WorldWideScience

Sample records for brake lines

  1. 49 CFR 393.44 - Front brake lines, protection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Front brake lines, protection. 393.44 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.44 Front brake lines, protection. On every bus, if... any of the front wheels is broken, the driver can apply the brakes on the rear wheels despite such...

  2. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

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

  3. Research to longevity brake lines on the exploitations

    Directory of Open Access Journals (Sweden)

    Sergey TUJRIN

    2015-08-01

    Full Text Available Brake lines are tested for strength and durability. However, tests of strength are short-term, but tests of durability are durable, since their aim is to assess the effectiveness of the brake linings during operation. Therefore, reduction of time evaluating the durability of brake linings exploitation is urgent. The article describes the results of the research on the longevity of the brake linings of different types of vehicles based on their controllable operation and the method of accelerated estimation of the longevity of brake linings based on the operation of their analogues

  4. Asbestos exposure during routine brake lining manufacture.

    Science.gov (United States)

    Kakooei, Hossein; Sameti, Mahmod; Kakooei, Ali Akbar

    2007-12-01

    Occupational exposure to asbestos fiber and total dust of workers of a major brake lining manufacture plant in a developing country were examined and compared with those in developed countries. Time weighted average of total dust and asbestos fiber concentration in the potential sources of exposure were monitored. All personal air sampling were collected on membrane filters and analyzed by phase contrast optical microscopy (PCM) for comparison with the occupational safety and health administration (OSHA) permissible exposure limit (PEL) of 0.1 f/cc, 8-h time--weighted average. This study demonstrates that routine mixing, polishing and beveling process in the brake lining production can result in elevated levels of airborne asbestos. Greater releases of airborne asbestos were observed during mixing process and mixer machine. The results also showed that the employees working in the process had the exposure to total dust concentrations ranging from 2.08 to 16.32 mg/m(3) that is higher than OSHA, recommendation. According to OSHA definition of fibers, it has been indicated that from 3,000 counted particles, 90% of particles are in the form of non-fiber and reaming have fiber-shaped. The particle analyze gives the geometric mean diameter as 6.02 mum, and also indicated that the arithmetic mean of the number distribution for the particle population was 8.4 mum. Approximately 60.4% of the counted fibers were lower than 10 mum in length, from which only 8% consists of fibers (>5 mum in length). In conclusion, the analysis showed a presence in the air of only chrysotile asbestos and an absence of other types of asbestos. During an 8-h shift, the average asbestos fiber exposure (0.78 f/cc) were 7.8 time in excess of OSHA PEL. Additional studies in occupational exposure to asbestos are needed.

  5. Research to longevity brake lines on the exploitations

    National Research Council Canada - National Science Library

    Sergey TUJRIN; Grigory BOYKO; Alexander REVIN; Vitaliy FEDOTOV

    2015-01-01

    .... The article describes the results of the research on the longevity of the brake linings of different types of vehicles based on their controllable operation and the method of accelerated estimation...

  6. 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.

  7. Development of fly ash-based automotive brake lining

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, S.; Chugh, Y.P. [South Illinois University, Carbondale, IL (United States). College of Engineering

    2007-07-15

    Coal-fired power plants all over the world generate huge amounts of fly ash each year, 70 million tons of which are produced in the United States alone. Only 40% of all fly ashes generated in the USA find beneficial applications and rest have to be disposed off, which is burden for the generation industry. Fly ash particles possess certain characteristics that make them suitable for use in friction composites as a filter material. An attempt has been made through this research to incorporate more than 50wt% of fly ash particles in automotive brake lining friction composites. This paper presents the research carried out on development of friction composites, using fly ash obtained from a specific power plant in Illinois. Ingredients such as phenolic resin, aramid pulp, glass fiber, potassium titanate, graphite, aluminum fiber and copper powder were used in the composite development phase, in addition to the fly ash. The developed brake lining composites have exhibited consistent coefficients of friction in the range of 0.35-0.4, and wear rates lower than 12wt%.

  8. 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

  9. Study of the mechanical properties of hybrid composite basalt / alumina / shells for brake lining pads

    Science.gov (United States)

    Adi Atmika, I. K.; Ary Subagia, IDG.; Surata, I. W.; Sutantra, I. N.

    2017-05-01

    Brake lining pad as one of the active safety components in motor vehicles has been studied thoroughly. Asbestos is the main material forming the brake in addition to other alloy materials that have a negative impact on health and the environment. This paper explain the behavior of hybrid composites phenolic resin with basalt/alumina/clamshell powder reinforced on brake lining pad. This materials has been manufactured use compaction and sintering process through any steps, that an emphasis of 2,000 kg for 30 minutes at a constant temperature of 150° C. The research aims to investigate hardness characteristic of hybrid composite that test using the vickers according to standard ASTM E-384. The reinforced materials and phenolic resin composition is 60%: 40%. The results show for the average hardness VHN to 24.18, 25.11, 26.34, 27.21 and 28.83. The average hardness hybrid composite shows the hardness harder than asbestos materials.

  10. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Science.gov (United States)

    2010-10-01

    ... SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.47 Brake actuators... physical characteristics must provide for safe and reliable stopping of the commercial motor vehicle. (b....6 mm (1/16 inch) or less for hydraulic disc, drum and electric brakes. (2) Non-steering axle brakes...

  11. 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'. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  12. Boric acid effect in phenolic composites on tribological properties in brake linings

    Energy Technology Data Exchange (ETDEWEB)

    Mutlu, I. [AKU Technical Education Faculty, Afyon (Turkey); Oner, C. [Firat University, Technical Education Faculty, Elazig (Turkey); Findik, F. [Sakarya University, Technical Education Faculty, Kampus, Adapazari (Turkey)]. E-mail: findik@sakarya.edu.tr

    2007-07-01

    In the present work, using a pad-on-disc-type wear tester, the tribological properties of the pad next to the disk made of cast iron were investigated with changing the substance of the components. As well, micro-structural characterisation of braking pads was performed using scanning electron microscopy and also temperature outcome of the pads was examined at the temperatures of 50-400 {sup o}C in the pressure of 1050 and 3000 kPa. Finally, the effect of environment to the pads was studied in water, salty water, oil and braking liquid media.

  13. 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.

  14. THE STUDY OF THE TEMPERATURE OF THE HEATING DISC BRAKES OF PASSENGER CAR DURING THE ADJUSTING THE BRAKING

    Directory of Open Access Journals (Sweden)

    Yu. . Ya. Vodiannikov

    2007-11-01

    Full Text Available Results of research of the brake disk heating temperature under the brake shoe lining during the regulating braking of a passenger train are presented. It is established that the greatest temperature in the disk arises at an exit of a brake shoe lining on a direction of the wheel pair rotation, and its value depends on pressure in the brake cylinder (correlation factor 0.556 and braking time (correlation factor 0.331, the correlation factor for speed in the beginning of regulating braking was equal to 0.135.

  15. 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

  16. TGV disc brake squeal

    Science.gov (United States)

    Lorang, X.; Foy-Margiocchi, F.; Nguyen, Q. S.; Gautier, P. E.

    2006-06-01

    The discomfort generated by the noise emission of braking systems in trains has aroused recently many studies on the mechanical modelling of brake noise in France. A theoretical and numerical discussion on the phenomenon of brake squeal is given in this paper in relation with some experimental data. This study is based upon a flutter instability analysis giving unstable modes of the brake system under the contact and Coulomb friction.

  17. Roller Locking Brake

    Science.gov (United States)

    Vranish, John M.

    1993-01-01

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

  18. 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.

  19. XXVI. International {mu} symposium - brake conference; XXVI. Internationales {mu}-Symposium - Bremsen-Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, B. (ed.)

    2006-07-01

    The progress of brake technology contributes consistently and considerably to the safety of vehicle occupants, but also to the prevention of vehicle collisions with pedestrians and bikers. The symposia of the {mu} club have for 25 years informed the attendees about the latest findings, methods, developments and products in the field of brakes and promoted the exchange of information and the personal interaction between the experts in many brake related disciplines. Topics of the XXVI{sup th} {mu} symposium are innovation and processes in the field of brake rotors, methods to assess their irregular wear, the determination of the value of friction between brake pads and brakes, an innovative self reinforced disc brake with electronic control, regenerative braking in hybrid vehicles and the fascination of innovation. This year's papers are presented by four brake manufacturers, one brake linings manufacturer and one university. (orig.)

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

    National Research Council Canada - National Science Library

    Dalimus, Zaini

    2014-01-01

    .... 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...

  1. BRAKE DISC PRODUCTION IS OPTIMIZATION POSSIBLE?

    Directory of Open Access Journals (Sweden)

    M. Colditz

    2015-01-01

    Full Text Available The article compares different aspects of brake disc production using vertically parted flaskless molding lines and horizontal parted tight flask molding lines. In the first section the vertical molding process demonstrates advantages in terms of investment costs. Furthermore, annual energy consumption of the molding lines in relation to castings produced is discussed, again demonstrating clear benefits from the Disamatic-technology. In the second section a comparison between two molding technologies for the production of brake discs is made on the basis of production data from the South Korean foundry Hyundai Sungwoo. The Disamatic molding process, however, offers advantages in terms of tooling costs and energy consumption.

  2. Wind Braking of Magnetars

    Science.gov (United States)

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

    2013-05-01

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

  3. 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

  4. 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.

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

    National Research Council Canada - National Science Library

    2008-01-01

    .... Major factors to be considered in the evaluation of vehicle braking systems are stopping and grade holding ability, vehicle stability and control during brake applications, and individual braking...

  6. 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.

  7. Indonesian commercial bus drum brake system temperature model

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-29

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

  8. 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 functional...

  9. Transnet regenerative braking concept definition

    CSIR Research Space (South Africa)

    Giesler, Achmed

    2015-09-01

    Full Text Available Transnet has shown an interest in the concept of regenerative braking on their freight trains. Regenerative braking is the capturing, storing and re-using energy currently being wasted during regenerative braking. Currently all the energy is dumped...

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

    OpenAIRE

    Guodong Yin; XianJian Jin

    2013-01-01

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

  11. 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.

  12. 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.

  13. A Transient Dynamic Model of Brake Corner and Subsystems for Brake Creep Groan Analysis

    Directory of Open Access Journals (Sweden)

    Dejian Meng

    2017-01-01

    Full Text Available To improve the understanding of brake creep groan, both experimental and numerical studies are conducted in this paper. Based on a vehicle road test under the condition of downhill, complicated stick-slip type motion of caliper and its correlation with the interior noise were analyzed. In order to duplicate these brake creep groan phenomena, a transient dynamic model including brake corner and subsystems was established using finite element method. In the model, brake components were considered to be flexible body, and the subsystems including driveline, suspension, tire, and vehicle body were considered to be rigid body. Simulation and experimental results of caliper vibration in time and frequency domains were compared. It was demonstrated that the new model is effective for the prediction and analysis of brake creep groan, and it has higher accuracy compared to the previous model without the subsystems. It is also found that the lining and caliper not only have stick-slip motion in each coordinate direction but also have translational and torsional movements in plane, which relate to the microscopic sticking and slipping, friction coefficient, and forces, as well as the contact status at the friction interface.

  14. Hydraulic brake-system for a bicycle

    NARCIS (Netherlands)

    Van Frankenhuyzen, J.

    2007-01-01

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

  15. 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.

  16. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Vacuum brake assist unit and vacuum brake system... Vehicles With GVWR of More Than 10,000 Pounds § 570.56 Vacuum brake assist unit and vacuum brake system. The following requirements apply to vehicles with vacuum brake assist units and vacuum brake systems...

  17. CO-Ordinated Action Design of Rheostatic and Air Brakes on the Electric Railcar Series 6 111

    Directory of Open Access Journals (Sweden)

    Josip Zavada

    2012-10-01

    Full Text Available The paper presents the solution for the modification of thebrakes on the electric railcar series 6111 used in suburban traffic.It also gives the results of the performed measurements aswell as their analysis.The mentioned electric railcar is fitted with air and rheostaticbrakes whose activation is mutually independent. Sincesuburban traffic means frequent slopping, and since the enginedriver does not use the rheostatic brake regularly, but only theair brake, the wear of the brake lining and wheels is higher, andthe heat load on the brake elements is substantial. By regularapplication of rheostatic brake, the air brake could be LLSed lessthus contributing to a lower wear of the friction elements.The presented solution for the modification of the brakeconsists of co-ordinated and automatic action of the rheostaticand air brake with every braking

  18. Thermal Characterisation of Brake Pads

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  19. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

    ... constructed so that: (1) If any electrical, pneumatic, hydraulic, or mechanical connecting or transmitting element fails, or if any single source of hydraulic or other brake operating energy supply is lost, it is... hydraulic system following a failure in, or in the vicinity of, the brakes is insufficient to cause or...

  20. 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

  1. Anti-lock brake system: an assessment of training on driver effectiveness.

    Science.gov (United States)

    Mollenhauer, M A; Dingus, T A; Carney, C; Hankey, J M; Jahns, S

    1997-01-01

    When activated correctly, Anti-Lock Brake Systems (ABS) can provide drivers with the ability to stop a vehicle in shorter distances and allow for more vehicle control under heavy braking than conventional brake systems. This is especially true under wet or icy road conditions. However, it is believed that many drivers are either unaware of the correct method of activation or they revert back to the old method of pumping the brakes when they are faced with a hard braking situation. This paper examines the effectiveness of implementing low-cost training methods for alerting drivers to the correct brake activation technique. A 4-page, color training pamphlet was developed and subjects were given a short period of time to read it over before being asked to drive on an icy test track. Results indicated that those subjects who received the training were able to stop in shorter distances in a straight line braking event and more often used the correct brake activation technique than those subjects who did not receive the training. However, the stopping distance benefits were not realized in the curved and surprise braking events. These results suggest that the transfer of verbal knowledge may have value as a means for solving the apparent problem of improper ABS usage. However, some additional research should be done to validate these results. Since this experiment was conducted directly after the material was read, the possibility exists that without reinforcement, the trained braking techniques might become extinct in a short period of time.

  2. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... 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 the... train is operating under worst-case adhesion conditions. (b) The brake system shall be designed to allow...

  3. 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.

  4. Mountain Braking Test Venue Study

    Science.gov (United States)

    2013-12-12

    FMVSS 105 Inertia Brake Dynamometer Test Procedure for vehicles above 4 540 kg GVWR; FMVSS Test Sequence, 2nd Fade Section,” November 2011.(15) Scope...Test Brake Temperature and Speed The U.S. Department of Defense Army Tank Purchase Description 2354A (ATPD-2354A) includes dynamometer test...11, March 1992. [12] "Performance Requirements for Determining Tow -Vehicle Gross Combination Weight Rating and Trailer Weight Rating", SAE Surface

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

    OpenAIRE

    He, Ren; Hu, Donghai

    2015-01-01

    Since theoretical guidance is lacking in the design and control of the integrated system of electromagnetic brake and frictional brake, this paper aims to solve this problem and explores the nonlinear coupling characteristics and dynamic characteristics of the integrated system of electromagnetic brake and frictional brake. This paper uses the power bond graph method to establish nonlinear coupling mathematical model of the integrated system of electromagnetic brake and frictional brake and c...

  6. Experimental Research on Brake Squeal

    Science.gov (United States)

    Wallner, Daniel; Bernsteiner, Stefan

    Since many years experimental researches have been performed in order to get an insight into the issue of brake squeal. This work presents an innovative test setup for analyzing friction-excited vibrations and squeal triggering mechanisms. The investigated brake system showed brake squeal issues at certain operating points. The purpose was to analyse the brake system in detail on a test rig. Because the well-known methods of investigation such as laser vibrometer were not possible, the aim was to develop and generate new measuring points, which are close to the contact area of disc and pad. Therefore the brake calliper has been modified; hence the guide are replaced by modified ones. At these pins the friction force can be measured. Because of an optimized shape it is possible to measure the vibration of the friction force. The measured signal correlates with a parallel measured microphone signal. Next the brake disc will be assembled with triaxial accelerometers. Thus it is possible to determine the operating deflection shape of the disc. With the results of this work a new contact algorithm should be developed which can be used e.g. in Finite Element calculations.

  7. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    WINTEC

    friction and anti-wear characteristics along with provid- ing high temperature stability. The constituents used in the composite are extremely economical and are hence ap- propriate for industrial applications. The resins used in the composite are priced in the range of $2⋅5 to $3 per kg while the fillers in the range of $0⋅25 ...

  8. THE EFFECT OF HEAT VARIATION ON DIFFERENT BRAKE DISK BRAKING FORCES

    Directory of Open Access Journals (Sweden)

    Mesut DÜZGÜN

    2009-01-01

    Full Text Available In this study, two different ventilated brake discs were manufactured and their braking force performances and heat generations were investigated experimentally together with a solid disc. Braking force outputs were examined in sudden and continuous braking conditions and disc temperatures were simply measured in continuous braking conditions. Fourteen pedal forces were used in sudden braking tests and eight periodic measurements were executed in continuous braking tests. Experiment results showed that ventilation applications not only increased the brake force outputs up to 42.6 %, but also reduced the heat formation on discs up to 31.5 % depending on test conditions.

  9. Thermal analysis on motorcycle disc brake geometry

    Science.gov (United States)

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

    2017-08-01

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

  10. 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.

  11. Brake System Analysis, Reliability Testing And Control Using Bench Experiments

    OpenAIRE

    Xu, Z.; Yang, B.

    1997-01-01

    In this project, the authors investigated the dynamics and reliability of a brake control system using a test bench which is a Lincoln Town Car brake system. The objectives of the project are to: 1) experimentally characterize the brake system; 2) obtain good nonlinear models of the brake system; 3) perform reliability analysis of the brake control system; and, 4) develop algorithms for brake malfunction detection and brake reliability enhancement. By using the brake test bench, the dynamic c...

  12. 49 CFR 393.41 - Parking brake system.

    Science.gov (United States)

    2010-10-01

    ... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles... road (free of ice and snow). Hydraulic-braked vehicles which were not subject to the parking brake... spring action. If other energy is used to apply the parking brake, there must be an accumulation of that...

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    O. Je. Nishhenko

    2009-06-01

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

  15. A Demonstration of Car Braking Instabilities.

    Science.gov (United States)

    Irwin, Jack; Swinson, Derek

    1990-01-01

    Detailed are the construction of a demonstration car, apparatus and procedures used in the demonstration, and the analysis of the effects of car braking. The cases of rear-wheel and front-wheel braking are considered. (CW)

  16. 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.

  17. 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...

  18. BRAKING OF HIGH-SPEED PASSENGER TRAINS WITH REGARD TO THE OPERATION OF AN ELECTROMAGNETIC RAIL BRAKE

    Directory of Open Access Journals (Sweden)

    N. Je. Naumenko

    2009-03-01

    Full Text Available The research of the braking process of high-speed passenger train with the use of compressed-air, electropneumatic and electromagnetic track brakes is carried out. The dependences of braking distance on motion speed for vehicles equipped by block or disk brakes as well as for a case of electromagnetic track brakes used in addition to existing braking means.

  19. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake system. 238.231 Section 238.231... Equipment § 238.231 Brake system. Except as otherwise provided in this section, on or after September 9... train's primary brake system shall be capable of stopping the train with a service application from its...

  20. MATHEMATICAL MODELING OF DYNAMICS BRAKING BIAXIAL TROLLEYBUS

    Directory of Open Access Journals (Sweden)

    K. I. Mazanik

    2014-01-01

    Full Text Available The article describes the questions of braking of trolleybus by working braking system with connected and disconnected electric drive motor. Main constructive differences of trolleybuses are shown including characteristics of electric drive motor in the mode of braking. Methods of road test are given. Comparison of the theoretical and experimental  research has analyzed. 

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Guodong Yin

    2013-01-01

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

  3. Brake blending strategy for a hybrid vehicle

    Science.gov (United States)

    Boberg, Evan S.

    2000-12-05

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

  4. 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.

  5. Oxygen-Diffused Titanium as a Candidate Brake Rotor Material

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

    2009-01-01

    Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

  6. 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

  7. Utilisation of optimisation solutions to control active suspension for decreased braking distance

    Science.gov (United States)

    Edrén, Johannes; Jonasson, Mats; Jerrelind, Jenny; Stensson Trigell, Annika; Drugge, Lars

    2015-02-01

    This work deals with how to utilise active suspension on individual vehicle wheels in order to improve the vehicle performance during straight-line braking. Through numerical optimisation, solutions have been found as regards how active suspension should be controlled and coordinated with friction brakes to shorten the braking distance. The results show that, for the studied vehicle, the braking distance can be shortened by more than 1 m when braking from 100 km/h. The applicability of these results is studied by investigating the approach for different vehicle speeds and actuator stroke limitations. It is shown that substantial improvements in the braking distance can also be found for lower velocities, and that the actuator strokes are an important parameter. To investigate the potential of implementing these findings in a real vehicle, a validated detailed vehicle model equipped with active struts is analysed. Simplified control laws, appropriate for on-board implementation and based on knowledge of the optimised solution, are proposed and evaluated. The results show that substantial improvements of the braking ability, and thus safety, can be made using this simplified approach. Particle model simulations have been made to explain the underlying physical mechanisms and limitations of the approach. These results provide valuable guidance on how active suspension can be used to achieve significant improvements in vehicle performance with reasonable complexity and energy consumption.

  8. 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.

  9. Increasing reliability of braking systems in mine hoisting machines

    Energy Technology Data Exchange (ETDEWEB)

    Shapovalov, N.I.; Kurchenko, E.M.

    1980-05-01

    This article reviews the braking systems used in hoisting machines in vertical and inclined shafts in coal mines. Braking systems used in hoisting machines can generally be divided into two groups: lack of pressure in the braking system cylinder turns on the brakes, or lack of pressure turns the brakes off. Manual operation of the braking system can sometimes create problems as sudden movement of the brake lever into position, i.e. braking, causes intensive braking with all its negative consequences for the installation. Therefore, an electric device is presented which can be included in the electric circuit of the braking system. A scheme of the apparatus is shown. When the proposed apparatus is included in the electric control system of the brakes, moving the lever into position i.e. braking, causes gradual changes in the flow of electric current, and therefore braking is smoother. (In Russian)

  10. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Science.gov (United States)

    2010-10-01

    ... with other than an AB, ABD, ABDX, 26-C, or equivalent brake system. (e) Cab cars. The brake equipment... schedule: (1) Every 1,476 days for that portion of the cab car brake system using brake valves that are identical to the passenger coach 26-C brake system; (2) Every 1,104 days for that portion of the cab car...

  11. 49 CFR 393.40 - Required brake systems.

    Science.gov (United States)

    2010-10-01

    ... NECESSARY FOR SAFE OPERATION Brakes § 393.40 Required brake systems. (a) Each commercial motor vehicle must have brakes adequate to stop and hold the vehicle or combination of motor vehicles. Each commercial..., and 393.52 of this subpart. (4) Electric brake systems. Motor vehicles equipped with electric brake...

  12. 49 CFR 230.77 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

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

  13. New material technologies for brakes

    Energy Technology Data Exchange (ETDEWEB)

    Haug, T.; Rebstock, K.

    2000-07-01

    Brake discs made of grey cast iron are produced today in large quantities in seconds clock pulse. In spite of less tolerance and greater quality demands, extremely small unit costs are realised. On the one hand, the reason for this may be found in the low prices of the raw materials, refined production technology and large production numbers. On the other hand, the technical potential of grey cast-iron has essentially been exhausted. For further technical innovations in the area of brakes, new materials such as Al-MMC and CMC play an important role. The potential has already been demonstrated. In part an assembly installation has already been successful (see rail traffic) or will be shortly (see SLR at the IAA 99). The main hindrance to further assembly installation of a large number of items is the high installation costs. Therefore, in the future, along with the reduction of raw material costs (for example, C-Fibre) the main direction that will need to be taken to further reduce production costs, wil have to be in the realisation of a production technology with reliable processes suitable for large volumes. Otherwise, alternative brake disc material will only have a reduced significance. (orig.)

  14. 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.

  15. Coefficient of Friction of a Brake Disc-Brake Pad Friction Couple

    National Research Council Canada - National Science Library

    A.W. Orłowicz; M. Mróz; G. Wnuk; O. Markowska; W. Homik; B. Kolbusz

    2016-01-01

    The paper concerns evaluation of the coefficient of friction characterising a friction couple comprising a commercial brake disc cast of flake graphite grey iron and a typical brake pad for passenger motor car...

  16. Talking about the Automobile Braking System

    Science.gov (United States)

    Xu, Zhiqiang

    2017-12-01

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

  17. STUDY REGARDING THE CAR BRAKE DISC TEMPERATURE VARIATION DURING THE LENGTHY BRAKING

    OpenAIRE

    DRAGOMIR George; PANCU Rares; MITRAN Tudor Adrian; GEORGESCU Liviu; MOCA Sorin; CHIOREANU Catalin

    2015-01-01

    When a car descends a slope with a great length, the thermal stresses resulting from contact between the brake discs and brake pads, there is possible to exceed the maximal limits of the materials resistance, resulting the rapid wear, decreasing performance of braking or the loss control of movement and the road accidents are producing. The study refers to establishment the dependence between the braking intensity and time when the temperature achieves a maximum limit ...

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

    OpenAIRE

    Guoshun Wang; Rong Fu

    2013-01-01

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

  19. STUDY REGARDING THE CAR BRAKE DISC TEMPERATURE VARIATION DURING THE LENGTHY BRAKING

    OpenAIRE

    DRAGOMIR George; PANCU Rares; MITRAN Tudor Adrian; GEORGESCU Liviu

    2015-01-01

    When a car descends a slope with a great length, the thermal stresses resulting from contact between the brake discs and brake pads, there is possible to exceed the maximal limits of the materials resistance, resulting the rapid wear, decreasing the performance of braking or the loss control of movement and the road accidents are producing. The study refers to establishment the dependence between the braking intensity and time when the temperature achieves a the maximu...

  20. XXIX. International {mu} symposium. Brake conference; XXIX. Internationales {mu}-Symposium. Bremsen-Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, Bert (ed.)

    2010-07-01

    The future of the car is in intensive research for decreasing fuel consumption (mile-age) thus reducing CO{sub 2} emissions and leading to the stabilisation of our climate and the introduction of electrification of road vehicle drive systems. In many cases this also applies to the brake system, that being the main topic of our conference this year. This year's programme will highlight this topic from various angles with speeches about lithium ion technology, the impact on brake linings of the future, brake discs in a lightweight environment, friction materials on rail vehicles, the ''Formula Student'' racing cars, and the influence of future vehicle architectures over the brake system. (orig.)

  1. 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…

  2. Laboratory Scale Testing of Thermoelectric Regenerative Braking System

    National Research Council Canada - National Science Library

    P Sevvel; I S Stephan Thangaiah; S Mars Mukesh; G Mohammed Anif

    2015-01-01

      Thermoelectric Regenerative Braking System (TERBS) employs an energy recovery mechanism by utilizing the energy conversion at the time of braking in an automobile to generate electricity accordingly...

  3. Safety of winder disc brakes - a structural approach

    Energy Technology Data Exchange (ETDEWEB)

    Brodzinski, S.

