paper we report results of a study regarding such calculation which adapts the canonical model (which admits that pulsars are rotating magnetic dipoles) basically by introducing a compensating component in the energy conservation equation of the system. This component would correspond to an effective force that varies with the first power of the tangential velocity of the pulsar's crust. We test the proposed model using data available and predict braking indices values for different stars. We comment on the high braking index recently measured of the pulsar J1640-4631.

  14. Vibration control of an artificial muscle manipulator with a magnetorheological fluid brake

    Science.gov (United States)

    Tomori, H.; Midorikawa, Y.; Nakamura, T.

    2013-02-01

    Recently, proposed applications of robots require them to contact human safely. Therefore, we focus on pneumatic rubber artificial muscle. This actuator is flexible, light, and has high-power density. However, because the artificial muscle is flexible, it vibrates when there is a high load. Therefore, we paid attention to the magnetorheological (MR) fluid. We propose a control method of the MR brake considering energy of the manipulator system. By this control method, MR brake dissipates energy leading to vibration of the manipulator. In this paper, we calculated the energy and controlled the MR brake. And, we deliberated the proposal method by simulation using the dynamic model of the manipulator, and experiment.

  15. Design and Development of Hydraulic Disc Brake Systems for Well Servicing Rig Drawworks

    Institute of Scientific and Technical Information of China (English)

    Gao xiangqian; Zhou Yongxia

    1996-01-01

    @@ The conventional band brakes have been known to be important but also the most unlnerable part in servicing rig deawworks.. The failures in braking and releasing operations haven't well been avoided. There have evidently existed the problems of difficult operation and inconvenient maintenance in this connection. The use of power-assisted hydraulic cylinders or pneumatic cylinders can not meet the requirements of operations either. Since the late 1980s, we have cooperated with Shengli oilfields and others in the successful design and development of PST25 hydraulic disc brake systems for well servicing rig in a fully closed working state.

  16. Braking indices of pulsars obtained in the presence of an effective force

    Science.gov (United States)

    Magalhaes, N. S.; Okada, A. S.; Frajuca, C.

    2016-10-01

    Braking indices of pulsars present a scientific challenge as their theoretical calculation is still an open problem. In this paper, we report results of a study regarding such calculation which adapts the canonical model (which admits that pulsars are rotating magnetic dipoles) basically by introducing a compensating component in the energy conservation equation of the system. This component would correspond to an effective force that varies with the first power of the tangential velocity of the pulsar's crust. We test the proposed model using data available and predict braking indices values for different stars. We comment on the high braking index recently measured of the pulsar J1640-4631.

  17. A Molecular Brake in the Kinase Hinge Region Regulates the Activity of Receptor Tyrosine Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Chen,H.; Ma, J.; Li, W.; Eliseenkova, A.; Xu, C.; Neubert, T.; Miller, W.; Mohammadi, M.

    2007-01-01

    Activating mutations in the tyrosine kinase domain of receptor tyrosine kinases (RTKs) cause cancer and skeletal disorders. Comparison of the crystal structures of unphosphorylated and phosphorylated wild-type FGFR2 kinase domains with those of seven unphosphorylated pathogenic mutants reveals an autoinhibitory 'molecular brake' mediated by a triad of residues in the kinase hinge region of all FGFRs. Structural analysis shows that many other RTKs, including PDGFRs, VEGFRs, KIT, CSF1R, FLT3, TEK, and TIE, are also subject to regulation by this brake. Pathogenic mutations activate FGFRs and other RTKs by disengaging the brake either directly or indirectly.

  18. 机动车坡道驻车制动效能检验的现状与探新%Status and New Exploration on the Performance Test of Automotive Vehicle Rampway Hand Brake

    Institute of Scientific and Technical Information of China (English)

    黄俊平

    2011-01-01

    By analyzing the status of the performance test of automotive vehicle rampway hand brake, the paper points out the problems of the current test method that test line desktop brake test results replace the actual rampway hand brake performance of vehicle, tries to explore the accurate,safe, convenient, economical way to test motor vehicle parking by developing the simulation platform of automotive vehicle rampway hand brake.%文章通过对机动车驻车效能检验的现状分析,指出了目前以检测线台式制动方式检验结果代替车辆在实际坡道驻车制动效能的检验方式所带来的一些问题,提出了通过研发机动车坡道驻车制动模拟平台,探索精确、安全、便捷、经济的机动车驻车检验方式.

  19. Genetic Algorithms Based Approach for Designing Spring Brake Orthosis – Part I: Spring Parameters

    Directory of Open Access Journals (Sweden)

    M. S. Huq

    2012-01-01

    Full Text Available Spring brake orthosis (SBO concentrates purely on the knee to generate the swing phase of the paraplegic gait with the required hip flexion occurring passively as a consequence of the ipsilateral knee flexion, generated by releasing the torsion spring mounted at the knee joint. Electrical stimulation then drives the knee back to full extension, as well as restores the spring potential energy. In this paper, genetic algorithm (GA and its variant multi-objective GA (MOGA is used to perform the search operation for the ‘best’ spring parameters for the SBO spring mounted on an average sized subject simulated in the sagittal plane. Conventional torsion spring is tested against constant torque type spring in terms of swing duration as, based on first principles, it is hypothesized that constant torque spring would be able to produce slower SBO swing phase as might be preferred in assisted paraplegic gait. In line with the hypothesis, it is found that it is not possible to delay the occurrence of the flexion peak of the SBO swing phase further than its occurrence in the natural gait. The use of conventional torsion spring causes the swing knee flexion peak to appear rather faster than that of the natural gait, resulting in a potentially faster swing phase and hence gait cycle. The constant torque type spring on the other hand is able to stretch duration of the swing phase to some extent, rendering it the preferable spring type in SBO.

  20. A laboratory activity on the eddy current brake

    Science.gov (United States)

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

    2012-05-01

    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 electromagnetic properties of the magnet on the magnetic drag force. This video-based experiment is ideal for the study of kinematic graphs and the application of Newton's laws. Video motion analysis software enables students to make precise measurements of the magnet's position at incremental times during its motion, thus allowing them to quantify electromagnetic induction phenomena. The equipment needed for this experiment and data collection software are present in most physics teaching laboratories or are inexpensive and available.

  1. Slide Mode Control for Integrated Electric Parking Brake System

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2013-01-01

    Full Text Available The emerging integrated electric parking brake (IEPB system is introduced and studied. Through analyzing the various working stages, the stages switched IEPB system models are given with the consideration of the friction and system idle inertia. The sliding mode control (SMC method is adopted to control the clamping force by the widely used motor angle and clamping force relationship method. Based on the characteristics of the state equations, two sliding surfaces are built to control the motor angle and current, respectively. And in every working stage, the control stability is guaranteed by choosing the control parameters based on Lyapunov theory and SMC reachability. The effectiveness of the proposed control system has been validated in Matlab/Simulink.

  2. Atmospheric testing of wind turbine trailing edge aerodynamic brakes

    Energy Technology Data Exchange (ETDEWEB)

    Miller, L.S. [Wichita State Univ., KS (United States); Migliore, P.G. [National Renewable Energy Lab., Golden, CO (United States); Quandt, G.A.

    1997-12-31

    An experimental investigation was conducted using an instrumented horizontal-axis wind turbine that incorporated variable span trailing-edge aerodynamic brakes. A primary goal was to directly compare study results with (infinite-span) wind tunnel data and to provide information on how to account for device span effects during turbine design or analysis. Comprehensive measurements were utilized to define effective changes in the aerodynamic coefficients, as a function of angle of attack and control deflection, for three device spans and configurations. Differences in the lift and drag behavior are most pronounced near stall and for device spans of less than 15%. Drag performance is affected only minimally (<70%) for 15% or larger span devices. Interestingly, aerodynamic controls with characteristic vents or openings appear most affected by span reductions and three-dimensional flow.

  3. Discuss on Elevator Braking Capacity Assessment%电梯制动能力评估方法的探讨

    Institute of Scientific and Technical Information of China (English)

    邓剑鹏

    2015-01-01

    主要探讨电梯制动能力评估的方法。从制动器的国标检验要求、实际测试的制动数据以及制动器的出厂设置数据,总结出电梯紧急制动所体现的制动性能。在现场制动力测试中,如何排除曳引力对制动力测试数据的影响,以及在评估中影响制动力的关键因素:闸瓦接触面、机械结构、温升、电气控制、制动器的动作检测五个方面,论述评估中的注意事项。%This paper describes the elevator safety technology assessment of the braking capacity. According to the national standard requirements for braking inspection, actual braking test data and brake factory settings data, the braking performance in elevator emergency braking is summed up. In the ifeld test of braking force, it is discussed how to exclude the impact of the traction force on the braking test data, and the key factors affecting the braking force in the assessment: shoe contact surfaces, mechanical structure, temperature rise, electrical control, motion detection brakes, and the matters need attention in assessment.

  4. Development of an Engine Air-Brake for Quiet Drag Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel quiet engine air-brake (EAB) is proposed in response to NASA's solicitation for active and passive noise control concepts for conventional and advanced...

  5. Development of an Engine Air-Brake for Quiet Drag Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel quiet engine air-brake is proposed in response to NASA's solicitation for concepts for active and passive control of noise sources for conventional and...

  6. The Comparative Analysis and Evaluation of Ecological Characteristics of Drum and Disk Wheel Brakes

    Directory of Open Access Journals (Sweden)

    Aleksandr Revin

    2011-04-01

    Full Text Available It is well-known that automobile transport as well as industry are the main sources of air pollution. In addition to exhaust gases, the flow of traffic releases a cloud of dust, consisting of over 60% of micro- and ultramicroscopic particles with radius of 10.0–0.25 µm, which are formed due to wheel abrasion (caused by the road grip of a tyre and the use of the brake blocks (in braking. The products formed in the process of wearing of the wheel brake pads are also the sources of the mass of fine dispersed particles over an urban highway. The authors analyse and evaluate ecological characteristics of drum and disk wheel brakes of vehicles.Article in Russian

  7. FSC赛车制动系统设计%FSC racing brake system design

    Institute of Scientific and Technical Information of China (English)

    吴祥超; 赵运德; 鲁雄文

    2014-01-01

    A design method of brake system that is applicable to theFormula Student China racing car is proposed in this paper. A simple hydraulic disc brake system is chosen, and adding balance bar is to regulate the distribution coefficient of braking force. Calculation and analysis show that the braking system can meet the requirements of dynamic testing during the game.%本文提出了一套适用于FSC赛车制动系统的设计方法。选用简单液压盘式制动系统,并且加装平衡杆以调节制动器制动力分配系数。计算和分析表明,该制动系统能够满足比赛时动态测试的要求。

  8. Mathews Brake National Wildlife Refuge Deer Harvest Records from 2011 Season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Mathews Brake during the 2011 deer season. They measure weight, antler size, prevalence of milk, and number of deer harvested.

  9. Morgan Brake National Wildlife Refuge Deer Harvest Records from 2011 Season

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Morgan Brake during the 2011 deer season. They measure weight, antler size, prevalence of milk, and number of deer harvested.

  10. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2012 to 2015 - Mathews Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Mathews Brake National Wildlife Refuge between 2012 and 2015. Calls were classified using Bat Call ID...

  11. Mobile Acoustical Bat Monitoring Annual Summary Report CY 2012 to 2015 - Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These reports summarize bat calls collected along transects at Morgan Brake National Wildlife Refuge between 2012 and 2015. Calls were classified using Bat Call ID...

  12. Applications of magnetorheological brakes in manual control of lifting devices and manipulators

    Energy Technology Data Exchange (ETDEWEB)

    Chciuk, M [University of Zielona Gora, 65-246 Zielona Gora, ul. Podgorna 50 (Poland); Milecki, A; Myszkowski, A [Poznan University of Technology, 60-965 Poznan, ul. Piotrowo 3 (Poland)], E-mail: andrzej.milecki@put.poznan.pl

    2009-02-01

    The article is aimed to design and testing of joystick with force feedback used in direct, human control of lifting device. The paper starts with the basic description of designed and tested by us MR rotary brake. Some initial laboratory investigations results of such brakes are presented. The usage of MR brakes in 2 axis joystick is proposed. Such, built by as joystick, is described. It was used as Human-Machine Interface in active control of lifting device. The designed and built 2 axis manipulator with electrohydraulic drive is described. In the paper, the based on PC with input/output card, control system of mentioned above joystick with MR brake and manipulator is described. Finally the control algorithm is proposed.

  13. Application Research on Self-healing Technology with Microcapsules for Automobile Brake Pad

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; DONG Xiuping; ZHANG Heng

    2009-01-01

    In order to improve the performance of non-asbestos composite auto brake pads that are composed of matrix resin, reinforced material and fillers, a novel method with new technology of self-heal microcapsules was proposed. Nano reinforced fillers' effects were also considered in the experiment project. Five recipe designs for new composite auto brake pads were carried out and cor-responding samples were prepared as well. The friction coefficient and wearing properties at certain temperature, impact intensity and hardness were comparatively studied. Investigations indicate that properties of such composite auto brake pads meet the requirements of the national standards while microcapsule's weight content varies from 5.5wt%-1.09wt% of matrix resin and microcapsule's loca-tion varies in the pads. Nano reinforced fillers have the effects of increasing composites' impact in-tensity and hardness. Application of self-healing microcapsules in auto brake pads is feasible.

  14. STUDY ON THE CONTROL SYSTEM OF HYDRAULIC MOMENT-ADJUSTED BRAKE FOR DOWNWARD BELT CONVEYOR

    Institute of Scientific and Technical Information of China (English)

    孟国营; 徐志强; 霍森; 方佳雨

    1997-01-01

    Having analyzed the drawbacks on the design of control system of hydraulic momentadjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the basis of the concept of the critical time and the critical acceleration and its deductions, the working mode of the conveyer can be identified and controlled in feedback, furthermore, thus realize the process of soft start. In the deceleration process, the author points out the problems that exist in the present control system and sets forward the control process that acted by the combined function of brake moment of motor and the drag torque of hydraulic brake at the beginning of deceleration, it will further improved reliability of conveyor system.

  15. Environmental Assessment of the Proposed Opening of Mathews Brake National Wildlife Refuge to Fishing

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal calls for the opening of Mathews Brake NWR to sport fishing. General regulations pertaining to licenses, creel limits, and methods of taking fish will...

  16. Improvement of Flexible Linear Stepping Actuator Driven by Pneumatic Balloons and Brakes

    Directory of Open Access Journals (Sweden)

    Eguchi Yuya

    2016-01-01

    Full Text Available The development of soft actuator for the rehabilitation device and power assisting devices has been required based on aging society. However, a flexible actuator that can generate both larger force and longer displacement has not been developed. It is also difficult to realize a flexible displacement sensor with long stroke while deforming its form according to the actuator’s shape. In the previous study, the flexible actuator with larger force and longer stroke that can adjust its stroke by giving stepping motion using pneumatic balloons and brakes was proposed and tested. However, the slipping of the pneumatic brake prevents the larger generated force. In this paper, the improved pneumatic brake using a pneumatic balloon and a mechanical chuck is described. The fundamental performance of the actuator using the improved brake is also described.

  17. Dynamic Analysis of a Floating Vertical Axis Wind Turbine Under Emergency Shutdown Using Hydrodynamic Brake

    DEFF Research Database (Denmark)

    Wang, K.; Hansen, Martin Otto Laver; Moan, T.

    2014-01-01

    axis wind turbine were carried out for emergency shutdown cases over a range of environmental conditions based on correlated wind and wave data. When generator failure happens, a brake should be applied to stop the acceleration of the rotor to prevent the rotor from overspeeding and subsequent disaster....... In addition to the traditional mechanical brake, a novel hydrodynamic brake was presented to apply to the shutdown case. The effects of the hydrodynamic brake on the platform motions and structural loads under normal operating conditions and during the emergency shutdown events were evaluated. The use of both......Emergency shutdown is always a challenge for an operating vertical axis wind turbine. A 5-MW vertical axis wind turbine with a Darrieus rotor mounted on a semi-submersible support structure was examined in this study. Coupled non-linear aero-hydro-servo-elastic simulations of the floating vertical...

  18. Upper Ouachita and Handy Brake National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Upper Ouachita and Handy Brake NWRs for the next 15 years. This plan outlines the...

  19. Development and Analysis of Train Brake Curve Calculation Methods with Complex Simulation

    Directory of Open Access Journals (Sweden)

    Bela Vincze

    2006-01-01

    Full Text Available This paper describes an efficient method using simulation for developing and analyzing train brake curve calculation methods for the on-board computer of the ETCS system. An application example with actual measurements is also presented.

  20. A method to model anticipatory postural control in driver braking events

    NARCIS (Netherlands)

    Osth, J.; Eliasson, E.; Happee, R.; Brolin, K.

    2014-01-01

    Human body models (HBMs) for vehicle occupant simulations have recently been extended with active muscles and postural control strategies. Feedback control has been used to model occupant responses to autonomous braking interventions. However, driver postural responses during driver initiated brakin

  1. Design and control of a dual unidirectional brake hybrid actuation system for haptic devices.

    Science.gov (United States)

    Rossa, Carlos; Lozada, José; Micaelli, Alain

    2014-01-01

    Hybrid actuators combining brakes and motors have emerged as an efficient solution to achieve high performance in haptic devices. In this paper, an actuation approach using two unidirectional brakes and a DC motor is proposed. The brakes are coupled to overrunning clutches and can apply a torque in only one rotational direction. The associated control laws, that are independent of the virtual environment model, calculate the control gains in real time in order limit the energy and the stiffness delivered by the motor to ensure stability. The reference torque is respected using the combination of the motor and the brake. Finally, an user experiment has been performed to evaluate the influence of passive and active torque differences in the perception of elasticity. The proposed actuator has a torque range of 0.03 Nm to 5.5 Nm with a 17.75 kNm (-2) torque density.

  2. EXPERIMENTAL DETERMINATION OF BRAKE THERMAL EFFICIENCY AND BRAKE SPECIFIC FUEL CONSUMPTION OF DIESEL ENGINE FUELLED WITH BIO-DIESEL

    Directory of Open Access Journals (Sweden)

    M. SHIVA SHANKAR

    2010-10-01

    Full Text Available The rapid depletion in world petroleum reserves and uncertainty in petroleum supply due to political and economical reasons, as well as, the sharp escalations in the petroleum prices have stimulated the search for alternatives to petroleum fuels. The situation is very grave in developing countries like India which imports 70% of the required fuel, spending 30% of her total foreign exchange earnings on oil imports. Petroleum fuels are being consumed by agriculture and transport sector for which diesel engine happens to be the prime mover. Diesel fuelled vehicles discharge significant amount of pollutants like CO, HC, NOx, soot, lead compounds which are harmful to the universe. Though there are wide varieties of alternative fuels available, the research has not yet provided the right renewable fuel to replace diesel. Vegetable oils due to their properties being close to diesel fuel may be a promising alternative for its use in diesel engines. The high viscosity and low volatility are the major drawbacks of the use of vegetable oils in diesel engines. India is the second largest cotton producing country in the world today. The cotton seeds are available in India at cheaper price. Experiments were conducted on 5.2 BHP single cylinder four stroke water-cooled variable compression diesel engine. Methyl ester of cottonseed oil is blended with the commercially available Xtramile diesel. Cottonseed oil methyl ester (CSOME is blended in four different compositions varying from 10% to 40% in steps of 10 vol%. Using these four blends and Xtramile diesel brake thermal efficiency (BTE and brake specific fuel consumption (BSFC are determined at 17.5 compression ratio.

