WorldWideScience

Sample records for windmill brake state

  1. Classical ground states of Heisenberg and X Y antiferromagnets on the windmill lattice

    Science.gov (United States)

    Jeevanesan, Bhilahari; Orth, Peter P.

    2014-10-01

    We investigate the classical Heisenberg and planar (X Y ) spin models on the windmill lattice. The windmill lattice is formed out of two widely occurring lattice geometries: a triangular lattice is coupled to its dual honeycomb lattice. Using a combination of iterative minimization, heat-bath Monte Carlo simulations, and analytical calculations, we determine the complete ground-state phase diagram of both models and find the exact energies of the phases. The phase diagram shows a rich phenomenology due to competing interactions and hosts, in addition to collinear and various coplanar phases, also intricate noncoplanar phases. We briefly outline different paths to an experimental realization of these spin models. Our extensive study provides a starting point for the investigation of quantum and thermal fluctuation effects.

  2. Fighting Windmills

    DEFF Research Database (Denmark)

    Brandt, Urs Steiner; Svendsen, Gert Tinggaard

    2004-01-01

    the environmentalists) demand changes in behaviour on moral grounds. In contrast, the Bootleggers (the producers of renewable energy), who profit from the very regulation, keep a low profile. The actual heavy subsidisation of renewable energy sources, such as wind energy, can be viewed as a successful policy outcome...... to be just as tough as fighting windmills and needs to be addressed in future and more rigorous empirical research. At the end of the day, transparent incentives of relevant stakeholders in the climate change issue are necessary preconditions for progress in the climate change negotiations....

  3. Windmills and birds

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, N W; Poulsen, E

    1984-07-01

    The objective of this study is an investigation of potential conflicts between windmills and birds. Emphasis is on frightening, collision risk and biotopic changes due to windmill systems. The study is based on the environment of Koldby and Nibe windmills (South Jutland). Biotopic changes were not observed around the existing windmills. Drainage of mill grounds at Nibe had probably no effect on water level in the area around; a longer observation is necessary to draw any decisive conclusions.(EG).

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

    Science.gov (United States)

    Wolff, Andrzej

    2010-01-01

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

  5. Advanced composites for windmills

    Science.gov (United States)

    Bourquardez, G.

    A development status assessment is conducted for advanced composite construction techniques for windmill blade structures which, as in the case of composite helicopter rotors, promise greater reliability, longer service life, superior performance, and lower costs. Composites in wind turbine applications must bear aerodynamic, inertial and gravitational loads in complex interaction cycles. Attention is given to large Darrieus-type vertical axis windmills, to which composite construction methods may offer highly effective pitch-control mechanisms, especially in the 'umbrella' configuration.

  6. Windmills change direction

    Energy Technology Data Exchange (ETDEWEB)

    Musgrove, P

    1976-12-09

    Britain needs a national program for research and development of wind power to see if the North Sea's wind can compete with its oil and gas as an energy source. Environmental and land-use pressures will require that large windmills be built in shallow offshore waters where the high wind speeds can compensate for the extra cost. As the southern North Sea gas fields are depleted they will provide natural energy storage reservoirs for compressed air, which can then be used for power on windless days. Wind-generated energy can also be used to electrolyze water and the reservoirs used to store hydrogen. Costs for wind power are primarily interest and repayment for the capital investment since the energy source is free. Current estimates are 150 to 250 pounds per installed kilowatt, with a breakeven point higher than the 130 pounds needed to be economically feasible. When these figures are adjusted for inflation, however, the breakeven point is 200 pounds, the estimated cost for large-windmill systems. As conventional fuels are depleted and become more costly, wind power will be more attractive to future generations. Improvements in windmill design, particularly the high-speed vertical-axis windmill, will reduce capital costs. This design does not need to be oriented into the wind, and the electrical generator can be placed on ground level. The use of straight blades allows inexpensive construction materials. Small-scale windmills will be useful for farms, remote areas, and in developing countries. (DCK)

  7. Arusha windmill: a construction manual

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, D

    1977-01-01

    The advantages of the Arusha (Tanzania) low-cost windmill for rural communities in the Third World are described, and the history of its development is recounted. A description of the fan-bladed windmill's operation,d esign, cost, parts and materials, and tools required are given. The construction of such a windmill is described in extensive detail followed by discussions of the operation, maintenance and alterations of the windmill, pumps to be used with the windmill and other uses of the rotary power generated. Useful data and design formulae, a glossary and a unit conversion table are included.

  8. The windmill industry of Denmark

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Windmills are the strong asset of the Danish exporting industry. The share of the Danish industry of the windmill markets of the world is about 50 %. Denmark exported about 57 % more windmills in 1995 than in 1994. About 1500 different types of windmills, varying from farm-mills to large 600 kW wind power plants were sold abroad and 200 is in operation in Denmark. At present the largest export country of Denmark is Germany where the knowledge of environmental issues has nearly doubled the wind power export from Denmark. Germany produces most wind power in the Europe. The Netherlands is a strong competitor of Denmark in the field of wind power. The windmills sold or constructed abroad are mainly large, modern and effective 500 kW windmills. The annual energy production of a windmill corresponds, under good wind conditions, to the annual energy consumption of 200-300 detached houses. Danish Vestas is launching a 60 m tall, 1.5 MW windmill, the paddle-span of which will be 30 m. A good windmill has to be capable to produce power at least 97 % of the operation time. The remaining 3 % is left for maintenance and reparation of the mills. The maximum power of a windmill is estimated to be 1.5 MW. At present the windmill production employs about 10 000 persons in Denmark

  9. Historical development of the windmill

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, D.G.

    1990-12-01

    Throughout history, windmill technology represented the highest levels of development in those technical fields we now refer to as mechanical engineering, civil engineering, and aerodynamics. This report describes key stages in the technical development of windmills as prime movers -- from antiquity to construction of the well-known Smith-Putnam wind turbine generator of the 1940's, which laid the foundation for modern wind turbines. Subjects covered are windmills in ancient times; the vertical-axis Persian windmill; the horizontal-axis European windmill (including both post mills and tower mills); technology improvements in sails, controls, and analysis; the American farm windmill; the transition from windmills to wind turbines for generating electricity at the end of the 19th century; and wind turbine development in the first half of the 20th century. 43 refs.

  10. Windmills: selection method and results obtained by the Renewable Energy Center of UNESP - Guaratingueta Campus, Sao Paulo state, Brazil; Cata-vento: metodo de selecao e resultados obtidos pelo Centro de Energias Renovaveis da UNESP - Campus Guaratingueta

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Luis Fernando Silva; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis], e-mail: teofilo@feg.unesp.br, e-mail: lfernandosm@uol.com.br

    2004-07-01

    Windmills are always a good option to promote irrigate in areas with adequate potential wind. Its correct selection can guarantee the enough water supply with minimum cost. Since April 2004 the Renewable Energy Center of UNESP - Campus Guaratingueta' has tested a commercial windmill with 18 blades rotor and 3,4 diameter meters, that in a area with approximately 3 m/s average wind speed, has been obtained a average daily 1500 water liters. This volume is enough to supply a small country state, however, it could be get with a smaller capacity machine, if this worked properly. (author)

  11. Economic competitiveness of windmills

    Energy Technology Data Exchange (ETDEWEB)

    Lapin, E E

    1977-01-01

    The conditions under which windmills become competitive with the generation of electric power from fossil fuels are examined. The influence of cost of construction, financing arrangements, and the future cost of fuels is shown. Energy storage and network arrangements for mills are considered briefly, as are alternate uses for mills, e.g., the utilization of mill output directly for heating or for the production of a fuel.

  12. Sailboat as a windmill

    OpenAIRE

    Jaulin , Luc; Le Bars , Fabrice

    2013-01-01

    International audience; This paper proposes to transform a sailboat robot into a big wind turbine (or windmill) corresponding to the boat itself. The main idea is to make the sailboat rotating as fast as possible. When the wind open the sail, the mainsheet is able to pull a generator in order to produce electric energy. The resulting controller is simple to implement and its parameters are easy to tune. A simulated test-case shows that the proposed technique could generate an average power of...

  13. Exposition regarding small windmills

    International Nuclear Information System (INIS)

    1992-12-01

    Emphasis is laid on the elucidation of the current situation of small windmills in Denmark by estimating the industry's strengths and weaknesses and evaluating the technical status and user economy relevant to these wind turbines, in addition to their technical and marketing potentials within the next 3-5 years. It is also attempted to survey and forecast their situation within a competitive market which includes marketing and sales potential outside Denmark, often by way of development projects financed by DANIDA (Danish International Development Agency, a department under the Danish Foreign Ministry that takes responsibility for Danish aid to developing countries, often by direct agreement). It is noted that it is difficult to make predictions in the light of currently rapidly changing global political aspects, but it is suggested that sales of smaller Danish windmills within the country could amount to 300-700 wind turbines by the year 2000. Regarding sales abroad, it is concluded that the current number will not increase unless great efforts are made within the export market and the instigation of close cooperation with foreign companies which use an international sales network and have access to local distribution channels. (AB) (15 refs.)

  14. Industry Formation and State Intervention - The Case of the Windmill Industry in Denmark and the United States

    DEFF Research Database (Denmark)

    Vestergaard, Jens; Goddard, Robert D; Brandstrup, Lotte

    2003-01-01

    In some situations a strong case can be made for state interventio into the process of industry formation,the so called baby industry argument.The formation of the wind mill industry in both the US and Denmark represents case where the national governments decided to help in the formation...... of the wind mill industry. The form of the intervention is crucial to the outcome.Two forms of intervention and their results are analysed in this paper.A bottom up market driven approach in Denmark are compared to a top down research and development oriented approach in the US.The analysis clearly underline...

  15. The smaller windmill

    Energy Technology Data Exchange (ETDEWEB)

    Sanguinetti, P. [Trillium Windmills Inc., Orillia, ON (Canada)

    1997-06-01

    The importance of small windchargers, below a rating of 1000 watts, was discussed. These units can go wherever there is a need to charge a 12 volt or 24 volt battery and where there is no easily available conventional electricity source, such as a sailboat, farm, scientific site, or cottage. Trillium Windmills was set up to market the Rutland Windcharger which is a small windcharger rated at 75 watts in a 22 MPH wind. To give an indication of the size of the market, it was pointed out that two manufacturers, one in North America and one in England, have monthly production runs of more than 1000 small wind turbines of less than 500 watts.

  16. Windmilling of turbofan engine; calculation of performance characteristics of a turbofan engine under windmilling

    OpenAIRE

    Ramanathan, A.

    2014-01-01

    The turbofan is a type of air breathing jet engine that finds wide use in aircraft propulsion. During the normal operation of a turbofan engine installed in aircraft, the combustor is supplied with fuel, flow to the combustor is cut off and the engine runs under so called Windmilling conditions being driven only by the ram pressure ratio by producing drag. In-depth analysis is done to study the performance characteristics at this state.

  17. Offshore floating windmills

    International Nuclear Information System (INIS)

    1993-10-01

    The aim was to produce a general survey of the profitability of establishing floating offshore wind turbine arrays and to compare this with the cost and profitability of constructing offshore arrays with fixed foundations and arrays located on land sites. Aspects of design in all cases are described, also into relation to the special demands placed on dimensioning in relation to the types of location and foundation. The costs of the offshore arrays are evaluated in relation to capacity under conditions in Danish waters. The advantage of floating arrays is that they can be placed far out to sea where they can not be seen from the coast and thus not be considered to spoil the marine view. But as the water gets deeper the cost of floating foundations rises. It was found that it would not be technologically profitable to establish floating arrays at a depth of less than 30 - 40 meters which means that only the outer Danish waters can be taken into consideration. For depths of up to 70 meters, individual floating bases are more expensive than fixed ones but would be cheaper if a number of windmills could share the same anchor. For depths of more than 70 meters floating foundations would be the cheapest. The cost is dependent on the depth and distance from the coast and also on wind conditions. The main conclusion is that currently the cost of establishing wind turbine arrays in deeper outer waters on floating foundations is comparable to that of arrays sited at inner waters on solid foundations placed on the sea bed. (AB) (20 refs.)

  18. Design and Analysis of Windmill Simulation and Pole by Solidwork Program

    Science.gov (United States)

    Mulyana, Tatang; Sebayang, Darwin; R, Akmal Muamar. D.; A, Jauharah H. D.; Yahya Shomit, M.

    2018-03-01

    The Indonesian state of archipelago has great wind energy potential. For micro-scale power generation, the energy obtained from the windmill can be connected directly to the electrical load and can be used without problems. However, for macro-scale power generation, problems will arise such as the design of vane shapes, there should be a simulation and an accurate experiment to produce blades with a special shape that can capture wind energy. In addition, daily and yearly wind and wind rate calculations are also required to ensure the best latitude and longitude positions for building windmills. This paper presents a solution to solve the problem of how to produce a windmill which in the builder is very practical and very mobile can be moved its location. Before a windmill prototype is built it should have obtained the best windmill design result. Therefore, the simulation of the designed windmill is of crucial importance. Solid simulation express is a tool that serves to generate simulation of a design. Some factors that can affect a design result include the power part and the rest part of the part, material selection, the load is given, the security of the design power made, and changes in shape due to treat the load given to the design made. In this paper, static and thermal simulations of windmills have been designed. Based on the simulation result on the designed windmill, it shows that the design has been made very satisfactory so that it can be done prototyping fabrication process.

  19. Actuated rheology of magnetic micro-swimmers suspensions: Emergence of motor and brake states

    Science.gov (United States)

    Vincenti, Benoit; Douarche, Carine; Clement, Eric

    2018-03-01

    We study the effect of magnetic field on the rheology of magnetic micro-swimmers suspensions. We use a model of a dilute suspension under simple shear and subjected to a constant magnetic field. Particle shear stress is obtained for both pusher and puller types of micro-swimmers. In the limit of low shear rate, the rheology exhibits a constant shear stress, called actuated stress, which only depends on the swimming activity of the particles. This stress is induced by the magnetic field and can be positive (brake state) or negative (motor state). In the limit of low magnetic fields, a scaling relation of the motor-brake effect is derived as a function of the dimensionless parameters of the model. In this case, the shear stress is an affine function of the shear rate. The possibilities offered by such an active system to control the rheological response of a fluid are finally discussed.

  20. The establishment of the Danish windmill industry - was it worthwhile?

    International Nuclear Information System (INIS)

    Drud Hansen, J.; Jensen, C.; Stroejer Madsen, E.