    1986-01-01

    Analyzes reliability and safety of ASEA disc brakes installed in Polish mine hoist winding units. A theoretical assessment of disc brake safety is made; reliability diagrams for disc brake systems are established. A calculation example of safety assessment is also given, i.e. probability of brake failure of systems equipped with one or two pairs of brake discs. Furthermore, dangerous brake failures are explained as due to oil contaminations originating from hydraulic element leakage. Probability of failure of one-disk or two-disc brake systems is also determined. Schemes of the ASEA hydraulic disc brake system as well as working assembly and control assembly reliability diagrams are provided. 11 refs.

  4. Forecasting temperature fluctuations of brake discs on a hoisting machine

    Energy Technology Data Exchange (ETDEWEB)

    Barecki, Z.; Jankowski, A.

    1987-01-01

    Evaluates a method for forecasting temperature of brake discs on hoists used in underground coal mines. Formulae describing the following phenomena are derived: energy of mechanical braking, density of energy stream absorbed by the friction liners on disc brakes, temperature increase of a disc brake caused by braking, disc cooling intensity, disc temperature during repeated braking, minimum disc mass and surface. Use of the forecasting formulae is explained with the example of disc brake operation on 2 hoists. Temperature increase on disc surface and temperature increase of disc volume are treated as 2 basic indices characterizing disc brake operation. 11 refs.

  5. 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.

  6. Avoidance of brake squeal by a separation of the brake disc's eigenfrequencies: A structural optimization problem

    OpenAIRE

    Wagner, Andreas

    2013-01-01

    Brake squeal is a high-pitched noise in the frequency range between 1 kHz and 16 kHz originating from self-excited vibrations caused by the frictional contact between brake pads and brake disc. Since some decades, it has intensively been studied and many countermeasures have been proposed, including active and passive methods. It is known from experiments and has also been proved mathematically that splitting the eigenfrequencies of the brake rotor has a stabilizing effect and avoids brake sq...

  7. 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%.

  8. 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.

  9. New technical solutions of using rolling stock electrodynamical braking

    Directory of Open Access Journals (Sweden)

    Leonas Povilas LINGAITIS

    2009-01-01

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

  10. 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.

  11. Automotive brake wear: a review.

    Science.gov (United States)

    Wahid, Syed M S

    2018-01-01

    Road transport systems generate toxic particulate matter (PM) when in motion, that ultimately finds its way to the atmosphere. The PM produced by road transport systems can be broadly classified as exhaust and non-exhaust emissions. Exhaust emission is primarily due to product of combustion, as is the case of internal combustion engines and the PM is released to the atmosphere through the tail. Non-exhaust PM sources can be classified as sources such as emissions due to brake wear, tyre wear, road surface wear and resuspension. Both exhaust and non-exhaust sources generate PM of various sizes and shapes that has an impact on our health. Strict legislations by authorities have led to reduced exhaust emissions; however, due to the nature of complexity of PM generation by non-exhaust sources, effective control of non-exhaust emission still needs to be developed. Thus, as exhaust emissions are being controlled, non-exhaust is becoming a significant source of PM emission. The present paper reviews work done by previous researchers on non-exhaust PM and specifically, brake wear from road transport systems as this is one of the most important non-exhaust source of PM in the environment. The finding of the paper would be beneficial to policy makers and researchers.

  12. 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.

  13. 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.

  14. 49 CFR 232.305 - Single car air brake tests.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Single car air brake tests. 232.305 Section 232... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER... car air brake tests. (a) Single car air brake tests shall be performed by a qualified person in...

  15. 49 CFR 238.313 - Class I brake test.

    Science.gov (United States)

    2010-10-01

    ... side of each car's brake system responds properly to application and release signals; (2) The brake... applied on each car in the train until a release of the brakes has been initiated on each car in response... operating two-way radio system meets this requirement; (5) Each brake shoe or pad is securely fastened and...

  16. PROVIDING STABLE FRICTION PROPERTIES OF DISC BRAKES FOR RAILWAY VEHICLES

    Directory of Open Access Journals (Sweden)

    Yuri Y. OSENIN

    2017-04-01

    Full Text Available A new approach is developed to ensure the stability of the coefficient of friction at different braking modes for the entire speed range of braking high-speed ground transport. The new approach is a combination of friction materials with individual effort effects on the brake disc. A brake pad design and its performance are confirmed experimentally.

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

    African Journals Online (AJOL)

    Olive oil was used as the positive control while sodium azide served as the negative control. The results obtained showed the following rate of biodegradability in fresh water and marine water; Total brake fluid (20, 2.3 percent), Allied brake fluid (40%, 1%), Oando brake fluid (44%, 2.5%), and Ate brake fluid (13.3%, 2.1%).

  18. Dynamic analysis of three autoventilated disc brakes

    Directory of Open Access Journals (Sweden)

    Ricardo A. García-León

    2017-09-01

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

  19. Statistical analysis of brake squeal noise

    Science.gov (United States)

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

    2011-06-01

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

  20. Screw-released roller brake

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1999-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ren He

    2015-01-01

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

  2. Combined braking system for hybrid vehicle

    Science.gov (United States)

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

    2017-10-01

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

  3. 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.

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, J M [Instituto Superior de Engenharia de Lisboa, Avenida Conselheiro EmIdio Navarro 1, 1959-007 Lisboa (Portugal)], E-mail: jtavares@dem.isel.ipl.pt

    2009-07-15

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

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

    Science.gov (United States)

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

    2017-07-21

    Real-world cycling performance depends not only on exercise capacities, but also on efficiently traversing the bicycle through the terrain. The aim of this study was to determine if it was possible to quantify the braking done by a cyclist in the field. One cyclist performed 408 braking trials (348 on a flat road; 60 on a flat dirt path) over 5 days on a bicycle fitted with brake torque and angular velocity sensors to measure brake power. Based on Newtonian physics, the sum of brake work, aerodynamic drag and rolling resistance was compared with the change in kinetic energy in each braking event. Strong linear relationships between the total energy removed from the bicycle-rider system through braking and the change in kinetic energy were observed on the tar-sealed road (r2 = 0.989; p torque and angular velocity sensors are valid for calculating brake power on the disc brakes of a bicycle in field conditions. Such a device may be useful for investigating cyclists' ability to traverse through various terrains.

  7. 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.

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

    Science.gov (United States)

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

    2015-09-01

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

  9. LINES

    Directory of Open Access Journals (Sweden)

    Minas Bakalchev

    2015-10-01

    Full Text Available The perception of elements in a system often creates their interdependence, interconditionality, and suppression. The lines from a basic geometrical element have become the model of a reductive world based on isolation according to certain criteria such as function, structure, and social organization. Their traces are experienced in the contemporary world as fragments or ruins of a system of domination of an assumed hierarchical unity. How can one release oneself from such dependence or determinism? How can the lines become less “systematic” and forms more autonomous, and less reductive? How is a form released from modernistic determinism on the new controversial ground? How can these elements or forms of representation become forms of action in the present complex world? In this paper, the meaning of lines through the ideas of Le Corbusier, Leonidov, Picasso, and Hitchcock is presented. Spatial research was made through a series of examples arising from the projects of the architectural studio “Residential Transformations”, which was a backbone for mapping the possibilities ranging from playfulness to exactness, as tactics of transformation in the different contexts of the contemporary world.

  10. 30 CFR 57.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... carrying hazardous loads, such as explosives. (ii) The approach shall be of sufficient length to allow the... upon other available evidence to determine whether the service brake system meets the performance...

  11. 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...

  12. Method and apparatus for wind turbine braking

    Science.gov (United States)

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

    2009-02-10

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

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

    Science.gov (United States)

    2008-05-20

    are as follows: a. Micrometer calipers (inside, outside, and dial types). b. Surface finish gauges. c. Torque wrench. d. Brake shoe...HAZARDOUS CONDITION • The power assist unit fails to operate. 10. Front Drum Brakes Procedure: Equipment needed: Steel scale or Vernier ... Micrometer and dial indicator. Reject the vehicle if: • Rotors are broken or damaged, or cracks on the surface extend to the outer edges. • Two grooves

  14. Automated visual inspection of brake shoe wear

    Science.gov (United States)

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

    2015-10-01

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

  15. Design of high performance CMC brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Krenkel, W.; Henke, T. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Stuttgart (Germany)

    1999-03-01

    Ceramic matrix composite (CMC) materials based on 2D-carbon fibre preforms show high heat-absorption capacities and good tribological as well as thermomechanical properties. To take advantage of the full lightweight potential of these new materials in high performance automotive brake discs, the thermal conductivity transverse to the friction surface has to be high in order to reduce the surface temperature. Experimental tests showed, that lower surface temperatures prevent overheating of the brake`s periphery and stabilizes the friction behaviour. In this study different design approaches with improved transverse heat conductivity have been investigated by finite element analysis. C/C-SiC bolts as well as SiC coatings and combinations of them have been investigated and compared with an orthotropic brake disc, showing a reduction of temperature of up to 50%. Original sized brake discs with C/C-SiC have been manufactured and tested under real conditions which verified the calculations. Using only low-cost CMC materials and avoiding any additional processing steps, the potential of C/C-SiC brake discs are very attractive under tribological as well as under economical aspects. (orig.) 4 refs.

  16. Thermal/Mechanical Measurement and Modeling of Bicycle Disc Brakes

    Directory of Open Access Journals (Sweden)

    Ioan Feier

    2018-02-01

    Full Text Available Brake induced heating has become more difficult to control as bicycle component mass has been reduced. High-power braking with insufficient cooling or thermal capacitance can create excessive temperatures, boiling brake fluid, performance degradation, and damage. To better understand component heating, a disc braking dynamometer has been constructed with a motor driven disc, hydraulic braking, and a miniature wind tunnel. Disc temperatures are studied for various braking scenarios using infrared techniques and thermocouples. A transient, numerical, MATLAB, lumped parameter thermal/mechanical model is created to predict the impact of key design parameters on braking performance and to understand the heat loss mechanisms from the brake system components. Computational fluid dynamics (CFD simulations are used to estimate the disc surface convective cooling coefficients for the model. The final model provides transient temperature predictions based on bicycle velocity and braking power, and successfully matches dynamometer experimental data.

  17. FC TIP-BRAKE. Development of a novel aerodynamic brake for the FC-4000; FC TIP-BRAKE. Entwicklung einer neuartigen aerodynamischen brems fuer die FC-4000

    Energy Technology Data Exchange (ETDEWEB)

    Grohs, C. von [Gesamthochschule Kassel, Universitaet, Kassel (Germany)

    1993-09-01

    A novel brake has been developed for the FC-4000 WindMotor. The FC Tip Brake has been tested on this wind turbine and a computer program for structural improvements has been introduced. A comparison of the previous tip brake construction and the new one is given. (EG)

  18. ABOUT WAVEFORM OF BRAKING CYLINDER FILLING IN FREIGHT CARS

    Directory of Open Access Journals (Sweden)

    L. V. Ursuliak

    2016-04-01

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

  19. Dynamic analysis and control of an anti-lock brake system for a motorcycle with a camber angle

    Science.gov (United States)

    Huang, C. K.; Shih, M. C.

    2011-04-01

    This paper analyses the dynamic response of a motorcycle with an anti-lock brake system (ABS) and camber or steering angle. Most studies have assumed that motorcycles brake in a straight line - that is, without a steering or camber angle. In this work, the performance of an ABS modulator is designed and analysed at first. Then, a controller is designed for motorcycle turning. The controller uses angular acceleration and the pressure value in brake calipers on the front and rear wheels, camber angle and lateral acceleration as commands to control brake pressure on each wheel to prevent wheel locking. The equation of motion for a motorcycle is based on Weir's equations. This motorcycle model combines a mathematical equation of the ABS modulator, tyre model and controller in simulations.

  20. Electromagnetic brake/clutch device

    Science.gov (United States)

    Vranish, John M.

    1994-01-01

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

  1. Backup Mechanical Brake System of the Wind Turbine

    Science.gov (United States)

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

    2018-01-01

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

  2. [Asbestos risk in the textile industry: braking systems on machinery used until the 1990's].

    Science.gov (United States)

    Chiappino, G; Pellissetti, D; Moretto, O; Picchi, Ornella

    2005-01-01

    We recently described asbestos risk in the non-asbestos textile industry as the result of fibre dispersion from ceilings, pipe insulation and machines. The widespread use of brakes with asbestos linings on the machines as well as other functional details were considered for a proper evaluation of their role in producing atmospheric pollution All the information was collected on the basis of the personal technical experience of two of the Authors and by direct observation of the machines. All the textile machines (ring spinning, twisting, warping, winding, looms) used until the 1990's were without exception equipped with asbestos-lined mechanical brakes. The heavy action required produced relatively rapid wear of the linings and the dust produced was spread into the atmosphere by the continuous action of the "travelling blowing cleaners" and by the daily cleaning of the machines using compressed air at the end of the shift: violent air blowing undoubtedly caused redispersion of the fine dust from the brakes and also acted as a mechanical grinder on the bundles that sedimented on the machines from the ceilings and pipes, producing more ultrathin respirable fibres. the contribution of textile machinery to atmospheric pollution by asbestos fibres was significant and due both to the widespread use of brakes with asbestos-containing materials and to the continuous action on the machines of compressed air blowers. Asbestos pollution was certainly high in all the factories so that in the near future still further mesothelioma cases among ex-workers are to be expected.

  3. Evaluation of Squeal Noise from the WMATA Transit Car Disc Brake System : A Preliminary Investigation

    Science.gov (United States)

    1981-03-01

    The Washington Metropolitan Area Transit Authority (WMATA) rail transit car design adopted the use of disc brakes as the primary friction braking system. Unfortunately, while disc brakes are more efficient than the traditional tread brake designs, th...

  4. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R.

    1995-01-01

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

  5. Fully regenerative braking and improved acceleration for electrical vehicles

    OpenAIRE

    Melis, Wim J.C.; Chishty, Owais

    2013-01-01

    Generally, car brake systems use hydraulic brake technology, which converts the excess of kinetic energy into heat, effectively resulting in an energy loss. Regenerative braking technology focuses on converting this kinetic energy of the decelerating vehicle back into electrical energy that can then be reused for example during acceleration. Current hybrid vehicles are equipped with such regenerative braking technology, which makes them particularly interesting for situations with frequent de...

  6. 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...

  7. Regenerative Intelligent Brake Control for Electric Motorcycles

    Directory of Open Access Journals (Sweden)

    Juan Jesús Castillo Aguilar

    2017-10-01

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

  8. Brake squeal: Linear and nonlinear numerical approaches

    Science.gov (United States)

    Massi, Francesco; Baillet, Laurent; Giannini, Oliviero; Sestieri, Aldo

    2007-08-01

    "Brake squeal" groups a large set of high-frequency sound emissions from brake systems. They are generated during the braking phase and are characterized by a harmonic spectrum. The onset of squeal is due to an unstable behaviour occurring in linear conditions during the braking phase, and a general approach used by several authors to determine the system instabilities is the complex eigenvalues analysis. When the brake begins to squeal, the response of the system reaches a new limit cycle where the linear models cannot be used anymore. This paper presents the integration of two different numerical procedures to identify the mechanism bringing to squeal instability and to analyse its dynamics. The first approach is a finite element modal analysis of the brake system and is used to identify its eigenvalues and to relate them to the squeal occurrence. The second one is a specific finite element programme, Plast3, appropriate for nonlinear dynamic analyses in the time domain and is particularly addressed to study contact problems with friction between deformable bodies. This programme computes the contact stresses and permits to determine the dynamics of the system along the contact surface, both in the linear and nonlinear fields. The two models are compared and the onset of squeal is predicted both in the frequency domain by the linear model and in the time domain by the nonlinear one. The instability predictions, obtained by the two models, are discussed. To simplify the dynamics of its components, the study is carried out on a simple model, made of a disc, a small friction pad and a beam supporting the pad. The geometry of the model is related to an experimental set-up used to validate the models and to compare the numerical results with the experiments.

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

    Directory of Open Access Journals (Sweden)

    О. Sarayev

    2015-07-01

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

  10. Automating friction-testing automotive brake pads

    Energy Technology Data Exchange (ETDEWEB)

    Drews, R.; Schwarz, U.

    1984-06-01

    Friction-testing machines are used in the development of brake pad materials and for quality assurance. Automation was applied to three friction-testing machines operated in parallel in order to obtain evidence of consistent, reproducible test condition. The new system avoids lengthy manual evaluation periods coupled with the risk of errors. Other benefits are the ability to draw up test programs more easily and to implement modern evaluation techniques. One can expect friction-testing machines' area of application to be enlarged in the near future to include determination of the wet friction values and corrosion resistance of brake discs and pads.

  11. 49 CFR 393.48 - Brakes to be operative.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Brakes to be operative. 393.48 Section 393.48 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... NECESSARY FOR SAFE OPERATION Brakes § 393.48 Brakes to be operative. (a) General rule. Except as provided in...

  12. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ... the following tests. (1) Roller-type or drive-on platform tests. The force applied by the brake on a... shall be tested on a drive-on platform, or a roller-type brake analyzer with the capability of measuring... 49 Transportation 6 2010-10-01 2010-10-01 false Service brake system. 570.59 Section 570.59...

  13. 49 CFR 570.6 - Brake power unit.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Brake power unit. 570.6 Section 570.6... Pounds or Less § 570.6 Brake power unit. (a) Vacuum hoses shall not be collapsed, abraded, broken... brake pedal, the pedal shall fall slightly when the engine is started, demonstrating integrity of the...

  14. 30 CFR 77.1401 - Automatic controls and brakes.

    Science.gov (United States)

    2010-07-01

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

  15. 30 CFR 56.14102 - Brakes for rail equipment.

    Science.gov (United States)

    2010-07-01

    ... Equipment Safety Devices and Maintenance Requirements § 56.14102 Brakes for rail equipment. Braking systems on railroad cars and locomotives shall be maintained in functional condition. ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Brakes for rail equipment. 56.14102 Section 56...

  16. 49 CFR 232.215 - Transfer train brake tests.

    Science.gov (United States)

    2010-10-01

    ... coupled between all freight cars; (2) After the brake system is charged to not less than 60 psi as... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER NON-PASSENGER... reduction shall be made; and (3) An inspection shall be made to determine that the brakes on each car apply...

  17. 30 CFR 57.14102 - Brakes for rail equipment.

    Science.gov (United States)

    2010-07-01

    ... Equipment Safety Devices and Maintenance Requirements § 57.14102 Brakes for rail equipment. Braking systems on railroad cars and locomotives shall be maintained in functional condition. ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Brakes for rail equipment. 57.14102 Section 57...

  18. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

    ... and release of the brakes on the last car in the train; and (6) The communicating signal system is... be used to verify the set and release on cars so equipped. However, the observation of the brake... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake test. 238.315 Section 238.315...

  19. 49 CFR 238.319 - Running brake test.

    Science.gov (United States)

    2010-10-01

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

  20. 49 CFR 229.57 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

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

  1. 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 devices...

  2. 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

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

    National Research Council Canada - National Science Library

    О. Sarayev

    2015-01-01

    .... For the first time in relation to the modern models of vehicles equipped with anti-lock brakes there were obtained regression models describing the relationship between the coefficient of traction...

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

    Science.gov (United States)

    Wolny, Stanisław

    2017-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Jin Hua-wei

    2017-01-01

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

  6. 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.

  7. BRAKING PROCESS OF ENDURO AND HIGHWAY-TOURIST MOTORBIKES

    OpenAIRE

    Paweł SKRZYPCZYK; Robert KAŁUŻA; Piotr CZECH

    2015-01-01

    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.

  8. Use of elastomers in regenerative braking systems

    Science.gov (United States)

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

  9. 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.

  10. Performance requirements for locomotive braking systems

    CSIR Research Space (South Africa)

    Vermaak, P

    2000-02-01

    Full Text Available of underground locomotives, excluding those used on high speed main haulages. In addition a survey was carried out on the most widely used types of locomotives and the braking systems. The survey gave an insight into the knowledge of the mine personnel...

  11. Braking Distance of Hoist Conveyances Required for Safe Stopping Under the Conditions of Emergency Braking

    Science.gov (United States)

    Wolny, Stanisław

    2017-06-01

    This study investigates selected aspects of the dynamic behaviour of mine hoists during the emergency braking in an event of overtravel. Characteristics of the braking force that needs to be applied in the headgear and in the pit bottom to arrest the conveyance in the event of an overtravel are derived from laboratory and industrial test data and recalling the results reported in literature. The real hoist installation is replaced by a model whereby the equations of motion of rope elements are written as for elastic strings, taking into account the variable length of the hoisting rope section between the Koepe pulley and the conveyance being arrested in the head tower. Analytical formulas are provided whereby the displacement of the top conveyance with the payload for the constant elasticity coefficient of the hoisting rope section between the conveyance being arrested in the head tower and the Koepe pulley is expressed as the function of the braking force and of the operational parameters of the hoist gear. The hoist operation is investigated in the event of emergency braking, taking into account the two aspects of the cycle: - the time required for the conveyance to be stopped, - the distance travelled by the conveyance until it is stopped. The results of the dynamic analysis of the hoist installation in the conditions of emergency braking may be utilised in selection of the effective and adequate braking system guaranteeing the safety of the system operation.

  12. 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.

  13. Pedestrian injury mitigation by autonomous braking.

    Science.gov (United States)

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

    2010-11-01

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

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

    Directory of Open Access Journals (Sweden)

    I. Nazarov

    2016-12-01

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

  15. A Thermo-elastic Annular Plate Model for the Modeling of Brake Systems

    OpenAIRE

    Reyes Perez, Jose Luis; Heckmann, Andreas; Kaiser, Ingo

    2011-01-01

    The friction forces generated during braking between brake pads and discs produce high thermal gradients on the rubbing surfaces. These thermal gradients may cause braking problems such as brake fade, premature wear or hot spotting and the associated hot judder phenomenon in the frequency range below 100 Hz. Further consequences are comfort reductions, a defective braking process, inhomogeneous wear, cutbacks of the brake performance and even damage of brake components. The presen...

  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. 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.

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

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2016-01-01

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

  19. 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.

  20. 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.

  1. Thermal analysis of disc brakes using finite element method

    Science.gov (United States)

    Jaenudin, Jamari, J.; Tauviqirrahman, M.

    2017-01-01

    Disc brakes are components of a vehicle that serve to slow or stop the rotation of the wheel. This paper discusses the phenomenon of heat distribution on the brake disc during braking. Heat distribution on the brake disc is caused by kinetic energy changing into mechanical energy. Energy changes occur during the braking process due to friction between the surface of the disc and a disc pad. The temperature resulting from this friction rises high. This thermal analysis on brake discs is aimed to evaluate the performance of an electric car in the braking process. The aim of this study is to analyze the thermal behavior of the brake discs using the Finite Element Method (FEM) through examining the heat distribution on the brake disc using 3-D modeling. Results obtained from the FEM reflect the effects of high heat due to the friction between the disc pad with the disc rotor. Results of the simulation study are used to identify the effect of the heat distribution that occurred during the braking process.

  2. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Science.gov (United States)

    2010-10-01

    ...) A freight car equipped with an ECP brake system that is known to have arrived with ineffective or... in a train operating in ECP brake mode. (f) A freight car equipped with an ECP brake system that is... pneumatic brakes shall not operate with freight cars equipped with stand-alone ECP brake systems unless: (1...

  3. Wind turbine trailing edge aerodynamic brakes

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-04-01

    Five trailing-edge devices were investigated to determine their potential as wind-turbine aerodynamic brakes, and for power modulation and load alleviation. Several promising configurations were identified. A new device, called the spoiler-flap, appears to be the best alternative. It is a simple device that is effective at all angles of attack. It is not structurally intrusive, and it has the potential for small actuating loads. It is shown that simultaneous achievement of a low lift/drag ratio and high drag is the determinant of device effectiveness, and that these attributes must persist up to an angle of attack of 45{degree}. It is also argued that aerodynamic brakes must be designed for a wind speed of at least 45 m/s (100 mph).

  4. 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...SUPPLEMENTARY NOTES The original document contains color images. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...May 2007 FinalR1 UNCLAS: Dist A. Approved for public release Leo Miller, Technology Insertion Project Officer ( TIPO ) NAC Off-vehicle Brake Testing

  5. Simulating pneumatic brake systems with AMESIM

    OpenAIRE

    Schneider, Sebastian;Anton, T.

    2017-01-01

    AMESim is successfully used for the design of braking systems and components by a large number of manufacturers and OEMs. The motivation and the main goals for the research project between the Institute of Product Development and the Knorr-Bremse SfS are to show a tool for the project planning of the systems and to present guidelines for systems, which can support the product developers.

  6. Longitudinal wheel slip during ABS braking

    Science.gov (United States)

    Hartikainen, Lassi; Petry, Frank; Westermann, Stephan

    2015-02-01

    Anti-lock braking system (ABS) braking tests with two subcompact passenger cars were performed on dry and wet asphalt, as well as on snow and ice surfaces. The operating conditions of the tyres in terms of wheel slip were evaluated using histograms of the wheel slip data. The results showed different average slip levels for different road surfaces. It was also found that changes in the tyre tread stiffness affected the slip operating range through a modification of the slip value at which the maximum longitudinal force is achieved. Variation of the tyre footprint length through modifications in the inflation pressure affected the slip operating range as well. Differences in the slip distribution between vehicles with different brake controllers were also observed. The changes in slip operating range in turn modified the relative local sliding speeds between the tyre and the road. The results highlight the importance of the ABS controller's ability to adapt to changing slip-force characteristics of tyres and provide estimates of the magnitude of the effects of different tyre and road operating conditions.

  7. 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.

  8. In-depth analysis of bicycle hydraulic disc brakes

    Science.gov (United States)

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

    2017-10-01

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

  9. Practical Use of the Braking Attributes Measurements Results

    Directory of Open Access Journals (Sweden)

    Ondruš Ján

    2017-01-01

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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Modernised DC traction substation recuperating energy of braking

    Directory of Open Access Journals (Sweden)

    Drozdowski Piotr

    2016-01-01

    Full Text Available The traction substation composed of the 3-phase transformer and the output diode rectifier is still the fundamental device for DC traction supply. In this paper two technical solutions (power electronic converters allowing for braking energy recuperation to the AC mains are discussed. This has been thought as the modernisation of the existing traction substations allowing for high speed trains regenerative braking and braking of heavy train hollers. Such a solution brings some profits: energy recuperation, mechanical brakes saving and enhanced quality of traction vehicle control. For the proposed converters technical and economical advantages and drawbacks are indicated.

  15. Modeling thermal effects in braking systems of railway vehicles

    Directory of Open Access Journals (Sweden)

    Milošević Miloš S.

    2012-01-01

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

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

    OpenAIRE

    I. S. Shumilov

    2016-01-01

    The braking system of the landing gear wheels of a mainline aircraft has to meet mandatory requirements laid out in the Aviation Regulations AP-25 (Para 25.735. «Brakes and brake systems"). These requirements are essential when creating the landing gear wheel brake control system (WBCS) and are used as main initial data in its mathematical modeling. The WBCS is one of the most important systems to ensure the safe completion of the flight. It is a complex of devices, i.e. units (hydraulic, ele...