  3. 基于盐化工自动包装系统的缝包机刹车装置设计%A Sack Closer Brake Device Design Based on the Salt and Chemical Automatic Packaging System

    Institute of Scientific and Technical Information of China (English)

    王俊祁; 张伟东

    2016-01-01

    In view of the present domestic automatic salt sewing machine without brakes ,causeing sewing tail wire is too long and not beautifull, and sewing line may be winding roller, we designed a cutting knife brakes. This device can make motor pulley braking at the moment of sack closer cutting off the line. Thus, it will greatly shorten the sewing stern line.%针对目前国内全自动食盐缝包机没有刹车装置而导致缝包尾线过长、缝包不美观、缝包线可能缠绕辊道的问题,设计了一个缝包机皮带轮抱刹刹车装置,该装置可以在缝包机切刀动作的一瞬间,对缝包机电机皮带轮实行点动刹车,从而大幅度缩短缝包尾线。

  4. Morphology and properties of periwinkle shell asbestos-free brake pad

    OpenAIRE

    D.S. Yawas; S.Y.Aku; S.G. Amaren

    2016-01-01

    The development of asbestos-free automotive brake pad using periwinkle shell particles as frictional filler material is presented. This was with a view to exploiting the characteristics of the periwinkle shell, which is largely deposited as a waste, in replacing asbestos which has been found to be carcinogenic. Five sets of brake pads with different sieve size (710–125 μm) of periwinkle shell particles with 35% resin were produced using compressive moulding. The physical, mechanical and tribo...

  5. Design and research on the electronic parking brake system of the medium and heavy duty vehicles

    OpenAIRE

    Wang, Hongliang; Dong, Wei; Li, Nan; Dai, Xiaoming

    2015-01-01

    Focusing on auto control of parking brake system of the medium and heavy duty vehicles, the key problems are studied including the system design and control strategies. The structure and working principle of the parking brake system of the medium and heavy duty vehicles are analyzed. The functions of EPB are proposed. The important information of the vehicle are analyzed which could influence the EPB system. The overall plan of the pneumatic EPB system is designed, which adopts the two-positi...

  6. Reduced order brake models to study the effect on squal of pad redesign

    OpenAIRE

    Vermot Des Roches, Guillaume; Balmes, Etienne; CHIELLO, Olivier; Lorang, Xavier

    2013-01-01

    Brake squeal impacts trains during station parking, generating over 110 dB at the wheel vicinity. This disturbance is a problem for commuters and employees working close to trains and limits exploitation times. The only adjustable parameter is here the brake pad, since it is the only part with frequent replacement regarding the railway equipment lifetimes. To improve current pad design to limit noise emissions a numerical prototyping tool is required, providing noise level indicators post-tre...

  7. Pneumatic brake control for precision stopping of heavy-duty vehicles

    OpenAIRE

    Bu, Fanping; Tan, Han-Shue

    2007-01-01

    Precision stopping is an important automated vehicle control function that is critical in applications such as precision bus docking, automated truck or bus fueling, as well as automatic intersection, or toll booth stopping. The initial applications of this technology are most likely to be applied to heavy-duty vehicles such as buses or trucks. Such applications require specific attention to brake control since the characteristics of a typical pneumatic brake system of a heavy vehicle is inhe...

  8. Experiments on composites meant for making brake pads for the rolling stock

    Science.gov (United States)

    Socalici, A.; Pascu, L.; Ardelean, E.; Putan, V.

    2017-01-01

    For noise rail decrease and observance of the limits in UE rolling stock must be equipped with silent brake blocks of composite material to replace the conventional cast-iron blocks. For testing composite materials test pieces have been produced according to the characteristics of the experimental installation. The paper presents the laboratory experimentation phase on obtaining composite materials for brake blocks and wear behavior of the experimental test pieces.

  9. Gravitational Waves from Pulsars and Their Braking Indices: The Role of a Time Dependent Magnetic Ellipticity

    CERN Document Server

    de Araujo, José C N; Costa, César A

    2016-01-01

    We study the role of time dependent magnetic ellipticities ($\\epsilon_{B}$) on the calculation of the braking index of pulsars. Moreover, we study the consequences of such a $\\epsilon_{B}$ on the amplitude of gravitational waves (GWs) generated by pulsars with measured braking indices. We show that, since the ellipticity generated by the magnetic dipole is extremely small, the corresponding amplitude of GWs is much smaller than the amplitude obtained via the spindown limit.

  10. The mechanism of changes in the surface layer of grey cast iron automotive brake disc

    Directory of Open Access Journals (Sweden)

    Adam Polak

    2005-12-01

    Full Text Available The aim of the study was to create a model, describing the run of tribological processes in the surface layer of grey cast iron automotive brake discs. Grey cast iron discs mating with non-asbestos organic brake pads were chosen for the investigations, as the most widely used materials in car brakes. Samples for surface analysis were prepared from disc operating in stand and road conditions. Stand tests were pin-on-disc kind. Operating parameters for the stand tests were chosen on the basis of results of our earlier research. Topography of brake disc surface was evaluated by surface roughness measurements. The surface layer was examined with use of metallography and scanning electron microscopy. In order to differentiate structures of grey cast iron brake discs SE and BSE modes were used in scanning electron microscopy. Chemical investigations of samples were done by X-ray analysis linked with SEM. Studies showed influence of grey cast iron structures on tribological processes taking place in a brake friction pair. The surface layer of grey cast iron discs was described and features and functions of separated structures were presented. On the basis of the obtained results a physical model of friction mechanism was created. Special attention was paid to the influence of graphite on the run of tribological processes and mechanism of compaction and removal of wear debris.

  11. A geometrical optimization of a magneto-rheological rotary brake in a prosthetic knee

    Science.gov (United States)

    Gudmundsson, K. H.; Jonsdottir, F.; Thorsteinsson, F.

    2010-03-01

    Magneto-rheological (MR) fluids have been successfully introduced to prosthetic devices. One such device is a biomechanical prosthetic knee that uses MR fluids to actively control its rotary stiffness. The brake is rotational, utilizing the MR fluid in shear mode. In this study, the geometrical design of the MR brake is addressed. This includes the design of the magnetic circuit and the geometry of the fluid chamber. Mathematical models are presented that describe the rotary torque of the brake. A novel perfluorinated polyether (PFPE)-based MR fluid is introduced, whose properties are tailored for the prosthetic knee. On-state and off-state rheological measurements of the MR fluid are presented. The finite element method is used to evaluate the magnetic flux density in the MR fluid. The design is formulated as an optimization problem, aiming to maximize the braking torque. A parametric study is carried out for several design parameters. Subsequently, a multi-objective optimization problem is defined that considers three design objectives: the field-induced braking torque, the off-state rotary stiffness and the weight of the brake. Trade-offs between the three design objectives are investigated which provides a basis for informed design decisions on furthering the success of the MR prosthetic knee.

  12. Design Considerations and Experimental Verification of a Rail Brake Armature Based on Linear Induction Motor Technology

    Science.gov (United States)

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

    This paper describes the design considerations and experimental verification of an LIM rail brake armature. In order to generate power and maximize the braking force density despite the limited area between the armature and the rail and the limited space available for installation, we studied a design method that is suitable for designing an LIM rail brake armature; we considered adoption of a ring winding structure. To examine the validity of the proposed design method, we developed a prototype ring winding armature for the rail brakes and examined its electromagnetic characteristics in a dynamic test system with roller rigs. By repeating various tests, we confirmed that unnecessary magnetic field components, which were expected to be present under high speed running condition or when a ring winding armature was used, were not present. Further, the necessary magnetic field component and braking force attained the desired values. These studies have helped us to develop a basic design method that is suitable for designing the LIM rail brake armatures.

  13. Extended-Kalman-filter-based regenerative and friction blended braking control for electric vehicle equipped with axle motor considering damping and elastic properties of electric powertrain

    Science.gov (United States)

    Lv, Chen; Zhang, Junzhi; Li, Yutong

    2014-11-01

    Because of the damping and elastic properties of an electrified powertrain, the regenerative brake of an electric vehicle (EV) is very different from a conventional friction brake with respect to the system dynamics. The flexibility of an electric drivetrain would have a negative effect on the blended brake control performance. In this study, models of the powertrain system of an electric car equipped with an axle motor are developed. Based on these models, the transfer characteristics of the motor torque in the driveline and its effect on blended braking control performance are analysed. To further enhance a vehicle's brake performance and energy efficiency, blended braking control algorithms with compensation for the powertrain flexibility are proposed using an extended Kalman filter. These algorithms are simulated under normal deceleration braking. The results show that the brake performance and blended braking control accuracy of the vehicle are significantly enhanced by the newly proposed algorithms.

  14. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics

    Directory of Open Access Journals (Sweden)

    Dong-Chan Lee

    2015-11-01

    Full Text Available A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installation space and reducing financial budget costs. Since the brake caliper has a high nonlinearity, such as hysteresis resulting from friction and from the precompressed spring of the brake cylinder, we measured the hysteresis of the brake caliper clamping force for a mechanical brake system using loadcells, based on which a mathematical model was constructed for the hysteresis of the clamping force between the brake pad and the disk. Moreover, the pneumatic cylinder dynamics are identified and are implemented in three air tanks, together with hysteresis nonlinearity. The proposed brake hardware-in-the-loop simulation system is applied to the wheel-slide protection simulation of a railway vehicle with an initial speed of 80 km/h and demonstrated experimentally accounting for the hysteresis and brake cylinder dynamics.

  15. 静动液辅助制动系统恒转矩制动策略研究%Research on Constant Torque Braking Strategy of Hydrostatic and Hydraulic Auxiliary Braking System

    Institute of Scientific and Technical Information of China (English)

    吕建刚; 郭劭琰; 李彦路; 滕飞; 宋彬

    2012-01-01

    A constant torque braking strategy for tracked vehicle hydrostatic and hydraulic auxiliary braking system is studied. Combining the test and theoretical analysis results, the influence law of coupler filling liquid quantity and hydraulic pump discharge variation to vehicle braking force under the hydrodynamic braking and hydrostatic braking work condition is obtained. Absorbing the advantages of hydrodynamic braking and hydrostatic braking,aiming at the work condition of hydrodynamic - hydrostatic braking, the constant torque braking strategy is built. The vehicle constant torque braking is achieved through the automatic regulation of coupler filling liquid quantity and hydraulic pump discharge. The efficiency is verified through the comparison of energy recovery and braking length before and after using constant torque braking strategy.%对履带车辆液力辅助制动系统的恒转矩制动策略进行了研究.结合实验与理论分析的结果,得到了液压制动与液力制动工况下偶合器充液量、液压泵排量的变化对车辆制动力的影响规律,吸取了液压制动与液力制动的优点,针对液力-液压制动工况建立了恒转矩制动策略.通过对偶合器充液量、液压泵排量的自动调节,实现了车辆的恒转矩制动.最后对采用恒转矩制动策略前后的能量回收率与制动距离进行了对比,验证了该策略的效能.

  16. Simulation and Experimental Analysis of Braking Squeal of Disc Brake System Considering Thermo-mechanical Coupling Effect%盘式制动器制动尖叫热机耦合特性仿真分析

    Institute of Scientific and Technical Information of China (English)

    汪德成; 陈凌珊; 黄欣; 蒋培露

    2014-01-01

    利用试验和仿真相结合的方法,对某车型前通风盘式制动器进行研究。基于多功能制动器动力学试验台架,分别对两套同型号制动器试件进行制动尖叫试验,基于有限元建立制动器热机耦合分析模型,在拖滞制动模式下进行仿真计算。分析研究表明,拖滞制动模式是一个明显的热机耦合过程,其热机耦合效应与减速制动模式具有很多共同点。热机耦合效应对制动尖叫影响较大,考虑热机耦合效应有利于提高尖叫预测精度,并能够反映制动尖叫的时变特性。%Braking squeal of ventilation disc brake systems was studied through experimental and numerical analysis. Using multi-function brake dynamometer test rig, brake squeal tests of two disc brake systems were carried out. The finite element model of the disc brake was built, and the thermo-mechanical coupling effect was investigated under drag braking conditions. The simulation results show that the thermo-mechanical coupling effect exists obviously in drag braking mode, which is similar to that in emergency braking mode. This effect has a serious influence on braking squeal. It must be considered in the brake squeal simulation analysis to improve the prediction accuracy and to reflect the time-varying characteristics of the braking squeal.

  17. A global strategy based on experiments and simulations for squeal prediction on industrial railway brakes

    Science.gov (United States)

    Sinou, J.-J.; Loyer, A.; Chiello, O.; Mogenier, G.; Lorang, X.; Cocheteux, F.; Bellaj, S.

    2013-09-01

    This paper presents an overview of recent experimental and numerical investigations on industrial railway brakes. The goal of the present study is to discuss the relevance of the mechanical modeling strategy for squeal prediction. Specific experimental set-ups based on transient and controlled braking tests are designed for this purpose. Measurements are performed on it to investigate the dynamic behavior of TGV squeal noise and its squeal characterization through experiments. It will be demonstrated that it is possible to build consistent and efficient finite element models to simulate squeal events in TGV brake systems. The numerical strategy will be presented, including not only the modeling of the TGV brake system and the stability analysis, but also the transient nonlinear dynamic and computational process based on efficient reduced basis. This complete numerical strategy allows us to perform relevance squeal prediction on industrial railway brakes. This study comes within the scope of a research program AcouFren that is supported by ADEME (Agence De l'Environnement et de la Maîtrise de l'Energie) concerning the reduction of the squeal noise generated by high power railway disc brakes. experiments with an evolution of the rotational speed of the disc: these tests are called "transient braking tests" and correspond to real braking tests, experiments with a controlled steady rotational speed (i.e. dynamic fluctuations in rotational speed are not significant): these tests are called "controlled braking tests". In the present study, the Continuous Wavelet Transform (CWT) [20] is used to study the time-history responses of the TGV brake system. So, a brief basic theory of the wavelet analysis that transforms a signal into wavelets that are well localized both in frequency and time is presented in this part of the paper. Considering a function f(t), the associated Continuous Wavelet Transform (CWT) corresponds to a wavelet transform given by W(a,b

  18. Multi-objective optimization of the control strategy of electric vehicle electro-hydraulic composite braking system with genetic algorithm

    OpenAIRE

    Zhang Fengjiao; Wei Minxiang

    2015-01-01

    Optimization of the control strategy plays an important role in improving the performance of electric vehicles. In order to improve the braking stability and recover the braking energy, a multi-objective genetic algorithm is applied to optimize the key parameters in the control strategy of electric vehicle electro-hydraulic composite braking system. Various limitations are considered in the optimization process, and the optimization results are verified by a software simulation platform of el...

  19. ENERGY-LOADING OF DISKS IN FRICTION PAIRS OF “DISC-PAD” OF BRAKING DEVICES IN VEHICLES (part two

    Directory of Open Access Journals (Sweden)

    Krasin P. S.

    2015-06-01

    Full Text Available In the materials of the article we mention the regularities of changes in the volume and surface solid temperature gradients and self-ventilated brake discs and illustrate their impact on the main operating parameters of the friction pairs of disk-to-pad brakes of the A 172 bus; the relationship between thermo-physical parameters of polished and matte surfaces with areas of brake discs of various types. The influence of the type of tests on the pairs of loaded with energy friction disk and pad brakes of the vehicle. We have set the intensity of heat exchange processes from the surfaces of the brake discs of various types. It is shown that this leads to increased surface temperature gradient. The volume and the surface temperature gradients of the brake discs were determined with the involvement of the hypothesis of summation of temperatures on the surface when you post the generated electric currents. It was found that in the surface layer of the working surface of a solid brake disc at its pulse heating under the influence of the temperature of the flash nucleate cracks due to the thermal fatigue of the material of the disk. The features of the design of the brake discs were considered as well. On the basis of the calculation and the experimental data we have shown a correlation between the emissivity of brushed and polished surfaces and their areas in the disk-to-pad brakes when using solid and self-ventilated discs

  20. Inclination angle and braking index evolution of pulsars with plasma-filled magnetosphere: application to high braking index of PSR J1640-4631

    CERN Document Server

    Ekşi, Kazım Yavuz; Çıkıntoğlu, Sercan; Gügercinoğlu, Erbil; Motlagh, Armin Vahdat; Kızıltan, Bülent

    2016-01-01

    The recently discovered rotationally powered pulsar PSR J1640-4631 is the first to have a braking index measured, with high enough precision, to be greater than three. An inclined magnetic rotator in vacuum or plasma would be subject to not only spin-down torque but also to an alignment torque. The vacuum model can address the braking index only for an almost orthogonal rotator which is incompatible with the single peaked pulse profile. We show that the magnetic dipole model with the corotating plasma predicts braking indices between $3-3.25$ and can explain the braking index of $3.15$ for two different inclination angles, $18.5\\pm 3$ degrees and $56 \\pm 4$ degrees. Of these the former is preferred given the pulse profile has a single peak. We infer the change in the inclination angle to be at the rate $-0.23$ degrees per century, three times smaller in absolute value than the rate recently observed from the Crab pulsar.

  1. The Inclination Angle and Evolution of the Braking Index of Pulsars with Plasma-filled Magnetosphere: Application to the High Braking Index of PSR J1640-4631

    Science.gov (United States)

    Ekşi, K. Y.; Andaç, I. C.; Çıkıntoğlu, S.; Gügercinoğlu, E.; Vahdat Motlagh, A.; Kızıltan, B.

    2016-05-01

    The recently discovered rotationally powered pulsar PSR J1640-4631 is the first to have a braking index measured, with high enough precision, that is greater than 3. An inclined magnetic rotator in vacuum or plasma would be subject not only to spin-down but also to an alignment torque. The vacuum model can address the braking index only for an almost orthogonal rotator, which is incompatible with the single-peaked pulse profile. The magnetic dipole model with the corotating plasma predicts braking indices between 3 and 3.25. We find that the braking index of 3.15 is consistent with two different inclination angles, 18.°5 ± 3° and 56° ± 4°. The smaller angle is preferred given that the pulse profile has a single peak and the radio output of the source is weak. We infer the change in the inclination angle to be at the rate -0.°23 per century, three times smaller in absolute value than the rate recently observed for the Crab pulsar.

  2. Dopamine Rebound-Excitation Theory: Putting Brakes on PTSD

    Directory of Open Access Journals (Sweden)

    Jason C Lee

    2016-09-01

    Full Text Available It is not uncommon for humans or animals to experience traumatic events in their lifetimes. However, the majority of individuals are resilient to long-term detrimental changes turning into anxiety and depression, such as post-traumatic stress disorder (PTSD. What underlying neural mechanism accounts for individual variability in stress resilience? Hyperactivity in fear circuits, such as the amygdalar system, is well-known to be the major pathophysiological basis for PTSD, much like a stuck accelerator. Interestingly, increasing evidence demonstrates that dopamine (DA – traditionally known for its role in motivation, reward prediction, and addiction– is also crucial in regulating fear learning and anxiety. Yet how DA neurons control stress resilience is unclear, especially given that DA neurons have multiple subtypes with distinct temporal dynamics. Here, we propose the Rebound-Excitation Theory, which posits that DA neurons’ rebound-excitation at the termination of fearful experiences serves as an important brake by providing intrinsic safety-signals to fear-processing neural circuits in a spatially and temporally controlled manner. We discuss how DA neuron rebound-excitation may be regulated by genetics and experiences, and how such physiological properties may be used as a brain-activity biomarker to predict and confer individual resilience to stress and anxiety.