    2002-01-01

    The renewed interest for using wind energy commercially is not more than twenty-five years old. From an experimental stage of turning wind energy into electricity in the 1970s, a new industry for producing standardised windmills gained foothold in the beginning of the 1980s and since then it has developed rapidly through the 1980s and the 1990s. The Danish innovators of the new windmill technology have been the pioneers behind this development, and Denmark has succeeded in acquiring a first mover advantage on the world market. This position has been maintained and at present Denmark satisfies more than half of the world market's demand for windmills. There are at least two reasons for this pioneering position of the Danish windmill industry. First, Denmark is by nature very 'abundant' in wind energy due to its geographical position at the nexus between the Gulf Stream and the European continent. The windy climate makes given technologies of windmills more productive. Secondly, the production of electricity from wind power has been subsidised by state aid schemes among which the most important one has been a price guarantee per produced kWh (kilowatt-hours) to the owners of windmill. These subsidies have made production of electricity from windmills profitable for private investors and hence competitive on the market for electricity produced by fossil fuel. Although the public subsidies to produced electricity from wind power in Denmark have been motivated by environmental concerns over the emission of carbon dioxide (CO 2 ) from power plants using fossil fuels, the subsidies have resulted in the development of a new industry with a strong export performance. The development of the windmill industry thus illustrates an infant industry strategy where state aid in the upstart phase results in a build up of an internationally competitive industry in the long run. This is the Mill's test of an infant industry strategy. However, a precondition for a successful outcome of

  1. The economy of privately owned windmills

    International Nuclear Information System (INIS)

    1994-01-01

    The Danish government ordered that an investigation of the economy of privately owned windmills be undertaken from 1991. Updating is a part of the follow-up of Danish energy policy designated ''Energi 2000'' (Energy 2000). The report contains descriptions of the calculation methods used and related conditions, data on individual privately owned windmills, a summary of the most important tax and duty regulations, details of conditions for private windmill owners, a sensitivity analysis and an analysis of the development of the economy of privately owned windmills since 1991. It is concluded that, based on the current values named in the 1991 report, there is a drop in the case of cooperatively owned windmills of ca. 235,000 DKr and a rise in current value in the case of one-man owned windmills of 270,000 DKr. It is concluded that the changed conditions of the economy since 1991 has resulted in a poorer economy in relation to cooperatively owned windmills and an improvement in single-ownership windmills so that the current value in the latter is now positive. (AB)

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  3. 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

  4. The erection of larger windmills in the open countryside - an investigation of the visual effects

    International Nuclear Information System (INIS)

    1996-12-01

    The future use of larger windmills will result in new visual effects. The investigation points out that these effects will be dependent on the main characteristics of the landscape. Windmills with a height of 90 m will be taller than any other element found in the landscape with the exception of some chimneys, masts, etc. It is shown that very tall windmills should not be set up in large dominating groups, that it is important that the towers are slender and that the blades rotate slowly (in order to give a more peaceful effect), if the landscape should not be spoiled. Large windmills dominate an area of 1 - 3 kilometers, but at a distance of 10 - 12 km they can appear to fade away between woods and large buildings etc. Naturally, large windmills will be prominent on heaths and moors, and would not be welcome where there are buildings of cultural interest or where the landscape is under conservation. They could, it is stated, be placed amongst a group of smaller windmills, as this would help to lessen their dominance, but should not be positioned where one type of landscape merges into another, as here they would show up more. Local boundaries should also be taken into consideration. When planning where to locate windmills the overall visual effect over larger areas should be contemplated in addition to the preservation of views of buildings etc. of historical interest. Photographs should be taken of proposed sites so that paper models can be placed so as to produce an idea of the visual effects of erecting larger windmills in various positions in specified areas

  5. Windmill, sugar works, 'Springhall', St. Lucy, Barbados

    OpenAIRE

    Unknown

    2003-01-01

    204 x 143 mm. Showing the windmill and other refinery buildings with workers leading bullock teams loaded with cane towards the refinery. The Spring Hall Estate lies in the centre of St. Lucy Parish in northern Barbados.

  6. The windmill of learning processes

    DEFF Research Database (Denmark)

    Kragelund, Linda

    2011-01-01

    that part of the nursing education has been reduced in some countries as e.g. Denmark.  The approach is presented through a model termed the 'Windmill of Learning Processes', which draws on empirical data from a qualitative investigation with an explorative and descriptive design, and on the theoretical......This article presents a new approach to student nurses' learning from their interaction with psychiatric patients. Using the approach can enable students and mentors to exploit students' learning opportunities, and help students to get the most out of their clinical placement in a time, where...... concepts of 'disjuncture', and 'everyday life activities'. 'Disjuncture' is defined as a situation in which there is disharmony between a person's experiences and the current situation. In such a situation there is potential for learning. My analysis of the empirical data led to the identification of a new...

  7. Complaints about noise from windmills

    International Nuclear Information System (INIS)

    1992-10-01

    With the aim of examining the subject of noise made by windmills and discovering the characteristics that are commonly found with regard to complaints in this respect, 10 cases were selected from a total of 40 in order to carry out a critical examination of the matter. The chosen cases were concerned with both small and medium-sized wind turbines located in groups or standing alone. The authors of the complaints lived within a distance of 160-166 meters from the cited windmills which could be described as producing an average amount of noise in relation to their size. It was clear from available material (including telephone interviews) that noise was experienced as being the most disturbing, although light-flashing from turbine blades, shadowing and aesthetic considerations related to scenic location were also named. In most cases the noise was so distressing that it influenced people's decisions on whether, or where, to go outside their homes and whether or not to open their windows. Most complaints were about machine noise and other audible tones, and about half of them concerned the swish of turning blades. Most people were especially bothered when the wind did not blow so hard (so that the wind in the trees etc. was not so loud). The persistancy of the noise generated was considered to contribute most to the depreciation of life quality. It was found that the amount of irritation coincided with noise loads of L r at a wind velocity of 5 or 8 m/s. A table is presented to illustrate registered noise conditions. (AB)

  8. Solid state circuit controls direction, speed, and braking of dc motor

    Science.gov (United States)

    Hanna, M. F.

    1966-01-01

    Full-wave bridge rectifier circuit controls the direction, speed, and braking of a dc motor. Gating in the circuit of Silicon Controlled Rectifiers /SCRS/ controls output polarity and braking is provided by an SCR that is gated to short circuit the reverse voltage generated by reversal of motor rotation.

  9. 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.

  10. Better Brakes

    Science.gov (United States)

    1976-01-01

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

  11. Advanced simulation of windmills in electric power supply

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, Hans; Nielsen, Arne Hejde

    2000-01-01

    -connected windmills as a part of realistic electrical grid models. That means an arbitrary number of wind farms or single windmills within an arbitrary network configuration. The windmill model may be applied to study of electric power system stability and of power quality as well. It is found that a grid...

  12. Windmills: Ancestors of the wind power generation

    Institute of Scientific and Technical Information of China (English)

    Cesare ROSSI; Flavio RUSSO; Sergio SAVINO

    2017-01-01

    A brief description of the windmills from the second millennium BC to the Renaissance is presented.This survey is a part of several studies conducted by the authors on technology in the ancient world.The windmills are the first motor,other than human muscles,and are the ancestors of the modem wind turbines.Some authors' virtual reconstructions of old windmills are also presented.The paper shows that the operating principle of many modem machines had already been conceived in the ancient times by using a technology that was more advanced than expected,but with two main differences,as follows:Similar tasks were accomplished by using much less energy;and the environmental impact was nil or very low.Modem designers should sometimes consider simplicity rather than the use of a large amount of energy.

  13. Windmills: Ancestors of the wind power generation

    Science.gov (United States)

    Rossi, Cesare; Russo, Flavio; Savino, Sergio

    2017-09-01

    A brief description of the windmills from the second millennium BC to the Renaissance is presented. This survey is a part of several studies conducted by the authors on technology in the ancient world. The windmills are the first motor, other than human muscles, and are the ancestors of the modern wind turbines. Some authors' virtual reconstructions of old windmills are also presented. The paper shows that the operating principle of many modern machines had already been conceived in the ancient times by using a technology that was more advanced than expected, but with two main differences, as follows: Similar tasks were accomplished by using much less energy; and the environmental impact was nil or very low. Modern designers should sometimes consider simplicity rather than the use of a large amount of energy.

  14. Braking system

    Science.gov (United States)

    Norgren, D.U.

    1982-09-23

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

  15. Sprag solenoid brake

    Science.gov (United States)

    Dane, P. H.

    1972-01-01

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

  16. Magnetostrictive Brake

    Science.gov (United States)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

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

  17. Noise from windmills; Stoey fra vindmoeller

    Energy Technology Data Exchange (ETDEWEB)

    Solberg, Sigurd [KILDE Akustikk, (Norway)

    2000-07-01

    The report gives a technical description of noise from windmills. Characteristic levels of noise and noise calculations is described. The influence of wind in the area 5-15 m/s is surveyed. Rules and regulations in five other countries are summarized. (author)

  18. "Happiness and Education": Tilting at Windmills?

    Science.gov (United States)

    Verducci, Susan

    2013-01-01

    This essay explores the question: Is Nel Noddings a visionary who sees past the constraints of contemporary education or is she, like Don Quixote, madly tilting at windmills in her description and defense of happiness as an educational aim? Viewing the educational aim of happiness as an ideal raises substantial challenges for the practicality of…

  19. Windmills and the landscape. Architecture and aesthetics

    International Nuclear Information System (INIS)

    Birk Nielsen, F.

    1996-01-01

    The authors' hope is that this document, which is richly illustrated with colour photographs, will encourage new visions, demonstrate new architectural possibilities and the aesthetic consequences of locating windmills throughout the Danish landscape. It aims at being an inspiring tool for local planning authorities. (AB) 29 refs

  20. STUDY OF TECHNICAL STATE IMPACT OF BRAKE RETARDERS AT THE PROCESSING ABILITY OF HUMPS

    Directory of Open Access Journals (Sweden)

    D. M. Kozachenko

    2016-08-01

    Full Text Available Purpose. The research aims development of methods for calculating the estimated capacity humps for the loss conditions of brake power retarders. Methodology. The operation of humps is connected with large number of random factors, such as the characteristics of cuts, environmental conditions, the value of braking power implemented by retardants and others. In this regard, to research the set tasks the methods of simulation modeling and mathematical statistics are used. Determination of speed and motion time of cuts on the routes is carried out on the basis of rolling down modeling of their rolling down from the humps. Findings. If the brake power of retarders of the rolling down part of humps is not enough to stop the cuts, it should be provided the intervals during break-up to release the rolling routes from the preliminary cuts. The dependencies allowing to set the duration of these intervals were determined using the methods of the probability theory If the brake power of retarders at the rolling down part of humps and at the classification tracks is not enough to meet the requirements of the aimed regulation of the cuts rolling speed, it is necessary the use the additional brake shoes. The work develops the methods that on the basis of simulation modeling of the humping process allow one to set the desired value of the break-up duration increase. They ensure the traffic safety at the given number of car motion speed regulators. Originality. Authors firstly proposed the improved methods for determining the estimated capacity of humps. Unlike the existing ones, allow taking into account the technological limitations caused by the requirements of the humping process safety and can be used to assess the performance of the humps in the conditions of parametric failures of the retarders. Practical value. The use of the proposed methods allows assessing the influence of the retarders’ disrepair on the performance degradation of humps for the

  1. Scour Protection of Off-Shore Windmills

    DEFF Research Database (Denmark)

    Frigaard, Peter; Pedersen, Jan

    2002-01-01

    In the Eighties and Nineties wind turbines with a total rated power of app 1000 Mega watt were erected in Denmark. Today more that 13% of the electrical consumption in in Denmark is covered by electricity from wind turbines. Through, due to lack of good positions for the windmills and due...... to growing opposition against the the wind turbines, the Danish government initiated in 1999 the construction of several large off-shore wind farms....

  2. Friction brake cushions acceleration and vibration loads

    Science.gov (United States)

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

    1966-01-01

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

  3. Compact, Lightweight Servo-Controllable Brakes

    Science.gov (United States)

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

    2010-01-01

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

  4. 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.

  5. BRAKE DEVICE

    Science.gov (United States)

    O'Donnell, T.J.

    1959-03-10

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

  6. Exposition concerning small windmills. Appendix to main report. Volume 1

    International Nuclear Information System (INIS)

    1992-12-01

    This appendix to the main report entitled ''Exposition Concerning Small Windmills'' includes background information on the report, profiles of the participating companies and of those visited in Denmark and abroad, questionnaires and interview schemes sent to the participating companies, surveys of producers of Danish and foreign producers of small windmills and an appendix to the economical calculations found within the report. (AB)

  7. Windmilling of turbofan engine; calculation of performance characteristics of a turbofan engine under windmilling

    NARCIS (Netherlands)

    Ramanathan, A.

    2014-01-01

    The turbofan is a type of air breathing jet engine that finds wide use in aircraft propulsion. During the normal operation of a turbofan engine installed in aircraft, the combustor is supplied with fuel, flow to the combustor is cut off and the engine runs under so called Windmilling conditions

  8. Household windmills - an investigation of the visual conditions relating to the erection of household windmills in the open countryside

    International Nuclear Information System (INIS)

    Hasloev, D.B.; Lorentzen, M.; Koed, J.

    1994-08-01

    It is pointed out that household windmills, being smaller and more delicate in construction than other types of wind turbines, are not so noticeable as their larger counterparts. The fact that they are usually located close to the buildings for which they provide electricity also limits their visibility in the open landscape. Some of these windmills have been standing for a great number of years and are regarded as of cultural interest and as being almost a natural part of the countryside. It is recommended that if the number of household windmills is to increase significantly, they should be of a light construction. The visual conditions and effects of the setting up of more examples of this type of windmill are dealt with. Photographs of parts of the open Danish countryside, to which drawings of windmills are added in strategic positions are presented in order to illustrate the aesthetic effects of their design and location. It is recommended that regulations should ensure that the smaller windmills are placed in close relation to the buildings which they serve so they appear as part of an aesthetically pleasing whole. Placing them in relation to tall trees also helps to mitigate the visual effects of windmills on the landscape. Such windmills should be as lightly built as possible. Regulations should be made with regard to maximum height and heaviness of construction etc. (AB)

  9. Automotive Brake Systems.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

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

  10. Windmills and wind motors how to build and run them

    CERN Document Server

    Powell, F E

    2011-01-01

    Free, clean, and sustainable energy: wind power is an essential resource everyone can harness. This comprehensive and compact historical work provides everything you need to learn about the theory and construction of everyday windmills, from small ones intended solely as models to those large enough to generate electricity. Powell provides all the necessities to get you on your way, including detailed, step-by-step instructions, illustrations, and designs for every part of the project.Types of windmill projects include:A model windmill with sails two feet acrossA

  11. Windmills for Kaliningrad. Final report

    International Nuclear Information System (INIS)

    Ansoe, N.; Bugge, J.

    1999-06-01

    With the limitations stated below, the project has been successful: it has confirmed the applicability of wind power as a significant source of energy in Kaliningrad in accordance with the original assumptions. With regard to demonstration purposes, the project has fulfilled its purpose: the wind turbine is placed at a site well suited for public attention, it offers a good basis for information activities, and the annual energy production seems to meet the expectations. The project was seriously delayed, and there were significant changes in the scope, structure, and procedures, of the project. These changes were mutually connected. The scope of the project was reduced by the omission of the original direct technology transfer aspect with the aim to initiate a wind power industry in Kaliningrad and the St. Petersburg region based upon Danish technology in a close cooperation with the Danish industry. This approach was replaced by a more traditional demonstration approach with a commercial wind turbine delivery according to Danish standard procedures. The project structure was changed by the omission of original partners from St. Petersburg and the inclusion of Danish Power Consult. The resulting project cooperation was influenced by fundamental differences in approach. The originator of the project, Folkecenter, has a policy of emphasizing the practical implementation of appropriate technologies with a strong aspect of direct technology transfer. Danish Power Consult/SEAS has a cooperation with Yantarenergo at utility company level, both directly in Kaliningrad and through the Baltic Ring. In addition, Danish Power Consult performs consultancy for the Danish Energy Agengy concerning centralized energy planning in Kaliningrad. The difference in approach was a significant factor in the cause of the project, including the delays, the change of scope, and the annulment of the project procedures. Based upon the experience in this project, it may be concluded that a

  12. Wind Fab: Manufacturer of water pumping windmills in India

    International Nuclear Information System (INIS)

    Gurumoorthy, S.