  17. 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.

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

    OpenAIRE

    A. Turenko; S. Shuklinov

    2010-01-01

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

  19. 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, ...

  20. Research for Electric Brake Using NTC Thermistors on Micro Wind Turbine

    OpenAIRE

    Sugawara, Akira; Yamamoto, Kenichi; Yoshimi, Takeshi; Sato, Shingo; Tsurumaki, Akira; Ito, Tsuguru

    2006-01-01

    As a brake system for small wind turbine, mechanical brake and electric brake by the short circuit of 3-phase permanent magnet generator are used. However, an electric braking method may damage the rotor and/or blades by rapid stop of the generator revolution. Moreover, generator winding may also be damaged by large short-circuit current. In this paper, the electric braking method using NTC thermistors (negative temperature coefficient resistors) is proposed as a braking system for a cheaper ...

  1. Effects of main actor, outcome and affect on biased braking speed judgments

    Directory of Open Access Journals (Sweden)

    Ola Svenson

    2012-05-01

    Full Text Available Subjects who judged speed in a driving scenario overestimated how fast they could decelerate when speeding compared to when keeping within the speed limit (Svenson, 2009. The purpose of the present studies were to replicate studies conducted in Europe with subjects in the U.S., to study the influence of speed unit (kph vs. mph, affective reactions to outcome (collision and identity of main actor (driver on braking speed judgments. The results replicated the European findings and the outcome affective factor (passing a line/killing a child and the actor factor (subject/driver in general had significant effects on judgments of braking speed. The results were related to psychological theory and applied implications were discussed.

  2. Fuzzy Life-Extending Control of Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    Ahmed M. El-Garhy

    2013-12-01

    Full Text Available The repeated operation of the Anti-Lock Braking System (ABS causes accumulation of structural damages in its different subsystems leading to reduction in their functional life time. This paper proposes a Fuzzy Logic based Life-Extending Control (FLEC system for increasing the service life of the ABS. FLEC achieves significant improvement in service life by the trade-off between satisfactory dynamic performance and safe operation. The proposed FLEC incorporates structural damage model of the ABS. The model utilizes the dynamic behavior of the ABS and predicts the wear rates of the brake pads/disc. Based on the predicted wear rates, the proposed fuzzy logic controller modifies its control strategy on-line to keep safe operation leading to increase in service time of the ABS. FLEC is fine tuned via genetic algorithm and its effectiveness is verified through simulations of emergency stops of a passenger vehicle model.

  3. 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.

  4. Mercedes-Benz`s new Brake Assist active driver support in emergency braking situations; Der neue Brake Assist von Mercedes-Benz - aktive Fahrerunterstuetzung in Notsituationen

    Energy Technology Data Exchange (ETDEWEB)

    Kiesewetter, W. [Mercedes-Benz AG, Stuttgart (Germany); Klinkner, W. [Mercedes-Benz AG, Stuttgart (Germany); Reichelt, W. [Daimler Benz, Stuttgart (Germany); Steiner, M. [Mercedes-Benz AG, Stuttgart (Germany)

    1997-06-01

    Mercedes-Benz is the first automobile manufacturer in the world to develop an electronically controlled system for reducing stopping distance in emergency situations. It is called Brake Assist (BAS). This system has been standard in S-class and SL-class models since December 1996 and will be available in other Mercedes automobiles by the middle of 1997 - standardly, at no extra cost. The development of Brake Assist is based on the results of research carried out by Daimler-Benz which reveals that in critical situations, car drivers tend to put their foot down fast enough, but not firmly enough, on the brake pedal. In the initial stages of braking, the electronic Brake-Assist system automatically builds up maximum braking pressure within a fraction of a second, thereby considerably reducing the car`s stopping distance. After anti-lock brakes (ABS), airbag, acceleration skid control (ASR) and Electronic Stability Program (ESP), Mercedes-Benz is therefore making a further contribution towards improving road safety and reducing accident figures. (orig.) [Deutsch] Als weltweit erster Automobilhersteller hat Mercedes-Benz ein elektronisch gesteuertes System zur Verkuerzung des Bremsweges in Notsituationen entwickelt. Sein Name: Brake-Assist (BAS). Seit Dezember 1996 gehoert diese Technik bereits zur Serienausstattung der S- und SL-Klasse. Bis Mitte 1997 ist sie auch in den anderen Mercedes-Personenwagen serienmaessig vorhanden. Die Entwicklung des Brake Assist basiert auf Erkenntnissen der Daimler Benz Forschung, wonach Autofahrer in kritischen Situationen zwar schnell aber nicht kraeftig genug aufs Bremspedal treten. Der elektronische Bremsassistent baut schon am Beginn der Bremsung binnen Sekundenbruchteilen automatisch die maximale Bremskraftverstaerkung auf und verkuerzt dadurch den Anhalteweg erheblich. Damit leistet Mercedes-Benz nach Antiblockiersystem (ABS), Airbag, Antriebsschlupfregelung (ASR) und Electronic Stability Program (ESP) einen weiteren Beitrag zur

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

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed,Ibrahim; Fatouh, Yasser [Automotive and Tractors Technology Department, Faculty of Industrial Education, Helwan University, Cairo (Egypt); Aly, Wael [Refrigeration and Air-Conditioning Technology Department, Faculty of Industrial Education, Helwan University, Cairo (Egypt)

    2013-07-01

    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.

  6. 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.

  7. 49 CFR 238.317 - Class II brake test.

    Science.gov (United States)

    2010-10-01

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

  8. DC torque motor actuated anti-lock brake controller

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, P.D.; Kade, A.

    1989-02-21

    A wheel lock control system is described for limiting the brake pressure applied to the brake of a vehicle wheel traveling over a road surface, the system comprising: an actuator for controlling the brake pressure to the brake of the wheel, the actuator including a torque motor for generating a motor torque in response to motor current to control the applied brake pressure in accordance with the value of the motor torque, the motor torque having a value proportional to the value of the motor current; means for determining the tire torque tending to accelerate the wheel during the application of brake pressure; means for storing the value of motor current corresponding to the maximum determined value of tire torque; means for detecting an incipient wheel lockup condition; and means for establishing the motor current following a detected incipient wheel lockup condition at a value having a predetermined relationship to the stored value of motor current to control the brake pressure at a predetermined braking condition.

  9. 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

  10. 14 CFR 23.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

    ... and ground contacts must be those described in § 23.479 for level landings. (c) A drag reaction equal... at the ground contact point of each wheel with brakes, except that the drag reaction need not exceed the maximum value based on limiting brake torque. ...

  11. Perancangan Fixture Proses Gurdi untuk Produksi Komponen Brake Pads

    Directory of Open Access Journals (Sweden)

    Suci Rahmawati

    2010-10-01

    Full Text Available Brake pads is used to stop the rapid of vehicle while braking process is done. In making process if brake pads is needed a tool to make a operator work easier and can produce the brake pads component more precision, especially in making a hole process. A tool which is designed in drilling process in production of brake pads component use locator 3-2-1 principt in a placement the locator, using clamping to grip the component, and construction of jig dan fixture that is designed must be suitable with needs of making a hole process this brake pads component. To produce this tool, the cost must be calculated, such as direct cost, indirect cost and fixed cost to cover the 1200 lot sizes of this brake pads component. Based on design of this tool, it can be concluded that a tool which design of the drilling process can give benefit because it can help the operator in their work and it can produce the brake pads component more precision, and the rejected product can be minimized presisi. In addition, the set up time can be decreased and the cost be reduced.

  12. 49 CFR 393.55 - Antilock brake systems.

    Science.gov (United States)

    2010-10-01

    ... March 1, 1998 (except commercial motor vehicles engaged in driveaway-towaway operations), shall be... vehicle, and shall have the means for connection of the electrical circuit to the towed vehicle. The ABS... NECESSARY FOR SAFE OPERATION Brakes § 393.55 Antilock brake systems. Link to an amendment published at 75 FR...

  13. 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.

  14. A Comparative Study on Automotive Brake Testing Standards

    Science.gov (United States)

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

    2017-08-01

    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.

  15. Numerical Investigation of Aerodynamic Braking for a Ground Vehicle

    Science.gov (United States)

    Devanuri, Jaya Krishna

    2017-10-01

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

  16. Emergency braking is affected by the use of cruise control.

    Science.gov (United States)

    Jammes, Yves; Behr, Michel; Llari, Maxime; Bonicel, Sarah; Weber, Jean Paul; Berdah, Stephane

    2017-08-18

    We compared the differences in the braking response to vehicle collision between an active human emergency braking (control condition) and cruise control (CC) or adaptive cruise control (ACC). In 11 male subjects, age 22 to 67 years, we measured the active emergency braking response during manual driving using the accelerator pedal (control condition) or in condition mimicking CC or ACC. In both conditions, we measured the brake reaction time (BRT), delay to produce the peak braking force (PBD), total emergency braking response (BRT + PBD), and peak braking force (PBF). Electromyograms of leg and thigh muscles were recorded during braking. The tonic vibratory response (TVR), Hoffman reflex (HR), and M-waves were recorded in leg muscles to explore the change in sensorimotor control. No difference in PBF, TVR amplitude, HR latency, and H max /M max ratio were found between the control and CC/ACC conditions. On the other hand, BRT and PBD were significantly lengthened in the CC/ACC condition (240 ± 13 ms and 704 ± 70 ms, respectively) compared to control (183 ± 7 ms and 568 ± 36 ms, respectively). BRT increased with the age of participants and the driving experience shortened PBD and increased PBF. In male subjects, driving in a CC/ACC condition significantly delays the active emergency braking response to vehicle collision. This could result from higher amplitude of leg motion in the CC/ACC condition and/or by the age-related changes in motor control. Car and truck drivers must take account of the significant increase in the braking distance in a CC/ACC condition.

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

    Science.gov (United States)

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

    2017-12-01

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

  18. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Science.gov (United States)

    2010-08-20

    ... Expenses for the Anti-Lock Brake System and Underride Guard for Tractors and Trailers (74 FR 18803...; Technical Report on the Effectiveness of Antilock Braking Systems in Heavy Truck Tractors and Trailers... antilock braking systems (ABS) on all new air-braked vehicles with a GVWR of 10,000 pounds or greater. ABS...

  19. 49 CFR 232.205 - Class I brake test-initial terminal inspection.

    Science.gov (United States)

    2010-10-01

    ... of the brake system on each car in order to make the determinations and inspections required by this... of the brake system; (7) All parts of the brake equipment shall be properly secured. On cars where...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT...

  20. 76 FR 34801 - Petition for Modification of Single Car Air Brake Test Procedures

    Science.gov (United States)

    2011-06-14

    ... Federal Railroad Administration Petition for Modification of Single Car Air Brake Test Procedures In... locomotives in ``work'' trains, where the friction brakes operate in conjunction with the RT2 system of straight air brake employed on PATH cars. The single car air brake test described in Association of...

  1. Optimal design of a hybrid MR brake for haptic wrist application

    Science.gov (United States)

    Nguyen, Quoc Hung; Nguyen, Phuong Bac; Choi, Seung-Bok

    2011-03-01

    In this work, a new configuration of a magnetorheological (MR) brake is proposed and an optimal design of the proposed MR brake for haptic wrist application is performed considering the required braking torque, the zero-field friction torque, the size and mass of the brake. The proposed MR brake configuration is a combination of disc-type and drum-type which is referred as a hybrid configuration in this study. After the MR brake with the hybrid configuration is proposed, braking torque of the brake is analyzed based on Bingham rheological model of the MR fluid. The zero-field friction torque of the MR brake is also obtained. An optimization procedure based on finite element analysis integrated with an optimization tool is developed for the MR brake. The purpose of the optimal design is to find the optimal geometric dimensions of the MR brake structure that can produce the required braking torque and minimize the uncontrollable torque (passive torque) of the haptic wrist. Based on developed optimization procedure, optimal solution of the proposed MR brake is achieved. The proposed optimized hybrid brake is then compared with conventional types of MR brake and discussions on working performance of the proposed MR brake are described.

  2. An appraisal of safety of tractor-trailer braking system | Ogunjirin ...

    African Journals Online (AJOL)

    The tractor-traller braking system was appraised considering the effect of braking the tractor or trailer alone and also braking the combination of tractor and trailer simultaneously. The study became Imperative considering the Influx of trailers that are not equipped with the braking system and the danger It poses to the ...

  3. Vehicle Hybrid Braking Control Using Sliding Mode Control

    Science.gov (United States)

    Kasahara, Misawa; Kanai, Yuki; Shiraki, Ryoko; Mori, Yasuchika

    Anti-lock brake system and brake-by-wire are proposed in the vehicle control using a brake, and the braking power is expected to be improved more than ever. The researches such as an application to the ABS of Siliding mode control which considered a actuator dynamics and a hybrid control of the brake using model reference adaptive control are done so far. However, in the former case, speed following that becomes a target exists physically impossible situation by saturation of tire frictional force because only speed following is done. In the latter, the model error is caused because the simulation model and the controller design model are different. Therefore, there is a problem that an accurate follow cannot be done. In this paper, the braking control is performed using the sliding mode control which has high robustness for disturbance that fulfils matching conditions. In so doing, it aims at the achievement of optimal braking control to switch wheel speed following to slip ratio following.

  4. EEG potentials predict upcoming emergency brakings during simulated driving

    Science.gov (United States)

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

    2011-10-01

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

  5. Development of asbestos free brake pads using corn husks

    Directory of Open Access Journals (Sweden)

    Wisdom ASOTAH

    2017-12-01

    Full Text Available The development of asbestos free brake pads using corn husks as alternative filler was studied with a view to replacing asbestos, which has been known to be carcinogenic. Corn husks was sourced and milled, before been sieved into sieve grades of 100 and 200 μm. The varying proportions of the as-screened corn husk fibres and silicon carbide were mixed with fixed proportions of graphite, steel dust and resin to produce brake pads by using compressional moulding. The hardness, compressive strength, density, flame resistance, wear rate and porosity of the products were then determined. The result obtained showed that the brake pad produced with the corn husk passing the finer 100 μm screen gave better compressive strength, higher hardness, lower porosity and lower rate of wear, consequent on the finer distribution of the corn husks particles in the matrix. The results obtained for the brake pads were then compared with that of commercial brake pad (asbestos based and optimum formulation laboratory brake pad, corn husk based. The results were found to be in close agreement suggesting that corn husk can be used in the production of asbestos-free brake pads.

  6. A Comparative Study Between ABS and Disc Brake System Using Finite Element Method

    OpenAIRE

    Mobasseri, Saleh; Mobasseri, Mohammad

    2017-01-01

    This paper, refers to the history of the rise of brake system and describe its importance in passenger's lives. The Anti-lock Braking system (ABS), is the safety of vehicle systems to achieve maximum braking and decelerating in terms of increasing the stability and balance of the car and reduces the braking distance is designed. The performance of disc brake system and the Anti-lock Braking System (ABS) are also compared with each other by the kinetic analysis of the braking system and evalua...

  7. 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.

  8. Coefficient of Friction of a Brake Disc-Brake Pad Friction Couple

    Directory of Open Access Journals (Sweden)

    Orłowicz A.W.

    2016-12-01

    Full Text Available The paper concerns evaluation of the coefficient of friction characterising a friction couple comprising a commercial brake disc cast of flake graphite grey iron and a typical brake pad for passenger motor car. For the applied interaction conditions, the brake pressure of 0.53 MPa and the linear velocity measured on the pad-disc trace axis equalling 15 km/h, evolution of the friction coefficient μ values were observed. It turned out that after a period of 50 minutes, temperature reached the value 270°C and got stabilised. After this time interval, the friction coefficient value also got stabilised on the level of μ = 0.38. In case of a block in its original state, stabilisation of the friction coefficient value occurred after a stage in the course of which a continuous growth of its value was observed up to the level μ = 0.41 and then a decrease to the value μ = 0.38. It can be assumed that occurrence of this stage was an effect of an initial running-in of the friction couple. In consecutive abrasion tests on the same friction couple, the friction coefficient value stabilisation occurred after the stage of a steady increase of its value. It can be stated that the stage corresponded to a secondary running-in of the friction couple. The observed stages lasted for similar periods of time and ended with reaching the stabile level of temperature of the disc-pad contact surface.

  9. Finite element analysis of advanced bicycle precision brake disk forming technology

    Directory of Open Access Journals (Sweden)

    Chen Dyi-Cheng

    2015-01-01

    Full Text Available In recent years, the bicycle has become an environmentally friendly transportation. The bicycle can be divided into mountain bicycle and highway bicycle. Safe driving is the prior consideration. The bicycle braking system can be divided into oil pressure disk brakes and mechanical disk brakes. The brake disk system is one indispensable component of the safe system. In accordance to overall weight consideration of the bike, the brake disk should also focus on the lightweight design. This paper discussed an innovative brake disk forming technology for 6061 aluminum alloy by the rigid-plastic finite element analysis. The simulation parameters include geometric shapes of the brake disk and mold, die temperature, and friction factors. The stress and strain in forming, brake deformation and vibration modal analysis of brake disk in riding were studied. The paper is expected to offer some precision bicycle brake disk manufacture knowledge for industry.

  10. Electronics and braking systems; Elektronik in Bremssystemen

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-02-01

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

  11. Gravitational waves from pulsars with measured braking index

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-15

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

  12. CARS WEAVE IN THE BRAKING POSITION OF A HUMP

    Directory of Open Access Journals (Sweden)

    D. O. Serheiev

    2009-09-01

    Full Text Available The work contains a theoretical study of freight car vibrations while a group of the freight cars are under braking by retarder. The purpose is to discover possible causes of derailment. The corresponding analytical description is presented. The solution of the differential equations for the groups of carriages confirms an assumption, according to which a contact between the carriage wheel of and the rail can be lost due to the oscillations induced by braking. The results allow to present recommendation for choosing the safe regime of braking in order to avoid the derailment.

  13. 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...

  14. Finite element analysis of advanced bicycle precision brake disk forming technology

    OpenAIRE

    Chen Dyi-Cheng; Kang Jing-Hao; Lai Chia-Chun

    2015-01-01

    In recent years, the bicycle has become an environmentally friendly transportation. The bicycle can be divided into mountain bicycle and highway bicycle. Safe driving is the prior consideration. The bicycle braking system can be divided into oil pressure disk brakes and mechanical disk brakes. The brake disk system is one indispensable component of the safe system. In accordance to overall weight consideration of the bike, the brake disk should also focus on the lightweight design. This paper...

  15. The Theoretical Analysis of Test Result’s Errors for the Roller Type Automobile Brake Tester

    OpenAIRE

    Li, Jun; Zha, Xiaojing; Wu, Dongsheng

    2010-01-01

    International audience; The main testing parameter of the roller brake tester is the braking force. Actually, there are some differences in results even if the same vehicle is tested on the same tester. So it will bring trouble to evaluate the braking performance accurately. Based on force analysis, the mathematical model of the roller opposite force type automobile brake tester is built in this article. And then the factors of influencing braking force value will be analyzed by theoretical c...

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

    Science.gov (United States)

    Itoh, Makoto; Fujiwara, Yusuke; Inagaki, Toshiyuki

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

  17. "Ain't Necessarily So!": The Brake Industry's Impact on Asbestos Regulation in the 1970s.

    Science.gov (United States)

    Rosner, David; Markowitz, Gerald

    2017-09-01

    Canada is proposing a ban on asbestos, and the US Environmental Protection Agency has listed it among the first 10 materials it is investigating under the new Toxic Substances Control Act revisions. However, this effort is currently running up against enormous industry and political opposition. Here, we detail the activities in the early 1970s of the Friction Materials Standards Institute, an industry trade association, to stifle earlier attempts to regulate asbestos use in brake linings, one of the oldest and most obvious sources of asbestos exposure to mechanics, among others. (Am J Public Health. 2017: 1395-1399. doi: 10.2105/AJPH.2017.303901).

  18. 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.

  19. Brake System Design Optimization : Volume 2. Supplemental Data.

    Science.gov (United States)

    1981-04-01

    Existing freight car braking systems, components, and subsystems are characterized both physically and functionally, and life-cycle costs are examined. Potential improvements to existing systems previously proposed or available are identified and des...

  20. Brake System Design Optimization. Volume II : Supplemental Data.

    Science.gov (United States)

    1981-06-01

    Existing freight car braking systems, components, and subsystems are characterized both physically and functionally, and life-cycle costs are examined. Potential improvements to existing systems previously proposed or available are identified and des...

  1. Brake System Design Optimization : Volume 1. A Survey and Assessment.

    Science.gov (United States)

    1978-06-01

    Existing freight car braking systems, components, and subsystems are characterized both physically and functionally, and life-cycle costs are examined. Potential improvements to existing systems previously proposed or available are identified and des...

  2. AIRCRAFT BRAKE TEMPERATURE FROM A SAFETY POINT OF VIEW

    Directory of Open Access Journals (Sweden)

    Ján PIĽA

    2017-03-01

    Full Text Available Safety is critical throughout all stages of aircraft operation, from air mission to ground operation. One of the most important airframe systems that influences the efficacy of ground safety is a wheel brake system. Aircraft ground speed deceleration requires the dissipation of kinetic energy, which depends on aircraft weight and speed. Significant levels of aircraft kinetic energy must be dissipated in the form of heat energy. The brakes of heavy aircraft are especially prone to overheating during landing and taxiing on the ground. The aim of this paper is to focus on the dangers caused by aircraft brakes when overheating and ways in which to eliminate brake overheating problems from a safety perspective.

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. Fracture Analysis and Material Improvement of Brake Discs

    National Research Council Canada - National Science Library

    SAKAMOTO, Haruo; HIRAKAWA, Kenji

    2005-01-01

    .... This new brake disc, which proved to be satisfactory for Shinkansen vehicles, is capable of running at high speeds of more than 270km/h and therefore suitable for current vehicles such as the Nozomi and Tsubasa.

  10. RETROFIT OF A ROLLER BRAKE TESTER AT FAMENA

    OpenAIRE

    Božić, Mladen; Vučetić, Ante; Ilinčić, Petar; Lulić, Zoran

    2014-01-01

    The vehicle brake tester described in this paper is placed in the Laboratory for IC Engines and Motor Vehicles at the Faculty of Mechanical Engineering and Naval Architecture (FAMENA) in Zagreb. As the device, built in 1983, was inoperative, a decision was made for retrofit rather than repair. The retrofit included a reconstruction of some parts and modification of the braking force measurement. Adaptation of monitoring and control was made on electronic components that control the roller set...

  11. Modeling Hydraulic Components for Automated FMEA of a Braking System

    Science.gov (United States)

    2014-12-23

    to be reusable and, on the other hand, powerful enough to deliver the predictions relevant to FMEA of braking systems. In this paper, we present...context-independent,  analyze how a stimulus in terms of a local pressure change (e.g. pushing a brake pedal ) propagates through the system...mechanical components and the electronic control unit (ECU) and its software. It contains a tandem pedal actuation unit (with two pistons and two

  12. How Drivers Respond to Alarms Adapted to Their Braking Behaviour?

    Science.gov (United States)

    Abe, Genya; Itoh, Makoto

    Determining appropriate alarm timing for Forward Collision Warning Systems (FCWS) may play an important role in enhancing system acceptance by drivers. It is not always true that a common alarm trigger logic is suitable for all drivers, because presented alarms may be differently viewed for each driver, i.e., paying attention or requiring appropriate actions. The current study focused on adaptive alarm timing which was adjusted in response to braking behaviour for collision avoidance for the individual. In Experiment I, the braking performance of individual driver was measured repeatedly to assess the variation of each performance. We utilised the following two indices: elapsed time from the deceleration of the lead car to release of the accelerator (accelerator release time) and elapsed time to application of the brakes (braking response time). Two alarm timings were then determined based on these two indices: (i) the median of the accelerator release time of the driver and (ii) the median of the braking response time of the driver. Experiment II compared the two alarm timings for each driver in order to investigate which timing is more appropriate for enhancing driver trust in the driver-adaptive FCWS and the system effectiveness. The results showed that the timing of the accelerator release time increased the trust ratings more than the timing of braking response. The timing of the braking response time induced a longer response time to application of the brakes. Moreover, the degree to which the response time was longer depended on alarm timing preference of the driver. The possible benefit and drawback of driver-adaptive alarm timing are discussed.

  13. 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.

  14. Estimation of personal exposure to asbestos of brake repair workers.

    Science.gov (United States)

    Cely-García, María Fernanda; Curriero, Frank C; Sánchez-Silva, Mauricio; Breysse, Patrick N; Giraldo, Margarita; Méndez, Lorena; Torres-Duque, Carlos; Durán, Mauricio; González-García, Mauricio; Parada, Patricia; Ramos-Bonilla, Juan Pablo

    2017-07-01

    Exposure assessments are key tools to conduct epidemiological studies. Since 2010, 28 riveters from 18 brake repair shops with different characteristics and workloads were sampled for asbestos exposure in Bogotá, Colombia. Short-term personal samples collected during manipulation activities of brake products, and personal samples collected during non-manipulation activities were used to calculate 103 8-h TWA PCM-equivalent personal asbestos concentrations. The aims of this study are to identify exposure determinant variables associated with the 8-h TWA personal asbestos concentrations among brake mechanics, and propose different models to estimate potential asbestos exposure of brake mechanics in an 8-h work-shift. Longitudinal-based multivariate linear regression models were used to determine the association between personal asbestos concentrations in a work-shift with different variables related to work tasks and workload of the mechanics, and some characteristics of the shops. Monte Carlo simulations were used to estimate the 8-h TWA PCM-Eq personal asbestos concentration in work-shifts that had manipulations of brake products or cleaning activities of the manipulation area, using the results of the sampling campaigns. The simulations proposed could be applied for both current and retrospective studies to determine personal asbestos exposures of brake mechanics, without the need of sampling campaigns or historical data of air asbestos concentrations.

  15. Development and production of brake pad from sawdust composite

    Directory of Open Access Journals (Sweden)

    Sadiq Sius LAWAL

    2017-07-01

    Full Text Available This paper presents research work on new alternative materials for brake pad. A new asbestos free brake pad was developed using an agro waste material of sawdust along with other ingredients. This was with a view to exploiting the characteristics of sawdust which are largely deposited as waste around sawmills in replacing asbestos which has been found to be carcinogenic. A brake pad was produced using sawdust as a base material following the standard procedure employed by the manufacturers. The sawdust was sieved into sieve grades of 100μm, 355μm and 710μm. The sieved sawdust was used in production of brake pad in ratio of 55% sawdust, 15% steel dust, 5% graphite, 10% silicon carbide and 15% epoxy resin using compression moulding. The properties examined are microstructure analysis, hardness, compressive strength, density, ash content, wear rate and water absorption. 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 showed a close correlation. Hence sawdust can be used in production of asbestos-free brake pad.