  3. Big brake singularity is accommodated as an exotic quintessence field

    CERN Document Server

    Chimento, Luis P

    2015-01-01

    We describe a big brake singularity in terms of a modified Chaplygin gas equation of state $p=(\\ga_{m}-1)\\rho+\\al\\ga_{m}\\rho^{-n}$, accommodate this late-time event as an exotic quintessence model obtained from an energy-momentum tensor, and focus on the cosmological behaviour of the exotic field, its kinetic energy and the potential energy. At background level, the exotic field does not blow-up whereas its kinetic energy and potential both grow without limit near the future singularity. We evaluate the classical stability of this background solution by examining the scalar perturbations of the metric along with the inclusion of entropy perturbation in the perturbed pressure. Within the Newtonian gauge, the gravitational field approaches to a constant near the singularity plus additional regular terms. When the perturbed exotic field is associated with $\\al>0$, the perturbed pressure and contrast density both diverge whereas the perturbed exotic field and the divergence of exotic field's velocity go to zero e...

  4. Small satellite attitude determination during plasma brake deorbiting experiment

    Science.gov (United States)

    Khurshid, Osama; Selkäinaho, Jorma; Soken, Halil Ersin; Kallio, Esa; Visala, Arto

    2016-12-01

    This paper presents a study on attitude estimation during the Plasma Brake Experiment (PBE) onboard a small satellite. The PBE demands that the satellite be spun at a very high angular velocity, up to 200 deg/s, to deploy the tether using centrifugal force. The spin controller, based on purely magnetic actuation, and the PBE demands accurate attitude estimation for the successful execution of the experiment. The biases are important to be estimated onboard small satellites due to the closely integrated systems and relatively higher interference experienced by the sensors. However, bias estimation is even more important for PBE due to the presence of a high voltage unit, onboard the satellite, that is used to charge the tether and can be the source of interference. The attitude and the biases, when estimated simultaneously, results in an augmented state vector that poses a challenge to the proper tuning of process noise. The adaptation of process noise covariance has, therefore, been studied and analysed for the challenging PBE. It has been observed that adapting the process noise covariance improves the estimation accuracy during the spin-up phase. Therefore, it is very important to use adaptive process noise covariance estimation.

  5. Friction and wear behavior of carbon fiber reinforced brake materials

    Institute of Scientific and Technical Information of China (English)

    Du-qing CHENG; Xue-tao WANG; Jian ZHU; Dong-bua QIU; Xiu-wei CHENG; Qing-feng GUAN

    2009-01-01

    A new composite brake material was fabri-cated with metallic powders, barium sulphate and modified phenolic resin as the matrix and carbon fiber as the reinforced material. The friction, wear and fade character-istics of this composite were determined using a D-MS friction material testing machine. The surface structure of carbon fiber reinforced friction materials was analyzed by scanning electronic microscopy (SEM). Glass fiber-reinforced and asbestos fiber-reinforced composites with the same matrix were also fabricated for comparison. The carbon fiber-reinforced friction materials (CFRFM) shows lower wear rate than those of glass fiber- and asbestos fiber-reinforced composites in the temperature range of 100℃-300℃. It is interesting that the frictional coefficient of the carbon fiber-reinforced friction materials increases as frictional temperature increases from 100℃ to 300℃, while the frictional coefficients of the other two composites decrease during the increasing temperatures. Based on the SEM observation, the wear mechanism of CFRFM at low temperatures included fiber thinning and pull-out. At high temperature, the phenolic matrix was degraded and more pull-out enhanced fiber was demonstrated. The properties of carbon fiber may be the main reason that the CFRFM possess excellent tribological performances.

  6. On the potential of uncertainty analysis for prediction of brake squeal propensity

    Science.gov (United States)

    Zhang, Zhi; Oberst, Sebastian; Lai, Joseph C. S.

    2016-09-01

    Brake squeal is a source of significant warranty-related claims for automotive manufacturers because it is annoying and is often perceived by customers as a safety concern. A brake squeal analysis is complex due to changing environmental and operating conditions, high sensitivity to manufacturing and assembly tolerances as well as the not so well understood role of nonlinearities. Although brake squeal is essentially a nonlinear problem, the standard analysis tool in industry is the linear complex eigenvalue analysis (CEA) which may under-predict or over-predict the number of unstable vibration modes. A nonlinear instability analysis is more predictive than CEA but is still computationally too expensive to be used routinely in industry for a full brake finite element model. Also, although the net work analysis of a linearised brake system has shown potential in predicting the origin of brake squeal, it has not been extensively used. In this study, the net work of an analytical viscously damped self-excited 4-dof friction oscillator with cubic contact force nonlinearity is compared with the instability prediction using the CEA and a nonlinear instability analysis. Results show that both the net work analysis and CEA under-predict the instability because of their inability to detect the sub-critical Hopf bifurcation. Then, the uncertainty analysis is applied to examine if it can improve instability prediction of a nonlinear system using linear methods and its limitations. By applying a variance-based global sensitivity analysis to parameters of the oscillator, suitable candidates for an uncertainty analysis are identified. Results of uncertainty analyses by applying polynomial chaos expansions to net work and CEA correlate well with those of the nonlinear analysis, hence demonstrating the potential of an uncertainty analysis in improving the prediction of brake squeal propensity using a linear method.

  7. 汽车刹车盘性能综述%Review on brake discs performance

    Institute of Scientific and Technical Information of China (English)

    张小雪; 刘兰俊

    2012-01-01

    Brake disks,as a component to ensure the security are constantly submitted to relatively high temperature and high pressure during braking action. In order to effectively play braking effect, brake disks require some performance,such as excellent thermal transport ability,good wear resistance,high thermal fatigue performance and low brake squeal.The more A type graphite, the better thermal transport ability of cast iron .Thermal conductivity of cast iron is temperature inverse proportion function.Wear resistancenot is related to not only the matrix strength and hardness ,but also external factors,such as lubrication condition contact pressure and sliding distance. Crack resistance is attributed to thermal transport ability and strength and hardness.Brake squeal randomly occur,people do not understand its mechanism.The high performance of brake disc is obtained by Alloying 、advancing melting technology and proper Inoculation.%刹车盘做为保安件,为了有效起到制动作用,要求有优良的导热性、耐磨性、抗热疲劳性及小的刹车鸣叫.A型石墨数量越多,铸铁的导热性越好.铸铁的导热能力是温度的反比例函数.耐磨性不仅与基体的强度硬度有关,还与外界因素有关.材料的导热性能好,强度和硬度高,则抗裂能力强.可以通过合金化,提高熔炼工艺以及恰当的孕育,获得高性能的刹车盘.

  8. Tailpipe, resuspended road dust, and brake-wear emission factors from on-road vehicles

    Science.gov (United States)

    Abu-Allaban, Mahmoud; Gillies, John A.; Gertler, Alan W.; Clayton, Russ; Proffitt, David

    Intensive mass and chemical measurements were performed at roadside locations in Reno, Nevada, and Durham/Research Triangle Park), North Carolina to derive tailpipe, resuspended road dust, and brake-wear emission factors from in-use vehicles. Continuous particulate matter (PM) data were utilized to derive total emission factors while integrated PM data were used to attribute the calculated emission factors to different mechanisms using chemical mass balance receptor modeling and scanning electron microscopy techniques. Resuspended road dust and tailpipe emissions were found to be the dominant mechanisms that contribute significantly to the total PM 10 and PM 2.5 emission factors, respectively. Small contributions from brake-wear were observed at locations where strong braking occurs, but no tire-wear was seen at any sampling location. PM 10 emission rates from light-duty spark ignition (LDSI) vehicles ranged from 40 to 780 mg/km, 10 to 70 mg/km, and 0 to 80 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 10 emission rates from heavy-duty vehicles ranged from 230 to 7800 mg/km, 60 to 570 mg/km, and 0 to 610 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from LDSI vehicles ranged from 2 to 25 mg/km, 10 to 50 mg/km, and 0 to 5 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from heavy-duty vehicles ranged from 15 to 300 mg/km, 60 to 480 mg/km, and 0 to 15 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively.

  9. Influence of Friction Drive Lift Gears Construction on the Length of Braking Distance

    Institute of Scientific and Technical Information of China (English)

    LONKWIC Poul

    2015-01-01

    The friction drive elevators the influence of the braking distance has very high significance to meet certain safety regulations and comfort. During the emergency braking the delay for the system a frame and a cabin should be within the range from 0.2 to 9.81 m/s2. However, there are no specialist literatures regarding the issues connected with emergency braking of elevating devices either. The results of the own empirical research work are presented regarding the influence of design changes on the working parameters of the friction drive elevator gears. ASG100, KB160, PP16, PR2000UD and CHP2000 types of safety progressive gears are analyzed. ASG100, KB160, PP16, PR2000UD type progressive gears are already produced by European manufacturers. CHP2000 type gears are established as the alternative option for the already existing solutions. The unique cam system has been used in the CHP 2000 gears. The cam leverage gives the chance to unblock, in a very easy way, the clamed gears after braking. Thus, it is a key aspect to perform laboratory tests over the braking process of a newly created solution. The proper value of the braking distance has a significant influence on the value of delay in terms of binding standards. The influence of loading on the effective braking distance and the value of the falling elevator cabin speed are analyzed and the results are presented. The results presented are interesting from lift devices operation and a new model of CHP 2000 progressive gear point of view.

  10. 地铁车辆紧急制动旁路开关可行性研究%Feasibility Study on Bypass Switch for Emergency Brake of Metro Vehicle

    Institute of Scientific and Technical Information of China (English)

    许晶

    2015-01-01

    Taking the train operation on Hangzhou metro line 2 as an example, the paper analyzes the feasibility of metro train to install emergency brake bypass switch, and discusses the optimized setting and effect of use of the emergency brake bypass switch on train safety performance.%结合杭州地铁2号线列车运行实例,对地铁列车加装紧急制动旁路开关的可行性进行分析,阐述了合理设置和使用紧急制动旁路开关对列车安全保护性能的影响。

  11. Regenerative braking strategies, vehicle safety and stability control systems: critical use-case proposals

    Science.gov (United States)

    Oleksowicz, Selim A.; Burnham, Keith J.; Southgate, Adam; McCoy, Chris; Waite, Gary; Hardwick, Graham; Harrington, Cian; McMurran, Ross

    2013-05-01

    The sustainable development of vehicle propulsion systems that have mainly focused on reduction of fuel consumption (i.e. CO2 emission) has led, not only to the development of systems connected with combustion processes but also to legislation and testing procedures. In recent years, the low carbon policy has made hybrid vehicles and fully electric vehicles (H/EVs) popular. The main virtue of these propulsion systems is their ability to restore some of the expended energy from kinetic movement, e.g. the braking process. Consequently new research and testing methods for H/EVs are currently being developed. This especially concerns the critical 'use-cases' for functionality tests within dynamic events for both virtual simulations, as well as real-time road tests. The use-case for conventional vehicles for numerical simulations and road tests are well established. However, the wide variety of tests and their great number (close to a thousand) creates a need for selection, in the first place, and the creation of critical use-cases suitable for testing H/EVs in both virtual and real-world environments. It is known that a marginal improvement in the regenerative braking ratio can significantly improve the vehicle range and, therefore, the economic cost of its operation. In modern vehicles, vehicle dynamics control systems play the principal role in safety, comfort and economic operation. Unfortunately, however, the existing standard road test scenarios are insufficient for H/EVs. Sector knowledge suggests that there are currently no agreed tests scenarios to fully investigate the effects of brake blending between conventional and regenerative braking as well as the regenerative braking interaction with active driving safety systems (ADSS). The paper presents seven manoeuvres, which are considered to be suitable and highly informative for the development and examination of H/EVs with regenerative braking capability. The critical manoeuvres presented are considered to be

  12. Wear mechanism of disc-brake block material for new type of drilling rig

    Institute of Scientific and Technical Information of China (English)

    Xinhua WANG; Simin WANG; Siwei ZHANG; Deguo WANG

    2008-01-01

    To improve friction and wear performance and service life of the disc-brake pair material of a drilling rig, a new type of asbestos-free frictional material with better performance for disc-brake blocks is developed, and its wear mechanism is investigated by friction and wear experiments. Topography and ele-mentary components of the brake block's wear surface are analyzed by employing SEM and EDAX patterns, revealing its tribological behaviour and wear mechan-ism. When the frictional temperature is lower, the surface film of the brake block is thinner, dense, smooth with plasticity, and divided into the mixture area, Fe-abundant area, carbon-abundant area and spalling area. The mixture area consists of various constituents of frictional pairs without ploughing and rolling trace. The Fe-abundant area mainly consists of iron and other constituents. The carbon-abundant area is the zone where graphite and organic fibre are comparatively gathered, while the spalling area is the zone where the surface film is spalled and its surface is rough and uneven, with a loose and denuded state. During the period of high frictional temperature, the frictional surface is also divided into the mixture area, Fe-abundant area and spalling area. In this case, the mixture area consists of abrasive dust from friction pairs, and the surface film is distributed with crumby hard granules, exiguous oxide, carbide granules and sheared slender fibre. The Fe-abundant area is mostly an oxide layer of iron with a flaky distribution. Fracture and spalling traces as well as an overlapping structure of multilayer surface films can be easily found on the surface film. The components of the spalling area are basically the same as that of the matrix. At the beginning of wear, the hard peaks from the friction surface of the disc-brake plough on the surface of the brake block. With increasing frictional temperature, the friction surface begins to soften and expand, and oxidized wear occurs at the same

  13. Investigations upon the effects of an auxiliary brake system on the working parameters of diesel engines

    Science.gov (United States)

    Suciu, Cornel; Mihai, Ioan

    2016-12-01

    Classical systems have the main disadvantage of being unable to ensure that high load diesel engine vehicles are slowed in good conditions, for the entire range of combinations of inclinations and lengths of sloped public roads. On such roads, where brakes are used repeatedly and for long periods, friction components that enter classical braking systems will overheat and lead to failure. The present paper aims to investigate, the efficiency of a braking system based on compression release, called a Jake Brake. In such a system, the exhaust valve is actuated at a certain predetermined angle of the crankshaft. The presented research was conducted on an experimental rig based on a four-stroke mono-cylinder diesel engine model Lombardini 6 LD400. Pressure and temperature evolutions were monitored before and during the use of the Jake Brake system. As the generated phonic pollution is the main disadvantage of such systems, noise generated in the vicinity of the engine was monitored as well. The monitored parameters were then plotted in diagrams that allowed evaluating the performances of the system.

  14. Advanced Emergency Braking Controller Design for Pedestrian Protection Oriented Automotive Collision Avoidance System

    Directory of Open Access Journals (Sweden)

    Guo Lie

    2014-01-01

    Full Text Available Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian.

  15. Selection of magnetorheological brake types via optimal design considering maximum torque and constrained volume

    Science.gov (United States)

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

    2012-01-01

    This research focuses on optimal design of different types of magnetorheological brakes (MRBs), from which an optimal selection of MRB types is identified. In the optimization, common types of MRB such as disc-type, drum-type, hybrid-types, and T-shaped type are considered. The optimization problem is to find the optimal value of significant geometric dimensions of the MRB that can produce a maximum braking torque. The MRB is constrained in a cylindrical volume of a specific radius and length. After a brief description of the configuration of MRB types, the braking torques of the MRBs are derived based on the Herschel-Bulkley model of the MR fluid. The optimal design of MRBs constrained in a specific cylindrical volume is then analysed. The objective of the optimization is to maximize the braking torque while the torque ratio (the ratio of maximum braking torque and the zero-field friction torque) is constrained to be greater than a certain value. A finite element analysis integrated with an optimization tool is employed to obtain optimal solutions of the MRBs. Optimal solutions of MRBs constrained in different volumes are obtained based on the proposed optimization procedure. From the results, discussions on the optimal selection of MRB types depending on constrained volumes are given.

  16. Braking Distance Prediction by Hydroplaning Analysis of 3-D Patterned Tire Model

    Science.gov (United States)

    Cho, Jin-Rae; Choi, Joo-Hyoung; Lee, Hong-Woo; Woo, Jong-Shik; Yoo, Wan-Suk

    In this paper, we present a wet-road braking distance estimate for the vehicles equipped with ABS (Anti-lock Brake System). In order to effectively compute the interval-wise braking times and the resulting total braking distance, we divide the entire speed interval at braking into finite number of uniform sub-intervals and apply the energy conservation law to individual sub-intervals. The proposed method is based on a numerical-analytical approach such that the frictional energy loss of the patterned tire is computed by 3-D hydroplaning analysis while the other at the disc pad is analytically derived. The hydroplaning simulation is performed by generally coupling an Eulerian finite volume method and an explicit Lagrangian finite element method. The operation of ABS is numerically implemented by controlling the tire angular velocity such that the preset tire slip ratio on the wet road is maintained. Numerical results are presented to illustrative and verify the the proposed numerical estimate.

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

    Institute of Scientific and Technical Information of China (English)

    吴卫东; 尹用山

    2001-01-01

    Anti-lock brake systems (ABS) are now widely used on motor vehicles. To reduce product cost andto use currently available technologies, standard ABS uses only wheel speed sensors to detect wheel angularvelocities, which is not enough to directly obtain wheel slip ratios needed by the control unit, but can be usedto calculate reference slip ratios with measured wheel angular velocities and the estimated vehicle speed.Therefore, the road friction coefficient, which determines the vehicle deceleration during severe braking, is animportant parameter in estimating vehicle speed. This paper analyzes wheel acceleration responses insimulations of severe braking on different road surfaces and selects a pair of specific points to identify thewheel acceleration curve for each operating condition, such as road surface, pedal-braking torque and wheelvertical load. It was found that the curve using the selected points for each road surface clearly differs fromthat of the other road surfaces. Therefore, different road surfaces can be distinguished with these selectedpoints which represent their corresponding road surfaces. The analysis assumes that only wheel speed sensorsare available as hardware and that the road cohesion condition can be determined in the initial part of thesevere braking process.``

  18. Performance of a fully mechanical parking brake system for passenger cars

    Science.gov (United States)

    Rozaini, A. H.; Ishak, M. R.; Abu Bakar, A. R.; Mohd Zain, M. Z.

    2013-12-01

    In order to ensure that a vehicle remains stationary when it is parked at a certain road slope, the driver has to apply sufficient pulling force on the handbrake lever. Otherwise, the vehicle will start to rollaway where the torque generated by the parking brake system is lower that the torque required by the vehicle to remain stationary. This poses a danger situation not only to the vehicle's occupants but also to the people surrounding it. Thus, this paper aims to investigate performance of a typical parking brake system used in passenger cars. A theoretical model of drum-type parking brake system is derived and later being validated by test data that measured from the parking brake test bench. A good agreement is achieved between calculated and test results. Results from the model show that the parking brake system used in this work can hold the vehicle stationary at 11 degree slope less than 200 N of the applied force and thus it meets the regulation requirement, and also the vehicle will not rollaway even though there are four adult passengers inside it.