    1991-01-01

    Wind Fab is one of the four manufacturers appointed recently by the Indian government to produce a classic gear type wind pump for deep well pumping (H = 50-100 meter). In various regions, the ground water table has been lowering considerably and a deep well wind pump is required. Wind Fab is still producing the 12PU500 windmill. The main problem is that the wind pumps are applied in a wide range of climatological, hydrological and agricultural conditions. Different types of windmills suitable for the different application ranges should be produced. It is explained that the drawings of the 12PU500 windmills were easily available and consequently the windmills were produced all over the country. There was no quality control and the 12PU500 was applied under low lift to high lift conditions. 5 figs., 5 tabs

  13. Shoulder and Scapular Kinematics during the Windmill Softball Pitch

    OpenAIRE

    Backus, Sherry I.; Kraszewski, Andrew; Kontaxis, Andreas; Gibbons, Mandi; Bido, Jennifer; Graziano, Jessica; Hafer, Jocelyn; Jones, Kristofer J.; Hillstrom, Howard; Fealy, Stephen

    2013-01-01

    Objectives: Pitch count has been studied extensively in the overhand throwing athlete. However, pitch count and fatigue have not been systematically evaluated in the female windmill (underhand) throwing athlete. Direct kinematic measurements of the glenohumeral and scapulo-thoracic joint have not to be correlated and determined. The purpose is to measure scapular kinematics for the high school female windmill softball pitcher and identify kinematic adaptions and changes in pitching performanc...

  14. 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

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

    Science.gov (United States)

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

    1973-01-01

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

  16. Computer-aided design and engineering: A study of windmills in la Mancha (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Sola, Jose Ignacio [Universidad de Jaen, Escuela Politecnica Superior, Campus de las Lagunillas, s/n, 23071 Jaen (Spain); Gonzalez, Miguel Angel Gomez-Elvira; Martin, Enrique Perez [Universidad Politecnica de Madrid, E.T.S. Ingenieros Agronomos, Ciudad Universitaria, 28080 Madrid (Spain)

    2006-08-15

    This article presents a detailed study, of the Manchegan windmill. This type of windmill is a central symbol in the story of Don Quijote de la Mancha, by Cervantes, which this year celebrates its 4th centenary, and to which this article pays homage. There exist no publications dealing with the technical aspects of these windmills. Studies have been carried out on windmills in the south of Spain, but no comparison has been made between the two types of windmill. This paper studies the technological conditions of the original Manchegan windmills. We carry out a wind evaluation of the region, calculate the power and momentum of the windmills and discuss the results obtained with a comparison with the type of Southern Spanish windmill. (author)

  17. Wheeled vehicle deceleration as estimation parameter of adaptive brake control system state

    Directory of Open Access Journals (Sweden)

    Turenko A.

    2012-06-01

    Full Text Available The method of stability estimation of adaptive control system with signal adjustment based on Lyapunov’s direct method that allows to take into account the nonstationarity of the basic system and non-linearity in the form of limitation on control action restriction as well as error control is stated.

  18. 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, ...

  19. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

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

  20. Antiskid braking system

    Science.gov (United States)

    Pazdera, J. S.

    1974-01-01

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

  1. Deployable Brake for Spacecraft

    Science.gov (United States)

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

    1987-01-01

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

  2. 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.

  3. Exposition concerning small windmills. List of relevant publications

    International Nuclear Information System (INIS)

    Aurvig, D.

    1992-09-01

    In connection with the publication of the report entitled ''Exposition Concerning Small Windmills'', it was decided that searching in databases should also be used in relation to the collection of relevant information, and that the results of these searches should be published in the form of a reading list. This is presented here. The subject areas covered are technology, research and development, marketing, developing countries and agricultural areas - all relevant to small windmills. Risoe Library, Roskilde, Denmark (Telephone no. (45) 42371212) will be helpful in acquiring any publication(s) referenced in the reading list. The report number J.No. 51171/92-0019 should also be quoted. (AB)

  4. 3500 Windmills in Denmark which produce electric power

    International Nuclear Information System (INIS)

    Hagensen, F.

    1992-02-01

    In Denmark, the wind has been used for electricity production since 1891. The development in the amounth of wind turbines has been rather unstable, but information of 4245 wind turbines is presented, of which over 3500 is connected to the public grid. Each windmill registration refers to a code in the 1:100,000 maps from Geodaetisk Institut so that its location can be determined. Data on the efficiency, manufacturer and the year and month of installation are included. Two lists is presented according to the windmills position and the name of the manufacturer. (CLS)

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

    International Nuclear Information System (INIS)

    Adamowicz, Adam; Grzes, Piotr

    2011-01-01

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

  6. 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.

  7. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1995-09-12

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

  8. Feedback brake distribution control for minimum pitch

    Science.gov (United States)

    Tavernini, Davide; Velenis, Efstathios; Longo, Stefano

    2017-06-01

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

  9. Fighting windmills? EU industrial interests and global climate negotiations

    DEFF Research Database (Denmark)

    Brandt, Urs Steiner; Svendsen, Gert Tinggaard

    2003-01-01

    for setting a target of 15% of all energy to come from sources such as windmills, solar panels and waves by 2015. Such a target would further the EU's interests globally, and could explain, in economic terms, why the EU eagerly promotes GHG trade at a global level whereas the US has left the Kyoto agreement...

  10. Supporting Collective Training & Thinking in Joint Project Optic Windmill

    NARCIS (Netherlands)

    Jacobs, L.R.M.A.; Wiel, R.A.N. van de; Bosch, J.; Olthoff, R.

    2009-01-01

    In September 2008, the Missile Defence Group of the Royal Netherlands Air Force, together with the German Air Force and the US Missile Defence Agency, organised the 10th edition of Exercise Joint Project Optic Windmill (JPOW). Over the past decade JPOW has become a world leading Integrated Air and

  11. The Establishment of the Danish Windmill Industry - Was It Worthwhile?

    DEFF Research Database (Denmark)

    Hansen, Jørgen Drud; Jensen, Camilla; Madsen, Erik Strøjer

    2003-01-01

    the environmental damage of using fossil fuels should in principle be taken into account. However, the main benefits are related to the emergence of a new export sector. As the value of the windmill firms at the stock exchange by far exceeds that of the accumulated distorted loss in production of electricity...

  12. Model-Based Analysis of a Windmill Communication System

    DEFF Research Database (Denmark)

    Tjell, Simon

    2006-01-01

    This paper presents the experiences obtained from modeling and analyzing a real-world application of distributed embedded computing. The modeling language Coloured Petri Nets (CPN) has been applied to analyze the properties of a communication system in a windmill, which enables a group of embedded...

  13. 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,

  14. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Science.gov (United States)

    2010-02-03

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

  15. Brake Fundamentals. Automotive Articulation Project.

    Science.gov (United States)

    Cunningham, Larry; And Others

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

  16. Experimental development of a torsion arc blade type horizontal axis windmil; Nejire enko yokugata suihei jiku fusha no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, N. [Meiji Univ., Tokyo (Japan). Faculty of Scince and Technology

    1996-05-31

    To get more wind energy, longer rotating blades and higher towers of windmills are required. Therefore, the location of windmills is limited and the initial cost gets higher. In this study, a small size windmill which can generate electricity even in a city was developed and tested. A torsion arc blade type horizontal axis windmill was designed and the blade form, number and degree of distortion were investigated. Based on the results, a small windmill was made, rotation and generation tests were carried out and it was confirmed that the windmill could be used as a small scale wind power generation. The windmill is of simple construction having 6 arc blades and no high tower is required. This paper consists of 6 sections, i.e. Introduction, Windmill model, Tested windmill, Test facility and method, Test results and consideration, and Postscript. 2 refs., 18 figs., 1 tab.

  17. Reel safety brake

    Science.gov (United States)

    Carle, C. E. (Inventor)

    1976-01-01

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

  18. 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.

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

    OpenAIRE

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

    2017-01-01

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

  20. An antilock molecular braking system.

    Science.gov (United States)

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

    2012-08-17

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

  1. 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.

  2. Green Subsidies and Learning-by-doing in the Windmill Industry

    DEFF Research Database (Denmark)

    Hansen, Jørgen Drud; Jensen, Camilla; Madsen, Erik Strøjer

    2001-01-01

    of windmills a dynamic cost function for producing windmills is tested. The cost disadvantage of producing electricity by windmills relative to traditional power stations has narrowed considerably because of a strong learning-by-doing effect. The deliberate policy to subsidize production of electricity...... by windpower has placed Denmark in a first-mover position in this market and the future has to show whether this is a successful story of an infant industrial policy....

  3. Brake for rollable platform

    Science.gov (United States)

    Morris, A. L.

    1974-01-01

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

  4. The Establishment of the Danish Windmill Industry - Was it Worthwhile?

    DEFF Research Database (Denmark)

    Drud-Hansen, Jørgen; Jensen, Camilla; Madsen, Erik Strøjer

    2002-01-01

    the environmental damage of using fossil fuels should in principle be taken into account. However, the environmental effect is only evaluated by calculating an implicit price of the emission of carbon dioxide. The main benefits are related to the emergence of a new export sector. As the value of the windmill...... companies at the stock exchange by far exceeds that of the accumulated distorted loss in production of electricity, this case seems to make up an example of a successful infant industry strategy.......The paper examines the welfare effects of the Danish subsidies towards the production of electricity from windpower. This policy has been a precondition for the remarkable development of the Danish windmill industry resulting in a dominant position on the world market. The article demonstrates...

  5. Magnetorheological suspension electromagnetic brake

    International Nuclear Information System (INIS)

    Bica, Ioan

    2004-01-01

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

  6. Preliminary tests of a high speed vertical axis windmill model

    Energy Technology Data Exchange (ETDEWEB)

    South, P; Rangi, R S

    1971-01-01

    This report discusses a fixed-pitch vertical axis windmill that combines the inherent simplicity of this type of machine with a high aerodynamic efficiency and a high relative velocity. A three-bladed rotor was selected as the basic design, having constant chord symmetric airfoil blades configured in a catenary curve such that the rotor diameter is equal to the rotor height. In wind tunnel tests using a 30 inch scale model, it was found that once this rotor was given a very low rotational speed, it picked up speed and ran at a rotor tip velocity/wind speed ratio greater than 1. The number of blades was varied in the testing. A maximum power coefficient of 0.67 was achieved at 17 ft/s wind speed at a tip speed/wind speed ratio of 7.25 for a 2-bladed rotor. Increasing the number of blades above 3 did not result in higher power. The rotor could operate in gusts which double the mean wind velocity. Examination of Reynolds number effects, and taking into account the scale of the model, it was concluded that a full-scale windmill could run at lower velocity ratios than those predicted by the model tests, and that it could self-start under no-load conditions if the cut-in rpm are at least half the rpm for maximum power at the prevailing wind speed. Preliminary estimates show that a 15 ft diameter windmill of this design, designed to operate with a safety factor of 2.5 up to a maximum wind speed of 60 ft/s, would weigh ca 150 lb and could be marketed for ca $60.00, excluding the driven unit, if sufficient quantities were produced to make tooling costs negligible. Similarly, a 30 ft windmill would weigh ca 1000 lb and cost ca $400.00. 2 refs., 6 figs.

  7. WIND BRAKING OF MAGNETARS

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  8. Complex windmill transformation producing new purely magnetic fluids

    International Nuclear Information System (INIS)

    Lozanovski, C; Wylleman, L

    2011-01-01

    Minimal complex windmill transformations of G 2 IB(ii) spacetimes (admitting a two-dimensional Abelian group of motions of the so-called Wainwright B(ii) class) are defined and the compatibility with a purely magnetic Weyl tensor is investigated. It is shown that the transformed spacetimes cannot be perfect fluids or purely magnetic Einstein spaces. We then determine which purely magnetic perfect fluids (PMpfs) can be windmill-transformed into purely magnetic anisotropic fluids (PMafs). Assuming separation of variables, complete integration produces two, algebraically general, G 2 I-B(ii) PMpfs: a solution with zero 4-acceleration vector and spatial energy-density gradient, previously found by the authors, and a new solution in terms of Kummer's functions, where these vectors are aligned and non-zero. The associated windmill PMafs are rotating but non-expanding. Finally, an attempt to relate the spacetimes to each other by a simple procedure leads to a G 2 I-B(ii) one-parameter PMaf generalization of the previously found metric.

  9. Control system for a vertical-axis windmill

    Science.gov (United States)

    Brulle, R.V.

    1981-09-03

    A vertical-axis windmill having a rotating structure is provided with a series of articulated vertical blades whose positions are controlled to maintain a constant RPM for the rotating structure, when wind speed is sufficient. A microprocessor controller is used to process information on wind speed, wind direction and RPM of the rotating structure to develop an electrical signal for establishing blade position. The preferred embodiment of the invention, when connected to a utility grid, is designed to generate 40 kilowatts of power when exposed to a 20 mile per hour wind. The control system for the windmill includes electrical blade actuators that modulate the blades of the rotating structure. Blade modulation controls the blade angle of attack, which in turn controls the RPM of the rotor. In the preferred embodiment, the microprocessor controller provides the operation logic and control functions. A wind speed sensor provides inputs to start or stop the windmill, and a wind direction sensor is used to keep the blade flip region at 90 and 270/sup 0/ to the wind. The control system is designed to maintain constant rotor RPM when wind speed is between 10 and 40 miles per hour.

  10. Kinematics and kinetics of elite windmill softball pitching.

    Science.gov (United States)

    Werner, Sherry L; Jones, Deryk G; Guido, John A; Brunet, Michael E

    2006-04-01

    A significant number of time-loss injuries to the upper extremity in elite windmill softball pitchers has been documented. The number of outings and pitches thrown in 1 week for a softball pitcher is typically far in excess of those seen in baseball pitchers. Shoulder stress in professional baseball pitching has been reported to be high and has been linked to pitching injuries. Shoulder distraction has not been studied in an elite softball pitching population. The stresses on the throwing shoulder of elite windmill pitchers are similar to those found for professional baseball pitchers. Descriptive laboratory study. Three-dimensional, high-speed (120 Hz) video data were collected on rise balls from 24 elite softball pitchers during the 1996 Olympic Games. Kinematic parameters related to pitching mechanics and resultant kinetics on the throwing shoulder were calculated. Multiple linear regression analysis was used to relate shoulder stress and pitching mechanics. Shoulder distraction stress averaged 80% of body weight for the Olympic pitchers. Sixty-nine percent of the variability in shoulder distraction can be explained by a combination of 7 parameters related to pitching mechanics. Excessive distraction stress at the throwing shoulder is similar to that found in baseball pitchers, which suggests that windmill softball pitchers are at risk for overuse injuries. Normative information regarding upper extremity kinematics and kinetics for elite softball pitchers has been established.