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

    Science.gov (United States)

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

    2017-11-01

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

  17. Materials used for braking; Materiaux pour le freinage

    Energy Technology Data Exchange (ETDEWEB)

    Bricout, J.P.; Guerin, J.D.; Bartys, H.; Watremez, M. [Universite de Valenciennes et du Hainaut-Cambresis, UMR CNRS 8530, Lab. d' Automatique et de Mecanique Industrielles et Humaines, 59 - Valenciennes (France)

    2001-10-01

    The optimization of disc brakes used in the rail industry induces an increase of the capacity to dissipate energy, a significant lightening of the braking device as well as an improvement of the tribological performance under humidity. Two research studies have then been carried out: 1)the disc brakes with a weak thermal diffusivity and 2)the disc brakes with a high thermal diffusivity. For the systems having a weak thermal diffusivity, the NiCr-Cr{sub 3}C{sub 2} cermet coatings and the aluminium titanate brake pads are particularly interesting: stability of the friction coefficient, good wear resistance and low sensitivity to humidity. Meanwhile, the relative reliability of the coating having only a mechanical bond have oriented the researches towards coatings having metallurgical bonds as stellite. The tribological results obtained with 'nirec 6' and 'corec 6' stellite are very encouraging and even superiors to those of NiCr-Cr{sub 3}C{sub 2} cermet. The discs with high diffusivity coupled with organic brake pads have also interesting tribological performance as well as at dry than under humidity, with the advantage of a lightening of 50% to the steel disc having the same thermal capacity. With an equal dissipated power, the friction temperature is inferior to those of the conventional system and of the 'NiCr-Cr{sub 3}C{sub 2}/aluminium titanate cermet' system. (O.M.)

  18. 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.

  19. Control performance of an electrorheological valve based vehicle anti-lock brake system, considering the braking force distribution

    Science.gov (United States)

    Choi, S. B.; Lee, T. H.; Lee, Y. S.; Han, M. S.

    2005-12-01

    This paper presents the braking control performance of a vehicle anti-lock brake system featuring an electrorheological (ER) fluid. As a first step, a cylindrical type of ER valve is devised and its pressure controllability is experimentally confirmed. Then, a hydraulic booster for amplifying the field-dependent pressure drop obtained from the ER valve is constructed and its pressure amplification is demonstrated by presenting the pressure tracking control performance. Subsequently, the governing equation of the rear wheel model is derived by considering the braking force distribution, and a sliding mode controller for achieving the desired slip rate is designed. The controller is then realized through the hardware-in-the-loop simulation method and controlled responses are presented in the time domain. In addition, computer animations for the braking performance under unladen and laden conditions are presented, and a comparison of the proportioning valve and the proposed ER valve pressure modulator is made.

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

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-15

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

  2. 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.

  3. The braking performance of a vehicle anti-lock brake system featuring an electro-rheological valve pressure modulator

    Science.gov (United States)

    Choi, Seung-Bok; Sung, Kum-Gil; Cho, Myung-Soo; Lee, Yang-Sub

    2007-08-01

    This paper presents the braking performances of a vehicle anti-lock brake system (ABS) featuring an electro-rheological (ER) valve pressure modulator. As a first step, the principal design parameters of the ER valve and hydraulic booster are appropriately determined by considering the Bingham property of the ER fluid and the braking pressure variation during the ABS operation. An ER fluid composed of chemically treated starch particles and silicone oil is used. An electrically controllable pressure modulator is then constructed and its pressure controllability is empirically evaluated. Subsequently, a quarter-car wheel slip model is established and integrated with the governing equation of the pressure modulator. A sliding mode controller for slip rate control is designed and implemented via the hardware-in-the-loop simulation (HILS). In order to demonstrate the superior braking performance of the proposed ABS, a full car model is derived and a sliding mode controller is formulated to achieve the desired yaw rate. The braking performances in terms of braking distance and step input steering are evaluated and presented in time domain through full car simulations.

  4. 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.

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

    Science.gov (United States)

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

    2010-11-01

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

  6. A farewell to brake reaction times? Kinematics-dependent brake response in naturalistic rear-end emergencies.

    Science.gov (United States)

    Markkula, Gustav; Engström, Johan; Lodin, Johan; Bärgman, Jonas; Victor, Trent

    2016-10-01

    Driver braking behavior was analyzed using time-series recordings from naturalistic rear-end conflicts (116 crashes and 241 near-crashes), including events with and without visual distraction among drivers of cars, heavy trucks, and buses. A simple piecewise linear model could be successfully fitted, per event, to the observed driver decelerations, allowing a detailed elucidation of when drivers initiated braking and how they controlled it. Most notably, it was found that, across vehicle types, driver braking behavior was strongly dependent on the urgency of the given rear-end scenario's kinematics, quantified in terms of visual looming of the lead vehicle on the driver's retina. In contrast with previous suggestions of brake reaction times (BRTs) of 1.5s or more after onset of an unexpected hazard (e.g., brake light onset), it was found here that braking could be described as typically starting less than a second after the kinematic urgency reached certain threshold levels, with even faster reactions at higher urgencies. The rate at which drivers then increased their deceleration (towards a maximum) was also highly dependent on urgency. Probability distributions are provided that quantitatively capture these various patterns of kinematics-dependent behavioral response. Possible underlying mechanisms are suggested, including looming response thresholds and neural evidence accumulation. These accounts argue that a naturalistic braking response should not be thought of as a slow reaction to some single, researcher-defined "hazard onset", but instead as a relatively fast response to the visual looming cues that build up later on in the evolving traffic scenario. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Research on anti crack mechanism of bionic coupling brake disc

    Science.gov (United States)

    Shi, Lifeng; Yang, Xiao; Zheng, Lingnan; Wu, Can; Ni, Jing

    2017-09-01

    According to the biological function of fatigue resistance possessed by biology, this study designed a Bionic Coupling Brake Disc (BCBD) which can inhibit crack propagation as the result of improving fatigue property. Thermal stress field of brake disc was calculated under emergency working condition, and circumferential and radial stress field which lead to fatigue failure of brake disc were investigated simultaneously. Results showed that the maximum temperature of surface reached 890°C and the maximum residual tensile stress was 207 Mpa when the initial velocity of vehicle was 200 km/h. Based on the theory of elastic plastic fracture mechanics, the crack opening displacement and the crack front J integrals of the BCBD and traditional brake disc (TBD) with pre-cracking were calculated, and the strength of crack front was compared. Results revealed the growth behavior of fatigue crack located on surface of brake disc, and proved the anti fatigue resistance of BCBD was better, and the strength of crack resistance of BCBD was much stronger than that of TBD. This simulation research provided significant references for optimization and manufacturing of BCBD.

  8. Research on HILS Technology Applied on Aircraft Electric Braking System

    Directory of Open Access Journals (Sweden)

    Suying Zhou

    2017-01-01

    Full Text Available On the basis of analyzing the real-time feature of hardware-in-the-loop simulation of aircraft braking system, a new simulation method based on MATLAB/RTW (Real-Time Workshop and DSP is introduced. The purpose of this research is to develop a digital control unit with antilock brake system control algorithm for aircraft braking system using HILS. DSP is used as simulator. Using this method, a detailed mathematical modeling of system is proposed first. Studies on reducing sampling time with model simplification and modeling for applying to I/O interface of DSP and HILS are conducted. Compared with other methods, this method is low cost and convenient to implement. By using these methods, we can complete HIL simulation of aircraft braking under various experimental conditions, modify its control laws, and test its braking performance. The results have demonstrated that this platform has high reliability. The algorithm is verified by real-time closed loop test with HILS system and the results are presented.

  9. 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.

  10. Simulation and Robust Contol of Antilock Braking System ABS

    Directory of Open Access Journals (Sweden)

    David Jordan DELICHRISTOV

    2009-06-01

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

  11. The contribution of stereo vision to the control of braking.

    Science.gov (United States)

    Tijtgat, Pieter; Mazyn, Liesbeth; De Laey, Christophe; Lenoir, Matthieu

    2008-03-01

    In this study the contribution of stereo vision to the control of braking in front of a stationary target vehicle was investigated. Participants with normal (StereoN) and weak (StereoW) stereo vision drove a go-cart along a linear track towards a stationary vehicle. They could start braking from a distance of 4, 7, or 10m from the vehicle. Deceleration patterns were measured by means of a laser. A lack of stereo vision was associated with an earlier onset of braking, but the duration of the braking manoeuvre was similar. During the deceleration, the time of peak deceleration occurred earlier in drivers with weak stereo vision. Stopping distance was greater in those lacking in stereo vision. A lack of stereo vision was associated with a more prudent brake behaviour, in which the driver took into account a larger safety margin. This compensation might be caused either by an unconscious adaptation of the human perceptuo-motor system, or by a systematic underestimation of distance remaining due to the lack of stereo vision. In general, a lack of stereo vision did not seem to increase the risk of rear-end collisions.

  12. Improvement of Response and Efficiency of Railway Air Brake System by Modifying Software for Control

    National Research Council Canada - National Science Library

    NAKAZAWA, Shin-ichi; HIJIKATA, Daisuke

    2017-01-01

    Air brake systems are essential for the safety operation of railway vehicles. However, a certain amount of time is required to distribute compressed air through the pipe so that the brake cylinders fill...

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

    Science.gov (United States)

    Cikanek, Susan R.

    1994-01-01

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

  14. Performance of Linear Motor Type Rail Brake Using Roller Rig Test Bench

    National Research Council Canada - National Science Library

    SAKAMOTO, Yasuaki; KASHIWAGI, Takayuki; HASEGAWA, Hitoshi; SASAKAWA, Takashi; KARINO, Yasushi

    2012-01-01

    .... It is necessary however to install this brake between front and rear wheels of the bogie. A prototype rail brake system was designed and built and its electromagnetic characteristics were examined on a test bench with a roller rig...

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

    Directory of Open Access Journals (Sweden)

    Di Zhao

    2018-02-01

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

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

    Science.gov (United States)

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

    2017-08-01

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

  17. 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.

  18. 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.

  19. Double pulsed holography used to investigate noisy brakes

    Science.gov (United States)

    Fieldhouse, J. D.; Newcomb, T. P.

    1996-12-01

    The vibrational characteristics of a noisy passenger car disc brake have been studied using the double pulsed holographic technique which has been developed to allow three orthogonal visual images of a vibrating brake system to be recorded simultaneously. These images show the disc to be vibrating in a bending mode whereas the pad is seen to be excited in a variety of modes such as bending, torsion, and often a combination of both. The development of the technique includes alternative ways of triggering the laser and typical results from the application of these differing methods are also included along with mechanical signals which confirm the visual interpretations. Final results, using a laser trigger delay technique, show that the disc mode waveform rotates about the disc at a rate equivalent to the frequency of vibration divided by the diametral mode order. Early work on a passenger car drum brake is also introduced, this complementing commercial 'noise fix' solutions and a proposed theoretical model.

  20. Pulsar Braking Index: A Test of Emission Models?

    Science.gov (United States)

    Xu, R. X.; Qiao, G. J.

    2001-11-01

    Pulsar braking torques due to magnetodipole radiation and the unipolar generator are considered, which results in a braking index n of less than 3 and could be employed to test the emission models. Improved equations for the pulsar braking index and magnetic field are presented, which are true if the rotation energy-loss rate equals the sum of the energy-loss rate of dipole radiation and of relativistic particles powered by a unipolar generator. The magnetic field calculated conventionally could be good enough, but only if it were modified by a factor of at most ~0.6. Both inner and outer gaps may coexist in the magnetosphere of the Vela pulsar.

  1. Design optimization of an opposed piston brake caliper

    Science.gov (United States)

    Sergent, Nicolas; Tirovic, Marko; Voveris, Jeronimas

    2014-11-01

    Successful brake caliper designs must be light and stiff, preventing excessive deformation and extended brake pedal travel. These conflicting requirements are difficult to optimize owing to complex caliper geometry, loading and interaction of individual brake components (pads, disc and caliper). The article studies a fixed, four-pot (piston) caliper, and describes in detail the computer-based topology optimization methodology applied to obtain two optimized designs. At first sight, relatively different designs (named 'Z' and 'W') were obtained by minor changes to the designable volume and boundary conditions. However, on closer inspection, the same main bridge design features could be recognized. Both designs offered considerable reduction of caliper mass, by 19% and 28%, respectively. Further finite element analyses conducted on one of the optimized designs (Z caliper) showed which individual bridge features and their combinations are the most important in maintaining caliper stiffness.

  2. 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.)

  3. Characterization of surface morphology and its correlation with friction performance of brake pads

    OpenAIRE

    Neis, Patrick Daniel; Ferreira, Ney Francisco; Sukumaran, Jacob; DE BAETS, Patrick; Ando, Matyas; Matozo, Luciano Tedesco; Masotti, Diego

    2015-01-01

    The present work presents the morphology evolution of a brake material surface submitted to braking tests through a laboratory-scale tribometer. Optical microscope images of the material’s surface were obtained for every 10 braking operations. These images were post-processed in appropriate computational software. By means of the image segmentation technique, morphological parameters related to the brake material surface were estimated. The wear rate and also the coefficient of friction resul...

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

    OpenAIRE

    Supachai Lakkam; Kullayot Suwantaroj; Phupoom Puangcharoenchai; Songwut Mongkonlerdmanee; Saiprasit Koetniyom

    2013-01-01

    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 g...

  5. 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.

  6. Thermal-mechanical coupled analysis of a brake disk rotor

    Science.gov (United States)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-08-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer 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 with coupling to determine the deformation and the Von Mises stress established in the disk, the contact pressure distribution in pads. The results are satisfactory when compared to those of the specialized literature.

  7. Non-resonant magnetic braking on JET and TEXTOR

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  8. NUMERICAL THERMAL ANALYSIS OF A CAR BRAKING SYSTEM

    Directory of Open Access Journals (Sweden)

    Patryk Różyło

    2017-06-01

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

  9. Brake deceleration of cars with light luggage trailers

    Directory of Open Access Journals (Sweden)

    Jan FILIPCZYK

    2012-01-01

    Full Text Available This paper presents some aspects of employing measurements of deceleration for the technical analysis of the brake process of cars with light luggage trailers. The analysis of the deceleration enables to assess the technical state regarding traffic safety and it can also be used for analysing the course of traffic accidents. The measurements of deceleration enables to determine the influence of load on the brake process for different kinds of cars. This method can be employed as the only way of examining during the periodical inspections and services for some kinds of trailers.

  10. Temperature and Thermal Stresses of Vehicles Gray Cast Brake

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2013-10-01

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

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

    Science.gov (United States)

    2012-08-06

    ... risk and removed from revenue service until the brake adjustment problems are resolved. With respect to... RIN 2126-AB28 Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits AGENCY... the operators . The rule provides improved guidance concerning CMV brake adjustment limits. The...

  13. 75 FR 57393 - Parts and Accessories Necessary for Safe Operation: Antilock Brake Systems

    Science.gov (United States)

    2010-09-21

    ..., 2008, issue of the Federal Register (73 FR 3316). II. Abbreviations ABS Anti-lock Braking Systems CMV... for Safe Operation: Antilock Brake Systems AGENCY: Federal Motor Carrier Safety Administration (FMCSA... requirement in the Federal Motor Carrier Safety Regulations (FMCSRs) that trailers with antilock brake systems...

  14. 49 CFR 214.529 - In-service failure of primary braking system.

    Science.gov (United States)

    2010-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Basil Olufemi Akinnuli

    2017-11-01

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

  16. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Science.gov (United States)

    2010-10-01

    ... and one-half times the total fluid displacement resulting when all the wheel cylinders or caliper... approximate center of the facing length and width of the most heavily loaded shoe or disc pad, one per brake... the distance measured from the start of one brake application to the start of the next brake...

  17. 49 CFR 232.209 - Class II brake tests-intermediate inspection.

    Science.gov (United States)

    2010-10-01

    ... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER... the requirements contained in § 232.205(c)(1); (2) The air brake system shall be charged to the... accurate gauge or end-of-train device at the rear end of train; (3) The brakes on each car added to the...

  18. 49 CFR 232.211 - Class III brake tests-trainline continuity inspection.

    Science.gov (United States)

    2010-10-01

    ...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... performed on a train by a qualified person, as defined in § 232.5, to test the train brake system when the... have previously received a Class I brake test, have not been off air more than four hours, and the cars...

  19. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Science.gov (United States)

    2010-10-01

    ... examine and observe the functioning of all moving parts of the brake system on each car in order to make... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT AND OTHER... Class IA brake test. The most restrictive car or block of cars in the train shall determine the location...

  20. 49 CFR 232.307 - Modification of the single car air brake test procedures.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Modification of the single car air brake test...) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR FREIGHT... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other...

  1. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Science.gov (United States)

    2010-10-01

    ... use in hydraulic brake systems of motor vehicles. In addition, S5.3 applies to passenger cars.... This standard specifies requirements for fluids for use in hydraulic brake systems of motor vehicles... vehicle hydraulic brake system in which it will contact elastomeric components made of styrene and...

  2. 78 FR 44189 - Petition for Modification of Single Car Air Brake Test Procedures

    Science.gov (United States)

    2013-07-23

    ... the Federal Railroad Administration (FRA) per 49 CFR 232.307 to modify the single car air brake test procedures located in AAR Standard S-486, Code of Air Brake System Tests for Freight Equipment-- Single Car... Federal Railroad Administration Petition for Modification of Single Car Air Brake Test Procedures In...

  3. 49 CFR 232.309 - Equipment and devices used to perform single car air brake tests.

    Science.gov (United States)

    2010-10-01

    ... (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRAKE SYSTEM SAFETY STANDARDS FOR... Testing Requirements § 232.309 Equipment and devices used to perform single car air brake tests. (a) Equipment and devices used to perform single car air brake tests shall be tested for correct operation at...

  4. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

    ... passenger cars.\\7\\ \\6\\ Response to Petitions for Reconsideration, Motorcycle Brake Systems, 37 FR 11973... CFR Part 571 Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems; Final Rule #0;#0... Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems AGENCY: National Highway Traffic Safety...

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

    Directory of Open Access Journals (Sweden)

    A. Turenko

    2010-01-01

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

  6. 49 CFR 232.503 - Process to introduce new brake system technology.

    Science.gov (United States)

    2010-10-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Guo, Hongqiang

    2015-01-01

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

  9. Assessing the potential benefits of the motorcycle autonomous emergency braking using detailed crash reconstructions.

    Science.gov (United States)

    Savino, Giovanni; Giovannini, Federico; Baldanzini, Niccolò; Pierini, Marco; Rizzi, Matteo

    2013-01-01

    The aim of this study was to assess the feasibility and quantitative potential benefits of a motorcycle autonomous emergency braking (MAEB) system in fatal rear-end crashes. A further aim was to identify possible criticalities of this safety system in the field of powered 2-wheelers (PTWs; e.g., any additional risk introduced by the system itself). Seven relevant cases from the Swedish national in-depth fatal crash database were selected. All crashes involved car-following in which a non-anti-lock braking system (ABS)-equipped motorcycle was the bullet vehicle. Those crashes were reconstructed in a virtual environment with Prescan, simulating the road scenario, the vehicles involved, their precrash trajectories, ABS, and, alternatively, MAEB. The MAEB chosen as reference for the investigation was developed within the European Commission-funded Powered Two-Wheeler Integrated Safety (PISa) project and further detailed in later studies, with the addition of the ABS functionality. The boundary conditions of each simulation varied within a range compatible with the uncertainty of the in-depth data and also included a range of possible rider behaviors including the actual one. The benefits of the MAEB were evaluated by comparing the simulated impact speed in each configuration (no ABS/MAEB, ABS only, MAEB). The MAEB proved to be beneficial in a large number of cases. When applicable, the benefits of the system were in line with the expected values. When not applicable, there was no clear evidence of an increased risk for the rider due to the system. MAEB represents an innovative safety device in the field of PTWs, and the feasibility of such a system was investigated with promising results. Nevertheless, this technology is not mature yet for PTW application. Research in the field of passenger cars does not directly apply to PTWs because the activation logic of a braking system is more challenging on PTWs. The deployment of an autonomous deceleration would affect the

  10. Comparative study on the lateral run-out of friction surfaces measurement of brake discs using a brake roller tester and a dial gauge

    OpenAIRE

    Toma Marius; Andreescu Cristian; Micu Dan

    2017-01-01

    Brake system diagnosis is one of the most common and necessary technical operations applied to the car, regardless of its type and operating phases. Measuring the diagnostic parameters on a roller brake tester is a fast operation with no disassembly necessary. Measuring the run-out of friction surfaces of brake discs with a dial gauge is an action that requires more extensive preparatory operations but it offers a high accuracy of the results. The paper aims to analyze the correlation between...

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

    Directory of Open Access Journals (Sweden)

    W. A. Akpan

    2012-12-01

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

  12. 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....

  13. 14 CFR 25.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

    ....493 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.493 Braked roll conditions. (a.... (e) In the absence of a more rational analysis, the nose gear vertical reaction prescribed in...

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

    OpenAIRE

    Trulove, Susan

    2008-01-01

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

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

    Science.gov (United States)

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

    2015-03-01

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

  16. SPECIFICITY AND TRENDS IN IMPROVEMENT OF TRACTOR TRAIN BRAKING DYNAMICS

    Directory of Open Access Journals (Sweden)

    G. A. Tayanovsky

    2015-01-01

    Full Text Available The paper considers an important problem in improvement of  braking dynamics potential as part of the overall tractor train dynamics consisting of  an all-wheel drive tractor and heavy-duty trailers which are either locally manufactured or developed with the participation of the paper’s authors. The trailers have a mechanical drive for their wheels from the tractor engine. The trains are intended for transportation peat, organic fertilizers and various loads in  forest exploitation and under other complicated soil and climatic and road conditions where there is justified necessity to activate the trailer wheels.Methodological tools have been developed with the purpose to analyze an influence of the blocked inter-double-reduction axle drive of an active tractor train on distribution of braking forces in double-reduction axles with due account of the heavy-duty peat trailer specificity. Theoretical provisions for wheeled vehicles have been developed with regard to the braking application specificity of active tractor trains with mechanical multi-path drive for wheels of a multi-double-reduction axle propulsion device. The paper presents calculation and theoretical data in order to estimate  distribution of specific braking forces in the double-reduction axle links of the active tractor train when the blocked inter-double-reduction axle drive of the tractor and trailer wheels is switched on and also in the case when the tractor engine is involved in braking process and a clutch coupling is switched-on.Sequence of the calculation formula has been completely carried out in the paper. They represent clear design and operational parameters of the active tractor train. Such approach has made it possible to realize them in the form of a software application which is convenient for analysis of the braking process pertaining to the investigated objects in order to select means for improvement of braking dynamics, rational parameters of multi

  17. Airborne Wear Particles Emissions ofCommercial Disc Brake Materials– Disc Brake Test Stand Simulations at LowContact Pressures and Rotors Pre-conditionedwith Rust

    OpenAIRE

    Wahlström, Jens; Olander, Lars; Olofsson, Ulf

    2008-01-01

    Most modern passenger cars have disc brakes on the front wheels, which unlike drum brakes are not sealed off to the ambient air. During braking, there is wear to both the rotor and the pads. This wear process generates particles, which may become airborne. A problem with measuring airborne wear particles in field tests is to distinguish them from the background noise. Therefore, a disc brake laboratory test stand that allows control of the cleanness of the surrounding air is used. With this t...

  18. Comparative study on the lateral run-out of friction surfaces measurement of brake discs using a brake roller tester and a dial gauge

    Directory of Open Access Journals (Sweden)

    Toma Marius

    2017-01-01

    Full Text Available Brake system diagnosis is one of the most common and necessary technical operations applied to the car, regardless of its type and operating phases. Measuring the diagnostic parameters on a roller brake tester is a fast operation with no disassembly necessary. Measuring the run-out of friction surfaces of brake discs with a dial gauge is an action that requires more extensive preparatory operations but it offers a high accuracy of the results. The paper aims to analyze the correlation between the dial gauge measured values and the diagnostic obtained using the brake roller tester.

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

    Science.gov (United States)

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

    2018-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Boyi Xiao

    2017-11-01

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

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

    Science.gov (United States)

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

    2016-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-29

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

  3. 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.

  4. 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...

  5. The lug with wedges re-launches the electric braking; L'etrier a coins relance le freinage electrique

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, A.

    2005-10-01

    Electric-powered braking systems are lighter than hydraulic ones but require lot of energy. A system developed by Siemens VDO, named EWB (electronic wedge brake) uses the kinetic energy of the wheel to mechanically move the brake blocks aside and press the pads against the disc. Electric motors are used to move the blocks tangentially and start-up the braking but the main part of the braking energy comes from the system itself. Short paper. (J.S.)

  6. 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

  7. 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.

  8. Use of a hydraulic brake as a source of thermal energy for the railway rolling stock

    Directory of Open Access Journals (Sweden)

    V.A.Gabrinets

    2012-12-01

    Full Text Available Introduction: In this paper the braking issues of passenger trains which have a great speed and frequent stops are examines. Problem statement: These processes are ехpensive and have big energy losses. The proposed solution to the problem: The kinetic energy of braking prosses propose to turn into thermal energy of heating fluid. For this purpose special hydraulic brake is proposed. The brake is connected with the wheel carriage pairs. The process is based on the energy dissipation in liqid when the disks with spikes rotate in it. Because the real liquid has friction and viscosity, it will be heat up, when the mechanical parts of the hydraulic brake are moved in it. The design, operating principle and characteristics of the hydraulic brake are proposed. Transmission of kinetic energy of carriage motion to brake system executed by mechanical clutches. It connected with the wheel pair and transmitting the energy the wheels rotation to hydraulic brake discs. The cylindrical rods are installed on the discs. Rods location fits the profile of the curved centrifugal pump vanes. As result, the fluid heatind prosess by rotatinge discs with rods take place also at the same time with the liquid pumping through the inner volume of brake system.Conclusions: Affordable passenger carriage braking dynamic is achieved by varying the size and number of rods. The heated liquid may be subsequently used for household needs and for heating the passenger carriage.

  9. Braking energy efficiently. Design of self-strengthing electro-hydraulic brake; Energieeffizient bremsen. Auslegung der Selbstverstaerkenden Elektro-Hydraulischen Bremse

    Energy Technology Data Exchange (ETDEWEB)

    Ewald, Julian; Liermann, Matthias; Murrenhoff, Hubertus [RWTH Aachen (Germany). Inst. fuer fluidtechnische Antriebe und Steuerungen

    2009-05-15

    Part of the project ''intelligent, Integrated mono-wheel-drivebrake-module'', sponsored by the German Research Foundation DFG at RWTH Aachen University is the research on a hydraulic brake with minimized energy consumption. The paper describes the boundary conditions for the development of the integrated brake. Based on the depiction of the new brake principle of self-energizing hydraulic brake, the technical solutions to fulfil the train-specific demands are visualized. To ensure a low consumption of the hydraulic energy gained from the retardation force, leakage-free ABS seat valves are used in the implemented concept. The measurement results from a first prototype verify the effect of hydraulic self-energisation. A second prototype is currently assembled at IFAS. It can be used together with both automotive and train brake discs. (orig./GL)

  10. Thermal design of AOTV heatshields for a conical drag brake

    Science.gov (United States)

    Pitts, W. C.; Murbach, M. S.