  19. Human-simulated intelligent control of train braking response of bridge with MRB

    Science.gov (United States)

    Li, Rui; Zhou, Hongli; Wu, Yueyuan; Wang, Xiaojie

    2016-04-01

    The urgent train braking could bring structural response menace to the bridge under passive control. Based on the analysis of breaking dynamics of a train-bridge vibration system, a magnetorheological elastomeric bearing (MRB) whose mechanical parameters are adjustable is designed, tested and modeled. A finite element method (FEM) is carried out to model and optimize a full scale vibration isolation system for railway bridge based on MRB. According to the model above, we also consider the effect of different braking stop positions on the vibration isolation system and classify the bridge longitudinal vibration characteristics into several cases. Because the train-bridge vibration isolation system has multiple vibration states and strongly coupling with nonlinear characteristics, a human-simulated intelligent control (HSIC) algorithm for isolating the bridge vibration under the impact of train braking is proposed, in which the peak shear force of pier top, the displacement of beam and the acceleration of beam are chosen as control goals. The simulation of longitudinal vibration control system under the condition of train braking is achieved by MATLAB. The results indicate that different braking stop positions significantly affect the vibration isolation system and the structural response is the most drastic when the train stops at the third cross-span. With the proposed HSIC smart isolation system, the displacement of bridge beam and peak shear force of pier top is reduced by 53.8% and 34.4%, respectively. Moreover, the acceleration of bridge beam is effectively controlled within limited range.

  20. Development of Refined Natural Resin based Cashew Nut Shell Oil Liquid (CNSL) for Brake Pads Composite

    Science.gov (United States)

    Wahyuningsih, S.; Ramelan, A. H.; Rahmawati, P.; Tamtama, B. P. N.; Sari, P. P.; Sari, P. L.; Ichsan, S.; Kristiawan, Y. R.; Aini, F. N.

    2017-02-01

    Brake is one of the most important components in the vehicle. One type of brake that widely used is brake-based composites. One of the manufacture of composite material is resin. Cashew Nut Shell Liquid (CNSL) is a natural material which has chemical structure similar to synthetic phenol so it can be an alternative as a resin. Brake pads manufacture using CNSL as resin composites made to obtain the brake which is strong, wear-resistant, and environmentally friendly. The composite made using powder metallurgy techniques by mixing ingredients such as rubber, fibre glass, carbon, mineral sands and phenolic resin. Two formulas were composed by varying the resin and iron mineral sands in 5 grams. Composites were tested using Universal Testing Machine (UTM). The tensile strength result of those formulas are 600 N and 900 N and the elongations are 1.98 mm and 2.59 mm respectively. Formula 2 has a better tensile strength due to the addition of more resin is 15%. Since the better properties, formula 2 was derivated to 4 extended formulas and showed excellent pressure strength reached 20.000 N. It indicates that the addition of the resin can improve the mechanical properties of a composite.

  1. Synthesis and Characterisation of Nano Silver Particle-based Magnetorheological Fluids for Brakes

    Directory of Open Access Journals (Sweden)

    Chiranjit Sarkar

    2015-05-01

    Full Text Available Magnetorheological (MR fluids can be used as brake friction materials subject to heat transfer properties of the fluids to dissipate the heat generated during braking action. The aim of this manuscript is to synthesise MR fluids having higher heat transfer properties than that of the conventional MR fluid. The coating of nano-silver-particles, having thermal conductivity more than five-times than that of iron particles used in the MR fluids, has been tried to enhance the heat dissipation rate of MR fluids. To perform feasibility study on usage of silver particles, three composition of MR fluids (without any silver particles, with 0.25 per cent weight and 0.50 per cent weight silver particles were synthesised. The scanning electron microscopic photographs and EDX analysis of the iron particles have been presented. Shear strengths of all three different compositions of MR fluids were measured using magnetorheometer and the results have been plotted. The effect of silver particles on shear stress of MR fluids has been described. A flywheel-based MR brake experimental setup was developed to analyse the performance of synthesised MR fluids. ‘T’ type thermocouples were used to avail the temperature distribution of the fabricated MR brake. The results of temperature distribution of brakes containing three different compositions of MR fluids have been presented and compared.Defence Science Journal, Vol. 65, No. 3, May 2015, pp.252-258, DOI: http://dx.doi.org/10.14429/dsj.65.7879

  2. Evaluation of the deposition, translocation and pathological response of brake dust with and without added chrysotile in comparison to crocidolite asbestos following short-term inhalation: Interim results

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, David M., E-mail: davidb@itox.ch [Consultant in Toxicology, 1208 Geneva (Switzerland); Rogers, Rick, E-mail: rarogers5@yahoo.com [Rogers Imaging, Needham, MA 02494 (United States); Sepulveda, Rosalina [Rogers Imaging, Needham, MA 02494 (United States); Kunzendorf, Peter, E-mail: Peter.Kunzendorf@GSA-Ratingen.de [GSA Gesellschaft für Schadstoffanalytik mbH, D-40882 Ratingen (Germany); Bellmann, Bernd [Fraunhofer Institute for Toxicology and Experimental Medicine, D-30625 Hannover (Germany); Ernst, Heinrich, E-mail: Heinrich.ernst@item.fraunhofer.de [Fraunhofer Institute for Toxicology and Experimental Medicine, D-30625 Hannover (Germany); Phillips, James I., E-mail: jim.phillips@nioh.nhls.ac.za [National Institute for Occupational Health, National Health Laboratory Service (South Africa); Department of Biomedical Technology, Faculty of Health Sciences, University of Johannesburg (South Africa)

    2014-04-01

    Chrysotile has been frequently used in the past in manufacturing brakes and continues to be used in brakes in many countries. This study was designed to provide an understanding of the biokinetics and potential toxicology following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake dust or crocidolite asbestos. No significant pathological response was observed at any time point in either the brake dust or chrysotile/brake dust exposure groups. The long chrysotile fibers (> 20 μm) cleared quickly with T{sub 1/2} estimated as 30 and 33 days, respectively in the brake dust and the chrysotile/brake dust exposure groups. In contrast, the long crocidolite fibers had a T{sub 1/2} > 1000 days and initiated a rapid inflammatory response in the lung following exposure resulting in a 5-fold increase in fibrotic response within 91 days. These results provide support that brake dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung following short term inhalation. - Highlights: • We evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology observed at any time point in the brake-dust groups. • Crocidolite produced pathological response - Wagner 4 interstitial fibrosis by 32d.

  3. Energy-Regenerative Braking Control of Electric Vehicles Using Three-Phase Brushless Direct-Current Motors

    Directory of Open Access Journals (Sweden)

    Bo Long

    2013-12-01

    Full Text Available Regenerative braking provides an effective way of extending the driving range of battery powered electric vehicles (EVs. This paper analyzes the equivalent power circuit and operation principles of an EV using regenerative braking control technology. During the braking period, the switching sequence of the power converter is controlled to inverse the output torque of the three-phase brushless direct-current (DC motor, so that the braking energy can be returned to the battery. Compared with the presented methods, this technology can achieve several goals: energy recovery, electric braking, ultra-quiet braking and extending the driving range. Merits and drawbacks of different braking control strategy are further elaborated. State-space model of the EVs under energy-regenerative braking operation is established, considering that parameter variations are unavoidable due to temperature change, measured error, un-modeled dynamics, external disturbance and time-varying system parameters, a sliding mode robust controller (SMRC is designed and implemented. Phase current and DC-link voltage are selected as the state variables, respectively. The corresponding control law is also provided. The proposed control scheme is compared with a conventional proportional-integral (PI controller. A laboratory EV for experiment is setup to verify the proposed scheme. Experimental results show that the drive range of EVs can be improved about 17% using the proposed controller with energy-regeneration control.

  4. Electromechanical imitator of antilock braking modes of wheels with pneumatic tire and its application for the runways friction coefficient measurement

    Science.gov (United States)

    Putov, A. V.; Kopichev, M. M.; Ignatiev, K. V.; Putov, V. V.; Stotckaia, A. D.

    2017-01-01

    In this paper it is considered a discussion of the technique that realizes a brand new method of runway friction coefficient measurement based upon the proposed principle of measuring wheel braking control for the imitation of antilock braking modes that are close to the real braking modes of the aircraft chassis while landing that are realized by the aircraft anti-skid systems. Also here is the description of the model of towed measuring device that realizes a new technique of runway friction coefficient measuring, based upon the measuring wheel braking control principle. For increasing the repeatability accuracy of electromechanical braking imitation system the sideslip (brake) adaptive control system is proposed. Based upon the Burkhard model and additive random processes several mathematical models were created that describes the friction coefficient arrangement along the airstrip with different qualitative adjectives. Computer models of friction coefficient measuring were designed and first in the world the research of correlation between the friction coefficient measuring results and shape variations, intensity and cycle frequency of the measuring wheel antilock braking modes. The sketch engineering documentation was designed and prototype of the latest generation measuring device is ready to use. The measuring device was tested on the autonomous electromechanical examination laboratory treadmill bench. The experiments approved effectiveness of method of imitation the antilock braking modes for solving the problem of correlation of the runway friction coefficient measuring.

  5. On airborne nano/micro-sized wear particles released from low-metallic automotive brakes.

    Science.gov (United States)

    Kukutschová, Jana; Moravec, Pavel; Tomášek, Vladimír; Matějka, Vlastimil; Smolík, Jiří; Schwarz, Jaroslav; Seidlerová, Jana; Safářová, Klára; Filip, Peter

    2011-04-01

    The paper addresses the wear particles released from commercially available "low-metallic" automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (release of nanoparticles was measured when the average temperature of the rotor reached 300°C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles.

  6. Comparison of Regenerative Braking Efficiencies of MY2012 and MY2013 Nissan Leaf

    Directory of Open Access Journals (Sweden)

    Albert Boretti

    2016-07-01

    Full Text Available The use of kinetic energy recovery systems (KERS is the best solution presently available to dramatically improve the energy economy of passenger cars. The paper presents an experimental analysis of the energy flow to and from the battery of a MY 2012 and a MY 2013 Nissan Leaf covering the Urban Dynamometer Driving Schedule (UDDS. The two vehicles differ for the integration of the electric drivetrain component, plus a different use of the electric motor and the regenerative brakes, in addition to a different weight. It is shown that while the efficiency propulsive power to vehicle / power from battery are basically unchanged, at about 87-89 %, the efficiency power to the battery / braking power to vehicle are significantly improved from values of about 70-80 % to values of 72-87 %. The analysis provides a state-of-the-art benchmark of the propulsion and regenerative braking efficiencies of electric vehicles.

  7. Research on motor rotational speed measurement in regenerative braking system of electric vehicle

    Science.gov (United States)

    Pan, Chaofeng; Chen, Liao; Chen, Long; Jiang, Haobin; Li, Zhongxing; Wang, Shaohua

    2016-01-01

    Rotational speed signals acquisition and processing techniques are widely used in rotational machinery. In order to realized precise and real-time control of motor drive and regenerative braking process, rotational speed measurement techniques are needed in electric vehicles. Obtaining accurate motor rotational speed signal will contribute to the regenerative braking force control steadily and realized higher energy recovery rate. This paper aims to develop a method that provides instantaneous speed information in the form of motor rotation. It addresses principles of motor rotational speed measurement in the regenerative braking systems of electric vehicle firstly. The paper then presents ideal and actual Hall position sensor signals characteristics, the relation between the motor rotational speed and the Hall position sensor signals is revealed. Finally, Hall position sensor signals conditioning and processing circuit and program for motor rotational speed measurement have been carried out based on measurement error analysis.

  8. Fuzzy System of Distribution of Braking Forces on the Engines of a Mobile Robot

    Directory of Open Access Journals (Sweden)

    Bobyr Maxim

    2016-01-01

    Full Text Available The article presents a fuzzy system of distribution of braking forces on the engines of a mobile robot during its lifting and going down.The block diagram of the system of distribution of braking forces and location of sensors on a mobile robot is given in the paper. Also, fuzzy mathematical model of redistribution of braking forces depending on the conditions of the movement a mobile robot is shown in the article. The result of the simulation of control parameters are presented in the article. The control system of a mobile robot is demonstrated on the example of an autonomous mini-robot on platform Pirate under the control of microprocessor Arduino Mega 2560.

  9. Thermal analysis of both ventilated and full disc brake rotors with frictional heat generation

    Directory of Open Access Journals (Sweden)

    Belhocine A.

    2014-06-01

    Full Text Available In automotive engineering, the safety aspect has been considered as a number one priority in development of a new vehicle. Each single system has been studied and developed in order to meet safety requirements. Instead of having air bags, good suspension systems, good handling and safe cornering, one of the most critical systems in a vehicle is the brake system. The objective of this work is to investigate and analyze 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 discs and to identify the critical temperature of the rotor. The analysis also gives us the heat flux distribution for the two discs.

  10. Structural optimization of an asymmetric automotive brake disc with cooling channels to avoid squeal

    Science.gov (United States)

    Wagner, Andreas; Spelsberg-Korspeter, Gottfried; Hagedorn, Peter

    2014-03-01

    Brake squeal is still a major issue in the automotive industry due to comfort complaints of passengers and resulting high warranty costs. Many measures to avoid squeal have been discussed in the engineering community reaching from purely passive measures like the increase of damping, e.g. by the application of shims, to the active or semiactive suppression of squeal. While active measures can be effective but are elaborate and therefore more expensive, passive measure are less complex in most cases. This leads to the necessity to develop passive, economic and robust measures to avoid squeal. Asymmetry of the brake rotor has been proposed to achieve this goal and the resulting split of all double eigenfrequencies of the brake rotor has lately been shown to stabilize the system.

  11. Compliant mechanism road bicycle brake: a rigid-body replacement case study

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, Brian M [Los Alamos National Laboratory; Howell, Larry L [NON LANL; Magleby, Spencer P [NON LANL

    2011-01-19

    The design of high-performance bicycle brakes is complicated by the competing design objectives of increased performance and low weight. But this challenge also provides a good case study to demonstrate the design of compliant mechanisms to replace current rigid-link mechanisms. This paper briefly reviews current road brake designs, demonstrates the use of rigid-body replacement synthesis to design a compliant mechanism, and illustrates the combination of compliant mechanism design tools. The resulting concept was generated from the modified dual-pivot brake design and is a partially compliant mechanism where one pin has the dual role of a joint and a mounting pin. The pseudo-rigid-body model, finite element analysis, and optimization algorithms are used to generate design dimensions, and designs are considered for both titanium and E-glass flexures. The resulting design has the potential of reducing the part count and overall weight while maintaining a performance similar to the benchmark.

  12. A New, Low Braking Index For the LMC Pulsar B0540-69

    CERN Document Server

    Marshall, F E; Harding, A K; Martin, P; Smith, D A

    2016-01-01

    We report the results of a 16-month monitoring campaign using the Swift satellite of PSR B0540-69, a young pulsar in the Large Magellanic Cloud. Phase connection was maintained throughout the campaign so that a reliable ephemeris could be determined, and the length of the campaign is adequate to accurately determine the spin frequency and its first and second derivatives. The braking index is 0.031 +/- 0.013 (90% confidence), a value much lower than previously reported for B0540-69 and almost all other young pulsars. We use data from the extensive monitoring campaign with RXTE to show that timing noise is unlikely to significantly affect the measurement. This is the first measurement of the braking index in the pulsar's recently discovered high spin-down state. We discuss possible mechanisms for producing the low braking index.

  13. A New, Low Braking Index For the LMC Pulsar B0540-69

    Science.gov (United States)

    Marshall, Francis E.; Guillemot, Lucas; Kust Harding, Alice; Martin, Pierrick; Smith, David A.

    2017-01-01

    We report the results of a 16 month monitoring campaign using the Swift satellite of PSR B0540-69, a young pulsar in the Large Magellanic Cloud. Phase connection was maintained throughout the campaign so that a reliable ephemeris could be determined, and the length of the campaign is adequate to accurately determine the spin frequency and its first and second derivatives. The braking index n is 0.031 ± 0.013 (90% confidence), a value much lower than previously reported for B0540-69 and almost all other young pulsars. The monitoring campaign is continuing, and the pulsar remains in its high spin-down state. We use data from the extensive monitoring campaign with RXTE to show that timing noise is unlikely to significantly affect the measurement. This is the first measurement of the braking index in the pulsar's recently discovered high spin-down state. We discuss possible mechanisms for producing the low braking index.

  14. Calculation of braking distance and time for crane lifting brake%起重机起升制动器制动距离和时间的计算

    Institute of Scientific and Technical Information of China (English)

    叶勇

    2012-01-01

    介绍了制动器的工作工况,对制动器额定制动力矩进行了定义,同时对制动器在急停情况下的工况进行了分析.以一集装箱起重机的制动器计算为例,详细阐述了制动器力矩MK值有效投入前加速下降的行程S1,以及高速轴制动器的全部制动力矩∑MK有效制动期间的减速制动行程S2的计算方法,得出了起重机起升制动器在急停过程中所下降的总行程和总时间,为此类制动器装置的设计和计算提供依据.%The paper introduces the working condition of the brake, with definition of rated braking torque, and analyzes its working condition in emergency. With calculation of a container crane brake as an example, the paper details a calculation method of the acceleration lowering travel S1 before effective input of brake torque value MK, and the deceleration braking travel S1 during the effective braking of all braking torque of high-speed shaft brake, and then, the total lowered travel and total time during emergency stop of crane lifting brake are figured out, which provide reference for design and calculation of the similar brakes.

  15. Optimal design method for force in vibration control of multi-body system with quick startup and brake

    Institute of Scientific and Technical Information of China (English)

    TANG Hua-ping; PENG Ya-qing

    2005-01-01

    A kind of active vibration control method was presented through optimal design of driving load of multi-body system with quick startup and brake. Dynamical equation of multi-body system with quick startup and brake was built, and mathematical model of representing vibration control was also set up according to the moving process from startup to brake. Then optimization vibration control model of system driving load was founded by applying theory of optimization control, which takes rigid body moving variable of braking moment as the known condition, and vibration control equation of multi-body system with quick startup and brake was converted into boundary value problem of differential equation. The transient control algorithm of vibration was put forward, which is the analysis basis for the further research. Theoretical analysis and calculation of numerical examples show that the optimal design method for the multi-body system driving load can decrease the vibration of system with duplication.

  16. 分布式电驱动汽车 AFS 与电液复合制动集成控制%Integrated Control of Active Front Steering and Motor/Hydraulic Hybrid Braking in Distributed Electric Drive Vehicles

    Institute of Scientific and Technical Information of China (English)

    袁希文; 桂林; 周兵

    2016-01-01

    F vehicle model in MATLAB/Simulink environment have shown that the control strategy can significantly enhance vehicle directional stability and ensure braking energy recovery in split-μstraight-line braking,and can better track ideal yaw rate with vehicle lateral stability improvement when cornering.