  11. 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

  12. On friction braking demand with regenerative braking

    NARCIS (Netherlands)

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

    2002-01-01

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

  13. Vehicle brake testing system

    Science.gov (United States)

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

    2002-11-19

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

  14. 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.

  15. Control allocation for for regenerative braking of electric vehicles with an electric motor at the front axle using the state-dependent Riccati equation control technique

    NARCIS (Netherlands)

    Kanarachos, S.A.; Alirezaei, M.; Jansen, S.T.H.; Maurice, J.P.

    2014-01-01

    In this paper the systematic development of an integrated braking controller for a vehicle driven by an electric motor on the front axle is presented. The objective is to engage the electric motor only during braking, up to the point at which the vehicle reaches its manoeuvrability and stability

  16. Load proportional safety brake

    Science.gov (United States)

    Cacciola, M. J.

    1979-01-01

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

  17. Scale in technology and learning-by-doing in the windmill industry

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Jensen, Camilla; Hansen, Jørgen Drud

    2003-01-01

    that learning-by-doing in the Danish windmill industry has contributed significantly to improve the cost efficiency of the producers. The technological development has been stimulated both by process and product innovations as the capacity of the individual mills has increased. The learning effect created......This paper examines the remarkable development of technology and the fast learning-by-doing in the windmill industry since it emerged in the beginning of the 1980s. Based on time series of prices of windmills, a dynamic cost function for producing windmills is tested. The estimations verified...... by early subsidies from the government has consolidated the competitive advantages of the windmill cluster in Denmark and preserved the first mover advantages at the world market. The article concludes that the industry probably will enter into a matured phase in the future with more modest technological...

  18. Scale in Technology and Learning-by-Doing in the Windmill Industry

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Jensen, Camilla; Hansen, Jørgen Drud

    that learning-by-doing in the Danish windmill industry has contributed significantly to improve the cost efficiency of the producers. The technological development has been stimulated both by process and product innovations as the capacity of the individual mills has increased. The learning effect created......This paper examines the remarkable development of technology and the fast learning-by-doing in the windmill industry since it emerged in the beginning of the 1980s. Based on time series of prices of windmills a dynamic cost function for producing windmills is tested. The estimations verified...... by early subsidies from the government has consolidated the competitive advantages of the windmill cluster in Denmark and preserved the first mover advantages at the world market. The article concludes that the industry probably will enter into a matured phase in the future with more modest technological...

  19. Scale in technology and learning-by-doing in the windmill industry

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Jensen, Camilla; Hansen, Jørgen Drud

    2003-01-01

    This paper examines the remarkable development of technology and the fast learning-by-doing in the windmill industry since it emerged in the beginning of the 1980s. Based on time series of prices of windmills, a dynamic cost function for producing windmills is tested. The estimations verified...... that learning-by-doing in the Danish windmill industry has contributed significantly to improve the cost efficiency of the producers. The technological development has been stimulated both by process and product innovations as the capacity of the individual mills has increased. The learning effect created...... by early subsidies from the government has consolidated the competitive advantages of the windmill cluster in Denmark and preserved the first mover advantages at the world market. The article concludes that the industry probably will enter into a matured phase in the future with more modest technological...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

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

    Science.gov (United States)

    Belhocien, Ali; Omar, Wan Zaidi Wan

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

  2. Unidirectional high gain brake stop

    Science.gov (United States)

    Lang, David J. (Inventor)

    1987-01-01

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

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

    OpenAIRE

    Ji, Fenzhu; Tian, Mi

    2010-01-01

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

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  6. 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.

  7. Performance of heavy ductile iron castings for windmills

    Directory of Open Access Journals (Sweden)

    Iulian Riposan

    2010-05-01

    Full Text Available The main objective of the present paper is to review the specific characteristics and performance obtaining conditions of heavy ductile iron (DI castings, typically applied in windmills industry, such as hubs and rotor housings. The requirements for high impact properties in DI at low temperatures are part of the EN-GJS-400-18U-LT (SRN 1563 commonly referred to as GGG 40.3 (DIN 1693. Pearlitic influence factor (Px and antinodularising action factor (K1 were found to have an important influence on the structure and mechanical properties, as did Mn and P content, rare earth (RE addition and inoculation power. The presence of high purity pig iron in the charge is extremely beneficial, not only to control the complex factors Px and K1, but also to improve the ‘metallurgical quality’ of the iron melt. A correlation of C and Si limits with section modulus is very important to limit graphite nodule flotation. Chunky and surface-degenerated graphite are the most controlled graphite morphologies in windmills castings. The paper concluded on the optimum iron chemistry and melting procedure, Mg-alloys and inoculants peculiar systems, as well as on the practical solutions to limit graphite degeneration and to ensure castings of the highest integrity, typically for this field.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  9. Safety brake for tape reels

    Science.gov (United States)

    Carle, C. E.

    1977-01-01

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

  10. Neutrons put the brakes on stress

    International Nuclear Information System (INIS)

    Gill, Katynna

    2006-01-01

    extent the stresses are from the manufacturing process. 'he only previous study of residual stress in a brake disc we could find showed these stresses in a new brake disc to be relatively small,'aid Ripley. 'So we started to think about how much of the runout was caused by residual stress, as had previously been assumed, and how much of this distortion was due to other factors from usage.' The early results will have the car industry rethinking their ideas. Like the previous study, Kirstein and Ripley found there were not large residual stresses in the new disc brakes. But the used disc brake was another story, with large stresses found. 'Our results suggest that perhaps runout is not caused by relaxation of residual stresses that were in the brake discs from manufacture,' Ripley stated. 'It looks more likely that runout is due to uneven cooling of the hot disc through use -from severe braking, for example - because we found such large stresses in the old worn-out brake compared with the new one.' With their results showcasing the power of neutrons to measure residual stress in important commercial components, Kirstein and Ripley hope to spark the car industry's interest. W ith the insight of neutrons, the industry may find in combination with improved modelling techniques new ways of manufacturing components to overcome these problems,' Kirstein said

  11. Exposition concerning small windmills. Appendix to the main report. Vol. 2

    International Nuclear Information System (INIS)

    1992-12-01

    The second appendix to the main report entitled ''Exposition Concerning Small Windmills'' contains a description of the search for literature on the subject, a survey of relevant properties and a calculation of the ''shadow'' effect of small windmills, demands on electrical technology placed on small windmills, a survey of participating institutions and consultants, descriptions of the way the project was carried out (divided into phases) and maps of developing countries with details of wind conditions and possibilities of obtaining loans from the World Bank. (AB)

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

    OpenAIRE

    Yin, Guodong; Jin, XianJian

    2013-01-01

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

  13. 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.

  14. 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.

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

    Science.gov (United States)

    Cikanek, S.R.

    1994-10-25

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

  16. Output characteristics of torsion arc blade type horizontal axis windmill; Nejire enko yokugata suiheijiku fusha no shutsuryoku tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, N; Kishimura, K [Meiji University, Tokyo (Japan)

    1997-11-25

    The previous paper theoretically analyzes characteristics of a torsion arc blade type (TABT) horizontal axis windmill to derive the theoretical equations, which give the results in good agreement with the observed ones, when multiplied by a blade shape factor. This paper discusses that the theoretical and observed results are in good agreement with each other by taking into consideration shape-related solidity and number of blades. The following findings are obtained, when parameters related to a 6-blade TABT horizontal axis wind mill are introduced and hysteresis brake is used as the load resistance for torque measurement. Shape factor can be represented by two factors of blade number and solidity. The same equation for shape factor is applicable to both elliptical and rectangular blades. These blades need different theoretical equations to give the results in agreement with the observed ones, when operated at a tip speed ratio (TSR) of 1.77 and 1.58, respectively. Rotational force is affected by the rear blade shape when they are operated at a respective TSR below the above level, but unaffected at beyond the above level. 5 refs., 9 figs., 1 tab.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  18. The design of high-speed windmills suitable for driving electric generators

    Energy Technology Data Exchange (ETDEWEB)

    Klein, G J

    1975-01-01

    A simple windmill theory is presented for designing a small, horizontal axis windmill for powering an automobile-type generator used along with a storage battery. Windmills designed by the method presented in this paper have maximum efficiencies in the order of 0.40 to 0.45, which approaches 75% of the theoretical maximum. Wind tunnel tests were performed on a two-bladed unit designed for a tip speed/wind speed ratio of 7. Maximum efficiency was close to 0.45 at a tip speed/wind speed ratio of slightly over 6. This windmill, if fitted directly to a specially wound three-brush automobile type generator, wil begin to charge a 6-volt battery at a wind speed of 7.5-8 mph. 2 refs., 7 figs., 1 tab.

  19. Modelling of windmill induction generators in dynamic simulation programs

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, Hans

    1999-01-01

    with and without a model of the mechanical shaft. The reason for the discrepancies are explained, and it is shown that the phenomenon is due partly to the presence of DC offset currents in the induction machine stator, and partly to the mechanical shaft system of the wind turbine and the generator rotor......For AC networks with large amounts of induction generators-in case of e.g. windmills-the paper demonstrates a significant discrepancy in the simulated voltage recovery after faults in weak networks, when comparing result obtained with dynamic stability programs and transient programs, respectively....... It is shown that it is possible to include a transient model in dynamic stability programs and thus obtain correct results also in dynamic stability programs. A mechanical model of the shaft system has also been included in the generator model...

  20. Windmill Noise Annoyance, Visual Aesthetics, and Attitudes towards Renewable Energy Sources

    Science.gov (United States)

    Klæboe, Ronny; Sundfør, Hanne Beate

    2016-01-01

    A small focused socio-acoustic after-study of annoyance from a windmill park was undertaken after local health officials demanded a health impact study to look into neighborhood complaints. The windmill park consists of 31 turbines and is located in the South of Norway where it affects 179 dwellings. Simple exposure-effect relationships indicate stronger reactions to windmills and wind turbine noise than shown internationally, with the caveat that the sample size is small (n = 90) and responses are colored by the existing local conflict. Pulsating swishing sounds and turbine engine hum are the main causes of noise annoyance. About 60 per cent of those who participated in the survey were of the opinion that windmills degrade the landscape aesthetically, and were far from convinced that land-based windmills are desirable as a renewable energy source (hydropower is an important alternative source of renewables in Norway). Attitudes play an important role in addition to visual aesthetics in determining the acceptance of windmills and the resulting noise annoyance. To compare results from different wind turbine noise studies it seems necessary to assess the impact of important modifying factors. PMID:27455301

  1. Structural analysis of the Danish windmill industry. Strukturanalyse af dansk vindmoelleindustri

    Energy Technology Data Exchange (ETDEWEB)

    1988-09-15

    Most Danish windmill manufacturers have experienced a grave economic crisis during the last three years. In 1987, the total windmill industry in this country ran at a loss of 40 million Danish crowns where the turnover was 550 million crowns. Danish firms are too small and seem to lack professional management. Production costs are too high and there is an urgent need for structural rationalization. Danish windmills cannot at the present time compete with the foreign market, largely because of lack of marketing know-how and financial backing. Yet today, many countries energy policies include the development of renewable energy resources, especially in the case of wind power. This should mean that the world market for windmills will increase, but so will the number of foreign competitors. The authors suggest the merging of Danish windmill manufacturing firms, and these mergers should include corporations that produce electricity. Possibilities for raising financial backing for running costs and export activities are mentioned, and ideas for rationalizing and reconstructing the whole Danish windmill industry are described in detail. (AB).

  2. Study Orientation Ply of Fiberglass on Blade Salt Water Pump Windmill using Abaqus

    Science.gov (United States)

    Badruzzaman, B.; Sifa, A.

    2018-02-01

    Windmill is one tool to generate energy from wind energy is converted into energy motion, salt production process still using traditional process by utilizing windmill to move sea water to salt field With a windmill driven water system, a horizontal axis type windmill with an average windmill height of 3-4 m, with a potential wind speed of 5-9 m / s, the amount of blade used for salt water pumps as much as 4 blades, one of the main factor of the windmill component is a blade, blade designed for the needs of a salt water pump by using fiberglass material. On layer orientation 0°,30°,45°,60° and 90° with layer number 10 and layer thickness 2 mm, the purpose of this study was to determine the strength of fiberglass that was influenced by the orientation of the layer, and to determine the orientation of fiberglass layer before making. This method used Finite Element Analysis method using ABAQUS, with homogenous and heterogeneous layer parameters. The simulation result shows the difference in von misses value at an angle of 0°, 30°, 45°,60° homogeneous value is greater than heterogeneous value, whereas in orientation 90 heterogeneous values have value 1,689e9 Pa, greater than homogenous 90 orientation value of 1,296e9 Pa.

  3. Windmill Noise Annoyance, Visual Aesthetics, and Attitudes towards Renewable Energy Sources

    Directory of Open Access Journals (Sweden)

    Ronny Klæboe

    2016-07-01

    Full Text Available A small focused socio-acoustic after-study of annoyance from a windmill park was undertaken after local health officials demanded a health impact study to look into neighborhood complaints. The windmill park consists of 31 turbines and is located in the South of Norway where it affects 179 dwellings. Simple exposure-effect relationships indicate stronger reactions to windmills and wind turbine noise than shown internationally, with the caveat that the sample size is small (n = 90 and responses are colored by the existing local conflict. Pulsating swishing sounds and turbine engine hum are the main causes of noise annoyance. About 60 per cent of those who participated in the survey were of the opinion that windmills degrade the landscape aesthetically, and were far from convinced that land-based windmills are desirable as a renewable energy source (hydropower is an important alternative source of renewables in Norway. Attitudes play an important role in addition to visual aesthetics in determining the acceptance of windmills and the resulting noise annoyance. To compare results from different wind turbine noise studies it seems necessary to assess the impact of important modifying factors.

  4. Deployable Engine Air Brake

    Science.gov (United States)

    2014-01-01

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

  5. Tether Deployer And Brake

    Science.gov (United States)

    Carroll, Joseph A.; Alexander, Charles M.

    1993-01-01

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

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

    Science.gov (United States)

    Dane, D. H. (Inventor)

    1974-01-01

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

  7. 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

  8. 49 CFR 393.52 - Brake performance.

    Science.gov (United States)

    2010-10-01

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

  9. 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.

  10. Combined hydraulic and regenerative braking system

    Science.gov (United States)

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

    1979-08-09

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

  11. 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.

  12. Fighting windmills? EU industrial interest and global climate negotiations

    International Nuclear Information System (INIS)

    Steiner Brand, U.; Tinggaard Svendsen, G.