    1985-01-01

    Results are presented from an on-going study of the thermal performance of thermal protection systems for a conical drag brake type AOTV. Three types of heatshield are considered: rigid ceramic insulation, flexible ceramic blankets, and ceramic cloths. The results for the rigid insulation apply to other types of AOTV as well. Charts are presented in parametric form so that they may be applied to a variety of missions and vehicle configurations. The parameters considered include: braking maneuver heat flux and total heat load, heatshield material and thickness, heatshield thermal mass and conductivity, absorptivity and emissivity of surfaces, thermal mass of support structure, and radiation transmission through thin heatshields. Results of temperature calculations presented show trends with and sensitivities to these parameters. The emphasis is on providing information that will be useful in estimating the minimum required mass of these heatshield materials.

  11. Thermal design of AOTV heatshields for a conical drag brake

    Science.gov (United States)

    Pitts, W. C.; Murbach, M. S.

    1985-06-01

    Results are presented from an on-going study of the thermal performance of thermal protection systems for a conical drag brake type AOTV. Three types of heatshield are considered: rigid ceramic insulation, flexible ceramic blankets, and ceramic cloths. The results for the rigid insulation apply to other types of AOTV as well. Charts are presented in parametric form so that they may be applied to a variety of missions and vehicle configurations. The parameters considered include: braking maneuver heat flux and total heat load, heatshield material and thickness, heatshield thermal mass and conductivity, absorptivity and emissivity of surfaces, thermal mass of support structure, and radiation transmission through thin heatshields. Results of temperature calculations presented show trends with and sensitivities to these parameters. The emphasis is on providing information that will be useful in estimating the minimum required mass of these heatshield materials.

  12. 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.

  13. Energy Efficiency in Heavy Vehicle Tires, Drivetrains, and Braking Systems

    Energy Technology Data Exchange (ETDEWEB)

    Peter J. Blau

    2000-04-26

    This document was prepared to support the primary goals of the Department of Energy, Office of Heavy Vehicle Technologies. These were recently stated as follows: ''Develop by 2004 the enabling technologies for a class 7-8 truck with a fuel efficiency of 10 mpg (at 65 mph) which will meet prevailing emission standards. For Class 3-6 trucks operating on an urban driving cycle, develop by 2004 commercially viable vehicles that achieve at least double the fuel economy of comparable current vehicles (1999), and as a research goal, reduce criteria pollutants to 30% below EPA standards. Develop by 2004 the diesel engine enabling technologies to support large-scale industry dieselization of Class 1 and 2 trucks, achieving a 35 % fuel efficiency improvement over comparable gasoline-fueled trucks, while meeting applicable emissions standards.'' The enabling technologies for improving the fuel efficiency of trucks, include not only engine technologies but also technologies involved with lowering the rolling resistance of tires, reducing vehicle aerodynamic drag, improving thermal management, and reducing parasitic frictional losses in drive train components. Opportunities also exist for making better use of the energy that might ordinarily be dissipated during vehicle braking. Braking systems must be included in this evaluation since safety in truck operations is vital, and braking requirements are greater for vehicles having lowered resistance to rolling. The Office of Heavy Vehicle Technologies has initiated a program to improve the aerodynamics of heavy vehicles through wind tunnel testing, computational modeling, and on-road evaluations. That activity is described in a separate multi-year plan; therefore, emphasis in this document will be on tires, drive trains, and braking systems. Recent, dramatic fluctuations in diesel fuel prices have emphasized the importance of effecting savings in truck fuel economy by implementing new component designs and

  14. Simulation study of the plasma-brake effect

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2014-10-01

    Full Text Available Plasma brake is a thin, negatively biased tether that 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 (i.e. smooth and not turbulent 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 in which the magnetic field is aligned with the flow can also be unstable, but does not result in notable thrust reduction. We also correct an error in an earlier reference. According to the simulations, the predicted thrust of the plasma brake is large enough to make the method promising for low-Earth-orbit (LEO satellite deorbiting. As a numerical example, we estimate that a 5 km long plasma-brake tether weighing 0.055 kg could produce 0.43 mN breaking force, which is enough to reduce the orbital altitude of a 260 kg object mass by 100 km over 1 year.

  15. 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.

  16. Design and multi-physics optimization of rotary MRF brakes

    Science.gov (United States)

    Topcu, Okan; Taşcıoğlu, Yiğit; Konukseven, Erhan İlhan

    2018-03-01

    Particle swarm optimization (PSO) is a popular method to solve the optimization problems. However, calculations for each particle will be excessive when the number of particles and complexity of the problem increases. As a result, the execution speed will be too slow to achieve the optimized solution. Thus, this paper proposes an automated design and optimization method for rotary MRF brakes and similar multi-physics problems. A modified PSO algorithm is developed for solving multi-physics engineering optimization problems. The difference between the proposed method and the conventional PSO is to split up the original single population into several subpopulations according to the division of labor. The distribution of tasks and the transfer of information to the next party have been inspired by behaviors of a hunting party. Simulation results show that the proposed modified PSO algorithm can overcome the problem of heavy computational burden of multi-physics problems while improving the accuracy. Wire type, MR fluid type, magnetic core material, and ideal current inputs have been determined by the optimization process. To the best of the authors' knowledge, this multi-physics approach is novel for optimizing rotary MRF brakes and the developed PSO algorithm is capable of solving other multi-physics engineering optimization problems. The proposed method has showed both better performance compared to the conventional PSO and also has provided small, lightweight, high impedance rotary MRF brake designs.

  17. SPINDOWN OF ISOLATED NEUTRON STARS: GRAVITATIONAL WAVES OR MAGNETIC BRAKING?

    Energy Technology Data Exchange (ETDEWEB)

    Staff, Jan E. [Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803-4001 (United States); Jaikumar, Prashanth; Chan, Vincent [Department of Physics and Astronomy, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, CA 90840 (United States); Ouyed, Rachid [Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada)

    2012-05-20

    We study the spindown of isolated neutron stars from initially rapid rotation rates, driven by two factors: (1) gravitational wave emission due to r-modes and (2) magnetic braking. In the context of isolated neutron stars, we present the first study including self-consistently the magnetic damping of r-modes in the spin evolution. We track the spin evolution employing the RNS code, which accounts for the rotating structure of neutron stars for various equations of state. We find that, despite the strong damping due to the magnetic field, r-modes alter the braking rate from pure magnetic braking for B {<=} 10{sup 13} G. For realistic values of the saturation amplitude {alpha}{sub sat}, the r-mode can also decrease the time to reach the threshold central density for quark deconfinement. Within a phenomenological model, we assess the gravitational waveform that would result from r-mode-driven spindown of a magnetized neutron star. To contrast with the persistent signal during the spindown phase, we also present a preliminary estimate of the transient gravitational wave signal from an explosive quark-hadron phase transition, which can be a signal for the deconfinement of quarks inside neutron stars.

  18. Neuroendocrine brake for the treatment of morbid obesity. Preliminary report

    Directory of Open Access Journals (Sweden)

    Aureo Ludovico de Paula

    2005-06-01

    Full Text Available Objectives: To demonstrate the preliminary results of a newtechnique named neuroendocrine brake, for surgical treatment ofmorbid obesity. Methods: In November 2003, three patientsunderwent the neuroendocrine brake operation performed by thelaparoscopic approach. The mean age was 46.4 years; all patientswere female. Mean BMI was 42.3 kg/m2. The patients selectedpresented some relative or absolute contraindications to the useof gastrointestinal bypass techniques, including gastric ulcer anda family history of gastric malignancy(1 and chronic anemia (2.All patients had associated diseases, including type II diabetesmellitus (2, hypertension (2, obstructive sleep apnea (1,dyslipidemia (3, cholecystolithiasis (1, gastric ulcer (1 andchronic anemia (2. The laparoscopic technique consisted of anileal interposition at the proximal jejunum and longitudinalgastrectomy. Results: There was no conversion to open surgery orpostoperative complications. Sixteen months later, the meanpercentage of initial body weight loss was 44.6% and the meanBMI was 24.3 kg/m2. Glucose, triglyceride and cholesterol levelswere normalized, and sleep apnea showed remission. Conclusion:In spite of the reduced number of patients and short term followup, the good results suggest that the neuroendocrine brake maybecome an option for surgical treatment of morbid obesity in thenear future.

  19. Further experimental studies in wet-brake friction

    Energy Technology Data Exchange (ETDEWEB)

    Staph, H.E.; Marbach, H.W. Jr.

    1986-01-01

    This paper describes further experimental efforts to determine friction characteristics that define the chatter potential in wet-brake systems as used in tractors and other off-road applications. Changes and improvements to a bench facility described at the 1985 Off-Highway Conference are described. Of particular interest is the decision to examine the very low sliding velocity regime, particularly below 0.34 m/s sliding velocity. Interesting and informative data have been obtained by feeding the input of an accelerometer attached in effect to the caliper brake pads to a frequency analyzer. A spectrum of the energy developed by the vibrating pads over the frequency range of 0 to 250 Hz while the sliding velocity is increased from 0 to 0.85 m/s is obtained. Specifically, the area under the composite frequency curve from 70 to 125 Hz shows good correlation to the chatter propensity of the oil. The results of tests on several oils are described. The ultimate purpose of the research is to provide a relatively rapid screening test for evaluating brake oils for the John Deere-type qualification tests. The overall results emphasize the importance of a low ratio between the breakaway friction and the friction at moderate sliding velocities for low or no chatter.

  20. 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.

  1. Predictive model of squeal noise occurring on a laboratory brake

    Science.gov (United States)

    Giannini, Oliviero; Sestieri, Aldo

    2006-09-01

    This paper on brake squeal instability presents a reduced order model of a laboratory brake considered in a previous paper, and presents a description of the squeal mechanism occurring during experiments. The model uses the modal parameters of the laboratory brake components, the disc and the caliper, when they are not in contact between them. Successively, the caliper and the disc are put in contact through the pad that is modeled as a one degree of freedom system while the Coulomb law models the friction interaction between them. No stick slip motion of the pad is considered, because it was not observed in the experimental tests. As a result the model is linear and particularly suited for a parametric analysis. The stability of the model is studied by a complex eigenvalue analysis and the obtained results show a good agreement with the experimental data, provided that the key parameters of the model are consistent with the experimental set-up. The key role of the disc and the pad dynamics are discussed.

  2. The Application of Vibration Accelerations in the Assessment of Average Friction Coefficient of a Railway Brake Disc

    Directory of Open Access Journals (Sweden)

    Sawczuk Wojciech

    2017-06-01

    Full Text Available Due to their wide range of friction characteristics resulting from the application of different friction materials and good heat dissipation conditions, railway disc brakes have long replaced block brakes in many rail vehicles. A block brake still remains in use, however, in low speed cargo trains. The paper presents the assessment of the braking process through the analysis of vibrations generated by the components of the brake system during braking. It presents a possibility of a wider application of vibroacoustic diagnostics (VA, which aside from the assessment of technical conditions (wear of brake pads also enables the determination of the changes of the average friction coefficient as a function of the braking onset speed. Vibration signals of XYZ were measured and analyzed. The analysis of the results has shown that there is a relation between the values of the point measures and the wear of the brake pads.

  3. The Application of Vibration Accelerations in the Assessment of Average Friction Coefficient of a Railway Brake Disc

    Science.gov (United States)

    Sawczuk, Wojciech

    2017-06-01

    Due to their wide range of friction characteristics resulting from the application of different friction materials and good heat dissipation conditions, railway disc brakes have long replaced block brakes in many rail vehicles. A block brake still remains in use, however, in low speed cargo trains. The paper presents the assessment of the braking process through the analysis of vibrations generated by the components of the brake system during braking. It presents a possibility of a wider application of vibroacoustic diagnostics (VA), which aside from the assessment of technical conditions (wear of brake pads) also enables the determination of the changes of the average friction coefficient as a function of the braking onset speed. Vibration signals of XYZ were measured and analyzed. The analysis of the results has shown that there is a relation between the values of the point measures and the wear of the brake pads.

  4. 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.

  5. COMPARISON OF THERMOELASTIC RESULTS IN TWO TYPES OF FUNCTIONALLY GRADED BRAKE DISCS

    Directory of Open Access Journals (Sweden)

    Z.N. Ismarrubie

    2012-06-01

    Full Text Available A thermoelastic simulation of functionally graded (FG brake discs is performed using finite element (FE ANSYS. The material properties of two types of FG brake discs are assumed to vary in both radial and thickness directions according to a power law distribution. The brake discs are in contact with one hollow pure pad disc. Dry contact friction is considered as the heat source. The proper thicknesses of pad discs are found to have full-contact status. The behaviour of the thermoelastic results for thickness and radial FG brake discs are compared. The results show that the behaviour of temperature and vertical displacement in these two types of FG brake discs are the same. However, the variations of radial displacement for different grading indices are not the same. The behaviour of other results are quite similar. Thus, it can be concluded that the variation direction of material properties in FG brake discs can affect the results.

  6. The method of feed-in energy on disc brake squeal

    Science.gov (United States)

    Guan, Dihua; Huang, Jinchun

    2003-03-01

    Brake squeal is studied in this paper by feed-in energy analysis. Based on the brake closed-loop coupling model, a calculation method of feed-in energy for squeal mode is derived. Result of the feed-in energy indicates squeal tendency of the brake system, while formula for calculating it discloses the relation among brake squeal phenomenon and structural parameters, such as frictional coefficient, geometric shape of brake pads, elastic modulus of frictional material, substructure modal shape, etc. The method also helps to analyze the effectiveness of various structural modification schemes attempted to eliminate the squeal noise. Finally, this method is illustrated by application to a typical squealing disc brake.

  7. An Extended Prediction Model for Airplane Braking Distance and a Specification for a Total Braking Prediction Systems. Volume 2

    Science.gov (United States)

    1977-03-01

    o this repoi t describes the hardware and antiskid systems used on the brake control simulator as well as the test conditions and parameters used in...Figure 3.-B-52H Locked Wheel anid Skid Detector -7 IiV C)i j I tA IL (n:ZIL i ouo \\r Ix LA-J ji U1L 8sLALJZ -jI B. LOCKED- WHELL AND "TOUCHDOWN PROTE

  8. Design of an innovative bike brake integrated into the wheel hub

    OpenAIRE

    Crescenti, M.; Ortiz Marzo, José Antonio

    2012-01-01

    The public urban bike services demand more robust mechanical devices to resist misuse and vandalism. An innovative wheel hub integrated bike brake was designed making use of CAD-3D and numerical analysis tools and considering both technological and economical criteria. Unlike the other existing hub integrated bike brakes, the new design ensures an homogeneous pressure distribution on the braking pads, which maximizes its lifespan, reduces the maintenance costs and guarantees an uniform perfor...

  9. Experimental and numerical analysis of thermal striping in automotive brake discs

    OpenAIRE

    Augustins, L; Hild, Francois; Billardon, R; Boudevin, S

    2017-01-01

    International audience; In the present study, thermal striping development on friction bands of brake discs is investigated through an experimental and numerical analysis. A test consisting of a series of several hundred severe brakings was carried out on a specific bench at PSA Peugeot Citroën. The experimental observations of the crack network evolution and a numerical analysis of a brake disc with a single crack helped to propose a macroscopic criterion capable of predicting the criticalit...

  10. COMPARISON OF THERMOELASTIC RESULTS IN TWO TYPES OF FUNCTIONALLY GRADED BRAKE DISCS

    OpenAIRE

    Z.N. Ismarrubie; M. Bayat; M.M. Shahzamanian; B.B. Sahari; F. Mustapha

    2012-01-01

    A thermoelastic simulation of functionally graded (FG) brake discs is performed using finite element (FE) ANSYS. The material properties of two types of FG brake discs are assumed to vary in both radial and thickness directions according to a power law distribution. The brake discs are in contact with one hollow pure pad disc. Dry contact friction is considered as the heat source. The proper thicknesses of pad discs are found to have full-contact status. The behaviour of the thermoelastic res...

  11. Dynamic performance analysis of a seismically isolated bridge under braking force

    Science.gov (United States)

    Yu, Fang; Wen, Liuhan ·heisha; Zhou, Fulin; Ye, Lieping

    2012-03-01

    In order to study the dynamic performance of seismically isolated bridges under the most unfavorable loads in the longitudinal direction, a dynamic equation for vehicle braking in the longitudinal direction is established. A four or fiveorder Runge-Kutta method is adopted to obtain the time-history response of a wheel set under braking force. The quadratic discretization method is then used to transform this time-history into a braking and bending force time-history of a structural fixed node, and a dynamic response analysis of the seismically isolated bridge under the vehicle's braking force is carried out using ANSYS, a universal finite element analysis software. According to the results, seismic isolation design results in a more rational distribution of braking force among piers; the influence of the initial braking velocity on the vehicle braking force is negligible; the location where the first wheel set leaves the bridge is the most unfavorable parking location; a seismic isolation bridge bearing constructed according to typical design methods enters into a yield stage under the braking force, while the shearing force at the bottom of the pier declines as the isolation period is extended; the design requirements can be met when the yield displacement of the seismic isolation bearing is less than 5 mm and the yield strength is greater than the braking force.

  12. Brake fault diagnosis using Clonal Selection Classification Algorithm (CSCA – A statistical learning approach

    Directory of Open Access Journals (Sweden)

    R. Jegadeeshwaran

    2015-03-01

    Full Text Available In automobile, brake system is an essential part responsible for control of the vehicle. Any failure in the brake system impacts the vehicle's motion. It will generate frequent catastrophic effects on the vehicle cum passenger's safety. Thus the brake system plays a vital role in an automobile and hence condition monitoring of the brake system is essential. Vibration based condition monitoring using machine learning techniques are gaining momentum. This study is one such attempt to perform the condition monitoring of a hydraulic brake system through vibration analysis. In this research, the performance of a Clonal Selection Classification Algorithm (CSCA for brake fault diagnosis has been reported. A hydraulic brake system test rig was fabricated. Under good and faulty conditions of a brake system, the vibration signals were acquired using a piezoelectric transducer. The statistical parameters were extracted from the vibration signal. The best feature set was identified for classification using attribute evaluator. The selected features were then classified using CSCA. The classification accuracy of such artificial intelligence technique has been compared with other machine learning approaches and discussed. The Clonal Selection Classification Algorithm performs better and gives the maximum classification accuracy (96% for the fault diagnosis of a hydraulic brake system.

  13. Effectiveness of Flashing Brake and Hazard Systems in Avoiding Rear-End Crashes

    Directory of Open Access Journals (Sweden)

    Guofa Li

    2014-01-01

    Full Text Available Three experiments were conducted to examine the effectiveness of two forward crash warning systems, a flashing brake system and a flashing hazard system, using an advanced driving simulator. In Experiment 1, 20 subjects followed a lead vehicle with a desired time gap and braked when necessary. Results showed that time gap, velocity, and deceleration of the lead vehicle all significantly affected drivers’ brake response times. In Experiment 2, six brake response times to a sudden lead vehicle deceleration (0.6 g at 80 km/h were measured for six time gaps. Results showed that flashing brake system and flashing hazard system reduced drivers' brake response times by 0.14~0.62 s and 0.03~0.95 s, respectively, in the various situations tested. The effects of flashing color and illuminated size on drivers' brake response times were examined in Experiment 3. Results showed that flashing amber lamps reduced drivers' brake response times significantly by 0.11 s (10% on average compared with red lamps. These findings demonstrate the effectiveness of both flashing systems in reducing drivers' brake response times in urgent situations and may warrant further consideration by manufacturers.

  14. Aspects regarding manufacturing technologies of composite materials for brake pad application

    Science.gov (United States)

    Craciun, A. L.; Hepuţ, T.; Pinca-Bretotean, C.

    2018-01-01

    Current needs in road safety, requires the development of new technical solutions for automotive braking system. Their safe operation is subject to following factors: concept design, materials used and electronic control. Among the factors previously listed, choice of materials and manufacturing processes are difficult stage but very important for achieving technical performance and getting a relatively small cost of constituting parts of brake system. The choice is based on the promotion of organic composite material, popular in areas where the weight of materials plays an important role. The brake system is composed of many different parts including brake pads, a master cylinder, wheel cylinders and a hydraulic control system. The brake pads are an important component in the braking system of automotive. These are of different types, suitable for different types of automotive and engines. Brake pads are designed for friction stability, durability, minimization of noise and vibration. The typology of the brake pads depends on the material which they are made. The aim of this paper is to presents the manufacturing technologies for ten recipes of composite material used in brake pads applications. In this work will be done: choosing the constituents of the recipes, investigation of their basic characteristics, setting the proportions of components, obtaining the composite materials in laboratory, establishing the parameters of manufacturing technology and technological analysis.

  15. A parametric study of golf car and personal transport vehicle braking stability and their deficiencies.

    Science.gov (United States)

    Seluga, Kristopher J; Baker, Lowell L; Ojalvo, Irving U

    2009-07-01

    This paper describes research and parametric analyses of braking effectiveness and directional stability for golf cars, personal transport vehicles (PTVs) and low speed vehicles (LSVs). It is shown that current designs, which employ brakes on only the rear wheels, can lead to rollovers if the brakes are applied while traveling downhill. After summarizing the current state of existing safety standards and brake system designs, both of which appear deficient from a safety perspective, a previously developed dynamic simulation model is used to identify which parameters have the greatest influence on the vehicles' yaw stability. The simulation results are then used to parametrically quantify which combination of these factors can lead to yaw induced rollover during hard braking. Vehicle velocity, steering input, path slope and tire friction are all identified as important parameters in determining braking stability, the effects of which on rollover propensity are presented graphically. The results further show that when vehicles are equipped with front brakes or four-wheel brakes, the probability of a yaw induced rollover is almost entirely eliminated. Furthermore, the parametric charts provided may be used as an aid in developing guidelines for golf car and PTV path design if rear brake vehicles are used.

  16. Effects of cryogenic treatment on the wear properties of brake discs

    Science.gov (United States)

    Nadig, D. S.; Shivakumar, P.; Anoop, S.; Chinmay, Kulkarni; Divine, P. V.; Harsha, H. P.

    2017-02-01

    Disc brakes are invariably used in all the automobiles either to reduce the rotational speed of the wheel or to hold the vehicle stationary. During the braking action, the kinetic energy is converted into heat which can result in high temperatures resulting in fading of brake effects. Brake discs produced out of martensite stainless steel (SS410) are expected to exhibit high wear resistance properties with low value of coefficient of friction. These factors increase the useful life of the brake discs with minimal possibilities of brake fade. To study the effects of cryogenic treatment on the wear behaviour, two types of brake discs were cryotreated at 98K for 8 and 24 hours in a specially developed cryotreatment system using liquid nitrogen. Wear properties of the untreated and cryotreated test specimens were experimentally determined using the pin on disc type tribometer (ASTM G99-95). Similarly, the Rockwell hardness (HRC) of the specimens were tested in a hardness tester in accordance with ASTM E18. In this paper, the effects of cryotreatment on the wear and hardness properties of untreated and cryotreated brake discs are presented. Results indicate enhancement of wear properties and hardness after cryogenic treatment compared with the normal brakes discs.

  17. 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.

  18. 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

  19. An Experimental Study on Hysteresis Characteristics of a Pneumatic Braking System for a Multi-Axle Heavy Vehicle in Emergency Braking Situations

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2017-08-01

    Full Text Available This study aims to investigate the hysteresis characteristics of a pneumatic braking system for multi-axle heavy vehicles (MHVs. Hysteresis affects emergency braking performance severely. The fact that MHVs have a large size and complex structure leads to more nonlinear coupling property of the pneumatic braking system compared to normal two-axle vehicles. Thus, theoretical analysis and simulation are not enough when studying hysteresis. In this article, the hysteresis of a pneumatic brake system for an eight-axle vehicle in an emergency braking situation is studied based on a novel test bench. A servo drive device is applied to simulate the driver’s braking intensions normally expressed by opening or moving speed of the brake pedal. With a reasonable arrangement of sensors and the NI LabVIEW platform, both the delay time of eight loops and the response time of each subassembly in a single loop are detected in real time. The outcomes of the experiment show that the delay time of each loop gets longer with the increase of pedal opening, and a quadratic relationship exists between them. Based on this, the pressure transient in the system is fitted to a first-order plus time delay model. Besides, the response time of treadle valve and controlling pipeline accounts for more than 80% of the loop’s total delay time, indicating that these two subassemblies are the main contributors to the hysteresis effect.

  20. 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.

  1. Brake Reaction Time After Ankle and Subtalar Arthroscopy.

    Science.gov (United States)

    Sittapairoj, Tinnart; Anthony, Chris A; Rungprai, Chamnanni; Gao, Yubo; Barg, Alexej; Phisitkul, Phinit

    2017-11-01

    To evaluate preoperative and postoperative brake reaction time (BRT) of patients undergoing right-sided ankle or subtalar arthroscopy. Patients who underwent right-sided ankle or subtalar arthroscopy were evaluated between May 2015 and February 2017. The inclusion criteria consisted of patients older than 18 years who possessed a valid driver's license, primarily drove vehicles that had automatic transmission, and used their right foot to depress the brake pedal. Patients were excluded if they had medical problems that precluded safe and legal driving. An automotive simulation device was used to calculate BRT from all participants. Each patient underwent testing on a computerized driving simulator preoperatively and then postoperatively at 2, 6, and 12 weeks or until their BRT was equal to or less than 0.7 seconds. BRT was defined as the time from stop stimulus until brake depression of 5%. The study enrolled 17 patients and 19 age-matched normal subjects. Patients showed an average BRT at 2 weeks postoperatively (0.57 ± 0.06 seconds) that was greater than the BRT in the control group (0.55 ± 0.06 seconds, P = .84) and lower than the patients' preoperative BRT (0.59 ± 0.06 seconds, P = .08). These BRTs were lower than the 0.70-second BRT threshold for safe driving in the United States. The results of this study show that emergency BRT after right-sided ankle or subtalar arthroscopy improves by 2 weeks after surgery and is under the previously set benchmark of 0.7 seconds. In patients who undergo right-sided ankle or subtalar arthroscopic procedures, it is not unsafe to drive a vehicle at 2 weeks. Level III, retrospective comparative study. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  2. 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

  3. Effect of various pre-crash braking strategies on simulated human kinematic response with varying levels of driver attention

    NARCIS (Netherlands)

    Rooij, L. van

    2011-01-01

    In this study, human kinematic response resulting from various pre-crash braking scenarios is quantified. The underlying question is what kind of effect do pre-crash braking systems have on the driver or the front seat passenger.

  4. 49 CFR 232.103 - General requirements for all train brake systems.

    Science.gov (United States)

    2010-10-01

    ... of stopping the train with a service application from its maximum operating speed within the signal...) Reducing valve for high-speed brake (minimum) 50 [66 FR 4193, Jan. 17, 2001, as amended at 67 FR 17581, Apr... 49 Transportation 4 2010-10-01 2010-10-01 false General requirements for all train brake systems...

  5. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Science.gov (United States)

    2010-10-01

    ... is conducted with no electrical power supplied to the vehicle's propulsion motor(s), but with the RBS... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 135; Light vehicle brake systems. 571... Federal Motor Vehicle Safety Standards § 571.135 Standard No. 135; Light vehicle brake systems. S1. Scope...