  17. Vehicle longitudinal velocity estimation during the braking process using unknown input Kalman filter

    Science.gov (United States)

    Moaveni, Bijan; Khosravi Roqaye Abad, Mahdi; Nasiri, Sayyad

    2015-10-01

    In this paper, vehicle longitudinal velocity during the braking process is estimated by measuring the wheels speed. Here, a new algorithm based on the unknown input Kalman filter is developed to estimate the vehicle longitudinal velocity with a minimum mean square error and without using the value of braking torque in the estimation procedure. The stability and convergence of the filter are analysed and proved. Effectiveness of the method is shown by designing a real experiment and comparing the estimation result with actual longitudinal velocity computing from a three-axis accelerometer output.

  18. Thermomechanical behavior of dry contacts in disc brake rotor with a grey cast iron composition

    Directory of Open Access Journals (Sweden)

    Belhocine Ali

    2013-01-01

    Full Text Available The main purpose of this study is to analysis the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on the calculation code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.

  19. Fuzzy Control Strategy of Battery Management for PHEV during Regenerative Braking

    Directory of Open Access Journals (Sweden)

    Zhumu Fu

    2014-01-01

    Full Text Available Based on analyzing the structure of Parallel Hybrid Electric Vehicle (PHEV and its operation during regenerative braking, a fuzzy control strategy of battery management is proposed. Firstly, the state of charging is estimated by establishing the mathematical relationship between open circuit voltage and the internal resistance model. Secondly, the fuzzy logic controller is designed in regenerative braking system. Finally, by modeling and simulation in ADVISOR, it is shown that the rate of energy recovery with the fuzzy control strategy is increased by 12.3, 18.3 and 7.6%, respectively in three different driving cycles, compared with the benchmark control strategy in the same driving cycles.

  20. Wear and Corrosion of Cast Al Alloy Piston with and without Brake Oil

    OpenAIRE

    Olawale Olarewaju Ajibola; Daniel Toyin Oloruntoba

    2015-01-01

    The effects of wear and corrosion of cast AA6061 aluminium alloy were studied with and without brake fluid using a wear jig while the corrosion rate was determined in brake fluid for 70 days under two experimental set-ups. The tests, yielded 0.00000123 g/mm2/min highest wear rate at 147000 wear cycles and 0.0334 mg/mm2/yr as the highest corrosion rate within the early 39th day of immersion in oil, the values being considered comparatively lower than those obtained for Al alloy in most common ...

  1. Numerical Analysis of Temperature Field in a Disc Brake at Different Cover Angle of the Pad

    Directory of Open Access Journals (Sweden)

    Grześ Piotr

    2014-12-01

    Full Text Available In the paper an influence of the cover angle of the pad on temperature fields of the components of the disc brake is studied. A three-dimensional finite element (FE model of the pad-disc system was developed at the condition of equal temperatures on the contacting surfaces. Calculations were carried out for a single braking process at constant deceleration assuming that the contact pressure corresponds with the cover angle of the pad so that the moment of friction is equal in each case analysed. Evolutions and distributions of temperature both for the contact surface of the pad and the disc were computed and shown.

  2. Braking and propulsive impulses in individuals with patellofemoral pain syndrome when walking up and down stairs

    Directory of Open Access Journals (Sweden)

    Marcelo Camargo Saad

    2014-12-01

    Full Text Available Patellofemoral pain syndrome (PFPS is a prevalent clinical condition and it affects gait behavior. Braking and propulsive impulses are important biomechanical parameters obtained from ground reaction forces (GRF, which combine the amount of force applied over a period of time. The aim of this study was to evaluate these impulses while walking up and down stairs in healthy controls and PFPS individuals. The results did not reveal significant differences in braking and propulsive impulses between groups during these activities. Thus, the painful condition on a simple functional activity was insufficient to change the motor strategy to walking up or down the stairs.

  3. Potential wells with a unique brake orbit. Counterexamples to a conjecture by H. Seifert

    CERN Document Server

    Giambo', R; Piccione, P

    2012-01-01

    In this paper we prove the existence of real-analytic natural Hamiltonian systems - i.e. where H(q,p)=T(q,p)+V(q) in the 2N-dimensional real space, where N is any integer greater than 1 - with non critical energy levels E for the potential V such that the sublevel E of V is homeomorphic to the N-dimensional disk, and that only one brake orbit of energy E exists. A famous conjecture formulated by H. Seifert in 1948 claimed the existence of at least N distinct brake orbits for this situation.

  4. Model-based Sliding Mode Controller of Anti-lock Braking System

    Science.gov (United States)

    Zheng, Lin; Luo, Yue-Gang; Kang, Jing; Shi, Zhan-Qun

    2016-05-01

    The anti-lock braking system (ABS) used in automobiles is used to prevent wheel from lockup and to maintain the steering ability and stability. The sliding mode controller is able to control nonlinear system steadily. In this research, a one-wheel dynamic model with ABS control is built up using model-based method. Using the sliding model controller, the simulation results by using Matlab/Simulink show qualified data compared with optimal slip rate. By using this method, the ABS brake efficiency is improved efficiently.

  5. Research on Electro Hydraulic Proportional Control for Heavy Vehicle Blend Braking System

    Institute of Scientific and Technical Information of China (English)

    XU Ming

    2009-01-01

    A blend braking system of heavy vehicle was proposed. The main control part of the system is the electro hydraulic proportional servo valve. A nonlinear model of brake cylinder controlled by the valve was deduced through the analysis of its control property and system feature. The transfer function of the system was also proposed, and the hydraulic inherent frequency and the PID closed-loop system feature were calculated. The simulated result is consistent with those tested in the bench and on the site with 50t heavy vehicle. The experimental result shows that the control method has quick response and high precision.

  6. Classical and quantum Big Brake cosmology for scalar field and tachyonic models

    Energy Technology Data Exchange (ETDEWEB)

    Kamenshchik, A. Yu. [Dipartimento di Fisica e Astronomia and INFN, Via Irnerio 46, 40126 Bologna (Italy) and L.D. Landau Institute for Theoretical Physics of the Russian Academy of Sciences, Kosygin str. 2, 119334 Moscow (Russian Federation); Manti, S. [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy)

    2013-02-21

    We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field . It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical - quantum correspondence, because soft singularities are traversable in classical cosmology, while the strong Big Bang and Big Crunch singularities are not traversable.

  7. Classical and quantum Big Brake cosmology for scalar field and tachyonic models

    CERN Document Server

    Kamenshchik, A

    2013-01-01

    We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field . It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical - quantum correspondence, because soft singularities are traversable in classical cosmology, while the strong Big Bang and Big Crunch singularities are not traversable.

  8. Classical and Quantum Big Brake Cosmology for Scalar Field and Tachyonic Models

    Science.gov (United States)

    Kamenshchik, Alexander; Manti, Serena

    2015-01-01

    We study a relation between the cosmological singularities in classical and quantum theory, comparing the classical and quantum dynamics in some models possessing the Big Brake singularity - the model based on a scalar field and two models based on a tachyon-pseudo-tachyon field. It is shown that the effect of quantum avoidance is absent for the soft singularities of the Big Brake type while it is present for the Big Bang and Big Crunch singularities. Thus, there is some kind of a classical - quantum correspondence, because soft singularities are traversable in classical cosmology, while the strong Big Bang and Big Crunch singularities are not traversable.

  9. A new strategy for transient stability using augmented generator control and local dynamic braking

    Energy Technology Data Exchange (ETDEWEB)

    Dorsey, J.; Jiang, H.; Habetler, T. [Georgia Inst. of Tech., Atlanta, GA (United States); Qu, Z. [University of Central Florida, Orlando, FL (United States)

    1994-12-31

    A decentralized automatic control strategy for significantly improving the transient stability of a large power system is introduced. The strategy combines local dynamic braking and a straightforward augmentation of the existing turbine / governor control system that uses only local feedback. The brake resistor, which employs thick film, metal oxide technology, has no inductance and is of very low resistance, allowing its use during fault to show a generator`s acceleration. Simulation results using the 39 Bus New England system show that the strategy dramatically increases the global stability of a power system. (author) 15 refs., 7 figs., 1 tab.

  10. Planning the most suitable travel speed for high frequency railway lines

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.

    2005-01-01

    This paper presents a new method to calculate the most suitable travel speed for high frequency railway lines to achieve as much capacity as possible for congested railway lines. The method calculates the most suitable travel speed based on the braking distance and information about...... of the railway line, and the more buffer time on the railway line, the better punctuality and the better possibilities to run more trains. Based on the described method a case example from the suburban railway lines of Copenhagen will be shown. The case example shows that a reduction of the maximum travel speed...

  11. Discussing the Brake Performance of Electro-pneumatic Brake Type F8%对F8电空制动机制动性能初探

    Institute of Scientific and Technical Information of China (English)

    池海

    2001-01-01

    通过对F8电空制动机在两次试验中数据的分析、比较,从结构和原理上对该制动机两个方面的性能进行初步的探讨。%By analyzing and contrasting to the data of two tests for Electro-pneumatic Brake Type F8, two ways of performance is discusse d from principle and structure.

  12. Control strategy for electro-mechanical braking based on curves of ECE regulations and ideal braking force%基于ECE法规和Ⅰ曲线的机电复合制动控制策略

    Institute of Scientific and Technical Information of China (English)

    刘丽君; 姬芬竹; 杨世春; 徐斌

    2013-01-01

    具有再生制动功能的电动汽车制动系统与传统燃油汽车的摩擦制动系统不同,在回收部分制动能量的同时其制动稳定性会发生变化.在保证安全制动距离的前提下,制动能量回收率的提高受到制动稳定性的制约和限制.针对电制动和常规摩擦制动组成的机电复合制动系统,建立了电制动力、电制动力矩和电池充电功率计算模型.考虑到电机转矩特性和电池充电功率限制,以最大化回收制动能量为目标,设计3种不同的机电复合制动控制策略.通过在ADVISOR软件中建立嵌入式仿真模块对制动能量回收率、电池荷电状态和纯电动模式的续驶里程进行了仿真计算和分析.计算结果表明:Ⅰ曲线和ECE(Economic Commissionof Europe safety regulations)法规边界线都不是理想的制动力分配曲线,所提出的制动力分配曲线OABCD综合性能较好,制动能量回收率达到59.56%,且一个循环的荷电状态变化很小,仅降低了4.29%.实车试验表明能量回收能够提高续驶里程.%The braking system of electric vehicle with regenerative braking is different from friction braking system of conventional fuel vehicle. Regenerative braking system makes braking stability of electric vehicles change when it recovers braking energy of vehicles. The improvement of braking energy recovery ration was restricted by the braking stability under the precondition of safe braking distance. Aiming at the electromechanical hybrid braking system composed of electric braking and conventional friction braking, the calculation models of electric braking force, electric braking torque and battery charging power were established. In view of the motor torque characteristics and battery charging power limit, three kinds of control strategies for e-lectro-mechanical hybrid braking were designed for recovering the maximal braking energy. The baking energy recovery ration, state of charge and driving range in

  13. 49 CFR 238.313 - Class I brake test.

    Science.gov (United States)

    2010-10-01

    ... occurs first, that the train remains in continuous passenger service. (c) Each passenger car and each... to train line electric, pneumatic, or other signals. This test shall include a verification that...

  14. 基于位移传感器的机车制动工况及轮对椭圆化在线监测研究%Displacement Sensor Locomotive Wheel Braking Condition and Online Monitoring Based on Ovalization

    Institute of Scientific and Technical Information of China (English)

    陈庆; 严俊

    2016-01-01

    Based on the displacement sensor ,real-time detection of the brake actuator and the displacement of wheel and tire tread surface,a SS Series locomotive braking condition of the oval and round on-line monitoring system was designed .IPC system by processing the acquired data was calculated after realization of the braking condition of remission .The problem of shoe wear,bra-king,tire wear and wheel real-time online monitoring of the ellipse of the situation and the braking condition adverse can be timely feedback and handled up ,ensuring road safety.Finally,the simulation curve round to elliptical detection ,verifing the feasibility of the design .%文中基于位移传感器,实时检测制动器传动装置以及车轮轮箍踏面的位移量,设计了一套SS系列机车制动工况及轮对椭圆化在线监测系统。系统通过上位机处理采样数据,计算后比对预置的参数,实现对制动工况及轮对椭圆化情况的实时在线监测;对制动工况中的缓解、闸瓦磨损情况、制动情况、轮箍磨损等问题进行及时反馈和处理,确保行车安全。文中仿真了轮对椭圆化检测的变化曲线,验证了系统方案的可行性。

  15. 起重机大车行走机构制动器制动距离的计算%Calculation of braking distance for travelling mechanism brake of crane

    Institute of Scientific and Technical Information of China (English)

    叶勇; 杨杰; 王亚斌

    2013-01-01

    The paper introduces the working conditions of travelling mechanism brake for container crane, with detailed analysis and calculation for working conditions of such brakes in emergencies. Taking one relevant case as an example , the paper specifies a calculation method for the distance S, of crane travelling in wind at the original speed within brake lag time of 0. 3 s, and the effective braking distance S2 after the brake lag time upon braking, in order to work out the total stroke of travelling mechanism brake upon emergent braking. The paper provides reference for design and calculation of similar brakes.%介绍了集装箱起重机大车行走机构制动器的工况,对大车行走机构制动器在急停情况下的工况进行了详细分析和计算,并以一集装箱起重机的大车行走机构制动器计算为例,详细论述了制动器切入后,急停电机至制动器有效作用期间,制动器滞后时间0.3s内,大车以原速度在风力作用下加速行走的距离S1和制动器滞后制动时间过后,制动器进行制动,起重机制动的有效距离S2的计算方法,得出了起重机大车行走机构制动器在急停情况下移动的总行程.为此类制动器装置的设计和计算提供了依据.

  16. Wear and Corrosion of Cast Al Alloy Piston with and without Brake Oil

    Directory of Open Access Journals (Sweden)

    Olawale Olarewaju Ajibola

    2015-01-01

    Full Text Available The effects of wear and corrosion of cast AA6061 aluminium alloy were studied with and without brake fluid using a wear jig while the corrosion rate was determined in brake fluid for 70 days under two experimental set-ups. The tests, yielded 0.00000123 g/mm2/min highest wear rate at 147000 wear cycles and 0.0334 mg/mm2/yr as the highest corrosion rate within the early 39th day of immersion in oil, the values being considered comparatively lower than those obtained for Al alloy in most common wet abrasion test and corrosion in aqueous solutions as previously reported in literature. The material loss rates to wear and corrosion were determined from the equations relating to wear and corrosion based on the ASTM designations. The results show that the combined actions of wear and corrosion contribute to the total loss of piston material immersed in brake oil. This is greater than either of their effects individually on cast Al alloy in the brake oil.

  17. DISTRIBUTION OF TRACTION AND BRAKING FORCES ON VEHICLE’S UNDER DIFFERENT RIDING CYCLES

    OpenAIRE

    Ivanov, A.; А. Timkov

    2011-01-01

    The method calculation wich can been used to determine the distribution of traction and braking force of the vehicle in different driving cycles and use it when choosing characteristics of a hybrid vehicle deviced. The differential equation of vehicle’s motion basis of Newton’s second law lies in the basis of the given methodology.

  18. THE ASSESSMENT OF BASIC TECHNICAL PARAMETERS OF THE COOLING SYSTEM OF THE LOCOMOTIVE DISK BRAKE

    Directory of Open Access Journals (Sweden)

    I. M. Biloborodova

    2009-04-01

    Full Text Available In the article a thermal (constructive calculation of the liquid-air recuperative heat exchanger is executed. Its purpose was an estimation of the areas of heat-exchange surfaces and the consumption of heat carriers necessary for dissipation of thermal energy generated by a locomotive disk brake.

  19. The anti-glitch of magnetar 1E 2259+586 in the wind braking scenario

    Energy Technology Data Exchange (ETDEWEB)

    Tong, H., E-mail: tonghao@xao.ac.cn [Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi, Xinjiang (China)

    2014-04-01

    The anti-glitch of magnetar 1E 2259+586 is analyzed theoretically. An enhanced particle wind during the observational interval takes away additional rotational energy of the neutron star, which will result in a net spin-down of the magnetar, i.e., an anti-glitch. In the wind braking scenario of the anti-glitch, there are several predictions: (1) a radiative event will always accompany the anti-glitch, (2) there will be a decrease/variation of the braking index after the anti-glitch, and (3) the anti-glitch is just a period of enhanced spin-down. If there are enough timing observations, a period of enhanced spin-down is expected instead of an anti-glitch. Applications to previous timing events of SGR 1900+14 and PSR J1846–0258 are also included. It is shown that current timing events of 1E 2259+586, SGR 1900+14, and PSR J1846–0258 can be understood safely in the wind braking model. The enhanced spin-down and absence of an anti-glitch before the giant flare of SGR 1806–20 is consistent with the wind braking scenario.

  20. Effect of periwinkles shell particle size on the wear behavior of asbestos free brake pad

    Science.gov (United States)

    Amaren, S. G.; Yawas, D. S.; Aku, S. Y.

    The effect of periwinkle shell particle size on the wear behavior of asbestos free brake pad has been investigated. The asbestos free brake pad produced by varying the periwinkle shell particles was from +125 to +710 μm with phenolic resin as the binder. The wear test was performed using pin on disk machine by varying the sliding speed, applied load, temperatures and periwinkle shell particle size. Full factorial design of four factor-two levels and analysis of variance were used in the study of the wear test. The results shown that wear rate increases with increasing the sliding speed, load, temperatures and periwinkle particle size. The co-efficient of friction obtained is within the recommended standard for automobile brake pad. The +125 μm particles of periwinkles gave the best wear resistance. Factorial design of the experiment can be successfully employed to describe the wear behavior of the samples and developed linear equation for predicting wear rate within selected experimental conditions. The results of this research indicate that periwinkle shell particles can be effectively used as a replacement for asbestos in brake pad manufacture.

  1. Automotive brake squeal analysis with rotating finite elements of asymmetric disc in time

    Science.gov (United States)

    Kang, Jaeyoung

    2017-04-01

    The new finite element brake squeal model is proposed where the finite elements of a real brake disc rotate in time. Contact nodal forces between the rotating disc and stationary pads are allocated to the moving contact area at every time step. When the proposed model is applied to an asymmetric automotive brake disc, it becomes the periodic time-varying brake system. The stability boundary of the discrete time-varying system is numerically calculated by the Floquet theory. Also, the quasi-static linearized eigenvalue analysis is conducted to show that the unstable modes repeatedly appear at the short interval of the disc rotation angle. The results are consistent with the angle-dependent local phenomenon of squeal termed squeal periodicity in the squeal experiment. In the nonlinear time-domain analysis, the squeal vibration increases and then decays in time for the rotating mode shape functions. It demonstrates that the rotation of an asymmetric disc can change the nonlinear squeal behavior as well as the linear stability character drastically.