    2003-01-01

    Why has the EU been so eager to continue the climate negotiations? Can it be solely attributed to the EU feeling morally obliged to be the main initiator of continued progress on the climate change negotiations, or can industrial interests in the EU, at least partly, explain the behaviour of the EU? We suggest that the EU has a rational economic interest in forcing the technological development of renewable energy sources to get a fast-mover advantage, which will only pay if a sufficient number of countries implement sufficiently stringent GHG reductions. The Kyoto Protocol, which imposes binding reductions on 38 OECD countries, implies that, as a first-mover, the EU will be to sell the necessary new renewable technologies, most prominently wind mills, to other countries, when they ratify and implement the Kyoto target levels. In the latest EU proposal made in Johannesburg, the EU pushed for setting a target of 15% of all energy to come from sources such as windmills, solar panels and waves by 2015. Such a target would further the EU's interests globally, and could explain, in economic terms, why the EU eagerly promotes GHG trade at a global level whereas the US has left the Kyoto agreement to save the import costs of buying the EU's renewable systems. (au)

  13. 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

  14. 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.

  15. Emergency Brake for Tracked Vehicles

    Science.gov (United States)

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

    1986-01-01

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

  16. Stability Control of Vehicle Emergency Braking with Tire Blowout

    OpenAIRE

    Chen, Qingzhang; Liu, Youhua; Li, Xuezhi

    2014-01-01

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

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

    Science.gov (United States)

    Guo, Jun; Fan, Jinwei

    2013-10-01

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

  18. “Frontload” in complex project program management to aim for lifetime sustainability of offshore windmill parks

    DEFF Research Database (Denmark)

    Brink, Tove

    2015-01-01

    This paper reveals how project program management can aim for lifetime sustainability of offshore windmill parks through innovation. The research is based on a qualitative focus group interview with 11 enterprises and 6 individual semi-constructed interviews with 6 enterprises. Offshore windmill...

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

    Science.gov (United States)

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

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

  20. Adjustable Tooling for Bending Brake

    Science.gov (United States)

    Ellis, J. M.

    1986-01-01

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

  1. 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...

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

    Science.gov (United States)

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

    2016-02-01

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

  3. Intelligent Braking System using the IR Sensor

    OpenAIRE

    Gajanan Koli

    2017-01-01

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

  4. Single acting translational/rotational brake

    Science.gov (United States)

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

    1996-01-01

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

  5. Brake Stops Both Rotation And Translation

    Science.gov (United States)

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

    1995-01-01

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

  6. 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.

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

    Science.gov (United States)

    Schramm, C.; Osland, Walt

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

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

    Science.gov (United States)

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

    2010-10-11

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

  9. An analysis of braking measures

    OpenAIRE

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

    2010-01-01

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

  10. Slowly braked, rotating neutron stars

    Science.gov (United States)

    Sato, H.

    1975-01-01

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

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

    OpenAIRE

    Ren He; Xuejun Liu; Cunxiang Liu

    2013-01-01

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

  12. Surface Electromyography of the Forearm Musculature During the Windmill Softball Pitch

    Science.gov (United States)

    Remaley, D. Trey; Fincham, Bryce; McCullough, Bryan; Davis, Kirk; Nofsinger, Charles; Armstrong, Charles; Stausmire, Julie M.

    2015-01-01

    Background: Previous studies investigating the windmill softball pitch have focused primarily on shoulder musculature and function, collecting limited data on elbow and forearm musculature. Little information is available in the literature regarding the forearm. This study documents forearm muscle electromyographic (EMG) activity that has not been previously published. Purpose: Elbow and upper extremity overuse injuries are on the rise in fast-pitch softball pitchers. This study attempts to describe forearm muscle activity in softball pitchers during the windmill softball pitch. Overuse injuries can be prevented if a better understanding of mechanics is defined. Study Design: Descriptive laboratory study. Methods: Surface EMG and high-speed videography was used to study forearm muscle activation patterns during the windmill softball pitch on 10 female collegiate-level pitchers. Maximum voluntary isometric contraction of each muscle was used as a normalizing value. Each subject was tested during a single laboratory session per pitcher. Data included peak muscle activation, average muscle activation, and time to peak activation for 6 pitch types: fastball, changeup, riseball, curveball, screwball, and dropball. Results: During the first 4 phases, muscle activity (seen as signal strength on the EMG recordings) was limited and static in nature. The greatest activation occurred in phases 5 and 6, with increased signal strength, evidence of stretch-shortening cycle, and different muscle characteristics with each pitch style. These 2 phases of the windmill pitch are where the arm is placed in the 6 o’clock position and then at release of the ball. The flexor carpi ulnaris signal strength was significantly greater than the other forearm flexors. Timing of phases 1 through 5 was successively shorter for each pitch. There was a secondary pattern of activation in the flexor carpi ulnaris in phase 4 for all pitches except the fastball and riseball. Conclusion: During the 6

  13. Surface Electromyography of the Forearm Musculature During the Windmill Softball Pitch.

    Science.gov (United States)

    Remaley, D Trey; Fincham, Bryce; McCullough, Bryan; Davis, Kirk; Nofsinger, Charles; Armstrong, Charles; Stausmire, Julie M

    2015-01-01

    Previous studies investigating the windmill softball pitch have focused primarily on shoulder musculature and function, collecting limited data on elbow and forearm musculature. Little information is available in the literature regarding the forearm. This study documents forearm muscle electromyographic (EMG) activity that has not been previously published. Elbow and upper extremity overuse injuries are on the rise in fast-pitch softball pitchers. This study attempts to describe forearm muscle activity in softball pitchers during the windmill softball pitch. Overuse injuries can be prevented if a better understanding of mechanics is defined. Descriptive laboratory study. Surface EMG and high-speed videography was used to study forearm muscle activation patterns during the windmill softball pitch on 10 female collegiate-level pitchers. Maximum voluntary isometric contraction of each muscle was used as a normalizing value. Each subject was tested during a single laboratory session per pitcher. Data included peak muscle activation, average muscle activation, and time to peak activation for 6 pitch types: fastball, changeup, riseball, curveball, screwball, and dropball. During the first 4 phases, muscle activity (seen as signal strength on the EMG recordings) was limited and static in nature. The greatest activation occurred in phases 5 and 6, with increased signal strength, evidence of stretch-shortening cycle, and different muscle characteristics with each pitch style. These 2 phases of the windmill pitch are where the arm is placed in the 6 o'clock position and then at release of the ball. The flexor carpi ulnaris signal strength was significantly greater than the other forearm flexors. Timing of phases 1 through 5 was successively shorter for each pitch. There was a secondary pattern of activation in the flexor carpi ulnaris in phase 4 for all pitches except the fastball and riseball. During the 6 pitches, the greatest muscular activity was in phases 5 and 6

  14. 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.

  15. Regional Courts as Judicial Brakes?

    Directory of Open Access Journals (Sweden)

    Metcalf Katrin Nyman

    2017-12-01

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

  16. Performance requirements for locomotive braking systems

    CSIR Research Space (South Africa)

    Vermaak, P

    2000-02-01

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

  17. 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.

  18. The design of brake fatigue testing system

    Directory of Open Access Journals (Sweden)

    Huang, Xiaoya

    2015-01-01

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

  19. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

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

  20. 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.

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

    African Journals Online (AJOL)

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

  2. 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...

  3. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

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

  4. The dynamics of antilock brake systems

    Science.gov (United States)

    Denny, Mark

    2005-11-01

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

  5. 49 CFR 236.712 - Brake pipe.

    Science.gov (United States)

    2010-10-01

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

  6. 49 CFR 229.46 - Brakes: General.

    Science.gov (United States)

    2010-10-01

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

  7. Brake wear warning device: A concept

    Science.gov (United States)

    Hawkins, S. F.

    1973-01-01

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

  8. 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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, H.R.

    2003-07-01

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

  10. Employee Identification with Corporate Values within the Danish Windmill Company NEG Micon

    DEFF Research Database (Denmark)

    Andersen, Mona Agerholm

    2008-01-01

    This paper presents the findings of a holistic study of the communication processes during a corporate value implementation within the Danish windmill company NEG Micon. This implies firstly a study of the different processes of management's formulation, construction and communication of the value...... statement and secondly, how the employees receive the values. The paper illuminates the potential problems that may occur during such a process and offer recommendations for future value implementation efforts in organisations....

  11. Muscle activation patterns of the upper and lower extremity during the windmill softball pitch.

    Science.gov (United States)

    Oliver, Gretchen D; Plummer, Hillary A; Keeley, David W

    2011-06-01

    Fast-pitch softball has become an increasingly popular sport for female athletes. There has been little research examining the windmill softball pitch in the literature. The purpose of this study was to describe the muscle activation patterns of 3 upper extremity muscles (biceps, triceps, and rhomboids [scapular stabilizers]) and 2 lower extremity muscles (gluteus maximus and medius) during the 5 phases of the windmill softball pitch. Data describing muscle activation were collected on 7 postpubescent softball pitchers (age 17.7 ± 2.6 years; height 169 ± 5.4 cm; mass 69.1 ± 5.4 kg). Surface electromyographic data were collected using a Myopac Jr 10-channel amplifier (RUN Technologies Scientific Systems, Laguna Hills, CA, USA) synchronized with The MotionMonitor™ motion capture system (Innovative Sports Training Inc, Chicago IL, USA) and presented as a percent of maximum voluntary isometric contraction. Gluteus maximus activity reached (196.3% maximum voluntary isometric contraction [MVIC]), whereas gluteus medius activity was consistent during the single leg support of phase 3 (101.2% MVIC). Biceps brachii activity was greatest during phase 4 of the pitching motion. Triceps brachii activation was consistently >150% MVIC throughout the entire pitching motion, whereas the scapular stabilizers were most active during phase 2 (170.1% MVIC). The results of this study indicate the extent to which muscles are activated during the windmill softball pitch, and this knowledge can lead to the development of proper preventative and rehabilitative muscle strengthening programs. In addition, clinicians will be able to incorporate strengthening exercises that mimic the timing of maximal muscle activation most used during the windmill pitching phases.

  12. Ground reaction forces, kinematics, and muscle activations during the windmill softball pitch.

    Science.gov (United States)

    Oliver, Gretchen D; Plummer, Hillary

    2011-07-01

    The aims of the present study were to examine quantitatively ground reaction forces, kinematics, and muscle activations during the windmill softball pitch, and to determine relationships between knee valgus and muscle activations, ball velocity and muscle activation as well as ball velocity and ground reaction forces. It was hypothesized that there would be an inverse relationship between degree of knee valgus and muscle activation, a direct relationship between ground reaction forces and ball velocity, and non-stride leg muscle activations and ball velocity. Ten female windmill softball pitchers (age 17.6 ± 3.47 years, stature 1.67 ± 0.07 m, weight 67.4 ± 12.2 kg) participated. Dependent variables were ball velocity, surface electromyographic (sEMG), kinematic, and kinetic data while the participant was the independent variable. Stride foot contact reported peak vertical forces of 179% body weight. There were positive relationships between ball velocity and ground reaction force (r = 0.758, n = 10, P = 0.029) as well as ball velocity and non-stride leg gluteus maximus (r = 0.851, n = 10, P = 0.007) and medius (r = 0.760, n = 10, P = 0.029) muscle activity, while there was no notable relationship between knee valgus and muscle activation. As the windmill softball pitcher increased ball velocity, her vertical ground reaction forces also increased. Proper conditioning of the lumbopelvic-hip complex, including the gluteals, is essential for injury prevention. From the data presented, it is evident that bilateral strength and conditioning of the gluteal muscle group is salient in the windmill softball pitch as an attempt to decrease incidence of injury.

  13. Analysis of Thermal Stresses and Strains Developing during the Heat Treatment of Windmill Shaft

    Directory of Open Access Journals (Sweden)

    Cebo-Rudnicka A.

    2017-06-01

    Full Text Available In the paper the results of evaluation of the temperature and stress fields during four cycles of the heat treatment process of the windmill shaft has been presented. The temperature field has been calculated from the solution to the heat conduction equation over the whole heat treatment cycles of the windmill shaft. To calculate the stress field an incremental method has been used. The relations between stresses and strains have been described by Prandtl-Reuss equation for the elastic-plastic body. In order to determine the changes in the temperature and stress fields during heat treatment of the windmill shaft self-developed software utilizing the Finite Element Method has been used. This software can also be used to calculate temperature changes and stress field in ingots and other axially symmetric products. In the mathematical model of heating and cooling of the shaft maximum values of the strains have been determined, which allowed to avoid the crack formation. The critical values of strains have been determined by using modified Rice and Tracy criterion.

  14. 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.

  15. BASIC STUDY ON TAILORMADE BRAKING SUPPORT SYSTEM

    Directory of Open Access Journals (Sweden)

    Toshiya HIROSE, M.S.

    2004-01-01

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

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

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

  18. Investigations into dynamics of a draft of mine cars with two locomotives during electric braking

    Energy Technology Data Exchange (ETDEWEB)

    Sikora-Iliew, R; Szklarski, L; Thuc, Thai Duy

    1983-03-01

    The computerized simulation of electric braking of a draft of GRANBY-5 mine cars and two locomotives (Ld2 locomotives with LDO30 electric series motors) is discussed. The following stages of simulation are analyzed: constructing a mathematical model of the draft of mine cars during electric (dynamic) braking, equations which describe dynamic states of locomotives, mine cars and electric motors during dynamic braking, equations for stability assessment of the draft during dynamic braking. The analog model for simulation of dynamic braking of the draft is given. Simulation results are shown in 10 diagrams. The WAT-1000 hybrid computer is used. Simulation shows that dynamic braking causes occurrence of maximum forces in the couplers between a locomotive and a mine car. When two locomotives are used the maximum force in couplers is lower than in a draft with one locomotive. Braking distance does not depend on position of locomotives in a draft of mine cars. Doubling draft speed causes braking distance to increase by 4 times. Optimum stability conditions of a draft of mine cars are guaranteed when one locomotive is placed at the draft head and a second is separated from the first one by one third of the draft length. 6 references

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

    Directory of Open Access Journals (Sweden)

    Hakan Köylü

    2016-08-01

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

  20. Light-gated molecular brakes based on pentiptycene-incorporated azobenzenes.

    Science.gov (United States)

    Tan, Wei Shyang; Chuang, Po-Ya; Chen, Chia-Huei; Prabhakar, Chetti; Huang, Shing-Jong; Huang, Shou-Ling; Liu, Yi-Hung; Lin, Ying-Chih; Peng, Shie-Ming; Yang, Jye-Shane

    2015-04-01

    Three azobenzene derivatives (2 R, 2 OR, and 2 NR) that differed in their terminal substituent (alkyl, alkyloxy, and dialkylamino, respectively) have been synthesized and investigated as molecular brakes, in which the rigid H-shaped pentiptycene group functioned as a rotor and the dinitrophenyl group as a "brake pad". The E and Z isomers of these compounds corresponded to the "brake-off" and "brake-on" states, respectively. The rotation rate of the rotor was evaluated by VT NMR spectroscopy for the brake-on state and by DFT calculations for the brake-off state. The difference between the rotation rates for the rotor in the two states was as large as eight orders of magnitude at ambient temperature. Photochemical switching of the azobenzene moieties afforded efficiencies of 55-67%. A combination of photochemical E→Z and thermal Z→E isomerization promoted the switching efficiency up to 78%. The terminal substituent affected both the photochemical and thermal switching efficiencies. Solvent polarity also played an important role in the lifetimes of the Z isomers. These azobenzene systems displayed similar braking powers but superior switching efficiencies to the stilbene analogue (1O R; ca. 60% vs 20%). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    Directory of Open Access Journals (Sweden)

    M. Podryhalo

    2015-07-01

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

  2. Space shuttle wheels and brakes

    Science.gov (United States)

    Carsley, R. B.