  6. Optimized antilock braking system and traction control system. Antiblockiersystem und Antriebsschlupfregelung der fuenften Generation

    Energy Technology Data Exchange (ETDEWEB)

    Jonner, W.D.; Maisch, W.; Mergenthaler, R.; Sigl, A.

    1993-11-01

    The structure and function of the ABS 5 and ABS/ASR 5 hydraulic units are shown here. Using a modified self-priming pump to supply energy for brake intervention and using a small 2/2-solenoid leads to compact, cost-effective hydraulic units. The brake circuits remain closed which provides maximum safety at minimum expense. (orig./HW)

  7. FEATURES OF RESOURCE TESTING OF THE HYDRAULIC BRAKE DRIVE ELEMENTS OF VEHICLES EQUIPPED WITH ABS

    Directory of Open Access Journals (Sweden)

    A. Revin

    2011-01-01

    Full Text Available The analysis of the resource testing facilities and methods of automobile brake cylinders in terms of ABS working process adequacy is carried out. A testing stand construction and a method of carrying out the resource testing of hydraulic drive elements of the automobile automated braking sys-tem is offered.

  8. 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.

  9. 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

  10. 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 require...

  11. A Novel Dynamic Measurement System for Evaluating the Braking Coordination of Articulated Vehicles

    Directory of Open Access Journals (Sweden)

    Xu Li

    2016-01-01

    Full Text Available The braking coordination between tractor and semitrailer is vital to the safety of articulated vehicles. Traditional evaluation about braking coordination is based on the pressure measurement along air braking pipeline, which needs to change original braking structure to install gauges and cannot directly reflect the final braking coordination of different wheels. To overcome these limitations, this paper proposes a novel dynamic measurement system for evaluating the braking coordination of articulated vehicles. During the brake test, all wheel velocities of the whole articulated vehicle are synchronously obtained through a specially designed distributed acquisition platform. To effectively eliminate gross errors and noises in wheel angular velocity data, a 3-order autoregressive (AR model and an improved-thresholding wavelet filtering algorithm are developed. Further, a novel direct evaluation method about braking coordination is proposed according to the differences in angular velocity dropping time of all wheels. Finally, the overall system is assessed through real field tests. The results validate the feasibility and effectiveness of the proposed system.

  12. 77 FR 39561 - Advanced Braking Technologies That Rely on Forward-Looking Sensors; Request for Comments

    Science.gov (United States)

    2012-07-03

    ... Sensors; Request for Comments AGENCY: National Highway Traffic Safety Administration (NHTSA), Department... technologies that rely on forward-looking sensors to supplement driver braking or to actuate automatic braking... information from forward-looking sensors, usually a camera or radar, to determine whether or not a crash is...

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

    OpenAIRE

    Tao Liu; Jincheng Zheng; Yongmao Su; Jinghui Zhao

    2013-01-01

    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/simul...

  14. Comparing Variability of Parameters between Roller Bed Brakes Testers and Dynamometric Platform of Ministry Of Transport Facilities

    OpenAIRE

    Senabre C; Valero S; Velasco E

    2015-01-01

    This study gives a comparison between which parameters may vary when braking on two different Ministry of Transport (MOT) brake testers, such as roller bed brake tester and dynamometric platform. A comparative study between both types of brake testers have been carried out by the mechanical engineering staffs at the mechanical laboratory at the Miguel Hernández University in Elche to determinate which parameters can vary the result of the test.

  15. Comparing Variability of Parameters between Roller Bed Brakes Testers and Dynamometric Platform of Ministry Of Transport Facilities

    Directory of Open Access Journals (Sweden)

    Senabre C

    2015-01-01

    Full Text Available This study gives a comparison between which parameters may vary when braking on two different Ministry of Transport (MOT brake testers, such as roller bed brake tester and dynamometric platform. A comparative study between both types of brake testers have been carried out by the mechanical engineering staffs at the mechanical laboratory at the Miguel Hernández University in Elche to determinate which parameters can vary the result of the test.

  16. The process of gas-dynamic design of pneumatic braking system using the baseline compressor

    Science.gov (United States)

    Novikova, Y.; Popov, G.; Goriachkin, E.; Baturin, O.; Zubanov, V.

    2017-08-01

    The article presents the results of work on the design of the air brake for testing of industrial gas turbine engines with free turbine. Designing of the air brake was performed on the basis of existing units using the program CFD - simulation Numeca FineTurbo. During the design the air brake arrangement was determined, which allows to utilize the required power to the shaft of the free turbine, increases stall margin of the air brake by waisting of the meridional flow channel. It was also made designing of the outlet guide vane to remove the residual twist. Unified nozzle also was designed to provide the air brake work at necessary points on the characteristic.

  17. NORMALIZATION OF AUTOMOTIVE BRAKE CHARACTERISTICS WHILE OPERATING THEM IN THE REPUBLIC OF BELARUS

    Directory of Open Access Journals (Sweden)

    I. Flerko

    2012-01-01

    Full Text Available Safety provision for the operated auto-transport facilities is of great significance all over the world. The problem is also considered as an actual one for the automotive transport of theRepublicofBelarus. Provision of higher brake system reliability for the operated vehicles is one of the directions to solve the problem pertaining to improve traffic safety.The paper contains an analysis of basic national standard documents which regulate brake characteristics for the operated vehicles, evaluates checking methods of braking efficiency and vehicle stability at the moment of braking, considers some problems pertaining to methods used for checking and estimation of braking control systems of transport facilities. 

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

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

    The new trend in adjustable speed drives (ASD) is to integrate the inverter and the motor into a single unit in order to reduce the production cost, the commissioning time, and the physical size of the equipment. This last issue becomes more important, making the matrix converter topology more...... attractive. Sinusoidal input currents and bi-directional power flow are other advantages of the matrix converter, but it is less immune to power grid disturbances compared to a standard ASD. In hoisting applications, short-term braking capability during a power outage is needed until the mechanical brake...... engages or to perform more effective a combined braking. This paper proposes a new method to provide short-term braking capability during a power outage for matrix converters. A braking chopper is needed in the clamp circuit, which allows for a drastically reduction of the capacitor size. The power flow...

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

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2002-01-01

    The new trend in Adjustable Speed Drives (ASD) is to integrate the inverter and the motor into a single unit in order to reduce the production cost, the commissioning time and the physical size of the equipment. This last issue becomes more important, making the matrix converter topology more...... attractive. Sinusoidal input currents and bi-directional power flow are other advantages of the matrix converter but it is less immune to power grid disturbances compared to a standard ASD. In hoisting applications, short-term braking capability during a power outage is needed until the mechanical brake...... engages or to perform more effective a combined braking.This paper proposes a new method to provide short-term braking capability during a power outage for matrix converters. A braking chopper is needed in the clamp circuit, which allows for a drastically reduction of the capacitor size. The power flow...

  20. 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.

  1. Investigation of regenerative braking in inclined mine hoisting systems during load lowering

    Energy Technology Data Exchange (ETDEWEB)

    Belobrov, V.I.; Sirotin, S.S. (IGTM AN UkSSR (USSR))

    1990-05-01

    Investigates operation of mine hoisting systems during regenerative braking and lowering of loads. Formulae for calculating deceleration and velocity during braking are given and discussed. Results of investigations of four different hoisting systems conducted in four mines with shafts inclined by 5-37 degrees are presented, e.g. deceleration time 1.74-4.3 s, cage (skip) velocity at deceleration begin 3.21-4.3 m/s, deceleration during regenerative braking 0.8-1.95 m/s{sup 2} and maximum braking force 56.48-110.98 kN. The effect of inclined deceleration and shaft inclination angle on hoisting rope behaviour and loads on ropes is discussed. The following conclusions were reached on the basis of investigation results: operation mode with regenerative braking is not less hazardous than hoisting and particular difficulties occur in shafts with significant differences in inclination angles. 2 refs.

  2. 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

  3. Choice of time-headway in car-following and the role of time-to-collision information in braking.

    Science.gov (United States)

    Van Winsum, W; Heino, A

    1996-04-01

    Time-headway (THW) during car-following and braking response were studied in a driving simulator from the perspective that behaviour on the manoeuvring level (e.g. choice of THW) may be linked to operational competence of vehicle control (e.g. braking) via a process of adaptation. Time-headway was consistent within drivers and constant over a range of speeds. Since time-headway represents the time available to the driver to reach the same level of deceleration as the lead vehicle in case it brakes, it was studied whether choice of time-headway was related to skills underlying braking performance. The initiation and control of braking were both affected by time-to-collision (TTC) at the moment the lead vehicle started to brake. This strongly supported the idea that time-to-collision information is used for judging the moment to start braking and in the control of braking. No evidence was found that short followers differ from long followers in the ability to accurately perceive TTC. There was, however, evidence that short followers are better able to programme the intensity of braking to required levels. Also, short followers tuned the control of braking better to the development of criticality in time during the braking process. It was concluded that short followers may differ from long followers in programming and execution of the braking response.

  4. Characterization of the high-frequency squeal on a laboratory brake setup

    Science.gov (United States)

    Giannini, Oliviero; Massi, Francesco

    2008-02-01

    This paper presents an experimental investigation on high-frequency brake squeal noise conducted on an appropriately designed experimental rig, called laboratory brake. Brake squeal is one of the major issues in the design process of an automotive brake and the development of a robust procedure for a "squeal-free" design is still under investigation. The high-frequency squeal is the most frequent noise generated by automotive brakes and is characterized by a wavelength of the "squealing mode" comparable to the length of the brake pad. The proposed "laboratory brake" is a good compromise between simple test rigs, such as the beam-on-disc, and the experimental setups that use real brakes. The beam-on-disc setup is a useful tool to understand the mechanism leading to the instability, but it does not simulate appropriately a real brake. On the other hand, real brakes are too complex for fundamental investigation and for efficient modeling. The experimental analysis shows a strong correlation between the length of the pad, the dynamic behavior of the system, and the squealing deformed shape. Moreover, depending on the length of the pad compared with the wavelength of the disc mode, three different kind of squeal instability may occur during experiments: the sine mode squeal, the cosine mode squeal and the rotating squeal. The latter is characterized by nodal diameters rotating during a squeal cycle. A linear reduced model, able to reproduce the dynamic behavior of the experimental setup, is used to predict the squeal occurrence. However, such linear model is not able to predict the rotating squeal characteristic that seems to be caused by nonlinear interactions due to the contact between the disc and the caliper.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Wind turbine trailing-edge aerodynamic brake design

    Energy Technology Data Exchange (ETDEWEB)

    Quandt, G.

    1996-01-01

    This report describes the design of a centrifugally actuated aerodynamic-overspeed device for a horizontal-axis wind turbine. The device will meet the following criteria; (1) It will be effective for airfoil angles of attack 0{degrees} to 45{degrees}. (2) It will be stowed inside the blade profile prior to deployment. (3) It will be capable of offsetting the positive torque produced by the overall blade. (4) Hinge moments will be minimized to lower actuator loads and cost. (5) It will be evaluated as a potential power modulating active rotor-control system. A literature review of aerodynamic braking devices was conducted. Information from the literature review was used to conceptualize the most effective devices for subsequent testing and design. Wind-tunnel test data for several braking devices are presented in this report. Using the data for the most promising configuration, a preliminary design was developed for a MICON 65/13 wind turbine with Phoenix 7.9-m rotor blades.

  10. Elemental composition of current automotive braking materials and derived air emission factors

    Science.gov (United States)

    Hulskotte, J. H. J.; Roskam, G. D.; Denier van der Gon, H. A. C.

    2014-12-01

    Wear-related PM emissions are an important constituent of total PM emissions from road transport. Due to ongoing (further) exhaust emission reduction wear emissions may become the dominant PM source from road transport in the near future. The chemical composition of the wear emissions is crucial information to assess the potential health relevance of these PM emissions. Here we provide an elemental composition profile of brake wear emissions as used in the Netherlands in 2012. In total, 65 spent brake pads and 15 brake discs were collected in car maintenance shops from in-use personal cars vehicles and analyzed with XRF for their metal composition (Fe, Cu, Zn, Sn, Al, Si, Zr, Ti, Sb, Cr, Mo, Mn, V, Ni, Bi, W, P, Pb and Co). Since car, engine and safety regulations are not nationally determined but controlled by European legislation the resulting profiles will be representative for the European personal car fleet. The brake pads contained Fe and Cu as the dominant metals but their ratio varied considerably, other relatively important metals were Sn, Zn and Sb. Overall a rather robust picture emerged with Fe, Cu, Zn and Sn together making up about 80-90% of the metals present in brake pads. Because the XRF did not give information on the contents of other material such as carbon, oxygen and sulphur, a representative selection of 9 brake pads was further analyzed by ICP-MS and a carbon and sulphur analyzer. The brake pads contained about 50% of non-metal material (26% C, 3% S and the remainder mostly oxygen and some magnesium). Based on our measurements, the average brake pad profile contained 20% Fe, 10% Cu, 4% Zn and 3% Sn as the dominant metals. The brake discs consisted almost entirely of metal with iron being the dominant metal (>95%) and only traces of other metals (brake discs to total brake wear. Based on this approach our hypothesis is that 70% of the brake wear originates from the discs and only 30% from the brake pads.

  11. Preiskave litih zavornih diskov iz kompozitov Al/SiC: Investigations of Al/SiC MMCs brake discs:

    OpenAIRE

    Breskvar, Bojan; Stadler, Zmago; Šuštaršič, Borivoj

    2000-01-01

    Sinter, Ljubljana, Slovenia is one of the world's largest producers of brake pads for go-karts. In high class and high price go-karts, the replacement of conventional grey cast-iron brake discs by lighter and frictionally more suitable brake discs based on Al/SiC MMCs is in progress. Besides the development of brake pads for the new disc mateial it was also necessary to develop a production technology for al/SiC brake discs. The characteristics of the new disc material, as well as the selecte...

  12. 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.

  13. 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.

  14. Research on transient thermal process of a friction brake during repetitive cycles of operation

    Science.gov (United States)

    Slavchev, Yanko; Dimitrov, Lubomir; Dimitrov, Yavor

    2017-12-01

    Simplified models are used in the classical engineering analyses of the friction brake heating temperature during repetitive cycles of operation to determine basically the maximum and minimum brake temperatures. The objective of the present work is to broaden and complement the possibilities for research through a model that is based on the classical scheme of the Newton's law of cooling and improves the studies by adding a disturbance function for a corresponding braking process. A general case of braking in non-periodic repetitive mode is considered, for which a piecewise function is defined to apply pulse thermal loads to the system. Cases with rectangular and triangular waveforms are presented. Periodic repetitive braking process is also studied using a periodic rectangular waveform until a steady thermal state is achieved. Different numerical methods such as the Euler's method, the classical fourth order Runge-Kutta (RK4) and the Runge-Kutta-Fehlberg 4-5 (RKF45) are used to solve the non-linear differential equation of the model. The constructed model allows during pre-engineering calculations to be determined effectively the time for reaching the steady thermal state of the brake, to be simulated actual braking modes in vehicles and material handling machines, and to be accounted for the thermal impact when performing fatigue calculations.

  15. Advanced brake system with highest flexibility; Konzept fuer eine elektromechanische Fahrzeugbremse

    Energy Technology Data Exchange (ETDEWEB)

    Balz, J.; Bill, K.; Boehm, J.; Scheerer, P.; Semsch, M.

    1996-06-01

    The general aspect of permanent improvement of active driving safety is increasingly taken into account by wheel-selective brake access like ABS, TCS and ASMS. In this context one basic problem occurs: Pedal pulsation or other interferences, caused by the intervention of the superset brake management which acts partially in superposition to the drivers brake demand and the wheel-brake actuation, which leads to a `Brake by Wire`-System. The ITT Automotive-approach of electromechanically actuated brakes presented in this paper demonstrates the enormous function potential in combination with environmental and cost aspects and describes the realization of a specific `fail-Safe` concept. (orig.) [Deutsch] Bremsanlagen fuer Automobile werden immer komplexer. Das Antiblockiersystem (ABS), die Traction-Control und Fahrzeug-Stabilisierungssysteme wie das ASMS von ITT Automotive verlangen individuelle Bremseingriffe fuer einzelne Raeder. Der Fahrer merkt dies beispielsweise durch das Pulsieren des Pedals bei der ABS-Regelung. Abhilfe schafft eine Entkoppelung von Radbremsbetaetigung und Pedal. Letzteres sorgt ueber geeignete Sensoren nur noch fuer die Erfassung des Fahrerwunsches. `Brake by Wire` heisst ein Loesungsansatz des Bremsenherstellers ITT Automotive (Marken Ate und Teves). Wie der Name schon sagt, arbeitet die Fahrzeugbremse elektromechanisch. Der Verzicht auf Hydraulikfluessigkeit ist auch ein Beitrag zum Umweltschutz. Wirtschaftliche Aspekte birgt beispielsweise der Wegfall von Hydraulikleitungen in sich. Und der Ausfallsicherheit wird durch das `Fail-Safe`-Konzept Rechnung getragen. (orig.)

  16. Three-dimensional finite element magnetic simulation of an innovative multi-coiled magnetorheological brake

    Science.gov (United States)

    Ubaidillah; Permata, A. N. S.; Mazlan, S. A.; Tjahjana, D. D. D. P.; Widodo, P. J.

    2017-10-01

    This research delivers a finite element magnetic simulation of a novel disk type multi-coil magnetorheological brake (MR brake). The MR brake axial design had more than one coil located outside of the casing. This design could simplify the maintenance process of brakes. One pair of coils was used as the representative of the entire coil in the simulation process, and it could distribute magnetic flux in all parts of the electromagnetic. The objective of this simulation was to produce magnetic flux on the surface of the disc brake rotor. The value of the MR brake magnetic flux was higher than that of the current MR brake having one coil with a larger size. The result of the simulation would be used to identify the effect of different fluids on each variation. The Magneto-rheological fluid MRF-132DG and MRF-140CG were injected in each gap as much as 0.50, 1.00, and 1.50 mm, respectively. On the simulation process, the coils were energized at 0.25, 0.50, 0.75, 1.00, 1.50, and 2.00 A, respectively. The magnetic flux produced by MRF-140CG was 336 m Tesla on the gap of 0.5 mm. The result of the simulation shows that the smaller the gap variation was, the higher the magnetic value was.

  17. A Study on Rotordynamic Characteristics of Swirl Brakes for Three Types of Seals

    Science.gov (United States)

    Xu, Wanjun; Yang, Jiangang

    2017-03-01

    In order to understand swirl brakes mechanisms and their influence on rotordynamic characteristics for different types of seals, a three-dimensional flow numerical simulation was presented. Three typical seals including labyrinth seal, fully partitioned damper seal and hole-pattern seal were compared under three inlet conditions of no preswirl, preswirl and preswirl with swirl brakes. FAN boundary condition was used to provide inlet preswirl. A modified identification method of effective damping was proposed. Feasibility of the swirl brakes on improving performance of damper seals was discussed. The results show that the swirl brakes influence the seal stability characteristics with whirl frequency. For the labyrinth seal the swirl brakes reverse the sign of effective damping at low frequency and improve the seal stability performance in a wide frequency range. The swirl brakes also improve the damper seals’ stability performance by increasing the low frequency effective damping and reducing their crossover frequency. Further results indicate the swirl brakes affect the rotational direction of the maximum (minimum) pressure positions and enhance the stability of the seals by reducing tangential force in each cavity.

  18. Frictional behavior of automotive brake materials under wet and dry conditions

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.; Martin, R.L. [Oak Ridge National Lab., TN (United States); Weintraub, M.H.; Jang, Ho; Donlon, W. [Ford Motor Co., Dearborn, MI (United States)

    1996-12-15

    The purpose of this effort was to develop an improved understanding of the relationship between the structure and frictional behavior of materials in the disc brake/rotor interface with a view toward improving the performance of automotive disc brakes. The three tasks involved in this Cooperative Research and Development Agreement (CRADA) were as follows: Task 1. Investigation of Brake Pads and Rotors. Characterize surface features of worn brake pads and rotors, with special attention to the transfer film which forms on them during operation. Ford to supply specimens for examination and other supporting information. Task 2. Effects of Atmosphere and Repeated Applications on Brake Material Friction. Conduct pin-on-disk friction tests at ORNL under controlled moisture levels to determine effects of relative humidity on frictional behavior of brake pad and rotor materials. Conduct limited tests on the characteristics of friction under application of repeated contacts. Task 3. Comparison of Dynamometer Tests with Laboratory Friction Tests. Compare ORNL friction data with Ford dynamometer test data to establish the degree to which the simple bench tests can be useful in helping to understand frictional behavior in full-scale brake component tests. This final report summarizes work performed under this CRADA.

  19. 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.

  20. 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.

  1. SBC - the electro-hydraulic brake system from Mercedes-Benz; SBC - Die elektrohydraulische Bremse von Mercedes-Benz

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, U.

    2000-07-01

    The electro-hydraulic brake (EHB) is the first generation of future 'Brake-by-Wire' systems for cars. EHB is a new mechatronic brake system, which links adaptive, digital control technology with integrated pressure sensors and high-precision hydraulic valves which are, however, fit for volume production. It permits highly dynamic, individual wheel brake pressure control which provides excellent stability and optimum short braking distances. The 'Brake-by-Wire' interface of the system permits driver-independent brake applications to improve vehicle safety. The system is developed by DaimlerChrysler in co-operation with the system supplier Robert Bosch under the brand name SBC (Sensotronic Brake Control) to series manufacture. (orig.) [German] Die elektrohydraulische Bremse EHB ist die erste Generation kuenftiger 'Brake-by-Wire'-Systeme im PKW. EHB ist ein neues mechatronisches Bremsensystem, das adaptive, digitale Regeltechnik mit integrierter Drucksensorik und hochpraezisen aber grossserienfaehigen Hydraulikventilen verbindet. Es ermoeglicht eine hochdynamische, radindividuelle Bremsdruckregelung fuer hervorragende Stabilitaet und optimal kurze Bremswege. Die 'Brake-by-Wire'-Schnittstelle des Systems gestattet fahrerunabhaengige Bremseneingriffe zur Verbesserung der Fahrzeugsicherheit. Das System wird von DaimlerChrysler in Zusammenarbeit mit dem Systemlieferanten Robert Bosch unter dem Markennamen SBC (Sensotronic Brake Control) zur Serienreife zu entwickeln. (orig.)

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. Noise and Vibration Modeling for Anti-Lock Brake Systems

    Science.gov (United States)

    Zhan, Wei

    A new methodology is proposed for noise and vibration analysis for Anti-Lock Brake Systems (ABS). First, a correlation between noise and vibration measurement data and simulation results need to be established. This relationship allows the engineers to focus on modeling and simulation instead of noise and vibration testing. A comprehensive ABS model is derived for noise and vibration study. The model can be set up to do different types of simulations for noise and vibration analysis. If some data is available from actual testing, then the test data can be easily imported into the model as an input to replace the corresponding part in the model. It is especially useful when the design needs to be modified, or trade-off between ABS performance and noise and vibration is necessary. The model can greatly reduce the time to market for ABS products. It also makes system level optimization possible.

  8. 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.

  9. Fracture Analysis and Material Improvement of Brake Discs

    Science.gov (United States)

    Sakamoto, Haruo; Hirakawa, Kenji

    Using a steel material for forging, development of new discs for the next Shinkansen had been started. However, a fracture in a forged disc occurred in a durability test. Subsequently, from the viewpoint of higher fracture toughness, material improvement to an extent sufficient to withstand such a fracture due to tensile residual stress accumulation became the goal of further development. Among the candidate materials, modified AISI 4330 was selected and evaluated in laboratory and field tests. Following the subsequent durability test in the field, modification for bolt sticking and forging formability was conducted. This new brake disc, which proved to be satisfactory for Shinkansen vehicles, is capable of running at high speeds of more than 270km/h and therefore suitable for current vehicles such as the Nozomi and Tsubasa.

  10. Braking Deceleration Measurement Using the Video Analysis of Motions by Sw Tracker

    Directory of Open Access Journals (Sweden)

    Ondruš Ján

    2015-06-01

    Full Text Available This contribution deals with the issue of car braking, particularly with the one of M1 category. Braking deceleration measurement of the vehicle Mazda 3 MPS was carried out by the declerograph XL MeterTM Pro. The main aim of the contribution is to perform comparison of the process of braking deceleration between the decelograph and the new alternative method of video analysis and to subsequently examine these processes. The test took place at the Rosina airfield, the airstrip in a small village nearby the town of Žilina. The last part of this paper presents the results, evlauation and comparison of the measurements carried out.

  11. Compression Strength Testing for Automotive Brake Pads Used in Earthquake Energy Dampers

    Directory of Open Access Journals (Sweden)

    Dragoş Voiculescu

    2010-01-01

    Full Text Available In order to calibrate a friction damper which uses automotive brake pads it is necessary to determine the compression behaviour of the friction material. This paper summarizes the experimental results obtained for a set of automotive brake pads made in Romania. These results are useful in order to determine the slip load level in a seismic energy dissipation mechanism which uses this type of friction pads. The paper presents the experimental set up and the compression behaviour curves obtained for a set of four commercial brake pads. The testing was performed by the author as a part of his research work, using a hydraulic compression press.

  12. CFD Approach To Investigate The Flow Characteristics In Bi-Directional Ventilated Disc Brake

    Science.gov (United States)

    Munisamy, Kannan M.; Yusoff, Mohd. Zamri; Shuaib, Norshah Hafeez; Thangaraju, Savithry K.

    2010-06-01

    This paper presents experimental and Computational Fluids Dynamics (CFD) investigations of the flow in ventilated brake discs. Development of an experiment rig with basic measuring devices are detailed out and following a validation study, the possible improvement in the brake cooling can be further analyzed using CFD analysis. The mass flow rate is determined from basic flow measurement technique following that the conventional bi-directional passenger car is simulated using commercial CFD software FLUENT™. The CFD simulation is used to investigate the flow characteristics in between blade flow of the bi-directional ventilated disc brake.

  13. Real life safety benefits of increasing brake deceleration in car-to-pedestrian accidents: Simulation of Vacuum Emergency Braking.

    Science.gov (United States)

    Jeppsson, Hanna; Östling, Martin; Lubbe, Nils

    2018-02-01

    The objective of this study is to predict the real-life benefits, namely the number of injuries avoided rather than the reduction in impact speed, offered by a Vacuum Emergency Brake (VEB) added to a pedestrian automated emergency braking (AEB) system. We achieve this through the virtual simulation of simplified mathematical models of a system which incorporates expected future advances in technology, such as a wide sensor field of view, and reductions in the time needed for detection, classification, and brake pressure build up. The German In-Depth Accident Study database and the related Pre Crash Matrix, both released in the beginning of 2016, were used for this study and resulted in a final sample of 526 collisions between passenger car fronts and pedestrians. Weight factors were calculated for both simulation model and injury risk curves to make the data representative of Germany as a whole. The accident data was used with a hypothetical AEB system in a simulation model, and injury risk was calculated from the new impact speed using injury risk curves to generate new situations using real accidents. Adding a VEB to a car with pedestrian AEB decreased pedestrian casualties by an additional 8-22%, depending on system setting and injury level, over the AEB-only system. The overall decrease in fatalities was 80-87%, an improvement of 8%. Collision avoidance was improved by 14-28%. VEB with a maximum deceleration in the middle of the modelled performance range has an effectiveness similar to that of an "early activation" system, where the AEB is triggered as early as 2 s before collision. VEB may therefore offer a substantial increase in performance without increasing false positive rates, which earlier AEB activation does. Most collisions and injuries can be avoided when AEB is supplemented by the high performance VEB; remaining cases are characterised by high pedestrian walking speed and late visibility due to view obstructions. VEB is effective in all analysed

  14. 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...