  2. Dynamic response of a vehicle with planar suspension system (PSS) under differential braking

    Science.gov (United States)

    Zhu, Jian Jun; Khajepour, Amir; Esmailzadeh, Ebrahim

    2012-01-01

    To absorb the vibrations and shocks caused by road obstacles effectively in any direction within the wheel rotation plane, a planar suspension system (PSS), in which there are spring-damper struts in both the vertical and longitudinal directions, is proposed to improve the ride quality of a vehicle with such novel suspension systems. The longitudinal spring-damper strut in a PSS is considerably soft compared with the longitudinal connection in a conventional suspension. Consequently, the wheels in a vehicle with PSS can move forth and back with respect to the body. The dynamic behaviours of a PSS vehicle under some special conditions, such as a differential braking in which the braking torque applied to the wheels at two sides of an axle are uneven, may exhibit special characteristics. The directional stability of the PSS vehicle in such a case may be one of the major concerns. The dynamic performance of the PSS vehicle in the differential braking condition is thus necessary to be investigated. This paper presents the investigation results of the transient response of a vehicle with the PSS in such a case. The simulation results are also compared with those of a similar vehicle with conventional suspensions. The study demonstrates that the PSS vehicle is directionally stable in differential braking conditions. The dynamic behaviour of the PSS vehicle is generally comparable with that of a conventional vehicle.

  3. Braking PSR J1734-3333 with a possible fall-back disk

    Science.gov (United States)

    Liu, Xiong-Wei; Xu, Ren-Xin; Qiao, Guo-Jun; Han, Jin-Lin; Tong, Hao

    2014-01-01

    The very small braking index of PSR J1734-3333, n = 0.9 ± 0.2, challenges the current theories of braking mechanisms in pulsars. We present a possible interpretation that this pulsar is surrounded by a fall-back disk and braked by it. A modified braking torque is proposed based on the competition between the magnetic energy density of the pulsar and the kinetic energy density of the fall-back disk. With this torque, a self-similar disk can fit all the observed parameters of PSR J1734-3333 with natural initial values of parameters. In this regime, the star will evolve to the region having anomalous X-ray pulsars and soft gamma repeaters in the P - Ṗ diagram in about 20 000 years and stay there for a very long time. The mass of the disk around PSR J1734-3333 in our model is about 10M⊕, similar to the observed mass of the disk around AXP 4U 0142+61.

  4. TECHNOLOGICAL METHODS FOR LASER HARDENING OF INTERNAL CONTACT SURFACES OF «BELARUS» TRACTOR BRAKE MECHANISMS

    Directory of Open Access Journals (Sweden)

    O. S. Kobjakov

    2008-01-01

    Full Text Available The paper considers pertaining to higher wear resistance of «Belarus» tractor brake mechanisms details are considered. Properties of ВЧ-50-cast iron are investigated due to laser hardening while using various technological methods.

  5. Design and research on the electronic parking brake system of the medium and heavy duty vehicles

    Directory of Open Access Journals (Sweden)

    Hongliang WANG

    2015-04-01

    Full Text Available Focusing on auto control of parking brake system of the medium and heavy duty vehicles, the key problems are studied including the system design and control strategies. The structure and working principle of the parking brake system of the medium and heavy duty vehicles are analyzed. The functions of EPB are proposed. The important information of the vehicle are analyzed which could influence the EPB system. The overall plan of the pneumatic EPB system is designed, which adopts the two-position three-way electromagnetic valve with double coil as actuator. The system could keep the vehicle parking brake status or parking release status for a long time without power supply. The function modules of the system are planned, and the control strategies of automatic parking brake and parking release are made. The experiment is performed on a medium-sized commercial vehicle which is experimentally modified. The overall plan of the pneumatic EPB system and the automatic parking function are proved through real vehicle tests.

  6. 76 FR 54721 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Science.gov (United States)

    2011-09-02

    ... Necessary for Safe Operation: Brakes; Adjustment Limits AGENCY: Federal Motor Carrier Safety Administration... actuator readjustment limits in the Federal Motor Carrier Safety Regulations (FMCSRs). The purpose of this notice of proposed rulemaking (NPRM) is to amend the readjustment limits, clarify their application,...

  7. Effects of High-Speed Power Training on Muscle Performance and Braking Speed in Older Adults

    Directory of Open Access Journals (Sweden)

    Stephen P. Sayers

    2012-01-01

    Full Text Available We examined whether high-speed power training (HSPT improved muscle performance and braking speed using a driving simulator. 72 older adults (22 m, 50 f; age = 70.6 ± 7.3 yrs were randomized to HSPT at 40% one-repetition maximum (1RM (HSPT: n=25; 3 sets of 12–14 repetitions, slow-speed strength training at 80%1RM (SSST: n=25; 3 sets of 8–10 repetitions, or control (CON: n=22; stretching 3 times/week for 12 weeks. Leg press and knee extension peak power, peak power velocity, peak power force/torque, and braking speed were obtained at baseline and 12 weeks. HSPT increased peak power and peak power velocity across a range of external resistances (40–90% 1RM; P<0.05 and improved braking speed (P<0.05. Work was similar between groups, but perceived exertion was lower in HSPT (P<0.05. Thus, the less strenuous HSPT exerted a broader training effect and improved braking speed compared to SSST.

  8. The Development of a Fuzzy Predictive Control System for Automotive Anti-lock Braking System

    Institute of Scientific and Technical Information of China (English)

    HUANGFU Shihui; BAO Xiangying

    2006-01-01

    This paper presents the model of one-tire kinetics、tires、the braking system and the model of control system. On virtual road, this paper builds a fuzzy predictive control system to insure the best attachment coefficient between tires and road. And it turns out to be that this fuzzy predictive control method has achieved good performances.

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

    Science.gov (United States)

    2013-02-11

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL11 Federal Motor Vehicle Safety... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... published a final rule in the Federal Register amending Federal Motor Vehicle Safety Standard (FMVSS)...

  10. Toroidal rotation braking with n = 1 magnetic perturbation field on JET

    DEFF Research Database (Denmark)

    Sun, Y; Liang, Y; Koslowski, H R;

    2010-01-01

    A strong toroidal rotation braking has been observed in plasmas with application of an n = 1 magnetic perturbation field on the JET tokamak. Calculation results from the momentum transport analysis show that the torque induced by the n = 1 perturbation field has a global profile. The maximal valu...

  11. Time headway in car following and operational performance during unexpected braking

    NARCIS (Netherlands)

    Brouwer, W.H.; van Winsum, W.

    1997-01-01

    The relation between car-following behaviour and braking performance was studied in a driving simulator. The theoretical perspective was that individual differences in tactical car-driving behaviour may be related to skills on the operational level of the driving task via a process of adaptation. In

  12. New long-term braking index measurements for glitching pulsars using a glitch-template method

    CERN Document Server

    Espinoza, C M; Stappers, B W

    2016-01-01

    Braking index measurements offer the opportunity to explore the processes affecting the long-term spin evolution of pulsars and possible evolutionary connections between the various pulsar populations. For young pulsars the long-term trends are generally obscured by short term phenomena such as timing noise and the recoveries form large glitches. Here we present a new method to overcome the latter and report on braking index measurements for the Vela-like pulsars PSR B1800-21 and PSR B1823-13, an updated measurement for Vela and new estimates for four more glitching pulsars observed at Jodrell Bank Observatory. The values of braking indices describe the long-term evolution of the pulsars across the P-P' diagram. Despite some measurements being affected by considerable uncertainties, there is evidence for a common trend involving low braking indices (n 10. We interpret both short and long term trends as signatures of the large glitch activity, and speculate that they are driven by short-term post-glitch re-cou...

  13. Tribological characteristics of C/C-SiC braking composites under dry and wet conditions

    Institute of Scientific and Technical Information of China (English)

    LI Zhuan; XIAO Peng; XIONG Xiang; ZHU Su-hua

    2008-01-01

    C/C-SiC braking composites, based on reinforcement of carbon fibers and rnatrices of carbon and silicon carbide, were fabricated by warm compaction and in situ reaction process. The tribological characteristics of C/C-SiC braking composites under dry and wet conditions were investigated by means of MM-1000 type of friction testing machine. The influence of dry and wet conditions on the tribological characteristics of the C/C-SiC composites was ascertained. Under dry condition, C/C-SiC braking composites show superior tribological characteristics, including high coefficient of friction (0.38), good abrasive resistance (thickness loss is 1.10 μm per cycle) and steady breaking. The main wear mechanism is plastic deformation and abrasion caused by plough. Under wet condition, frictional films form on the worn surface. The coefficient of friction (0.35) could maintain mostly, and the thickness loss (0.70 μm per cycle) reduces to a certain extent. Furthermore, braking curves are steady and adhesion and oxidation are the main wear mechanisms.

  14. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Science.gov (United States)

    2010-10-01

    ... compressed air or vacuum only to assist the driver in applying muscular force to hydraulic or mechanical... transmission of response or control signals in the vehicle's antilock brake system. The indicator lamp shall...) S5.1.6.3Antilock power circuit for towed vehicles. Each truck tractor manufactured on or after...

  15. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Science.gov (United States)

    2010-10-01

    ... the sequence specified in S7. Corresponding test procedures of S7 are indicated in parentheses. If a... brake-fluid reservoir filler plug or cap; and (c) Of a color that contrasts with its background, if it... Newtons (10 pounds) of the fade test baseline check average force (S7.6.3), but not less than 0 Newtons...

  16. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ... signal or signals. Electric vehicle or EV means a motor vehicle that is powered by an electric motor... or control signals in an antilock brake system, or a total functional electrical failure in a... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 105; Hydraulic and electric...

  17. Model-based fuzzy control solutions for a laboratory Antilock Braking System

    DEFF Research Database (Denmark)

    Precup, Radu-Emil; Spataru, Sergiu; Rǎdac, Mircea-Bogdan;

    2010-01-01

    This paper gives two original model-based fuzzy control solutions dedicated to the longitudinal slip control of Antilock Braking System laboratory equipment. The parallel distributed compensation leads to linear matrix inequalities which guarantee the global stability of the fuzzy control systems...

  18. 基于最佳制动效果的并联式混合动力汽车再生制动控制策略%Regenerative Braking Control Strategy for PHEV Based on Optimal Braking Effect

    Institute of Scientific and Technical Information of China (English)

    高爱云; 邓效忠; 张明柱; 付主木

    2015-01-01

    Based on the principles of the braking force distribution,a regenerative braking control strategy was proposed on the basis of the optimal braking effect and fuzzy control,where mechanical braking could cooperate with regenerative braking and front and rear wheel braking force were distribG uted reasonably.Taking the braking strength and the state of charge of batteries as inputs,and reG garding the expected regenerative braking force as an output,a fuzzy controller was designed.The control strategy designed was simulated from parts performance,braking energy recovery and braking sense compared with the default control strategy in ADVISOR.At the same time,the hardwareintheloop simulation was developed to prove the simulation results in ADVISOR effective.The results show that the control strategy presented can assure the driver of satisfactory braking sense based on the braking stability,and improve energy efficiency at the same time and at last achieve optimal braG king effect.%在遵循制动力分配原则的基础上,提出了基于最佳制动效果和模糊控制的再生制动控制策略,使机械制动和再生制动可以很好地协同工作,实现前后轮制动力合理分配。设计了以制动强度和蓄电池荷电状态为输入变量,以期望再生制动力为输出变量的模糊控制器。利用仿真软件 ADVISOR,对所设计的控制策略进行了部件性能、制动能量回收、制动感觉三方面仿真分析。同时,为验证ADVISOR仿真结果的有效性,搭建了硬件在环仿真实验平台。结果表明,所设计的控制策略在保证汽车制动稳定性的前提下,能够使驾驶员获得满意的制动感觉,同时有效提高了汽车能量利用率,最终达到了最佳制动效果。

  19. New long-term braking index measurements for glitching pulsars using a glitch-template method

    Science.gov (United States)

    Espinoza, C. M.; Lyne, A. G.; Stappers, B. W.

    2017-04-01

    Braking index measurements offer the opportunity to explore the processes affecting the long-term spin evolution of pulsars and possible evolutionary connections between the various pulsar populations. In most cases, such measurements are difficult because of the presence of short-term phenomena, such as glitches and timing noise, which obscure the long-term trends. In particular, recoveries from large glitches are the main obstacle to measuring the braking indices of young pulsars like the Vela and Crab pulsars. We present a new method to overcome this problem and report on braking index measurements for the Vela-like pulsars, PSR B1800-21 and PSR B1823-13, together with an updated measurement for Vela. Additionally, the use of the method is extended to six more young glitching pulsars observed at Jodrell Bank Observatory and we are able to estimate four new braking indices. Values of braking indices describe the long-term evolution of the pulsars across the P-dot{P} diagram. Despite some measurements being affected by considerable uncertainties, there is evidence for a common trend among young glitching pulsars, characterized by low braking indices n ≤ 2. Such values introduce a new variant in the evolution of young pulsars, and their relationship with other populations in the P-dot{P} diagram, and imply that these pulsars could be a few times older than indicated by standard formulae. In this context, we analyse the case of PSR B1757-24 and conclude that the pulsar could be old enough to be related to the supernova remnant G5.4-1.2. Between glitches, the short-term evolution of Vela-like pulsars is characterized by large interglitch braking indices nig > 10. We interpret both short- and long-term trends as signatures of the large glitch activity, and speculate that they are driven by short-term post-glitch re-coupling and a cumulative long-term decoupling of superfluid to the rotation of the star.

  20. STATISTIC, PROBABILISTIC, CORRELATION AND SPECTRAL ANALYSES OF REGENERATIVE BRAKING CURRENT OF DC ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    A. V. Nikitenko

    2014-04-01

    Full Text Available Purpose. Defining and analysis of the probabilistic and spectral characteristics of random current in regenerative braking mode of DC electric rolling stock are observed in this paper. Methodology. The elements and methods of the probability theory (particularly the theory of stationary and non-stationary processes and methods of the sampling theory are used for processing of the regenerated current data arrays by PC. Findings. The regenerated current records are obtained from the locomotives and trains in Ukraine railways and trams in Poland. It was established that the current has uninterrupted and the jumping variations in time (especially in trams. For the random current in the regenerative braking mode the functions of mathematical expectation, dispersion and standard deviation are calculated. Histograms, probabilistic characteristics and correlation functions are calculated and plotted down for this current too. It was established that the current of the regenerative braking mode can be considered like the stationary and non-ergodic process. The spectral analysis of these records and “tail part” of the correlation function found weak periodical (or low-frequency components which are known like an interharmonic. Originality. Firstly, the theory of non-stationary random processes was adapted for the analysis of the recuperated current which has uninterrupted and the jumping variations in time. Secondly, the presence of interharmonics in the stochastic process of regenerated current was defined for the first time. And finally, the patterns of temporal changes of the correlation current function are defined too. This allows to reasonably apply the correlation functions method in the identification of the electric traction system devices. Practical value. The results of probabilistic and statistic analysis of the recuperated current allow to estimate the quality of recovered energy and energy quality indices of electric rolling stock in the

  1. Evaluation laterally loaded liquid of inhomogeneous trains at various mode of braking

    Directory of Open Access Journals (Sweden)

    Y. Romanyuk

    2012-12-01

    Full Text Available Problem statement. By means of mathematical modelling it is investigated longitudinal forces of non-uniform bulk trains at various ways of braking. Various schemes of formation of the bulk trains, consisting of four-axised and eight-axised tanks with various level of incomplete filling of transported liquid are considered. It is estimated the influence of level of filling of a copper of the tank by liquid on longitudinal forces of trains at braking. For the decision of the given problem the trains made from 30 four-axised and 30 eight-axised cars-tanks and one locomotive VL-8, located in the head of a train were considered. For the estimation of longitudinal forces emergency and full service braking at speeds of movement 30 km/h and 60 km/h on a horizontal site of a way were considered. At mathematical modelling it was supposed that tanks were filled by black oil in density ρ =0,99 t/m 3. Various variants of removal of the level free surface of liquid from the top internal surface of a copper of the tank were considered. The incomplete filling was accepted equal 0,4; 0,8; 1,2 metres. Scientific results. As a result of calculations diagrammes of distribution of the maximum longitudinal forces along the length of a train and brake ways for various schemes of formation and different level of incomplete filling of transported liquid have been received. Various braking of preliminary stretched and compressed trains are considered. Conclusions. The received results show that in need of driving the bulk non-uniform as cars-tanks (4- axised and 8- axised trains their formation should be made with installation of eight-axised tanks in the first half of the structure.

  2. An evaporating planet in the wind: stellar wind interactions with the radiatively braked exosphere of GJ436 b

    CERN Document Server

    Bourrier, Vincent; Ehrenreich, David; Tanaka, Yuki A; Vidotto, Aline A

    2016-01-01

    The warm Neptune GJ436b was observed with HST/STIS at three different epochs in the stellar Ly-alpha line, showing deep, repeated transits caused by a giant exosphere of neutral hydrogen. The low radiation pressure from the M-dwarf host star was shown to play a major role in the dynamics of the escaping gas. Yet by itself it cannot explain the time-variable spectral features detected in each transit. Here we investigate the combined role of radiative braking and stellar wind interactions using numerical simulations with the EVaporating Exoplanet code (EVE) and we derive atmospheric and stellar properties through the direct comparison of simulated and observed spectra. Our simulations match the last two epochs well. The observed sharp early ingresses come from the abrasion of the planetary coma by the stellar wind. Spectra observed during the transit can be produced by a dual exosphere of planetary neutrals (escaped from the upper atmosphere of the planet) and neutralized protons (created by charge-exchange wi...

  3. Composite braking control strategy of pure electric bus based on brake driving intention recognition%基于制动驾驶意图辨识的纯电动客车复合制动控制策略

    Institute of Scientific and Technical Information of China (English)

    赵轩; 马建; 汪贵平

    2014-01-01

    To research braking force distribution ratio of composite braking system for pure electric bus,a composite braking control strategy based on brake driving intention recognition was presented.A double-layer brake driving intention recognition model based on hidden Markov theory was set up and identified by using road experiment data.Based on recognized driving intention and vehicle speed,the distribution ratios of braking forces for front and rear wheels, ECE regulation, motor characteristics, slip ratios, battery characteristics, super capacitor characteristics and transmission system characteristics were taken as constraint conditions,the braking force distribution strategy of composite braking system was proposed,and the control strategy of composite braking system was simulated by Simulink software under 9 operating conditions.Simulation result shows that friction braking system and motor regenerative braking system can work coordinately and steadily under various operating conditions when the braking control strategy is applied,and braking energy can be recovered as much as possible under the premise of ensuring braking safety.Energy recovery efficiency is highest under slight brake when vehicle speed was low,and the efficiency can reach to 43 .84%.Energy recovery efficiency is lowest under emergency brake when vehicle speed is high,and the efficiency is only 0. 89%. 2 tabs,21 figs,23 refs.%为了研究纯电动客车复合制动系统制动力分配比例,提出了基于制动驾驶意图辨识的复合制动控制策略。基于隐形马尔科夫理论建立了双层制动驾驶意图辨识模型,运用道路试验数据对模型进行辨识验证。基于辨识出的驾驶意图和车速,以前后轮制动力分配比例、ECE 法规、电机特性、滑移率、蓄电池特性、超级电容特性与传动系统特性为约束条件,制定了复合制动系统制动力分配策略,在9种工况下,应用Simulink对复合制动系统进行建

  4. Assessment of the Braking Ability of Elevators and the Factors Affecting the Braking Ability%电梯制动能力的评估及影响制动能力的因素

    Institute of Scientific and Technical Information of China (English)

    王文钦

    2015-01-01

    列举了现行电梯标准和检验规则对电梯制动能力的要求,分析了3种配置不同曳引机的电梯紧急制动曲线数据,探讨了制动器制动能力的评估方法,总结了影响制动器制动能力的因素。%The requirements for elevator braking ability in the current elevator standards and inspection rules are listed. The emergency braking curve data of elevator for three kinds of conifgurations of dif erent traction machine are analyzed. The assessment methods of braking ability are discussed and the factors inlfuencing braking ability are summarized.