    1985-01-01

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

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

    OpenAIRE

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

    2013-01-01

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

  4. CFD modeling and computation of convective heat coefficient transfer of automotive disc brake rotors -Modelado CFD y cálculo de la transferencia de coeficientes de calor por convección de rotores de freno de disco automotores

    Directory of Open Access Journals (Sweden)

    Ali Belhocine

    2017-05-01

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

  5. 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...

  6. Research of braking peculiarities of used cars

    Directory of Open Access Journals (Sweden)

    V. Mitunevičius

    2002-06-01

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

  7. 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.

  8. Fatal accidental inhalation of brake cleaner aerosols.

    Science.gov (United States)

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

    2018-04-23

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

  9. 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.

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

    OpenAIRE

    Wang, Guoshun; Fu, Rong

    2013-01-01

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

  11. 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.

  12. Regenerative braking system of PM synchronous motor

    Science.gov (United States)

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

    2018-04-01

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

  13. 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…

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  15. Windmill-task as a New Quantitative and Objective Assessment for Mirror Movements in Unilateral Cerebral Palsy: A Pilot Study.

    Science.gov (United States)

    Zielinski, Ingar Marie; Steenbergen, Bert; Schmidt, Anna; Klingels, Katrijn; Simon Martinez, Cristina; de Water, Pascal; Hoare, Brian

    2018-03-23

    To introduce the Windmill-task, a new objective assessment tool to quantify the presence of mirror movements (MMs) in children with unilateral cerebral palsy (UCP), which are typically assessed with the observation-based Woods and Teuber scale (W&T). Prospective, observational, cohort pilot study. Children's hospital. Prospective cohort of children (N=23) with UCP (age range, 6-15y, mean age, 10.5±2.7y). Not applicable. The concurrent validity of the Windmill-task is assessed, and the sensitivity and specificity for MM detection are compared between both assessments. To assess the concurrent validity, Windmill-task data are compared with W&T data using Spearman rank correlations (ρ) for 2 conditions: affected hand moving vs less affected hand moving. Sensitivity and specificity are compared by measuring the mean percentage of children being assessed inconsistently across both assessments. Outcomes of both assessments correlated significantly (affected hand moving: ρ=.520; P=.005; less affected hand moving: ρ=.488; P=.009). However, many children displayed MMs on the Windmill-task, but not on the W&T (sensitivity: affected hand moving: 27.5%; less affected hand moving: 40.6%). Only 2 children displayed MMs on the W&T, but not on the Windmill-task (specificity: affected hand moving: 2.9%; less affected hand moving: 1.4%). The Windmill-task seems to be a valid tool to assess MMs in children with UCP and has an additional advantage of sensitivity to detect MMs. Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  16. Europe's largest solar thermal power plant. [200 kw thermal output supplemented by two 10-kw windmills

    Energy Technology Data Exchange (ETDEWEB)

    Bossel, U

    1976-03-01

    An overview is given over the solar heating plant which has recently been commissioned in the Camargue (France). This is the largest plant in Europe, with a mean heat output of about 200 kW, for the production of thermal energy from solar energy. The plant consists of 108 parabolic collectors (200 sq. metres) and 48 flat collectors (110 sq. metres). Two windmills with outputs of 10 kW each complete the system. The heat energy produced by the solar collectors is given up to 3 different stores, which in turn are connected to various consumers.

  17. Technical and functional analysis of Spanish windmills: 3D modeling, computational-fluid-dynamics simulation and finite-element analysis

    International Nuclear Information System (INIS)

    Rojas-Sola, José Ignacio; Bouza-Rodríguez, José Benito; Menéndez-Díaz, Agustín

    2016-01-01

    Highlights: • Technical and functional analysis of the two typologies of windmills in Spain. • Spatial distribution of velocities and pressures by computational-fluid dynamics (CFD). • Finite-element analysis (FEA) of the rotors of these two types of windmills. • Validation of the operative functionality of these windmills. - Abstract: A detailed study has been made of the two typologies of windmills in Spain, specifically the rectangular-bladed type, represented by the windmill ‘Sardinero’, located near the town of Campo de Criptana (Ciudad Real province, Spain) and the type with triangular sails (lateens), represented by the windmill ‘San Francisco’, in the town of Vejer de la Frontera (Cádiz province, Spain). For this, an ad hoc research methodology has been applied on the basis of three aspects: three-dimensional geometric modeling, analysis by computational-fluid dynamics (CFD), and finite-element analysis (FEA). The results found with the CFD technique show the correct functioning of the two windmills in relation to the spatial distribution of the wind velocities and pressures to which each is normally exposed (4–7 m/s in the case of ‘Sardinero’, and 5–11 for ‘San Francisco’), thereby validating the operative functionality of both types. In addition, as a result of the FEA, the spatial distribution of stresses on the rotor has revealed that the greatest concentrations of these occurs in the teeth of the head wheel in ‘Sardinero’, reaching a value of 12 MPa, and at the base of the masts in the case of the ‘San Francisco’, with a value of 24 MPa. Also, this analysis evidences that simple, effective designs to reinforce the masts absorb a great concentration of stresses that would otherwise cause breakage. Furthermore, it was confirmed that the oak wood from which the rotors were made functioned properly, as the windmill never exceeded the maximum admissible working stress, demonstrating the effectiveness of the materials

  18. Regenerative Braking System for Series Hybrid Electric City Bus

    OpenAIRE

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

    2008-01-01

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

  19. Accelerometer-controlled automatic braking system

    Science.gov (United States)

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

    1973-01-01

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

  20. THE DEVELOPMENT OF TROLLEYBUS DRIVE BRAKE SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. Safonau

    2011-01-01

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

  1. Air brake-dynamometer accurately measures torque

    Science.gov (United States)

    1965-01-01

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

  2. 30 CFR 56.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

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

  3. Tilting at Windmills: Colonialism, Communism, and the Limits of Coercion

    Science.gov (United States)

    2014-06-01

    existential threat to Jewry at the hands of Hitler, the Nazis, and their sympathizers had generated an elemental desire for recognition. If such...Strategic Context- Framing the Problem The existential threat to the United States, in the form of possible nuclear war with the Soviet Union...South East Asia. In Indochina’s case, the realpolitik consideration of “Europe first” would take precedence over more liberal, humanist policies on the

  4. Design of a magnetic braking system

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  5. 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.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  7. Distributional justice in Swedish wind power development – An odds ratio analysis of windmill localization and local residents’ socio-economic characteristics

    International Nuclear Information System (INIS)

    Liljenfeldt, Johanna; Pettersson, Örjan

    2017-01-01

    With a fast rise in large-scale wind power development in Sweden and other countries in recent years, issues related to energy justice generally and distributional justice specifically have become concerns in windmill siting. Some research, for instance, has indicated that it is easier to build windmills in economically marginalized communities. The evidence for this, however, is still limited. Thus, this study aims to statistically evaluate the extent to which the decisions to approve or reject windmill proposals in Sweden can be explained by factors related to the socio-economic characteristics of people living in the areas surrounding windmill sites. The study is based on an odds ratio analysis of decisions on all windmill proposals in Sweden, in which geo-referenced socio-economic data on an individual level for all inhabitants within 3 and 10 km of the windmill sites are studied. The results show skewness in the distribution of windmills, with a higher likelihood of rejection in areas with more highly educated people and people working in the private sector, compared to a higher likelihood of approval in areas with more unemployed people. This skewness, while not necessarily unjust, warrants further policy and research attention to distributional justice issues when developing wind power. - Highlights: • The distributional justice of windmill siting in Sweden is statistically evaluated. • Windmill siting decisions are related to people's socio-economic characteristics. • The results indicate some distributional skewness for wind power development. • The study gives statistical rigour and generalisability to energy justice findings. • The results warrant follow-ups and policy guides for how to handle benefit-sharing.

  8. Windmills by Design: Purposeful Curriculum Design to Meet Next Generation Science Standards in a 9-12 Physics Classroom

    Science.gov (United States)

    Concannon, James; Brown, Patrick L.

    2017-01-01

    The "Next Generation Science Standards" (NGSS) challenges science teachers to think beyond specific content standards when considering how to design and implement curriculum. This lesson, "Windmills by Design," is an insightful lesson in how science teachers can create and implement a cross-cutting lesson to teach the concepts…

  9. 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.

  10. 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.

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

    Science.gov (United States)

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

    2017-07-21

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

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

    Science.gov (United States)

    Yun, Dongwon; Koo, Jeong-Hoi

    2017-05-01

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

  13. Tribology of a Combined Yaw Bearing and Brake for Wind Turbines

    DEFF Research Database (Denmark)

    Poulios, Konstantinos

    disc brake is typically included as an independent system. However, the increasing size of wind turbines makes roller element bearings an economically costly option. Moreover, the additional brake system increases complexity and consequently adds further production and maintenance costs. One...... of the innovations aiming at reducing complexity in the yaw system consists in combining a segmented sliding bearing and a brake into a single system. This thesis studies the tribological implications of such a hybrid sliding bearing and brake for the yaw system of wind turbines. Based to a large extent...... that are affected by the tendency for building larger units, is the yaw system of horizontal axis wind turbines. State of the art wind turbine yaw systems consist of either a large roller element bearing or a corresponding segmented sliding bearing that connects the wind turbine nacelle and tower. An additional...

  14. The Combination of Coastal Resources Potential: Development of Windmill Techno Park in the Context of Edutourism and Hinterland Analysis

    Science.gov (United States)

    Hasanuddin, H.; Nurdin, H.; Waskito, W.; Refdinal, R.

    2018-04-01

    There are many coastal cities in Indonesia, among them the city of Padang and Pariaman in West Sumatra with the ownership of the grace of coastal resources, such as stunning coastal scenery and wind energy that can be converted to its potential. These two types of resources need to be combined utilization especially in relation to the development of tourism so as to have an impact on the regional development and the cities growth. This paper discusses of information related to the potential of coastal resources used as a parameter development of windmill techno park in the context of educational tourism. The discussion focuses on locational aspects and consideration of the design and modification for the windmill model to the enhancement of tourist attraction. In addition, it is also studying the presence of the windmill techno park as a development center in the context of hinterland in the regional analysis. Through the measurement results obtained average wind speed (2.5 - 6.5) m/s and meet the standards & criteria as a windmill design variables. While the geomorphology of the region, its location has a breathtaking coastal landscape as a tourist destination. Then through gravity analysis, the location of the windmill techno park development provides optimum strength to the growth of the city of Padang, with the value of interaction strength is higher than other regions. This means as a sub-urban area of the city the existence of windshield techno park later can support economic development and growth of cities around the coast.

  15. 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.

  16. 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.

  17. 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.

  18. 49 CFR 393.40 - Required brake systems.

    Science.gov (United States)

    2010-10-01

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

  19. Model-Based Brake Control including Tyre Behaviour

    NARCIS (Netherlands)

    De Vries, E.J.H.

    2012-01-01

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

  20. 49 CFR 393.43 - Breakaway and emergency braking.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    Allain, Robert

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

  2. 49 CFR 393.55 - Antilock brake systems.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    Hilley, Robert; Scarberry, Terry; Kellum, Mary

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

  4. 49 CFR 236.701 - Application, brake; full service.

    Science.gov (United States)

    2010-10-01

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

  5. 49 CFR 393.41 - Parking brake system.

    Science.gov (United States)

    2010-10-01

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

  6. 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.

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

    Science.gov (United States)

    Tanner, J. A.

    1972-01-01

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

  8. 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.

  9. Wheel slip dump valve for railway braking system

    Science.gov (United States)

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

    2017-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Damian HADRYŚ

    2008-01-01

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

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

    OpenAIRE

    Damian HADRYŚ; Tomasz WĘGRZYN; Michał MIROS

    2008-01-01

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

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

    International Nuclear Information System (INIS)

    Tavares, J M

    2009-01-01

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

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

    OpenAIRE

    Vladimirov, Oleg

    2005-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  15. The waterfront windmill project and TREC's windshare model for community-based renewables development

    International Nuclear Information System (INIS)

    Young, B.

    2002-01-01

    Plans have been developed for building two wind turbines on Toronto's waterfront, on the grounds of the exhibition for the project called Waterfront Windmill Project. The electricity generated by each individual turbine, 1,400,000 kilowatt hours per year, could meet the needs of 250 four-person homes. This project represents an emissions-free power generation, and the energy will be distributed to the hydropower grid of the City of Toronto. The requirement for nuclear and coal-generated energy will therefore be reduced while reducing the emissions of carbon dioxide and other greenhouse gases into the atmosphere. The creation of an urban-based community-owned turbine fits well with the policy of the Toronto Renewable Energy Coop, which is committed to working with the marketplace. The lower cost to the consumer of the market deregulation coal generated energy is a concern. figs

  16. Maximize Producer Rewards in Distributed Windmill Environments: A Q-Learning Approach

    Directory of Open Access Journals (Sweden)

    Bei Li

    2015-03-01

    Full Text Available In Smart Grid environments, homes equipped with windmills are encouraged to generate energy and sell it back to utilities. Time of Use pricing and the introduction of storage devices would greatly influence a user in deciding when to sell back energy and how much to sell. Therefore, a study of sequential decision making algorithms that can optimize the total pay off for the user is necessary. In this paper, reinforcement learning is used to tackle this optimization problem. The problem of determining when to sell back energy is formulated as a Markov decision process and the model is learned adaptively using Q-learning. Experiments are done with varying sizes of storage capacities and under periodic energy generation rates of different levels of fluctuations. The results show a notable increase in discounted total rewards from selling back energy with the proposed approach.

  17. 14 CFR 29.735 - Brakes.

    Science.gov (United States)

    2010-01-01

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

  18. 14 CFR 27.735 - Brakes.

    Science.gov (United States)

    2010-01-01

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

  19. Plasma brake model for preliminary mission analysis

    Science.gov (United States)

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

    2018-03-01

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

  20. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    WINTEC

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

  1. Clutches and brakes design and selection

    CERN Document Server

    Orthwein, William C

    2004-01-01

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

  2. 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.

  3. Rotary Speed Sensor for Antilocking Brakes

    Science.gov (United States)

    Berdahl, C. M.

    1986-01-01

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

  4. 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.

  5. 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.

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

    International Nuclear Information System (INIS)

    Staff, Jan E.; Jaikumar, Prashanth; Chan, Vincent; Ouyed, Rachid

    2012-01-01

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

  7. Electromagnetic brake/clutch device

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1994-01-01

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

  8. Magnetic braking in galactic flows

    International Nuclear Information System (INIS)

    Sparke, L.S.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  10. 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.

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

    Science.gov (United States)

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

    2014-01-01

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

  12. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

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

  13. 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.

  14. Adaptive controller for regenerative and friction braking system

    Science.gov (United States)

    Davis, Roy I.