  15. Downward Slope Driving Control for Electric Powered Wheelchair Based on Capacitor Regenerative Brake

    Science.gov (United States)

    Seki, Hirokazu; Takahashi, Yoshiaki

    This paper describes a novel capacitor regenerative braking control scheme of electric powered wheelchairs for efficient driving on downward slopes. An electric powered wheelchair, which generates the driving force by electric motors, is expected to be widely used as a mobility support system for elderly people and disabled people; however the energy efficiency has to be further improved because it is driven only by battery energy. This study proposes a capacitor regenerative braking circuit and two types of velocity control schemes with variable duty ratio. The proposed regenerative braking circuit is based on the step-up/down circuit with additional resistance and connects right and left motors in series in order to obtain a larger braking power. Some driving experiments on a practical downward slope show the effectiveness of the proposed control system.

  16. Regenerative Braking Control Strategy of Electric-Hydraulic Hybrid (EHH Vehicle

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-07-01

    Full Text Available A novel electric-hydraulic hybrid drivetrain incorporating a set of hydraulic systems is proposed for application in a pure electric vehicle. Models of the electric and hydraulic components are constructed. Two control strategies, which are based on two separate rules, are developed; the maximum energy recovery rate strategy adheres to the rule of the maximization of the braking energy recovery rate, while the minimum current impact strategy adheres to the rule of the minimization of the charge current to the battery. The simulation models were established to verify the effects of these two control strategies. An ABS (Anti-lock Braking System fuzzy control strategy is also developed and simulated. The simulation results demonstrate that the developed control strategy can effectively absorb the braking energy, suppress the current impact, and assure braking safety.

  17. 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

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

    Directory of Open Access Journals (Sweden)

    Geza Tarnai

    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.

  19. ANALYSIS OF POSSIBILITY TO AVOID A RUNNING-DOW ACCIDENT TIMELY BRAKING

    Directory of Open Access Journals (Sweden)

    Sarayev, A.

    2013-06-01

    Full Text Available Such circumstances under which the drive can stop the vehicle by applying timely braking before reaching the pedestrian crossing or decrease the speed to the safe limit to avoid a running-down accident is considered.

  20. RESEARCH OF VEHICLE’S BRAKING DYNAMICS AT TRAFFIC ACCIDENT ANALYSIS

    Directory of Open Access Journals (Sweden)

    A. Turenko

    2010-01-01

    Full Text Available The problem of vehicles braking process after the road accident is reviewed. The inaccuracies are analyzed for the purpose of deceleration determination occurance at the application of out-of-date statistical database by experts.

  1. 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...

  2. 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.

  3. Mobile Acoustical Bat Monitoring Annual Summary Report CY 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 for the CY 2015. Calls were classified using Bat Call ID...

  4. Comparative Analysis of Classifiers for Classification of Emergency Braking of Road Motor Vehicles

    Directory of Open Access Journals (Sweden)

    Albert Podusenko

    2017-11-01

    Full Text Available We investigate the feasibility of classifying (inferring the emergency braking situations in road vehicles from the motion pattern of the accelerator pedal. We trained and compared several classifiers and employed genetic algorithms to tune their associated hyperparameters. Using offline time series data of the dynamics of the accelerator pedal as the test set, the experimental results suggest that the evolved classifiers detect the emergency braking situation with at least 93% accuracy. The best performing classifier could be integrated into the agent that perceives the dynamics of the accelerator pedal in real time and—if emergency braking is detected—acts by applying full brakes well before the driver would have been able to apply them.

  5. Suggested Research Method for Testing Selected Tribological Properties of Friction Components in Vehicle Braking Systems

    Directory of Open Access Journals (Sweden)

    Borawski Andrzej

    2016-09-01

    Full Text Available The braking system is one of the most important systems in any vehicle. Its proper functioning may determine the health and life the people inside the vehicle as well as other road users. Therefore, it is important that the parameters which characterise the functioning of brakes changed as little as possible throughout their lifespan. Multiple instances of heating and cooling of the working components of the brake system as well as the environment they work in may impact their tribological properties. This article describes a method of evaluating the coefficient of friction and the wear speed of abrasive wear of friction working components of brakes. The methodology was developed on the basis of Taguchi’s method of process optimization.

  6. An analysis of the friction mechanism on brake gear of railway rolling stock

    Directory of Open Access Journals (Sweden)

    J. H. Barnard

    1985-03-01

    Full Text Available Friction energy dissipation at an interface involves a wide range of interdisciplinary concepts. As the demand for higher operating speeds increased, the limitations of cast iron as the traditional friction material for rail transport brakes became more apparent. Only through an intensive analysis of the interfacial interaction between the brake block and brake path could the problems encountered with other promising friction materials be solved. The article deals with the difficulties pertaining to the early composite materials, and indicates how these were overcome by the understanding and implementation of new techniques not previously associated with conventional systems connected with railway braking. Two composite materials, that is 840/N for locomotives and freight wagons where mass oriented momentum dominates, and high friction composite 655/C for passenger vehicles with a predominantly speed-oriented momentum, are presently used.

  7. THE VERIFICATION BRAKE MECHANISM OF WINDING MACHINES WITH SINGLE CABLE DRIVING WHEELS ON

    Directory of Open Access Journals (Sweden)

    Răzvan Bogdan ITU

    2017-12-01

    Full Text Available The development in safe conditions of the extracting process continuously imposes the need of optimal functioning of the extracting installations as important links in the transport flow. Diagnosis of winding engine brake mechanism in mines is important to provide normal extraction vessel movement in the shaft, or stopping machines in a certain position of the vessels in disturbances or failures. The paper presents the calculus of safety coefficients in the use of safety and maneuver brakes. Mine winding engines brake mechanisms is important to provide normal extraction vessel movement along the shaft, or stopping the engine in a certain position of the vessel in disturbances or failures. To assess the real safety coefficient, results obtained by tensiometric measurements were used. After diagnosis, necessary information is obtained to improve present maintenance system and repair this category of machines in view of increasing safety in use of winding installations, with possibility of monitoring brake mechanism...

  8. 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

  9. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ...), and Navistar Truck Group (Navistar). The petitions focused on four main issues. The main issues... hybrid disc brake configuration. The vehicle was used in the agency's research to support the reduced...

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

    Directory of Open Access Journals (Sweden)

    Dembitskyi V.

    2016-08-01

    Full Text Available Increased safety can be carried out at the expense the installation on vehicles of automatic braking systems, that monitor the traffic situation and the actions of the driver. In this paper considered the advantages and disadvantages of automatic braking systems, were analyzed modern tracking tools that are used in automatic braking systems. Based on the statistical data on accidents, are set the main dangers, that the automatic braking system will be reduced. In order to ensure the accuracy of information conducted research for determination of optimal combination of different sensors that provide an adequate perception of road conditions. The tracking system should be equipped with a combination of sensors, which in the case of detection of an obstacle or dangers of signal is transmitted to the information processing system and decision making. Information from the monitoring system should include data for the identification of the object, its condition, the speed.

  11. 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...

  12. 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

    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...... 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...... the hydrodynamic brake and mechanical brake was also investigated. The application of the hydrodynamic brake is expected to be efficient for rotor shutdown and for reducing the platform motions and structural loads....

  13. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Science.gov (United States)

    2010-02-03

    ... into contact with brake fluid, including iron, steel, aluminum, brass, copper, and SBR. Currently in... corrosion and pitting. Disregard staining or discoloration. (c) Place the strips in a dessicator containing...

  14. Mobile Acoustical Bat Monitoring Annual Summary Report CY 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 for the CY 2015. Calls were classified using Bat Call ID...

  15. Appendix F. Developmental enforcement algorithm definition document : predictive braking enforcement algorithm definition document.

    Science.gov (United States)

    2012-05-01

    The purpose of this document is to fully define and describe the logic flow and mathematical equations for a predictive braking enforcement algorithm intended for implementation in a Positive Train Control (PTC) system.

  16. Development of an operationally efficient PTC braking enforcement algorithm for freight trains.

    Science.gov (United States)

    2013-08-01

    Software algorithms used in positive train control (PTC) systems designed to predict freight train stopping distance and enforce a penalty brake application have been shown to be overly conservative, which can lead to operational inefficiencies by in...

  17. Mathews Brake National Wildlife Refuge public use review and development plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document addresses the ten Public Use Requirements for Mathews Brake National Wildlife Refuge as well as General Impressions of the review team.

  18. Brake rotor design and comparison using finite element analysis : an investigation in topology optimization

    OpenAIRE

    Domond, Kenneth

    2010-01-01

    Disc brake technology used for mountain bikes, and mountain bike technology in general, has improved significantly as the sport of mountain biking has evolved. Disc brakes on bicycles are relatively new compared to their use on other vehicles. Rotor design is varied for rotors of the same intended use for many companies; some still use the same initial rotor designs that were introduced over a decade ago. Through the finite element analysis and optimization process, understanding the difficul...

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

    Science.gov (United States)

    2016-08-01

    ARL-TN-0770 ● AUG 2016 US Army Research Laboratory Modification of General Research Corporation ( GRC ) Dynatup 8200 Drop Tower...Research Laboratory Modification of General Research Corporation ( GRC ) Dynatup 8200 Drop Tower Rebounding Brake System by David Gray and...Research Corporation ( GRC ) Dynatup 8200 Drop Tower Rebounding Brake System 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  20. Fault Diagnostics in Power Electronics Based Brake-by-Wire Systems

    Science.gov (United States)

    2006-05-22

    brake-by-wire system as soon as they occur. We developed a brake-by-wire ( BBW ) system model using Simplorer software that implements the full control...the BBW system. It has the capabilities of detecting faulty conditions immediately after they occur, and pinpointing to specific faulty conditions...within less than 0.02s on the bench setup BBW . The performance of the hierarchical fuzzy diagnostic system is also compared with two other fuzzy

  1. On the running-in of brake pads and discs for dyno bench tests

    OpenAIRE

    Matějka, V.; Metinöz, I.; Wahlström, Jens; Alemani, M.; PERRICONE G

    2017-01-01

    Running-in process of low metallic brake pads and cast iron discs are investigated using full scale inertia brake dynamometer designed for particle emission studies. The airborne particles are measured using ELPI+ and collected on filters. The pads and disc contact surfaces are studied using microscopy techniques. It is observed that the particle emissions from the new pads and discs are significantly higher compared with the used ones and indicates importance of proper running-in of the pads...

  2. 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.

  3. A reciprocating pin-on-plate test-rig for studying friction materials for holding brakes

    DEFF Research Database (Denmark)

    Poulios, Konstantinos; Drago, Nicola; Klit, Peder

    2014-01-01

    This paper refers to testing of friction materials for holding brakes. In contrast to the more typical case of high energy brakes, holding brakes operate usually in a reciprocating sense, at very low sliding speeds and allow significantly higher clamping pressures. The design of a reciprocating p...... different friction materials running against an unhardened steel surface are presented as a usage case. © 2014 Elsevier B.V.......This paper refers to testing of friction materials for holding brakes. In contrast to the more typical case of high energy brakes, holding brakes operate usually in a reciprocating sense, at very low sliding speeds and allow significantly higher clamping pressures. The design of a reciprocating pin......-on-plate test-rig for studying the evolution of wear by monitoring the pin height reduction using Eddy-current proximity sensors is presented. Moreover, a new mechanism for recording the friction force is suggested. Apart from the design of the test-rig, friction force and wear rate measurements for two...

  4. Suitability of Hydraulic Disk Brakes for Passive Actuation of Upper-Extremity Rehabilitation Exoskeleton

    Directory of Open Access Journals (Sweden)

    Arno H. A. Stienen

    2009-01-01

    Full Text Available Passive, energy-dissipating actuators are promising for force-coordination training in stroke rehabilitation, as they are inherently safe and have a high torque-to-weight ratio. The goal of this study is to determine if hydraulic disk brakes are suitable to actuate an upper-extremity exoskeleton, for application in rehabilitation settings. Passive actuation with friction brakes has direct implications for joint control. Braking is always opposite to the movement direction. During standstill, the measured torque is equal to the torque applied by the human. During rotations, it is equal to the brake torque. Actively assisting movement is not possible, nor are energy-requiring virtual environments. The evaluated disk brake has a 20 Nm bandwidth (flat-spectrum, multi-sine of 10 Hz; sufficient for torques required for conventional therapy and simple, passive virtual environments. The maximum static output torque is 120 Nm, sufficient for isometric training of the upper extremity. The minimal impedance is close zero, with only the inertia of the device felt. In conclusion, hydraulic disk brakes are suitable for rehabilitation devices.

  5. Manufacturing and CMC component development for brake disks in automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Gadow, R.; Speicher, M. [Institute for Manufacturing Technologies of Ceramic Components and Composites (IFKB), University of Stuttgart (Germany)

    2000-07-01

    Disk brake systems have been developed to high technical standards in the automotive industry since more than 40 years. Hydraulic brake systems for serial passenger cars as well as for trucks and trains include a disk made of cast iron in a variety of sophisticated designs. With appropriate friction properties its wear and corrosion resistance and its high temperature stability are insufficient. For light weight economy cars and improved comfort of vehicle suspension, the total and specific weight of brake components must be lowered. Based on first experiments in aeroplane brakes, carbon fiber composites (CFC) for disk brakes have been developed for competition cars in 2D and 3D design, mainly with metal wheel hub. The high temperature stability and friction behaviour perform superior retardation under extreme conditions. With respect to costs and insufficient all weather braking behaviour, CFC disks cannot be used in serial passenger cars. Their limited oxidation resistance, their critical and non comfortable low temperature retardation, the wear and unsteady friction coefficient show further limitations in industrial use. (orig.)

  6. 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.

  7. Development of compacted vermicular graphite cast iron for railway brake discs

    Science.gov (United States)

    Lim, Choong-Hwan; Goo, Byeong-Choon

    2011-04-01

    In the case of employing brake discs as a key component of mechanical brake equipment, the initiation of thermal cracking owing to repetitive thermal shock generated during braking may potentially lead to higher maintenance costs, worsened braking performance, and greater risk of railway accidents. The purpose of this study is to gain basic data to facilitate application of compacted vermicular (C. V.) graphite cast iron to brake discs in order to obtain high thermal crack resistance and improved lifetime. To this end, this study developed three types of C. V. graphite cast iron with differing content of key elements, including Ni, Cr, and Mo. Each test specimen underwent numerous tests for evaluation of materials characteristics, and the results were compared with those obtained for existing materials. The test results show that the thermal fatigue lifetime of material C is nearly double that of the conventional material. This demonstrates the suitability of material C as a material for brake discs in mid- to high-speed railway vehicles.

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

    Science.gov (United States)

    van Winsum, W; Brouwer, W

    1997-06-01

    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 a sample of 16 young and middle-aged experienced drivers independent assessments were made of preferred time headway during car following and of braking skill. Starting from modern theories of visual-motor learning, braking performance was analyzed in terms of a reaction time component, an open-loop visual-motor component, and a closed-loop visual-motor component involving the precise adjustment of braking (timing and force) to the situation. The efficiency of the visual-motor component of braking was a strong and significant predictor of choice of time headway to the lead vehicle in such a way that less efficient braking indicated a preference for a longer time headway. This result supports the theory of adaptation on the individual level.

  9. 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.

  10. 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.

  11. Parameters Tuning Approach for Proportion Integration Differentiation Controller of Magnetorheological Fluids Brake Based on Improved Fruit Fly Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Xinhua Liu

    2017-07-01

    Full Text Available In order to improve the response performance of a proportion integration differentiation (PID controller for magnetorheological fluids (MRF brake and to reduce the braking fluctuation rate, an improved fruit fly optimization algorithm for PID controller parameters tuning of MRF brake is proposed. A data acquisition system for MRF brake is designed and the transfer function of MRF brake is identified. Moreover, an improved fruit fly optimization algorithm (IFOA through integration of PID control strategy and cloud model algorithm is proposed to design a PID controller for MRF brake. Finally, the simulation and experiment are carried out. The results show that IFOA, with a faster response output and no overshoot, is superior to the conventional PID and fruit fly optimization algorithm (FOA PID controller.

  12. Finite element parametric study of the influence of friction pad material and morphological characteristics on disc brake vibration phenomena

    Science.gov (United States)

    Forte, P.; Frendo, F.; Rodrigues, R. N.

    2016-09-01

    Since nowadays the NVH performance of vehicles has become an important priority, the noise radiating from brakes is considered a source of considerable passenger discomfort and dissatisfaction. Creep groan and squeal that show up with annoying vibrations and noise in specific frequency ranges are typical examples of self-excited brake vibrations caused by the stick-slip effect, the former, by the mode coupling of brake disc and friction pads or calliper, the latter. In both cases, the friction coefficient, which depends, among other factors, on the morphology of the mating surfaces and on the operating conditions, is a fundamental parameter but not the only one for the occurrence of the vibratory phenomena. Finite element complex eigenvalue parametric analyses were performed on a disc brake assembly to evaluate propensity to dynamic instability of brakes with multiple pads, as in railway brakes, as a function of the number of pads, pad shape and size, and material parameters.

  13. 49 CFR 570.5 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ... body or chassis. Hoses shall not be cracked, chafed, or flattened. Protective devices, such as “rub... height of rubbing surface of lining over rivet heads. Measure bonded lining thickness over shoe surface...

  14. 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

  15. Brake reactions of distracted drivers to pedestrian Forward Collision Warning systems.

    Science.gov (United States)

    Lubbe, Nils

    2017-06-01

    Forward Collision Warning (FCW) can be effective in directing driver attention towards a conflict and thereby aid in preventing or mitigating collisions. FCW systems aiming at pedestrian protection have been introduced onto the market, yet an assessment of their safety benefits depends on the accurate modeling of driver reactions when the system is activated. This study contributes by quantifying brake reaction time and brake behavior (deceleration levels and jerk) to compare the effectiveness of an audio-visual warning only, an added haptic brake pulse warning, and an added Head-Up Display in reducing the frequency of collisions with pedestrians. Further, this study provides a detailed data set suited for the design of assessment methods for car-to-pedestrian FCW systems. Brake response characteristics were measured for heavily distracted drivers who were subjected to a single FCW event in a high-fidelity driving simulator. The drivers maintained a self-regulated speed of 30km/h in an urban area, with gaze direction diverted from the forward roadway by a secondary task. Collision rates and brake reaction times differed significantly across FCW settings. Brake pulse warnings resulted in the lowest number of collisions and the shortest brake reaction times (mean 0.8s, SD 0.29s). Brake jerk and deceleration were independent of warning type. Ninety percent of drivers exceeded a maximum deceleration of 3.6m/s 2 and a jerk of 5.3m/s 3 . Brake pulse warning was the most effective FCW interface for preventing collisions. In addition, this study presents the data required for driver modeling for car-to-pedestrian FCW similar to Euro NCAP's 2015 car-to-car FCW assessment. Practical applications: Vehicle manufacturers should consider the introduction of brake pulse warnings to their FCW systems. Euro NCAP could introduce an assessment that quantifies the safety benefits of pedestrian FCW systems and thereby aid the proliferation of effective systems. Copyright © 2017

  16. Measurement Performance Assessment: Dynamic Calibration Compared with Static Calibration Method for Roller Tester of Vehicle Brake Force

    OpenAIRE

    Guan Xu; Jian Su; Rong Chen; Hongda Pan; Libin Zhang; Xing Wang

    2014-01-01

    The measurement performance of the roller tester for the vehicle brake force is evaluated by both proposed dynamic calibration and traditional static calibration to find an effective way for ensuring the vehicle safety. Three static parameters, brake force error of a single bench, difference of the left and right benches, and measurement repeatability, are verified to be eligible in the experiments. However, the experimental results of the dynamic calibration prove that the same brake tester ...

  17. Influence of the braking power control of the traction asynchronous machine in the voltage vector control system under DC

    Directory of Open Access Journals (Sweden)

    Юлія Олександрівна Слободенюк

    2016-11-01

    Full Text Available At braking the traction motors are transferred to generator mode and produce electrical energy which passes to the contact mains or storage device in the DC mains for further use. Such braking is called regenerative. The resulting electrical energy can be spent by trains in traction mode. Regenerative braking reduces the consumption of electric power for traction. In electric railways of our country more than 3% of the consumed electrical energy is given back to contact mains annually. As this takes place there arises the task to control the braking of the traction motors with minimal impact on electric power quality and maintaining proper braking performance. Based on the analysis of the characteristics of the brake traction of an electric locomotive with asynchronous electric machines the main braking modes have been chosen: at a constant sliding speed and the stator constant voltage; at constant braking power and the stator constant voltage; at a power value more than the nominal braking power; at a constant load torque; at a constant frequency of the stator. The vector control system with the formation of the reactive component of the stator current and the EMF regulator was chosen, basing on the working conditions characteristics in the electric braking mode (recuperation; namely, that the characteristics are defined by the laws regulating the frequency and voltage across the stator windings. This control system can fully reproduce any predetermined trajectory of traction and braking performance and adjust braking power. The offered system with recuperation can be used as a means of compensation in emergency situations with a power failure

  18. 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.

  19. Measurement Performance Assessment: Dynamic Calibration Compared with Static Calibration Method for Roller Tester of Vehicle Brake Force

    Directory of Open Access Journals (Sweden)

    Guan Xu

    2014-05-01

    Full Text Available The measurement performance of the roller tester for the vehicle brake force is evaluated by both proposed dynamic calibration and traditional static calibration to find an effective way for ensuring the vehicle safety. Three static parameters, brake force error of a single bench, difference of the left and right benches, and measurement repeatability, are verified to be eligible in the experiments. However, the experimental results of the dynamic calibration prove that the same brake tester fails on the repeatability with a 10.4% error. The dynamic calibration method improves the measurement performance of the brake tester in practical applications.

  20. The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle.

    Science.gov (United States)

    Lee, Nam-Jin; Kang, Chul-Goo

    2015-01-01

    A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component's purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system.

  1. The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle.

    Directory of Open Access Journals (Sweden)

    Nam-Jin Lee

    Full Text Available A brake hardware-in-the-loop simulation (HILS system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component's purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system.

  2. The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle

    Science.gov (United States)

    Lee, Nam-Jin; Kang, Chul-Goo

    2015-01-01

    A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component’s purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system. PMID:26267883

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

    DEFF Research Database (Denmark)

    Landex, Alex; Kaas, Anders H.

    2005-01-01

    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......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...... the interlocking system. Based on the braking distance it is possible to calculate the minimum headway time, and thereby determine the buffer time when knowing the frequency. Hence the headway time can be divided into minimum headway time and buffer time. The buffer time is an indicator for the spare capacity...

  4. 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

  5. Diabetic Driving Studies-Part 1: Brake Response Time in Diabetic Drivers With Lower Extremity Neuropathy.

    Science.gov (United States)

    Meyr, Andrew J; Spiess, Kerianne E

    Although the effect of lower extremity pathology and surgical intervention on automobile driving function has been a topic of contemporary interest, we are unaware of any analysis of the effect of lower extremity diabetic sensorimotor neuropathy on driving performance. The objective of the present case-control investigation was to assess the mean brake response time in diabetic drivers with lower extremity neuropathy compared with that of a control group and a brake response safety threshold. The driving performances of participants were evaluated using a computerized driving simulator with specific measurement of the mean brake response time and frequency of abnormally delayed brake responses. We analyzed a control group of 25 active drivers with neither diabetes nor lower extremity neuropathy and an experimental group of 25 active drivers with type 2 diabetes and lower extremity neuropathy. The experimental group demonstrated a 37.89% slower mean brake response time (0.757 ± 0.180 versus 0.549 ± 0.076 second; p diabetic patients with lower extremity neuropathy and might raise the potential for impaired driving function in this population. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  6. Regenerative braking systems with torsional springs made of carbon nanotube yarn

    Science.gov (United States)

    Liu, S.; Martin, C.; Lashmore, D.; Schauer, M.; Livermore, C.

    2014-11-01

    The 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 an energy-storing actuator for regenerative braking systems. Originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing until failure. The maximum extractable energy density is measured to be as high as 6.13 kJ/kg. The tests also reveal structural reorganization and hysteresis in the torsional loading curves. A regenerative braking system is built to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yam'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 system are up to 4.69 kJ/kg and 1.21 kW/kg, respectively. A slightly lower energy density of up to 1.23 kJ/kg and a 0.29 kW/kg mean power density are measured for the CNT yarns in a more complex system that mimics a unidirectional rotating regenerative braking mechanism. The lower energy densities for CNT yarns in the regenerative braking systems as compared with the yarns themselves reflect the frictional losses of the regenerative systems.

  7. 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.

  8. 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.

  9. Energy recapture through deceleration - regenerative braking in electric vehicles from a user perspective.

    Science.gov (United States)

    Cocron, Peter; Bühler, Franziska; Franke, Thomas; Neumann, Isabel; Dielmann, Benno; Krems, Josef F

    2013-01-01

    We report results from a 1-year field study (N = 80) on user interactions with regenerative braking in electric vehicles. Designed to recapture energy in vehicles with electric powertrains, regenerative braking has an important influence on both the task of driving and energy consumption. Results from user assessments and data from onboard data loggers indicate that most drivers quickly learned to interact with the system, which was triggered via accelerator. Further, conventional braking manoeuvres decreased significantly as the majority of deceleration episodes could only be executed through regenerative braking. Still, some drivers reported difficulties when adapting to the system. These difficulties could be addressed by offering different levels of regeneration so that the intensity of the deceleration could be individually modified. In general, the system is trusted and regarded as a valuable tool for prolonging range. Regenerative braking in electric vehicles has direct implications for the driving task. We found that drivers quickly learn to use and accept a system, which is triggered via accelerator. For those reporting difficulties in the interaction, it appears reasonable to integrate options to customise or switch off the system.

  10. Stability Optimization of a Disc Brake System with Hybrid Uncertainties for Squeal Reduction

    Directory of Open Access Journals (Sweden)

    Hui Lü

    2016-01-01

    Full Text Available A hybrid uncertain model is introduced to deal with the uncertainties existing in a disc brake system in this paper. By the hybrid uncertain model, the uncertain parameters of the brake with enough sampling data are treated as probabilistic variables, while the uncertain parameters with limited data are treated as interval probabilistic variables whose distribution parameters are expressed as interval variables. Based on the hybrid uncertain model, the reliability-based design optimization (RBDO of a disc brake with hybrid uncertainties is proposed to explore the optimal design for squeal reduction. In the optimization, the surrogate model of the real part of domain unstable eigenvalue of the brake system is established, and the upper bound of its expectation is adopted as the optimization objective. The lower bounds of the functions related to system stability, the mass, and the stiffness of design component are adopted as the optimization constraints. The combinational algorithm of Genetic Algorithm and Monte-Carlo method is employed to perform the optimization. The results of a numerical example demonstrate the effectiveness of the proposed optimization on improving system stability and reducing squeal propensity of a disc brake under hybrid uncertainties.