  5. Simulation Research on Braking Performance of Tracked Vehicle Hydraulic Energy Storage Braking System%履带车辆液压储能式制动系统制动性能仿真研究

    Institute of Scientific and Technical Information of China (English)

    赵广俊; 吕建刚; 宋彬; 滕飞

    2011-01-01

    为了实现对履带车辆制动能量的回收利用,针对某型履带车辆建立其液压储能式制动系统,分析系统工作模式;在AMESim下建立液压储能式制动系统及车辆模型,在Matlab/Simulink下建立控制系统模型;提出基于踏板行程逻辑门限值的模糊控制策略;在驾驶员不同的制动意图和系统负荷能力条件下,对履带车辆的制动工况进行联合仿真研究.结果表明,在该控制策略下液压储能式制动系统实现了对履带车辆的稳定制动和对制动能量的有效回收.%In order to achieve the tracked vehicle braking energy recovery and utilization, a certain type of tracked vehicle hydraulic energy storage braking system was established, and the working mode was analyzed. The model of hydraulic energy storage braking system and the vehicle was established in AMESim, and the control system model was established in Matlab/Simulink. Fuzzy logic control strategy based on pedal opening threshold was proposed. Under the driver's different braking intention and conditions of system load capacity, the tracked vehicle's braking process was researched under co-simulation. The results show that with the control strategy in the hydraulic energy storage braking system, the stable braking of tracked vehicle and the effective recovery of braking energy were achieved.

  6. Wheel slide protection control using a command map and Smith predictor for the pneumatic brake system of a railway vehicle

    Science.gov (United States)

    Lee, Nam-Jin; Kang, Chul-Goo

    2016-10-01

    In railway vehicles, excessive sliding or wheel locking can occur while braking because of a temporarily degraded adhesion between the wheel and the rail caused by the contaminated or wet surface of the rail. It can damage the wheel tread and affect the performance of the brake system and the safety of the railway vehicle. To safeguard the wheelset from these phenomena, almost all railway vehicles are equipped with wheel slide protection (WSP) systems. In this study, a new WSP algorithm is proposed. The features of the proposed algorithm are the use of the target sliding speed, the determination of a command for WSP valves using command maps, and compensation for the time delay in pneumatic brake systems using the Smith predictor. The proposed WSP algorithm was verified using experiments with a hardware-in-the-loop simulation system including the hardware of the pneumatic brake system.

  7. Analysis of torque transmitting behavior and wheel slip prevention control during regenerative braking for high speed EMU trains

    Science.gov (United States)

    Xu, Kun; Xu, Guo-Qing; Zheng, Chun-Hua

    2016-04-01

    The wheel-rail adhesion control for regenerative braking systems of high speed electric multiple unit trains is crucial to maintaining the stability, improving the adhesion utilization, and achieving deep energy recovery. There remain technical challenges mainly because of the nonlinear, uncertain, and varying features of wheel-rail contact conditions. This research analyzes the torque transmitting behavior during regenerative braking, and proposes a novel methodology to detect the wheel-rail adhesion stability. Then, applications to the wheel slip prevention during braking are investigated, and the optimal slip ratio control scheme is proposed, which is based on a novel optimal reference generation of the slip ratio and a robust sliding mode control. The proposed methodology achieves the optimal braking performance without the wheel-rail contact information. Numerical simulation results for uncertain slippery rails verify the effectiveness of the proposed methodology.

  8. Friction and wear studies on the temperature dependence of brake-pad materials containing brass

    Directory of Open Access Journals (Sweden)

    Eddoumy Fatima

    2013-11-01

    Full Text Available Brake pad materials for automobile applications are basically polymer matrix composites. Various reinforcing constituents used in brake pads are organic, metallic and ceramic fillers which play among others an important role on the mechanical and thermal properties, and the wear resistance at high temperature. Friction and wear depend on various parameters such as the micro-chemical structure of the pad and of the metallic counter-face, the rotation speed, the pressure, and the contact surface temperature (M.G. Jacko 1983. This latter parameter can be locally as high as 600 up to 1.500 ∘C depending on the brake type (M.G. Jacko 1983; Blau 2001. Thermal models have been developed to study interface effects at contacting surfaces (Majcherczak, Dufrenoy et al. 2007. Frictional energy can be dissipated through different mechanisms such as oxidation, rise in temperature, formation of wear particles, entropy changes associated to viscoelastic and viscoplastic deformation, and noise generation (Eddoumy, Addiego et al. 2011. Studies of friction brake show that more than 95% of the dissipated energy is transformed into heat (Kasem, Thevenet et al.; Majcherczak, Dufrenoy et al. 2007. Thermal analysis is therefore a primordial step in the study of brake systems since it provides thermo-mechanical properties (Majcherczak, Dufrenoy et al. 2007. The influence of the addition of metallic fibers on the performance of organic friction composites has been investigated using friction tests (Qu, Zhang et al. 2004. Benefits or limitations of the different fibers have been reported, however the issues of thermo-mechanical properties or effect of temperature on friction and wear behavior were not yet investigated (Bijwe, Kumar et al. 2008. No effort was done to correlate the thermo-mechanical and thermal properties with the friction and wear behavior. An important prerequisite is to get a good understanding on how brake materials behave. However, a link

  9. Engineering report. Part 2: NASA wheel and brake material tradeoff study for space shuttle type environmental requirements

    Science.gov (United States)

    Bok, L. D.

    1973-01-01

    The study included material selection and trade-off for the structural components of the wheel and brake optimizing weight vs cost and feasibility for the space shuttle type application. Analytical methods were used to determine section thickness for various materials, and a table was constructed showing weight vs. cost trade-off. The wheel and brake were further optimized by considering design philosophies that deviate from standard aircraft specifications, and designs that best utilize the materials being considered.

  10. Metro Vehicle Braking Control and Longitudinal Impact%地铁车辆制动控制与纵向冲击

    Institute of Scientific and Technical Information of China (English)

    王超

    2015-01-01

    主要介绍了地铁车辆的两个评价指标:稳定性和舒适度。列车纵向冲动是列车运行质量的关键影响因素,分析了列车减速度和纵向冲击率对于稳定性和舒适度的影响。研究地铁列车制动减速度与列车冲击率之间的关系,提出了针对地铁制动系统空气制动和复合制动的制动控制方法,通过优化制动控制策略提高了稳定性和舒适度。%This paper introduces two evaluation indexes of metro vehicles which mainly refer to stability and comfort.The longitudinal impact of train is a key influencing factor.This paper analyses the effect of train deceleration rate and longitudinal impact on the stabili-ty and comfort,studies the relationship between braking deceleration rate and impact for the metro vehicles and then proposes the bra-king controlling method of air braking and composite braking for metro braking system.The optimization of braking control is able to improve the stability and comfort.

  11. Low braking index of PSR J1734-3333: an interaction between fall-back disc and magnetic field?

    Science.gov (United States)

    Chen, Wen-Cong; Li, Xiang-Dong

    2016-01-01

    Recent timing observation reported that the radio pulsar PSR J1734-3333 with a rotating period P = 1.17 s is slowing down with a period derivative dot{P}=2.28× 10^{-12} s s^{-1}. Its derived braking index n = 0.9 ± 0.2 is the lowest value among young radio pulsars with the measured braking indices. In this Letter, we attempt to investigate the influence of the braking torque caused by the interaction between the fall-back disc and the strong magnetic field of the pulsar on the spin evolution of PSR J1734-3333. Analytical result show that this braking torque is obviously far more than that by magnetic dipole radiation for pulsars with spin period of >0.1 s, and play an important role during the spin-down of the pulsars. Our simulated results indicate that, for some typical neutron star parameters, the braking index and the period derivative approximately in agreement with the measured value of PSR J1734-3333 if the material inflow rate in the fall-back disc is 2 × 1017 g s- 1. In addition, our scenario can account for the measured braking indices of four young pulsars. However, our predicted X-ray luminosity are one to two order of magnitude higher than the observation. We proposed that this discrepancy may originate from the instability of fall-back disc.

  12. 曳引电梯制动性能分析%Analysis of the Elevator Braking Performance in Emergency

    Institute of Scientific and Technical Information of China (English)

    潘相晨

    2014-01-01

    The brakes is an important safety component of the elevator, the elevator accident caused by insufficient of braking performance happened from time to time. But the braking force is not the only factor that determines the elevator braking performance. According to the standards for the elevator braking performance, this paper analyzes the factors affecting the braking performance by creating a simple mathematical mode.%电梯制动器是电梯重要的安全部件,因电梯制动性能不足,而造成的电梯事故屡有发生。但电梯制动器制动力并不是决定电梯制动性能的唯一因素,本文依据标准对电梯制动器制动性能的要求,通过建立简单的数学模型,对影响电梯制动性能的因素进行了分析。

  13. Tribology of a Combined Yaw Bearing and Brake for Wind Turbines

    DEFF Research Database (Denmark)

    Poulios, Konstantinos

    A common goal among many countries worldwide is to increase the share of renewable energy in the overall energy supply. As response to such an aspiration, wind energy is becoming more and more cost effective through improved technology and increased size of wind turbines. One of the subsystems...... disc brake is typically included as an independent system. However, the increasing size of wind turbines makes roller element bearings an economically costly option. Moreover, the additional brake system increases complexity and consequently adds further production and maintenance costs. One...... that are affected by the tendency for building larger units, is the yaw system of horizontal axis wind turbines. State of the art wind turbine yaw systems consist of either a large roller element bearing or a corresponding segmented sliding bearing that connects the wind turbine nacelle and tower. An additional...

  14. Development of Quasi-3DOF upper limb rehabilitation system using ER brake: PLEMO-P1

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T; Fukushima, K; Furusho, J; Ozawa, T [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: kikuchi@mech.eng.osaka-u.ac.jp

    2009-02-01

    In recent years, many researchers have studied the potential of using robotics technology to assist and quantify the motor functions for neuron-rehabilitation. Some kinds of haptic devices have been developed and evaluated its efficiency with clinical tests, for example, upper limb training for patients with spasticity after stroke. However, almost all the devices are active-type (motor-driven) haptic devices and they basically require high-cost safety system compared to passive-type (brake-based) devices. In this study, we developed a new practical haptic device 'PLEMO-P1'; this system adopted ER brakes as its force generators. In this paper, the mechanism of PLEMO-P1 and its software for a reaching rehabilitation are described.

  15. Determination of minimum sample size for fault diagnosis of automobile hydraulic brake system using power analysis

    Directory of Open Access Journals (Sweden)

    V. Indira

    2015-03-01

    Full Text Available Hydraulic brake in automobile engineering is considered to be one of the important components. Condition monitoring and fault diagnosis of such a component is very essential for safety of passengers, vehicles and to minimize the unexpected maintenance time. Vibration based machine learning approach for condition monitoring of hydraulic brake system is gaining momentum. Training and testing the classifier are two important activities in the process of feature classification. This study proposes a systematic statistical method called power analysis to find the minimum number of samples required to train the classifier with statistical stability so as to get good classification accuracy. Descriptive statistical features have been used and the more contributing features have been selected by using C4.5 decision tree algorithm. The results of power analysis have also been verified using a decision tree algorithm namely, C4.5.

  16. Signal Processing for MoC brake rattle noise of moving vehicles using prony analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Cheol; Kwak, Yun Sang; Park, Jun Hong [Dept. of Mechanical Convergence Engineering, Hanyang University, Seoul (Korea, Republic of)

    2015-08-15

    To verify the possibility of generating rattling noise from a motor on caliper brake system, a test was conducted using a caliper excited with vibrations similar to that in a vehicle running on actual roads; this test was conducted using a quiet shaker installed in an anechoic room. After several hours of external excitation, the test assembly was loosened, and the frequency of rattling noise generation increased. A microphone was used to record the generated noise. The measured signals were analyzed by conventional spectrum analysis. Since the noise is generated as an impact response, the advantages of employing Prony analysis was discussed, and the results were compared to those obtained using conventional fast Fourier transforms. The accuracy of Prony analysis was through endurance tests on different brake systems.

  17. Autonomous collision avoidance system by combined control of steering and braking using geometrically optimised vehicular trajectory

    Science.gov (United States)

    Hayashi, Ryuzo; Isogai, Juzo; Raksincharoensak, Pongsathorn; Nagai, Masao

    2012-01-01

    This study proposes an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents. The proposed system prevents the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside. In the proposed system, to avoid the predicted colliding position based on constant-velocity obstacle motion assumption, the avoidance trajectory is derived as connected two identical arcs. The system then controls the vehicle autonomously by the combined control of the braking and steering systems. In this paper, the proposed system is examined by real car experiments and its effectiveness is shown from the results of the experiments.

  18. Mechanical testing and modelling of carbon-carbon composites for aircraft disc brakes

    Science.gov (United States)

    Bradley, Luke R.

    The objective of this study is to improve the understanding of the stress distributions and failure mechanisms experienced by carbon-carbon composite aircraft brake discs using finite element (FE) analyses. The project has been carried out in association with Dunlop Aerospace as an EPSRC CASE studentship. It therefore focuses on the carbon-carbon composite brake disc material produced by Dunlop Aerospace, although it is envisaged that the approach will have broader applications for modelling and mechanical testing of carbon-carbon composites in general. The disc brake material is a laminated carbon-carbon composite comprised of poly(acrylonitrile) (PAN) derived carbon fibres in a chemical vapour infiltration (CVI) deposited matrix, in which the reinforcement is present in both continuous fibre and chopped fibre forms. To pave the way for the finite element analysis, a comprehensive study of the mechanical properties of the carbon-carbon composite material was carried out. This focused largely, but not entirely, on model composite materials formulated using structural elements of the disc brake material. The strengths and moduli of these materials were measured in tension, compression and shear in several orientations. It was found that the stress-strain behaviour of the materials were linear in directions where there was some continuous fibre reinforcement, but non-linear when this was not the case. In all orientations, some degree of non-linearity was observed in the shear stress-strain response of the materials. However, this non-linearity was generally not large enough to pose a problem for the estimation of elastic moduli. Evidence was found for negative Poisson's ratio behaviour in some orientations of the material in tension. Additionally, the through-thickness properties of the composite, including interlaminar shear strength, were shown to be positively related to bulk density. The in-plane properties were mostly unrelated to bulk density over the range of

  19. Thermomechanical Simulation of Wear and Hot Bands in a Disc Brake by Adopting an Eulerian Approach

    OpenAIRE

    Rashid, Asim; Strömberg, Niclas

    2013-01-01

    In this paper frictional heating of a disc brake is simulated while taking wear into account. By performing thermomechanical finite element analysis, it is studied how the wear history will influence the development of hot bands. The frictional heat analysis is based on an Eulerian formulation of the disc, which requires significantly lower computational time as compared to a standard Lagrangian approach. A real disc-pad system to a heavy truck is considered, where complete three-dimensional ...

  20. Braking index of isolated pulsars. II. A novel two-dipole model of pulsar magnetism

    Science.gov (United States)

    Hamil, O.; Stone, N. J.; Stone, J. R.

    2016-09-01

    The magnetic dipole radiation model is currently the best approach we have to explain pulsar radiation. However, a most characteristic parameter of the observed radiation, the braking index nobs , shows deviations for all the eight best studied isolated pulsars, from the simple model prediction ndip=3 . The index depends upon the rotational frequency and its first and second time derivatives but also on the assumption that the magnetic dipole moment and inclination angle and the moment of inertia of the pulsar are constant in time. In a recent paper [Phys. Rev. D 91, 063007 (2015)], we showed conclusively that changes in the moment of inertia with frequency alone cannot explain the observed braking indices. Possible observational evidence for the magnetic dipole moment migrating away from the rotational axis at a rate α ˙ ˜0.6 ° per 100 years over the lifetime of the Crab pulsar has been recently suggested by Lyne et al. In this paper, we explore the magnetic dipole radiation model with constant moment of inertia and magnetic dipole moment but variable inclination angle α . We first discuss the effect of the variation of α on the observed braking indices and show they all can be understood. However, no explanation for the origin of the change in α is provided. After discussion of the possible source(s) of magnetism in pulsars, we propose a simple mechanism for the change in α based on a toy model in which the magnetic structure in pulsars consists of two interacting dipoles. We show that such a system can explain the Crab observation and the measured braking indices.

  1. Flatness-based model inverse for feed-forward braking control

    Science.gov (United States)

    de Vries, Edwin; Fehn, Achim; Rixen, Daniel

    2010-12-01

    For modern cars an increasing number of driver assistance systems have been developed. Some of these systems interfere/assist with the braking of a car. Here, a brake actuation algorithm for each individual wheel that can respond to both driver inputs and artificial vehicle deceleration set points is developed. The algorithm consists of a feed-forward control that ensures, within the modelled system plant, the optimal behaviour of the vehicle. For the quarter-car model with LuGre-tyre behavioural model, an inverse model can be derived using v x as the 'flat output', that is, the input for the inverse model. A number of time derivatives of the flat output are required to calculate the model input, brake torque. Polynomial trajectory planning provides the needed time derivatives of the deceleration request. The transition time of the planning can be adjusted to meet actuator constraints. It is shown that the output of the trajectory planning would ripple and introduce a time delay when a gradual continuous increase of deceleration is requested by the driver. Derivative filters are then considered: the Bessel filter provides the best symmetry in its step response. A filter of same order and with negative real-poles is also used, exhibiting no overshoot nor ringing. For these reasons, the 'real-poles' filter would be preferred over the Bessel filter. The half-car model can be used to predict the change in normal load on the front and rear axle due to the pitching of the vehicle. The anticipated dynamic variation of the wheel load can be included in the inverse model, even though it is based on a quarter-car. Brake force distribution proportional to normal load is established. It provides more natural and simpler equations than a fixed force ratio strategy.

  2. Cumulative asbestos exposure for US automobile mechanics involved in brake repair (circa 1950s-2000).

    Science.gov (United States)

    Finley, Brent L; Richter, Richard O; Mowat, Fionna S; Mlynarek, Steve; Paustenbach, Dennis J; Warmerdam, John M; Sheehan, Patrick J

    2007-11-01

    We analyzed cumulative lifetime exposure to chrysotile asbestos experienced by brake mechanics in the US during the period 1950-2000. Using Monte Carlo methods, cumulative exposures were calculated using the distribution of 8-h time-weighted average exposure concentrations for brake mechanics and the distribution of job tenure data for automobile mechanics. The median estimated cumulative exposures for these mechanics, as predicted by three probabilistic models, ranged from 0.16 to 0.41 fibers per cubic centimeter (f/cm(3)) year for facilities with no dust-control procedures (1970s), and from 0.010 to 0.012 f/cm(3) year for those employing engineering controls (1980s). Upper-bound (95%) estimates for the 1970s and 1980s were 1.96 to 2.79 and 0.07-0.10 f/cm(3) year, respectively. These estimates for US brake mechanics are consistent with, but generally slightly lower than, those reported for European mechanics. The values are all substantially lower than the cumulative exposure of 4.5 f/cm(3) year associated with occupational exposure to 0.1 f/cm(3) of asbestos for 45 years that is currently permitted under the current occupational exposure limits in the US. Cumulative exposures were usually about 100- to 1,000-fold less than those of other occupational groups with asbestos exposure for similar time periods. The cumulative lifetime exposure estimates presented here, combined with the negative epidemiology data for brake mechanics, could be used to refine the risk assessments for chrysotile-exposed populations.