    1990-01-01

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

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R. [Continental Teves (Germany)

    1999-06-01

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

  17. Analyzing Track Responses to Train Braking

    DEFF Research Database (Denmark)

    Bose, Tulika; Levenberg, Eyal; Zania, Varvara

    2018-01-01

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

  18. Consideration of materials for aircraft brakes

    Science.gov (United States)

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

    1974-01-01

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

  19. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

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

  20. 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.

  1. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

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

  2. 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.

  3. Hydromagnetic rotational braking of magnetic stars

    International Nuclear Information System (INIS)

    Fleck, R.C. Jr.

    1980-01-01

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

  4. Tire Models for Use in Braking Applications

    OpenAIRE

    Svendenius, Jacob

    2003-01-01

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

  5. Station Stopping of Freight Trains with Pneumatic Braking

    OpenAIRE

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

    2014-01-01

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

  6. Combined emergency braking and turning of articulated heavy vehicles

    OpenAIRE

    Morrison, G; Cebon, David

    2017-01-01

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

  7. Controlled braking scheme for a wheeled walking aid

    OpenAIRE

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

    2006-01-01

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

  8. Numerical simulation of heat transfer process in automotive brakes

    OpenAIRE

    Gonzalo Voltas, David

    2013-01-01

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

  9. 49 CFR 238.313 - Class I brake test.

    Science.gov (United States)

    2010-10-01

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

  10. 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...

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  13. 30 CFR 75.1404-1 - Braking system.

    Science.gov (United States)

    2010-07-01

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

  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. Physiology and pathophysiology of the ileal brake in humans

    NARCIS (Netherlands)

    Vu, My Kieu

    2007-01-01

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

  16. 49 CFR 393.49 - Control valves for brakes.

    Science.gov (United States)

    2010-10-01

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

  17. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

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

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

  19. 14 CFR 27.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

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

  20. 14 CFR 23.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

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

  1. 14 CFR 29.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

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

  2. 49 CFR 393.48 - Brakes to be operative.

    Science.gov (United States)

    2010-10-01

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

  3. 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...

  4. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Science.gov (United States)

    2010-07-01

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

  5. Regenerative Braking Compensatory Control Strategy Considering CVT Power Loss for Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2018-02-01

    Full Text Available Hybrid electric vehicles (HEV equipped with continuously variable transmission (CVT adjust the motor operating point continuously to achieve the optimal motor operating efficiency during regenerative braking. Traditional control strategies consider the CVT efficiency as constant, while the CVT efficiency varies in different operating conditions. In order to reflect the transmission efficiency more accurately during regenerative braking, the CVT theoretical torque loss model is firstly established which then leads to the battery–front motor–CVT joint operating efficiency model. The joint operating efficiency model indicates that the system efficiency is influenced by input speed, input torque, CVT speed ratio, and battery SOC (state of charge. The compensatory strategy for the front motor barking force is proposed to make full use of its braking power and the CVT speed ratio control strategy is modified to maintain the optimal operating efficiency of the system. The simulations are performed under three typical braking conditions and UDDS, NYCC, US06 respectively, the results show that the modified control strategy increases the front motor braking power and improves the system operating efficiency.

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

    Science.gov (United States)

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

    2016-04-01

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

  7. A pentiptycene-derived molecular brake: photochemical E→Z and electrochemical Z→E switching of an enone module.

    Science.gov (United States)

    Chen, Ying-Chen; Sun, Wei-Ting; Lu, Hsiu-Feng; Chao, Ito; Huang, Guan-Jhih; Lin, Ying-Chih; Huang, Shou-Ling; Huang, Hsin-Hau; Lin, Yan-Duo; Yang, Jye-Shane

    2011-01-24

    The synthesis and brakelike performance of a new molecular system (1) consisting of a pentiptycene rotor and a 2-methyleneindanone brake are reported. The rotation kinetics of the rotor was probed by both variable-temperature (1)H and (13)C NMR spectroscopy and DFT calculations, and the switching between the brake-on and brake-off states was conducted by a combination of photochemical and electrochemical isomerization. Because of the greater steric hindrance between the rotor and the brake units in the Z form ((Z)-1) than in the E form ((E)-1), rotation of the rotor is slowed down 500-fold at room temperature (298 K) on going from (E)-1 to (Z)-1, corresponding to the brake-off and brake-on states, respectively. The (E)-1→(Z)-1 photoisomerization in acetonitrile is efficient and reaches an (E)-1/(Z)-1 ratio of 11:89 in the photostationary state upon excitation at 290 nm, attributable to a much larger isomerization quantum efficiency for (E)-1 versus (Z)-1. An efficient (Z)-1→(E)-1 isomerization (96%) was also achieved by electrochemical treatment through the radical anionic intermediates. Consequently, the reversibility of the E-Z switching of 1 is as high as 85%. The repeated E-Z switching of 1 with alternating photochemical and electrochemical treatments is also demonstrated. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 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).

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

    Science.gov (United States)

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

    1975-01-01

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

  10. Application of adaptive control to windmill power system by computer simulation. Simulation ni yoru tekio seigyo no furyoku hatsuden system eno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Tomiya, T.; Matsuo, T. (Anan College of Technology, Tokushima (Japan)); Suzuki, T.; Kamano, T. (Tokushima University, Tokushima (Japan). Faculty of Engineering)

    1991-07-20

    A windmill power system using load DC generators having resistive load was subjected to discussions by simulation on development of a control method and its output characteristics to draw out the wind energy effectively even when the system characteristics are unknown. The control method used is a mountaineering method available among adaptive control methods. As a result of discussions, the effectiveness of the mountaineering method was confirmed in controlling the output either when the wind velocity is constant or variable. With respect to the control interval, which is a problem in carrying out a control, it was found that the control output stabilizes as the control interval is increased when the wind velocity is constant, but takes longer time before reaching a steady state output. When the wind velocity is variable, the increased control interval reduces the output slightly because of the load resistance change becoming coarser. It was also revealed that, on simulated natural winds, this control method can draw out more energy than by a fixed load resistance. 7 refs., 11 figs., 1 tab.

  11. 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.

  12. 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.

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

    Science.gov (United States)

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

    2016-01-01

    We report the results of a 16-month monitoring campaign using the Swift satellite of PSR 0540, a young pulsar in the Large Magellanic Cloud. Phase connection was maintained throughout the campaign so that a reliable ephemeris could be determined, and the length of the campaign is adequate to accurately determine the spin frequency and its first and second derivatives. The braking index n is 0.031 +/- 0.013 (90% confidence), a value much lower than previously reported for 0 540 and almost all other young pulsars. We use data from the extensive monitoring campaign with RXTE to showt hat timing noise is unlikely to significantly affect the measurement. This is the first measurement of the braking index in the pulsars recently discovered high spin-down state. We discuss possible mechanisms for producing the low braking index.

  14. Beryllium in aircraft brakes - a summary

    International Nuclear Information System (INIS)

    Zenczak, S.

    1977-01-01

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

  15. Wear determination in braking systems by radioisotopes

    International Nuclear Information System (INIS)

    Spruch, W.

    1979-01-01

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

  16. Braking Control for Improving Ride Comfort

    Directory of Open Access Journals (Sweden)

    Lee Jonghyup

    2018-01-01

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

  17. Calculations enable optimum design of magnetic brake

    Science.gov (United States)

    Kosmahl, H. G.

    1966-01-01

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

  18. 30 CFR 57.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

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

  19. 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.

  20. 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 ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Shi Xiaoming; Mitschke, M.

    1997-11-01

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

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

    OpenAIRE

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  4. 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.

  5. Influences of braking system faults on the vehicle dynamics

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

  6. 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.

  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. Experimental investigation of an accelerometer controlled automatic braking system

    Science.gov (United States)

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

    1972-01-01

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

  9. Prospects for small and marginal farmers in Trichy district (Tamil Nadu, India) to use water pumping windmills for irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Goedhart, P

    1984-05-01

    The economic, technical, and agricultural aspects of equiping poor farmers in India with wind-powered pumps were analyzed. It is concluded that the prospects for a market for windmills among nontarget group farmers (especially big farmers with diesel pumps) are better than the prospects among the target group farmers. Continuation of the project might lead to an improvement of the situation for the richer farmers, which would in turn lead to a decline in the situation of the original target group of the project, the small and marginal farmers.

  10. Synchronous Generator with HTS-2G field coils for Windmills with output power 1 MW

    Science.gov (United States)

    Kovalev, K.; Kovalev, L.; Poltavets, V.; Samsonovich, S.; Ilyasov, R.; Levin, A.; Surin, M.

    2014-05-01

    Nowadays synchronous generators for wind-mills are developed worldwide. The cost of the generator is determined by its size and weight. In this deal the implementation of HTS-2G generators is very perspective. The application of HTS 2G field coils in the rotor allows to reduce the size of the generator is 1.75 times. In this work the design 1 MW HTS-2G generator is considered. The designed 1 MW HTS-2G generator has the following parameters: rotor diameter 800 mm, active length 400 mm, phase voltage 690V, rotor speed 600 min-1 rotor field coils with HTS-2G tapes. HTS-2G field coils located in the rotating cryostat and cooled by liquid nitrogen. The simulation and optimization of HTS-2G field coils geometry allowed to increase feed DC current up to 50A. Copper stator windings are water cooled. Magnetic and electrical losses in 1 MW HTS-2G generator do not exceed 1.6% of the nominal output power. In the construction of HTS-2G generator the wave multiplier with ratio 1:40 is used. The latter allows to reduce the total mass of HTS-2G generator down to 1.5 tons. The small-scale model of HTS-2G generator with output power 50 kW was designed, manufactured and tested. The test results showed good agreement with calculation results. The manufacturing of 1 MW HTS-2G generator is planned in 2014. This work is done under support of Rosatom within the frames of Russian Project "Superconducting Industry".

  11. 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

  12. 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.

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

    Science.gov (United States)

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

    2018-01-17

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

  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. [Occupational health administrative coordination a propos of a case: brake linings with asbestos in a company].

    Science.gov (United States)

    García Gómez, Montserrat; Alonso Urreta, Iciar; Antón Tomey, Carlos; Bosque Peralta, Isabel; García-Gutierrez, María Jesús; Luna Lacarta, Francisco José; Martínez Arguisuelas, Nieves; Mena Marín, María Luisa; Vázquez Cortizo, Margarita

    2018-04-10

    The current structure of the Spanish State of Autonomies is characterized by institutional pluralism and the autonomy of the different public administrations. In this context, the principle of coordination is fundamental for the cohesion of the system, but experience shows that its implementation is difficult. This paper examines the set of actions carried out by the administrations in relation to an occupational and public health problem raised in March 2016. The Public Health General Direction of Aragon's Government was informed of a possible use of brake linings with asbestos to manufacture axles for agricultural machinery by a Company from Zaragoza; the collaboration from Aragon's Institute of Occupational Safety and Health, the Industry Department and the Labour and Social Security Inspectorate were asked; the joint action of these administrations detected the use of several models of brake linings with a content of 2-5% of Chrysotile. The brake linings came from a Chinese company. The axles nated are sold in several Spanish Autonomous Communities. A national alert was activated by the SIRIPQ (System of Rapid Exchange of Information on Chemical Products) which is coordinated by the Ministry of Health, Social Services and Equality. Several measures were taken including: ceasing the work with the brake linings, the replacement of brake linings with asbestos, the immobilization of brake linings in the company by application of the REACH Reglament, etc. This case shows that the cooperation and co-responsibility of public administrations from different territorial, sectoral and competence areas allows improving the occupational risks prevention and the public health.

  16. 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.

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

    Science.gov (United States)

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

    2018-03-01

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

  18. On the interpretation of pulsar braking indices

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-01

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

  20. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Science.gov (United States)

    2010-10-01

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

  1. 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.

  2. 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.

  3. 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.

  4. Test results for the Oasis 3C high performance water-pumping windmill

    Energy Technology Data Exchange (ETDEWEB)

    Eggleston, D.M. [DME Engineering, Midland, TX (United States)

    1997-12-31

    The WINDTech International, L.L.C. Oasis 3C, a 3 m diameter, high-performance water-pumping windmill, was tested at the DME Engineering Wind Test Site just south of Midland, Texas from August through December, 1996. This machine utilizes a 3:1 gearbox with rotating counterweights, similar to a conventional oilfield pumping unit, driven by a multibladed rotor. The rotating counterweight system balances most of the pumping loads and reduces gear loads and starting torque by a factor of at least two and often by a factor of four or more. The torque reduction substantially extends gear and bearing life, and reduces wind speeds required for starting by 30 to 50% or more. The O3C was tested pumping from a quiescent fluid depth of 12.2 m (40 ft) from a 28.3 m (93 ft)-deep well, with additional pumping depth simulated using a pressure regulator valve system. A 9.53 cm (3.75 in.) diameter Harbison-Fischer seal-less single-acting piston pump was used to eliminate pump seal friction as a variable, and standard O3C stroke lengths of 30.5 and 15.2 cm (12 and 6 inches) were used. The regulator spring was set to give a maximum stroke rate of 33 strokes per minute. The water pumped was returned to the well after flowing through a settling tank. The tests were performed in accordance with AWEA WECS testing standards. Instrumentation provided 16 channels of data to accurately measure machine performance, including starting wind speeds, flow rates, O3C azimuth, tail furl angle, wind direction tracking errors, RPM, sucker rod loads, and other variables. The most significant performance data is summarized herein. A mathematical model of machine performance was developed that fairly accurately predicts performance for each of three test conditions. The results verify that the O3C is capable of pumping water at wind speeds from 30% to more than 50% lower than comparable un-counterbalanced units.

  5. The Friction of Vehicle Brake Tandem Master Cylinder

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  6. 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.

  7. Evaluation of materials and design modifications for aircraft brakes

    Science.gov (United States)

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

    1975-01-01

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

  8. Asymmetric Barrier Lyapunov Function-Based Wheel Slip Control for Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Xiaolei Chen

    2015-01-01

    Full Text Available As an important device of the aircraft landing system, the antilock braking system (ABS has a function to avoid aircraft wheels self-locking. To deal with the strong nonlinear characteristics, complex nonlinear control schemes are applied in ABS. However, none of existing control schemes focus on the braking operating status, which directly reflects wheels self-locking degree. In this paper, the braking operating status region is divided into three regions: the healthy region, the light slip region, and the deep slip region. An ABLF-based wheel slip controller is proposed for ABS to constrain the braking system operating status in the healthy region and the light slip region. Therefore the ABS will be prevented from operating in the deep slip region. Under the proposed control scheme, self-locking is avoided completely and zero steady state error tracking of the wheel optimal slip ratio is implemented. The Hardware-In-Loop (HIL experiments have validated the effectiveness of the proposed controller.

  9. 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.

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

    Science.gov (United States)

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

    2014-03-01

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

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

    International Nuclear Information System (INIS)

    Chabat-Courrede, Jean.

    1981-01-01

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

  12. Indonesian commercial bus drum brake system temperature model

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  13. Indonesian commercial bus drum brake system temperature model

    Science.gov (United States)

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

    2016-03-01

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

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Changbao CHU

    2014-04-01

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

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

    International Nuclear Information System (INIS)

    Norgren, D.U.