  11. A Novel Assessment of Braking Reaction Time Following THA Using a New Fully Interactive Driving Simulator.

    Science.gov (United States)

    Ruel, Allison V; Lee, Yuo-Yu; Boles, John; Boettner, Friedrich; Su, Edwin; Westrich, Geoffrey H

    2015-07-01

    After total hip replacement surgery, patients are eager to resume the activities of daily life, particularly driving. Most surgeons recommend waiting 6 weeks after surgery to resume driving; however, there is no evidence to indicate that patients cannot resume driving earlier. Our purpose was to evaluate when in the recovery period following THA that patients regain or improve upon their preoperative braking reaction time, allowing them to safely resume driving. We measured and compared pre- and postoperative braking reaction times of 90 patients from 3 different surgeons using a Fully Interactive Driving Simulator (Simulator Systems International, Tulsa, OK). We defined a return to safe braking reaction time as a return to a time value that is either equal to or less than the preoperative braking reaction time. Patients tested at 2 and 3 weeks after surgery had slower braking reaction times than preoperative times by an average of 0.069 and 0.009 s, respectively. At 4 weeks after surgery, however, patients improved their reaction times by 0.035 s (p = 0.0398). In addition, at 2, 3, and 4 weeks postoperatively, the results also demonstrated that patient less than 70 years of age recovered faster. Based upon the results of this study, most patients should be allowed to return to driving 4 weeks following minimally invasive primary total hip arthroplasty.

  12. Advanced emergency braking controller design for pedestrian protection oriented automotive collision avoidance system.

    Science.gov (United States)

    Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

    2014-01-01

    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.

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

    Science.gov (United States)

    Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

    2014-01-01

    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. PMID:25097870

  14. 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.

  15. Aircraft Anti-Skid Brake Control Based on High-Speed on-off Valve

    Directory of Open Access Journals (Sweden)

    Li Wei

    2015-01-01

    Full Text Available Aircraft hydraulic brake system usually use pressure servo valve for anti-skid brake control. As pressure servo valve realizes the pressure closed loop by hydraulic feedback loop, this structure increased the complexity of the processing and manufacturing, restricted the pressure closed loop parameters adjustment, and increased the difficulty of debugging the system design. Pressure servo valve is expensive and difficult to process, poor ability to resist pollution. This paper proposed a slip ratio large closed loop aircraft anti-skid brake control method based on high-speed on-off valve, built the model of aircraft ground vertical taxiing and slip ratio large closed loop control algorithm in the MATLAB/SIMULINK, and built the model of aircraft hydraulic brake system based on on-off valve in the AMESim and a joint simulation was carried out. The simulation results show that the aircraft anti-skid brake control method based on high-speed on-off valve is feasible, and the on-off valve is cheap with strong ability to resist pollution, easy processing and manufacturing and so on, showing a good application prospect.

  16. 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.

  17. Development of remote data acquisition system based on OPC for brake test bench

    Science.gov (United States)

    Wang, Yiwei; Wu, Mengling; Tian, Chun; Ma, Tianhe

    2017-08-01

    The 1:1 train brake system test bench can be used to carry out brake-related adhesion-slid control, stability test, noise test and dynamic test. To collect data of the test bench, a data acquisition method is needed. In this paper, the remote data acquisition system of test bench is built by LabVIEW based on OPC technology. Unlike the traditional hardwire way connecting PLC acquisition module with sensors, the novel method is used to collect data and share them through the internal LAN built by Ethernet switches, which avoids the complex wiring interference in an easy, efficient and flexible way. The system has been successfully applied to the data acquisition activities of the comprehensive brake system test bench of CRRC Nanjing Puzhen Haitai Brake Equipment Co., Ltd., and the relationship test between the adhesion coefficient and the slip-ratio is realized. The speed signal, torque signal and brake disc temperature can be collected and displayed. The results show that the system is reliable, convenient, and efficient, and can meet the requirements of data acquisition.

  18. Driving and braking control of PM synchronous motor based on low-resolution hall sensor for battery electric vehicle

    Science.gov (United States)

    Gu, Jing; Ouyang, Minggao; Li, Jianqiu; Lu, Dongbin; Fang, Chuan; Ma, Yan

    2013-01-01

    Resolvers are normally employed for rotor positioning in motors for electric vehicles, but resolvers are expensive and vulnerable to vibrations. Hall sensors have the advantages of low cost and high reliability, but the positioning accuracy is low. Motors with Hall sensors are typically controlled by six-step commutation algorithm, which brings high torque ripple. This paper studies the high-performance driving and braking control of the in-wheel permanent magnetic synchronous motor (PMSM) based on low-resolution Hall sensors. Field oriented control (FOC) based on Hall-effect sensors is developed to reduce the torque ripple. The positioning accuracy of the Hall sensors is improved by interpolation between two consecutive Hall signals using the estimated motor speed. The position error from the misalignment of the Hall sensors is compensated by the precise calibration of Hall transition timing. The braking control algorithms based on six-step commutation and FOC are studied. Two variants of the six-step commutation braking control, namely, half-bridge commutation and full-bridge commutation, are discussed and compared, which shows that the full-bridge commutation could better explore the potential of the back electro-motive forces (EMF), thus can deliver higher efficiency and smaller current ripple. The FOC braking is analyzed with the phasor diagrams. At a given motor speed, the motor turns from the regenerative braking mode into the plug braking mode if the braking torque exceeds a certain limit, which is proportional to the motor speed. Tests in the dynamometer show that a smooth control could be realized by FOC driving control and the highest efficiency and the smallest current ripple could be achieved by FOC braking control, compared to six-step commutation braking control. Therefore, FOC braking is selected as the braking control algorithm for electric vehicles. The proposed research ensures a good motor control performance while maintaining low cost and high

  19. Comparison of real driving cycles and consumed braking power in suburban Slovakian driving

    Directory of Open Access Journals (Sweden)

    Gechev Tsvetomir

    2017-01-01

    Full Text Available The paper compares the features of suburban real driving cycles performed with CORRSYS DATRON measurement equipment on routes in the region of Žilina, Slovakia. It observes differences in the maximum and average vehicle velocities and the amount of braking in relation to the elevation profile of each individual cycle. Consumed braking power was also calculated in the different cycles in order to review the potential electricity regeneration capabilities of hybrid electric vehicles, operating on the same routes. The change in braking energy depending on vehicle mass and presence of grade on the routes in the measured cycles was also assessed. The calculations and plotting were done by using Matlab software.

  20. Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

    Directory of Open Access Journals (Sweden)

    Wenchuan Cai

    2014-01-01

    Full Text Available Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate the adhesion force or/and the resistance, based on which simple traction/braking control schemes are established under the consideration of actual wheel-rail adhesion condition. It is shown that the proposed controllers have simple structure and can be easily implemented from real applications. Numerical simulation also validates the effectiveness of the proposed control scheme.

  1. 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.

  2. Capacitor regenerative braking system of electric wheelchair for senior citizen based on variable frequency chopper control.

    Science.gov (United States)

    Takahashi, Yoshiaki; Seki, Hirokazu

    2009-01-01

    This paper proposes a novel regenerative braking control system of electric wheelchairs for senior citizen. "Electric powered wheelchair", which generates the driving force by electric motors according to the human operation, is expected to be widely used as a mobility support system for elderly people. This study focuses on the braking control to realize the safety and smooth stopping motion using the regenerative braking control technique based on fuzzy algorithm. The ride quality improvement and energy recycling can be expected by the proposed control system with stopping distance estimation and variable frequency control on the step-up/down chopper type of capacitor regenerative circuit. Some driving experiments confirm the effectiveness of the proposed control system.

  3. Driving Control for Electric Power Assisted Wheelchair Based on Regenerative Brake

    Science.gov (United States)

    Seki, Hirokazu; Takahashi, Kazuki; Tadakuma, Susumu

    This paper describes a novel safety driving control scheme for electric power assisted wheelchairs based on the regenerative braking system. “Electric power assisted wheelchair” which assists the driving force by electric motors is expected to be widely used as a mobility support system for elderly people and disabled people, however, the safe and secure driving performance especially on downhill roads must be further improved because electric power assisted wheelchairs have no braking devices. The proposed control system automatically switches the driving mode, from “assisting mode” to “braking mode”, based on the wheelchair's velocity and the declined angle and smoothly suppresses the wheelchair's acceleration based on variable duty ratio control in order to realize the safety driving and to improve the ride quality. Some experiments on the practical roads and subjective evaluation show the effectiveness of the proposed control system.

  4. PID-Type Fuzzy Control for Anti-Lock Brake Systems with Parameter Adaptation

    Science.gov (United States)

    Chen, Chih-Keng; Shih, Ming-Chang

    In this research, a platform is built to accomplish a series of experiments to control the Antilock Brake System (ABS). A commercial ABS module controlled by a controller is installed and tested on the platform. The vehicle and tire models are deduced and simulated by a personal computer for real time control. An adaptive PID-type fuzzy control scheme is used. Two on-off conversion methods: pulse width modulation (PWM) and conditional on-off, are used to control the solenoid valves in the ABS module. With the pressure signal feedbacks in the caliper, vehicle dynamics and wheel speeds are computed during braking. Road surface conditions, vehicle weight and control schemes are varied in the experiments to study braking properties.

  5. 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.

  6. THE RESEARCH ON AGEING OF GLYCOL-BASED BRAKE FLUIDS OF VEHICLES IN OPERATION

    Directory of Open Access Journals (Sweden)

    Jacek Caban

    2016-12-01

    Full Text Available The road safety depends on many factors, including the efficiency of the technical system and the disposal of the driver of the vehicle. As wear of most of the vehicle assemblies threatened only with a breakdown, excessive wear of the braking system components may pose a risk of a traffic accident. The article presents a study on the quality of the brake fluid conductivity as a function of temperature and water content conducted for a selected group of vehicles. This group of vehicles was characterized by different production date and had a different of vehicle mileage. We presented the methodology of statistical analysis of the quality of brake fluid tests in selected 38 passenger vehicles in operation.

  7. Design and analysis of Air flow duct for improving the thermal performance of disc brake rotor

    Science.gov (United States)

    Raja, T.; Mathiselvan, G.; Sreenivasulureddy, M.; Goldwin Xavier, X.

    2017-05-01

    safety in automotive engineering has been considered as a number one priority in development of new vehicle. A brake system is one of the most critical systems in the vehicle, without which the vehicle will put a passenger in an unsafe position. Temperature distribution on disc rotor brake and the performance brake of disc rotor is influenced by the air flow around the disc rotor. In this paper, the effect of air flow over the disc rotor is analyzed using the CFD software. The air flow over the disc rotor is increased by using a duct to supply more air flow over the disc rotor. The duct is designed to supply more air to the rotor surface and it can be placed in front of the vehicle for better performance. Increasing the air flow around the rotor will maximize the heat convection from the rotor surface. The rotor life and the performance can be improved.

  8. XXVII. International {mu} symposium. Brake conference; XXVII. Internationales {mu}-Symposium. Bremsen-Fachtagung

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, B. (ed.)

    2007-07-01

    Our meeting this year will be devoted to current brake technology in a presentation of the results of work undertaken at universities and by industrial organizations, based on different approaches. To begin with, one day after the first commercial flight of the Airbus A 380 from Singapore to Sydney, we will be given an insight into the brake system of this splendid European aeroplane for the first time, I believe, at an automotive conference. Subsequently, four presentations will focus our attention on the actual wheel brake before the part of the {mu} Symposium devoted to the presentation of papers - without a doubt, as always, enlivened by stimulating questions and discussions - will come to an end with a contribution on the subject of the stabilization of trailers. (orig.)

  9. Condition monitoring of an electro-magnetic brake using an artificial neural network

    Science.gov (United States)

    Gofran, T.; Neugebauer, P.; Schramm, D.

    2017-10-01

    This paper presents a data-driven approach to Condition Monitoring of Electromagnetic brakes without use of additional sensors. For safe and efficient operation of electric motor a regular evaluation and replacement of the friction surface of the brake is required. One such evaluation method consists of direct or indirect sensing of the air-gap between pressure plate and magnet. A larger gap is generally indicative of worn surface(s). Traditionally this has been accomplished by the use of additional sensors - making existing systems complex, cost- sensitive and difficult to maintain. In this work a feed-forward Artificial Neural Network (ANN) is learned with the electrical data of the brake by supervised learning method to estimate the air-gap. The ANN model is optimized on the training set and validated using the test set. The experimental results of estimated air-gap with accuracy of over 95% demonstrate the validity of the proposed approach.

  10. A NEW, LOW BRAKING INDEX FOR THE LMC PULSAR B0540–69

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, F. E.; Harding, A. K. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Guillemot, L. [Laboratoire de Physique et Chimie de l’Environnement et de l’Espace (LPC2E), CNRS-Université d’Orléans, F-45071 Orléans (France); Martin, P. [Institut de Recherche en Astrophysique et Planétologie, UPS/CNRS, UMR5277, F-31028 Toulouse Cedex 4 (France); Smith, D. A., E-mail: frank.marshall@nasa.gov [Centre d’Études Nucléaires de Bordeaux Gradignan, IN2P3/CNRS, Université de Bordeaux 1, BP120, F-33175, Gradignan Cedex (France)

    2016-08-20

    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 ν 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. We use data from the extensive monitoring campaign with Rossi X-ray Timing Explorer 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.

  11. 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.

  12. 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.

  13. 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.

  14. Development of a net shape manufacturing method for ventilated brake discs in single piece design

    Energy Technology Data Exchange (ETDEWEB)

    Zuber, Ch.; Heidenreich, B. [German Aerospace Center (DLR) Institute of Structures and Design, Pfaffenwaldring 38-40, 70569, Stuttgart (Germany)

    2006-04-15

    Carbon fibre reinforced ceramic matrix composites (CMC), originally developed for lightweight heat shields of spacecraft, are used for high performance brake discs in sports cars from different manufacturers. In contrast to the CMC materials for space applications, based on woven fabrics and costly manufacturing methods, these low cost friction materials are produced by liquid silicon infiltration of porous Carbon/Carbon (C/C) preforms, based on short fibre reinforced CFRP green bodies manufactured via warm press technique. In this work, different manufacturing methods for ventilated CMC brake discs are compared to each other, and the development of a new technology for the manufacture of single piece C/C-SiC brake discs in net shape technique is presented. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  15. Hot spot formation on passenger car brake discs; Hotspotbildung bei Pkw-Bremsscheiben

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, T.; Bruns, R. [Univ. der Bundeswehr, Hamburg (Germany). Lab. fuer Maschinenelemente und Foerderwesen

    1998-06-01

    Braking a passenger car from high speeds may, under certain circumstances, lead to the development of hot spots on the brake disc surface, causing the brake and steering systems to vibrate. Based on the findings of experiments carried out by the Laboratory of Mechanical Machine Components and Material Handling at the University of the Federal Armed Forces, Hamburg, a computational model has been developed to simulate the processes of hot spot formation. (orig.) [Deutsch] Das Abbremsen eines Pkw aus hohen Geschwindigkeiten bewirkt unter bestimmten Voraussetzungen Hitzeflecken auf der Bremsscheiben-Oberflaeche - die sogenannten Hotspots -, welche das Brems- und Lenksystem zu Schwingungen anregen. Aus den Erkenntnissen der am Laboratorium Maschinenelemente und Foerderwesen an der Universitaet der Bundeswehr Hamburg durchgefuehrten experimentellen Untersuchungen ist ein Rechenmodell entwickelt worden, mit dem die Vorgaenge der Hotspot-Bildung simuliert werden koennen. (orig.)

  16. 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.

  17. 78 FR 23622 - In the Matter of NewTech Brake Corp., Order of Suspension of Trading

    Science.gov (United States)

    2013-04-19

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION In the Matter of NewTech Brake Corp., Order of Suspension of Trading April 17, 2013. It appears to the Securities and Exchange Commission that there is a lack of current and accurate information concerning the securities of NewTech Brake Corp...

  18. 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.

  19. Theoretical research on the issue of heat stress that appears in mechanism of automotive braking system and their influence

    Directory of Open Access Journals (Sweden)

    Ulian Tudor

    2017-01-01

    Full Text Available The braking system is one of the most important car systems with application in traffic safety. The thermal stress in this system, especially when the brake is intensively used, is affecting the efficiency of the system, its response and therefore the road safety.

  20. Implementation and Performance Evaluation of a Regenerative Braking System Coupled to Ultracapacitors for a Brushless DC Hub Motor Driven Electric Tricycle

    OpenAIRE

    Kuruppu, Sandun

    2010-01-01

    Research related to electrical vehicles is gaining importance due to the, energy crisis. An electric vehicle itself is far ahead of an internal combustion, engine based vehicle due to its efficiency. Using regenerative braking when, braking, improves the efficiency of an electric vehicle as it recovers energy that, could go to waste if mechanical brakes were used. A novel regenerative braking, system for neighborhood electric vehicles was designed, prototyped and tested., The proposed system ...

  1. 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.

  2. Population distributions of time to collision at brake application during car following from naturalistic driving data.

    Science.gov (United States)

    Kusano, Kristofer D; Chen, Rong; Montgomery, Jade; Gabler, Hampton C

    2015-09-01

    Forward collision warning (FCW) systems are designed to mitigate the effects of rear-end collisions. Driver acceptance of these systems is crucial to their success, as perceived "nuisance" alarms may cause drivers to disable the systems. In order to make customizable FCW thresholds, system designers need to quantify the variation in braking behavior in the driving population. The objective of this study was to quantify the time to collision (TTC) that drivers applied the brakes during car following scenarios from a large scale naturalistic driving study (NDS). Because of the large amount of data generated by NDS, an automated algorithm was developed to identify lead vehicles using radar data recorded as part of the study. Using the search algorithm, all trips from 64 drivers from the 100-Car NDS were analyzed. A comparison of the algorithm to 7135 brake applications where the presence of a lead vehicle was manually identified found that the algorithm agreed with the human review 90.6% of the time. This study examined 72,123 trips that resulted in 2.6 million brake applications. Population distributions of the minimum, 1st, and 10th percentiles were computed for each driver in speed ranges between 3 and 60 mph in 10 mph increments. As speed increased, so did the minimum TTC experience by drivers as well as variance in TTC. Younger drivers (18-30) had lower TTC at brake application compared to older drivers (30-51+), especially at speeds between 40 mph and 60 mph. This is one of the first studies to use large scale NDS data to quantify braking behavior during car following. The results of this study can be used to design and evaluate FCW systems and calibrate traffic simulation models. Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.

  3. Calmodulin regulates Cav3 T-type channels at their gating brake.

    Science.gov (United States)

    Chemin, Jean; Taiakina, Valentina; Monteil, Arnaud; Piazza, Michael; Guan, Wendy; Stephens, Robert F; Kitmitto, Ashraf; Pang, Zhiping P; Dolphin, Annette C; Perez-Reyes, Edward; Dieckmann, Thorsten; Guillemette, Joseph Guy; Spafford, J David

    2017-09-25

    Calcium (Cav1 and Cav2) and sodium channels possess homologous CaM-binding motifs, known as IQ motifs in their C-termini, which associate with calmodulin (CaM), a universal calcium sensor. Cav3 T-type channels, which serve as pacemakers of the mammalian brain and heart, lack a C-terminal IQ motif. We illustrate that T-type channels associate with CaM using co-immunoprecipitation experiments and single particle cryo-electron microscopy. We demonstrate that protostome invertebrate (LCav3) and human Cav3.1, Cav3.2, and Cav3.3 T-type channels specifically associate with CaM at helix 2 of the gating brake in the I-II linker of the channels. Isothermal titration calorimetry results revealed that the gating brake and CaM bind each other with high nanomolar affinity. We show that the gating brake assumes a helical conformation upon binding CaM, with associated conformational changes to both CaM lobes as indicated by amide chemical shifts of the amino acids of CaM in 1H-15N HSQC NMR spectra. Intact Ca2+-binding sites on CaM and an intact gating brake sequence (first 39 aa of the I-II linker) were required in Cav3.2 channels to prevent the runaway gating phenotype, a hyperpolarizing shift in voltage sensitivities and faster gating kinetics. We conclude that the presence of high-nanomolar affinity binding sites for CaM at its universal gating brake and its unique form of regulation via the tuning of the voltage range of activity could influence the participation of Cav3 T-type channels in heart and brain rhythms. Our findings may have implications for arrhythmia disorders arising from mutations in the gating brake or CaM. Copyright © 2017, The American Society for Biochemistry and Molecular Biology.

  4. Continuous variable transmission and regenerative braking devices in bicycles utilizing magnetorheological fluids

    Science.gov (United States)

    Cheung, Wai Ming; Liao, Wei-Hsin

    2013-04-01

    The use of magnetorheological (MR) fluids in vehicles has been gaining popular recently due to its controllable nature, which gives automotive designers more dimensions of freedom in functional designs. However, not much attention has been paid to apply it to bicycles. This paper is aimed to study the feasibility of applying MR fluids in different dynamic parts of a bicycle such as the transmission and braking systems. MR continuous variable transmission (CVT) and power generator assisted in braking systems were designed and analyzed. Both prototypes were fabricated and tested to evaluate their performances. Experimental results showed that the proposed designs are promising to be used in bicycles.

  5. 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.

  6. 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.

  7. Wave pattern motion and stick-slip limit cycle oscillation of a disc brake

    Science.gov (United States)

    Kang, Jaeyoung; Krousgrill, Charles M.; Sadeghi, Farshid

    2009-08-01

    This paper examines the dynamic response of a rotating squealing disc brake subject to distributed nonlinear contact stresses where two brake pads are assumed to be stationary and rigid. The friction stresses produce high-frequency vibrations that exhibit standing or traveling waves on the disc surface. The wave pattern resulting from the binary flutter mechanism of one transverse doublet mode pair is studied here. The results show that the wave pattern is associated with mode-coupling character. For a steady-squealing mode, the stick zone of the contact area is determined by a smooth friction-velocity curve having both negative and positive slopes.

  8. 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.

  9. Copper Substitution and Noise Reduction in Brake Pads: Graphite Type Selection

    Directory of Open Access Journals (Sweden)

    Sanjeev Sharma

    2012-11-01

    Full Text Available Graphite is commonly used in brake pads. The use of graphite powder has the main goal of solid state lubrication and friction coefficient stabilization. In this article results on resin bonded brake pads with focus on noise performance and heat dissipation are presented. Experimental tests are based on model friction materials with a known formulation and a reduced number of components for a better identification of the role of the graphite type. Results clearly indicate that both noise performance and thermal conductivity are strongly affected by the type of graphite. Guidelines for the selection of graphite types for optimized friction materials are given.

  10. 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.

  11. Assessment and preliminary design of an energy buffer for regenerative braking in electric vehicles

    Science.gov (United States)

    Buchholz, R.; Mathur, A. K.

    1979-01-01

    Energy buffer systems, capable of storing the vehicle energy during braking and reusing this stored energy during acceleration, were examined. Some of these buffer systems when incorporated in an electric vehicle would result in an improvement in the performance and range under stop and go driving conditions. Buffer systems considered included flywheels, hydropneumatic, pneumatic, spring, and regenerative braking. Buffer ranking and rating criteria were established. Buffer systems were rated based on predicted range improvements, consumer acceptance, driveability, safety, reliability and durability, and initial and life cycle costs. A hydropneumatic buffer system was selected.

  12. 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.

  13. Machine & electrical double control air dryer for vehicle air braking system

    Science.gov (United States)

    Zhang, Xuan; Yang, Liu; Wang, Xian Yan; Tan, Xiao Yan; Wang, Wei

    2017-09-01

    As is known to all, a vehicle air brake system, in which usually contains moisture. To solve the problem, it is common to use air dryer to dry compressed air effectively and completely remove the moisture and oil of braking system. However, the existing air dryer is not suitable for all commercial vehicles. According to the operational status of the new energy vehicles in the initial operating period, the structure design principle of the machine & electric control air dryer is expounded from the aspects of the structure and operating principle, research & development process.

  14. Neutron scattering residual stress measurements on gray cast iron brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Spooner, S.; Payzant, E.A.; Hubbard, C.R. [and others

    1996-11-01

    Neutron diffraction was used to investigate the effects of a heat treatment designed to remove internal residual stresses in brake discs. It is believed that residual stresses may change the rate of deformation of the discs during severe braking conditions when the disc temperature is increased significantly. Neutron diffraction was used to map out residual strain distributions in a production disc before and after a stress-relieving heat treatment. Results from these neutron diffraction experiments show that some residual strains were reduced by as much as 400 microstrain by stress relieving. 5 refs., 5 figs., 1 tab.

  15. INVESTIGATION OF VEHICLE WHEEL ROLLING WITH MAXIMUM EFFICIENCY IN THE BRAKE MODE

    Directory of Open Access Journals (Sweden)

    D. Leontev

    2011-01-01

    Full Text Available Up-to-date vehicles are equipped by various systems of braking effort automatic control theparameters calculation of which do not as a rule have a rational solution. In order to increase theworking efficiency of such systems it is necessary to have the data concerning the impact of variousoperational factors on processes occurring at braking of the object of adjustment (vehicle wheel.Data availability concerning the impact of operational factors allows to decrease geometricalparameters of adjustment devices (modulators and maintain their efficient operation under variousexploitation conditions of vehicle’s motion.

  16. Adaptive regenerative braking for electric vehicles with an electric motor at the front axle using the state dependent Riccati equation control technique

    NARCIS (Netherlands)

    Jansen, S.; Alirezaei, M.; Kanarachos, S.

    2014-01-01

    In this paper a novel adaptive regenerative braking control concept for electric vehicles with an electric motor at the front axle is presented. It is well known that the "phased" type regenerative braking systems of category B maximize the amount of regenerative energy during braking. However,

  17. 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.

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

    Indian Academy of Sciences (India)

    disc application. V SARAVANAN1,∗, P R THYLA1 and S R BALAKRISHNAN2. 1Department of Mechanical Engineering, PSG College of Technology, Coimbatore ... The aim of this paper is to develop a light weight material for brake disc applications thereby substi- ..... This section presents an infrared (IR)-based wireless.

  19. 49 CFR 236.502 - Automatic brake application, initiation by restrictive block conditions stopping distance in...

    Science.gov (United States)

    2010-10-01

    ... restrictive block conditions stopping distance in advance. 236.502 Section 236.502 Transportation Other... TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR... Cab Signal Systems Standards § 236.502 Automatic brake application, initiation by restrictive block...

  20. Analysis of disc brake squeal using a ten-degree-of-freedom model ...

    African Journals Online (AJOL)

    It is a significant problem in passenger vehicles that has not been solved satisfactorily until recently. Many manufacturers of brake ... instability of the system. The results have show that the predicted squeal tendency at varying all the studies parameters is as less as possible to be 43 % compared to other single parameters.