  3. Modeling and Simulation of integrated steering and braking control for vehicle active safety system

    Directory of Open Access Journals (Sweden)

    Beibei Zhang

    2011-03-01

    Full Text Available Active chassis systems like braking, steering, suspension and propulsion systems are increasingly entering the market. In addition to their basic functions, these systems may be used for functions of integrated vehicle dynamics control. An experimental platform which aims to study the integration control of steering and braking is designed due to the research requirement of vehicle active safety control strategy in this paper. A test vehicle which is equipped with the systems of steer-by-wire and brake-bywire is provided and the Autobox, combined with Matlab/simulink and MSCCarsim, is used to fulfill the RCP (Rapid Control Prototyping and HIL (Hardware-in-loop. The seven-freedom vehicle model is constructed first and the approach of vehicle parameters estimation based on the Extended Kalman Filter (EKF is proposed. Testing the vehicle state through the sensor has its own disadvantage that the cost is high and easily affected by environment outside. To find a actual method of receiving the vehicle state using the ready-made sensors in vehicle, the researchers put forward various estimation method, of which have advantages and disadvantages. Based on the above, this paper applies the EKF to estimate the vehicle state, making the actual estimation come true. The primary control methods and controller designment is carried out to prove the validation of the platform.

  4. Optimization of Tribological Properties of Nonasbestos Brake Pad Material by Using Steel Wool

    Directory of Open Access Journals (Sweden)

    R. Vijay

    2013-01-01

    Full Text Available The gradual phasing out of typical brake pad material led to the spark of extensive research in development of alternatives. Henceforth we have performed a tribological study to improve the performance characteristics of the friction product (brake pad by using steel wool, a metallic material which has an excellent structural reinforcement property and high thermal stability which are indeed required to improve the performance of the brake pad. Under the study, five frictional composites were developed and optimized using the same ingredients in an appropriate proportion except steel wool (0%, 4%, 8%, 12%, and 16% which is compensated by synthetic barite, and the synthesized compositions are designated as Na01 to Na05. The developed pads are tested for tribological behaviour under conventional environment in a standard pin on disc tribometer. It is observed that increase in steel wool concentration resulted in high coefficient of friction and low wear rate of pad as resulted in Na05 composition. SEM analysis of the wear surface has proved to be useful in understanding the wear behaviour of the composites.

  5. A statistical approach to estimate the LYAPUNOV spectrum in disc brake squeal

    Science.gov (United States)

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

    2015-01-01

    The estimation of squeal propensity of a brake system from the prediction of unstable vibration modes using the linear complex eigenvalue analysis (CEA) in the frequency domain has its fair share of successes and failures. While the CEA is almost standard practice for the automotive industry, time domain methods and the estimation of LYAPUNOV spectra have not received much attention in brake squeal analyses. One reason is the challenge in estimating the true LYAPUNOV exponents and their discrimination against spurious ones in experimental data. A novel method based on the application of the ECKMANN-RUELLE matrices is proposed here to estimate LYAPUNOV exponents by using noise in a statistical procedure. It is validated with respect to parameter variations and dimension estimates. By counting the number of non-overlapping confidence intervals for LYAPUNOV exponent distributions obtained by moving a window of increasing size over bootstrapped same-length estimates of an observation function, a dispersion measure's width is calculated and fed into a BAYESIAN beta-binomial model. Results obtained using this method for benchmark models of white and pink noise as well as the classical HENON map indicate that true LYAPUNOV exponents can be isolated from spurious ones with high confidence. The method is then applied to accelerometer and microphone data obtained from brake squeal tests. Estimated LYAPUNOV exponents indicate that the pad's out-of-plane vibration behaves quasi-periodically on the brink to chaos while the microphone's squeal signal remains periodic.

  6. Active vibration control of multibody system with quick startup and brake based on active damping

    Institute of Scientific and Technical Information of China (English)

    TANG Hua-ping; TANG Yun-jun; TAO Gong-an

    2006-01-01

    A kind of active vibration control method was presented based on active damping and optimization design for driving load of multibody system with quick startup and brake. Dynamical equation of multibody system with quick startup and brake and piezoelectric actuators intelligent structure was built. The optimum driving load was calculated by applying the presented method. The self-sensing and self-tuning closed-loop active vibration control in quick startup and brake process was realized. The control algorithm, using local velocity negative feedback, i.e. the output of a sensor only affects the output of the actuator collocated, can induce damping effectively to actively suppress the system vibration. Based on the optimization design for driving load of multibody system with quick startup and bake, the active damping of piezoelectric actuators intelligent structure was used to farther suppress the vibration of system. Theoretical analysis and calculation of numerical show that the proposed method makes the vibration of system decrease more than the optimal design method for driving load of multibody system.

  7. Mycorrhizae increase arsenic uptake by the hyperaccumulator Chinese brake fern (Pteris vittata L.).

    Science.gov (United States)

    Al Agely, Abid; Sylvia, David M; Ma, Lena Q

    2005-01-01

    Chinese brake fern (Pteris vittata L.) is a hyperaccumulator of arsenic (As) that grows naturally on soils in the southern United States. It is reasonable to expect that mycorrhizal symbiosis may be involved in As uptake by this fern. This is because arbuscular mycorrhizal (AM) fungi have a well-documented role in increasing plant phosphorus (P) uptake, P and As have similar chemical properties, and ferns are known to be colonized by AM fungi. We conducted a factorial greenhouse experiment with three levels of As (0, 50, and 100 mg kg(-1)) and P (0, 25, and 50 mg kg(-1)) and with and without Chinese brake fern colonized by a community of AM fungi from an As-contaminated site. We found that the AM fungi not only tolerated As amendment, but their presence increased frond dry mass at the highest As application rate. Furthermore, the AM fungi increased As uptake across a range of P levels, while P uptake was generally increased only when there was no As amendment. These data indicate that AM fungi have an important role in arsenic accumulation by Chinese brake fern. Therefore, to effectively phytoremediate As-contaminated soils, the mycorrhizal status of ferns needs to be taken into account.

  8. Synthesis and characterization of magneto-rheological (MR fluids for MR brake application

    Directory of Open Access Journals (Sweden)

    Bhau K. Kumbhar

    2015-09-01

    Full Text Available Magneto rheological (MR fluid technology has been proven for many industrial applications like shock absorbers, actuators, etc. MR fluid is a smart material whose rheological characteristics change rapidly and can be controlled easily in presence of an applied magnetic field. MR brake is a device to transmit torque by the shear stress of MR fluid. However, MR fluids exhibit yield stress of 50–90 kPa. In this research, an effort has been made to synthesize MR fluid sample/s which will typically meet the requirements of MR brake applications. In this study, various electrolytic and carbonyl iron powder based MR fluids have been synthesized by mixing grease as a stabilizer, oleic acid as an antifriction additive and gaur gum powder as a surface coating to reduce agglomeration of the MR fluid. MR fluid samples based on sunflower oil, which is bio-degradable, environmentally friendly and abundantly available have also been synthesized. These MR fluid samples are characterized for determination of magnetic, morphological and rheological properties. This study helps identify most suitable localized MR fluid meant for MR brake application.

  9. A SVM framework for fault detection of the braking system in a high speed train

    Science.gov (United States)

    Liu, Jie; Li, Yan-Fu; Zio, Enrico

    2017-03-01

    In April 2015, the number of operating High Speed Trains (HSTs) in the world has reached 3603. An efficient, effective and very reliable braking system is evidently very critical for trains running at a speed around 300 km/h. Failure of a highly reliable braking system is a rare event and, consequently, informative recorded data on fault conditions are scarce. This renders the fault detection problem a classification problem with highly unbalanced data. In this paper, a Support Vector Machine (SVM) framework, including feature selection, feature vector selection, model construction and decision boundary optimization, is proposed for tackling this problem. Feature vector selection can largely reduce the data size and, thus, the computational burden. The constructed model is a modified version of the least square SVM, in which a higher cost is assigned to the error of classification of faulty conditions than the error of classification of normal conditions. The proposed framework is successfully validated on a number of public unbalanced datasets. Then, it is applied for the fault detection of braking systems in HST: in comparison with several SVM approaches for unbalanced datasets, the proposed framework gives better results.

  10. The braking index of PSR J1734-3333 and the magnetar population

    CERN Document Server

    Espinoza, Cristobal M; Kramer, Michael; Manchester, Richard N; Kaspi, Victoria

    2011-01-01

    PSR J1734-3333 is a radio pulsar rotating with a period P=1.17 s and slowing down with a period derivative Pdot=2.28 x 10^{-12}, the third largest among rotation-powered pulsars. These properties are midway between those of normal rotation-powered pulsars and magnetars, two populations of neutron stars that are notably different in their emission properties. Here we report on the measurement of the second period derivative of the rotation of PSR J1734-3333 and calculate a braking index n=0.9 +- 0.2. This value is well below 3, the value expected for an electromagnetic braking due to a constant magnetic dipole, and indicates that this pulsar may soon have the rotational properties of a magnetar. While there are several mechanisms which could lead to such a low braking index, we discuss this observation, together with the properties exhibited by some other high-Pdot rotation-powered pulsars, and interpret it as evidence of a possible evolutionary route for magnetars through a radio-pulsar phase, supporting a un...

  11. Braking of tearing mode rotation by ferromagnetic conducting walls in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, Richard [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712-1203 (United States)

    2015-09-15

    An in-depth investigation of the braking of tearing mode rotation in tokamak plasmas via eddy currents induced in external ferromagnetic conducting structures is performed. In general, there is a “forbidden band” of tearing mode rotation frequencies that separates a branch of high-frequency solutions from a branch of low-frequency solutions. When a high-frequency solution crosses the upper boundary of the forbidden band, there is a bifurcation to a low-frequency solution, and vice versa. The bifurcation thresholds predicted by simple torque-balance theory (which takes into account the electromagnetic braking torque acting on the plasma, as well as the plasma viscous restoring torque, but neglects plasma inertia) are found to be essentially the same as those predicted by more complicated time-dependent mode braking theory (which takes inertia into account). Significant ferromagnetism causes otherwise electromagnetically thin conducting structures to become electromagnetically thick and also markedly decreases the critical tearing mode amplitude above which the mode “locks” to the conducting structures (i.e., the high-frequency to low-frequency bifurcation is triggered). On the other hand, if the ferromagnetism becomes too large, then the forbidden band of mode rotation frequencies is suppressed, and the mode frequency consequently varies smoothly and reversibly with the mode amplitude.

  12. Hardware simulation of automatic braking system based on fuzzy logic control

    Directory of Open Access Journals (Sweden)

    Noor Cholis Basjaruddin

    2016-07-01

    Full Text Available In certain situations, a moving or stationary object can be a barrier for a vehicle. People and vehicles crossing could potentially get hit by a vehicle. Objects around roads as sidewalks, road separator, power poles, and railroad gates are also a potential source of danger when the driver is inattentive in driving the vehicle. A device that can help the driver to brake automatically is known as Automatic Braking System (ABS. ABS is a part of the Advanced Driver Assistance Systems (ADAS, which is a device designed to assist the driver in driving the process. This device was developed to reduce human error that is a major cause of traffic accidents. This paper presents the design of ABS based on fuzzy logic which is simulated in hardware by using a remote control car. The inputs of fuzzy logic are the speed and distance of the object in front of the vehicle, while the output of fuzzy logic is the intensity of braking. The test results on the three variations of speed: slow-speed, medium-speed, and high-speed shows that the design of ABS can work according to design.

  13. Evaluation of palm kernel fibers (PKFs for production of asbestos-free automotive brake pads

    Directory of Open Access Journals (Sweden)

    K.K. Ikpambese

    2016-01-01

    Full Text Available In this study, asbestos-free automotive brake pads produced from palm kernel fibers with epoxy-resin binder was evaluated. Resins varied in formulations and properties such as friction coefficient, wear rate, hardness test, porosity, noise level, temperature, specific gravity, stopping time, moisture effects, surface roughness, oil and water absorptions rates, and microstructure examination were investigated. Other basic engineering properties of mechanical overload, thermal deformation fading behaviour shear strength, cracking resistance, over-heat recovery, and effect on rotor disc, caliper pressure, pad grip effect and pad dusting effect were also investigated. The results obtained indicated that the wear rate, coefficient of friction, noise level, temperature, and stopping time of the produced brake pads increased as the speed increases. The results also show that porosity, hardness, moisture content, specific gravity, surface roughness, and oil and water absorption rates remained constant with increase in speed. The result of microstructure examination revealed that worm surfaces were characterized by abrasion wear where the asperities were ploughed thereby exposing the white region of palm kernel fibers, thus increasing the smoothness of the friction materials. Sample S6 with composition of 40% epoxy-resin, 10% palm wastes, 6% Al2O3, 29% graphite, and 15% calcium carbonate gave better properties. The result indicated that palm kernel fibers can be effectively used as a replacement for asbestos in brake pad production.

  14. SELECTED PARAMETERS OF THE WORK OF SPEED LIMITER IN LINE STRAINING SYSTEM IN A FRICTIONAL LIFT

    Directory of Open Access Journals (Sweden)

    Paweł Lonkwic

    2014-03-01

    Full Text Available The article presents the analysis of selected work parameters of speed limiter in line straining system. We analyzed the effect of changing the geometrical conditions of the new solution for the speed limiter in line straining system upon the working conditions in frictional lift braking system. Within the conducted simulations of the work of the system, which is responsible for lift braking with a tension with spring, a test bed was prepared, which simulated the work of tension-rope-limiter system. The tests were performed in the conditions reflecting the work of a lifting appliance. Analyzing the results obtained through empirical calculations, we can conclude that there is a possibility of applying the spring to eliminate the weight.

  15. 弹性盘型制动闸片装置振动特性研究%On Vibration Characteristics of Elastic Disc Brake Pad Device

    Institute of Scientific and Technical Information of China (English)

    杨宽; 张济民

    2013-01-01

    设计了一种新型的具有弹性的盘型制动闸片装置,建立了低速的轨道车辆弹性盘型制动的数学模型,与无弹性的制动闸片进行了单轴制动特性的动态仿真比较.仿真结果表明,具有弹性的闸片制动时同样能够保证车辆的制动性能;在制动盘或闸片摩擦面有缺陷时,弹性闸片能有效降低闸片与制动盘间摩擦力引起的振动.该设计为盘型制动系统的设计及分析提供了新的思路.%A new elastic disc brake pad device is designed, and a mathematical model on low speed railway vehicle e-lastic disc brake is established to compare with the non-elastic brake pad by single wheel-set braking simulation. The result shows that the elastic brake pad can guarantee the vehicle braking performance as same as the non-elastic brake pad. When the disc or the friction surface of brake pad has some defects, elastic brake pad can effectively reduce the friction and the vibration between the brake pad and the brake disc. The design has been proved to be correct and rational, it will provide new ideas for the design and analysis of the disc brake system.

  16. Fiscal Policy and Rebalancing in the Euro Area: A Critique of the German Debt Brake from a Post-Keynesian Perspective

    OpenAIRE

    Hein Eckhard; Truger Achim

    2014-01-01

    The German debt brake is often regarded as a great success story and has therefore served as a role model for the Euro area and it’s Fiscal Compact. In this paper we fundamentally criticise the debt brake. Firstly, we show that it suffers from serious shortcomings and that its success is far from certain even from a mainstream point of view. Secondly, we show that, from a Post-Keynesian perspective, the debt brake completely neglects the requirements for fi...

  17. Calculation of Temperature Fields of Electric Locomotive Wheels during Emergency Braking on Tangent Track at a Speed of 200 km/h

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    According to the heat transfer theory, an unsteady-state heat transfer model of electric locomotive wheels during emergency braking on tangent track at a speed of 200 km/h has been established in this paper. The explicit finite difference method is used in the numerical calculation of temperature fields of wheels. From the calculation results, the determination of braking distance and the material choice of brake shoes are discussed.

  18. 基于 Amesim 的整车制动系统建模与仿真%Braking System Model and Simulation Based on Amesim

    Institute of Scientific and Technical Information of China (English)

    王权; 周飞虎; 岳海姣

    2014-01-01

    In this paper , the structure program of the vehicle braking system is designed and its structure and working principle are also described .Based on the Amesim , the vehicle braking system model is established from the pedal , control system , the wheels and to the body .The model is used to simulate the braking process of three braking conditions such as the slight braking , conventional braking and emergency braking when the displacement of the vehicle braking pedal is at 30 mm, 40 mm and 50 mm respectively .The result shows that the result of simulation is consistent with the theoretical calculation and that the braking system model can accurately simulate the vehicle braking process , provide the theoretical basis for the developing the vehicle braking system , and shorten the development period of the braking system .%设计整车制动系统的结构方案,阐述其结构和工作原理。基于Amesim建立整车制动系统模型,通过该模型仿真汽车在制动踏板位移分别为30,40,50 mm时,分别进行轻微制动、常规制动与紧急制动等3种制动工况的制动过程,结果表明:仿真结果与理论计算一致,该制动系统模型可以准确的模拟汽车的制动过程,给汽车制动系统的研发提供理论依据,可缩短制动系统的研发周期。

  19. Chain of impact of the development of hot spots and hot rubbing in disk brakes of passenger cars; Wirkungskette der Entstehung von Hotspots und Heissrubbeln in Pkw-Scheibenbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Sarda, Angelo

    2009-07-01

    Aspects coupled with brake comfort represent challenges with the development of brake systems. During the brake process, so-called hot spots on the surface of brake disks are developed under certain conditions. These hot spots result in an irregular thermal expansion and deformation of the brake disk. This results in vibrations impacting the comfort and being known as 'hot rubbing'. The author of the contribution under consideration describes the most important results from extensive benchmark tests and supplies experimentally secured realizations to the chain of impact of the development of hot spots and 'hot rubbing' in a disc brake.

  20. 修井机盘式制动器模态分析%Mode Analysis of Disc Brakes in Workover Rig

    Institute of Scientific and Technical Information of China (English)

    李连峰; 高栋梁; 隋秀伟; 喇红云; 康文彬

    2011-01-01

    阐述了修井机盘式制动器的制动原理,通过对其有限元模型的简化,对制动盘制动时可能出现的抖动情况进行模态分析,并提出相应的改进措施,避免机构在实际过程中发生共振.%The Workover disc brake braking principle is described, using its finite element model of simplified, brake disc braking possible jitter analysis for mode, and appropriate measures to avoid bodies in the actual process of resonance is proposed.