    1984-01-01

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

  17. Development of a multi-pole magnetorheological brake

    International Nuclear Information System (INIS)

    Shiao, Yaojung; Nguyen, Quang-Anh

    2013-01-01

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

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

    Science.gov (United States)

    Harless, David W; Hoffer, George E

    2002-05-01

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

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

    Science.gov (United States)

    Norgren, Duane U.

    1984-01-01

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

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

    Science.gov (United States)

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

    1966-01-01

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

  1. Compressed gas system operates semitrailer brakes during winching operation

    Science.gov (United States)

    Tupper, W. E.

    1964-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  4. 16 CFR 1512.5 - Requirements for braking system.

    Science.gov (United States)

    2010-01-01

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

  5. 49 CFR 238.317 - Class II brake test.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

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

    1964-01-01

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

  7. 14 CFR 25.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

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

  8. 30 CFR 57.19006 - Automatic hoist braking devices.

    Science.gov (United States)

    2010-07-01

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

  9. 30 CFR 56.19006 - Automatic hoist braking devices.

    Science.gov (United States)

    2010-07-01

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

  10. IR-camera methods for automotive brake system studies

    Science.gov (United States)

    Dinwiddie, Ralph B.; Lee, Kwangjin

    1998-03-01

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

  11. Use of a magnetic force exciter to vibrate a piezocomposite generating element in a small-scale windmill

    International Nuclear Information System (INIS)

    Luong, Hung Truyen; Goo, Nam Seo

    2012-01-01

    A piezocomposite generating element (PCGE) can be used to convert ambient vibrations into electrical energy that can be stored and used to power other devices. This paper introduces a design of a magnetic force exciter for a small-scale windmill that vibrates a PCGE to convert wind energy into electrical energy. A small-scale windmill was designed to be sensitive to low-speed wind in urban regions for the purpose of collecting wind energy. The magnetic force exciter consists of exciting magnets attached to the device’s input rotor and a secondary magnet fixed at the tip of the PCGE. The PCGE is fixed to a clamp that can be adjusted to slide on the windmill’s frame in order to change the gap between exciting and secondary magnets. Under an applied wind force, the input rotor rotates to create a magnetic force interaction that excites the PCGE. The deformation of the PCGE enables it to generate electric power. Experiments were performed with different numbers of exciting magnets and different gaps between the exciting and secondary magnets to determine the optimal configuration for generating the peak voltage and harvesting the maximum wind energy for the same range of wind speeds. In a battery-charging test, the charging time for a 40 mA h battery was approximately 3 h for natural wind in an urban region. The experimental results show that the prototype can harvest energy in urban regions with low wind speeds and convert the wasted wind energy into electricity for city use. (paper)

  12. 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.

  13. Radial brake assembly for a control rod drive

    International Nuclear Information System (INIS)

    Hekmati, A.; Gibo, E.Y.

    1992-01-01

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

  14. Numerical Investigation of Aerodynamic Braking for a Ground Vehicle

    Science.gov (United States)

    Devanuri, Jaya Krishna

    2018-06-01

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

  15. 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.

  16. 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.)

  17. 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

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

    Science.gov (United States)

    2010-03-30

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

  19. 76 FR 55859 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems

    Science.gov (United States)

    2011-09-09

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

  20. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Science.gov (United States)

    2010-08-20

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Winterhagen, J.

    1996-09-01

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

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

    International Nuclear Information System (INIS)

    Ripley, Maurice I.; Kirstein, Oliver

    2006-01-01

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

  3. Brake lock mechanism for the two axis pointing system

    Science.gov (United States)

    Posey, Alan; Clark, Mike; Mignosa, Larry

    1991-01-01

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

  4. Pre-Extreme Automotive Anti-Lock Brake Systems

    Directory of Open Access Journals (Sweden)

    V. G. Ivanov

    2004-01-01

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

  5. 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.)

  6. Robust Switched Predictive Braking Control for Rollover Prevention in Wheeled Vehicles

    Directory of Open Access Journals (Sweden)

    Martín Antonio Rodríguez Licea

    2014-01-01

    Full Text Available The aim of this paper is to propose a differential braking rollover mitigation strategy for wheeled vehicles. The strategy makes use of a polytopic (piecewise linear description of the vehicle and includes translational and rotational dynamics, as well as suspension effects. The braking controller is robust and the system states are predicted to estimate the rollover risk up to a given time horizon. In contrast to existing works, the switched predictive nature of the control allows it to be applied only when risk of rollover is foreseen, interfering a minimum with driver’s actions. The stability of the strategy is analyzed and its robustness is illustrated via numerical simulations using CarSim for a variety of vehicles.

  7. Assessment of the effect of a windmill park at Overgaard on the existence of birds in the EU bird protection area no. 15

    International Nuclear Information System (INIS)

    Clausen, P.; Kyed Larsen, J.

    1999-01-01

    As part of the plans to establish a windmill park at Overgaard, Denmark, an assessment has been performed of the consequences for the occurrence of water birds in the EU bird protection area no. 15 which will be very close to the park. The report concludes that for all assessed species, apart from whooper swan and golden plover, none of the proposed windmill parks are expected to have any negative influence on the species' future occurrence and status in the EU bird protection area no. 15. For the golden plover the same conclusion is reached regarding its use of the area as resting-place during daytime. It is not possible to assess the effects, if any, on the plover's use of the area as forage area during the nights. For the whooper swan the area they have been using at Overgaard will be lost. Depending on the type of windmill park the lost area amounts to about 1-2,5 % of the bird protection area. It is expected, however, that the swans will move to other fields in the protection area for foraging. (ln)

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

    Science.gov (United States)

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

    1981-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    OpenAIRE

    Yang Yang; Chao Wang; Quanrang Zhang; Xiaolong He

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-07-01

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

  12. Experimental investigation of disc brakes for formula Bharat

    Science.gov (United States)

    Misra, Sheelam; Chandra, Sharad; Bagwadi, Ashutosh

    2018-05-01

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

  13. Numerical Modeling of Disc Brake System in Frictional Contact

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2014-03-01

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

  14. Implementation Of Fuzzy Automated Brake Controller Using TSK Algorithm

    Science.gov (United States)

    Mittal, Ruchi; Kaur, Magandeep

    2010-11-01

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

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

    Science.gov (United States)

    Itoh, Makoto; Fujiwara, Yusuke; Inagaki, Toshiyuki

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

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

    Directory of Open Access Journals (Sweden)

    Dongxu Li

    2016-05-01

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

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

    Science.gov (United States)

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

    1973-01-01

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

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

    Science.gov (United States)

    Daugherty, R. H.

    1983-01-01

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

  19. 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.

  20. 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.

  1. Estimation of Road Friction Coefficient in Different Road Conditions Based on Vehicle Braking Dynamics

    Science.gov (United States)

    Zhao, You-Qun; Li, Hai-Qing; Lin, Fen; Wang, Jian; Ji, Xue-Wu

    2017-07-01

    The accurate estimation of road friction coefficient in the active safety control system has become increasingly prominent. Most previous studies on road friction estimation have only used vehicle longitudinal or lateral dynamics and often ignored the load transfer, which tends to cause inaccurate of the actual road friction coefficient. A novel method considering load transfer of front and rear axles is proposed to estimate road friction coefficient based on braking dynamic model of two-wheeled vehicle. Sliding mode control technique is used to build the ideal braking torque controller, which control target is to control the actual wheel slip ratio of front and rear wheels tracking the ideal wheel slip ratio. In order to eliminate the chattering problem of the sliding mode controller, integral switching surface is used to design the sliding mode surface. A second order linear extended state observer is designed to observe road friction coefficient based on wheel speed and braking torque of front and rear wheels. The proposed road friction coefficient estimation schemes are evaluated by simulation in ADAMS/Car. The results show that the estimated values can well agree with the actual values in different road conditions. The observer can estimate road friction coefficient exactly in real-time and resist external disturbance. The proposed research provides a novel method to estimate road friction coefficient with strong robustness and more accurate.

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

    Science.gov (United States)

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

    1974-01-01

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

  3. Energy Efficiency in Heavy Vehicle Tires, Drivetrains, and Braking Systems; FINAL

    International Nuclear Information System (INIS)

    Peter J. Blau

    2000-01-01

    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 materials

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

    Science.gov (United States)

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

    2012-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

  6. Variability of a "force signature" during windmill softball pitching and relationship between discrete force variables and pitch velocity.

    Science.gov (United States)

    Nimphius, Sophia; McGuigan, Michael R; Suchomel, Timothy J; Newton, Robert U

    2016-06-01

    This study assessed reliability of discrete ground reaction force (GRF) variables over multiple pitching trials, investigated the relationships between discrete GRF variables and pitch velocity (PV) and assessed the variability of the "force signature" or continuous force-time curve during the pitching motion of windmill softball pitchers. Intraclass correlation coefficient (ICC) for all discrete variables was high (0.86-0.99) while the coefficient of variance (CV) was low (1.4-5.2%). Two discrete variables were significantly correlated to PV; second vertical peak force (r(5)=0.81, p=0.03) and time between peak forces (r(5)=-0.79; p=0.03). High ICCs and low CVs support the reliability of discrete GRF and PV variables over multiple trials and significant correlations indicate there is a relationship between the ability to produce force and the timing of this force production with PV. The mean of all pitchers' curve-average standard deviation of their continuous force-time curves demonstrated low variability (CV=4.4%) indicating a repeatable and identifiable "force signature" pattern during this motion. As such, the continuous force-time curve in addition to discrete GRF variables should be examined in future research as a potential method to monitor or explain changes in pitching performance. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R.

    1999-07-01

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

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

    Science.gov (United States)

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

    2009-11-01

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

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

    International Nuclear Information System (INIS)

    Tong, H.; Kou, F. F.

    2017-01-01

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-10

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

  12. 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.

  13. 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.

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

    Science.gov (United States)

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

    2018-05-01

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

  15. 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.

  16. 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.

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

    International Nuclear Information System (INIS)

    Nguyen, Q H; Choi, S B

    2010-01-01

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

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

    OpenAIRE

    Ma, Tian; Gai, Jiangtao; Ma, Xiaofeng

    2010-01-01

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

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

    OpenAIRE

    Jingang Guo; Xiaoping Jian; Guangyu Lin

    2014-01-01

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

  20. 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.

  1. 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.)

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

    Science.gov (United States)

    Jonasson, M.; Thor, M.

    2018-05-01

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

  3. Effect of the crone suspension control system on braking

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-07-01

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

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

    Science.gov (United States)

    Vogel-Ciernia, Annie; Wood, Marcelo A

    2012-01-01

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

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

    Science.gov (United States)

    Vogel-Ciernia, Annie

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Nguyen, Q H; Choi, S B

    2012-01-01

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

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

    Indian Academy of Sciences (India)

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

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

    Directory of Open Access Journals (Sweden)

    M. Kholodov

    2011-01-01

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

  9. 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.

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

    CSIR Research Space (South Africa)

    Chauke, L

    2012-10-01

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

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

    Science.gov (United States)

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

    2012-02-01

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

  12. 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.

  13. 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...

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

    International Nuclear Information System (INIS)

    1980-01-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

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

    OpenAIRE

    Dembitskyi V.; Mazylyuk P.; Sitovskyi O.

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-02-01

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

  19. 78 FR 44189 - Petition for Modification of Single Car Air Brake Test Procedures

    Science.gov (United States)

    2013-07-23

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

  20. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Science.gov (United States)

    2010-10-01

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

  1. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Science.gov (United States)

    2010-10-01

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

  2. 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.

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

    Science.gov (United States)

    2016-08-01

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

  4. 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...

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  6. 30 CFR 75.1403-2 - Criteria-Hoists transporting materials; brakes.

    Science.gov (United States)

    2010-07-01

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

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

    Science.gov (United States)

    Barthlome, D. E.

    1975-01-01

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

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

    OpenAIRE

    Maciua, Dragos

    1996-01-01

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

  9. 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

  10. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2013-02-11

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

  11. 76 FR 9717 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Science.gov (United States)

    2011-02-22

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

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

    Science.gov (United States)

    2011-09-13

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

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

    Directory of Open Access Journals (Sweden)

    A. Turenko

    2010-01-01

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

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

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    2010-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Basil Olufemi Akinnuli

    2017-11-01

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

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

    Science.gov (United States)

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

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

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

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    2011-02-10

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

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

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

  2. Coaxial magnetic brakes using single-domain YBCO

    International Nuclear Information System (INIS)

    Putman, P.T.; Salama, K.

    2008-01-01

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

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

    Science.gov (United States)

    Lin, Chih-Min; Hsu, C F

    2003-01-01

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

  4. MAGNETIC BRAKING AND PROTOSTELLAR DISK FORMATION: AMBIPOLAR DIFFUSION

    International Nuclear Information System (INIS)

    Mellon, Richard R.; Li Zhiyun

    2009-01-01

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

  5. 49 CFR 232.109 - Dynamic brake requirements.

    Science.gov (United States)

    2010-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Niemz, T.

    2007-07-01

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

  7. Magnetic braking in Solar-type close binaries

    Science.gov (United States)

    Maceroni, C.; Rucinski, S. M.

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

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

    Science.gov (United States)

    1976-12-01

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

  9. 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.

  10. Benchmarking of regenerative braking for a fully electric car

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    CSIR Research Space (South Africa)

    Jahajeeah, N

    2006-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

    Weiss, Norbert; Lacinová, L.

    2016-01-01

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

  13. A Laboratory Activity on the Eddy Current Brake

    Science.gov (United States)

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

    2012-01-01

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

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

    Science.gov (United States)

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

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

  15. 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....

  16. 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.

  17. Influences on nonlinear judder vibrations of railway brakes

    Science.gov (United States)

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

    2010-06-01

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

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

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2002-01-01

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

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

    Science.gov (United States)

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

    2012-05-01

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

  2. 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.

  3. Dynamic interaction of brakes, tyres and road surface; Dynamische Interaktion Bremse - Reifen - Strasse

    Energy Technology Data Exchange (ETDEWEB)

    Huinink, H.; Schroeder, C.

    1999-12-01

    Rubber friction of rough surfaces is characterised by the molecular physics of the highly dynamic interaction between a polymer network and the road on nano- micrao- and macroscale length. The problems of power transmission of ALS-controlled tyres at quasi-stationary conditions (interaction tyres/braking system) are described by the grip/slip characteristics defined for the area of tyre contact, which in terms forms the basis for the interaction between material and road surface (according to Persson 1997) under the respective technical conditions of the vehicle. ALS-braking with time-dependent brake torque is a technically highly dynamic system state within the interaction of material, tyres, vehicle and road surface. New systems based on sensors such as the side-torsion-sensor made by Continental AG improve safety, comfort and economy by combining this feature with a vehicle management system which uses tyre forces and -deformation as input parameters. [Deutsch] Die Gummireibung auf rauhen Oberflaechen ist durch eine molekulare Physik der hochdynamischen Interaktion Polymernetzwerk / Fahrbahn auf nano-, mikro- und makroskaligen Laengen gekennzeichnet. Die Problematik der Kraftuebertragung bei ABS-geregelten Reifen unter quasistationaeren Bedingungen (Interaktion Reifen - Bremssystem) wird durch die in der Bodenaufstandsflaeche ortsaufgeloesten Kraftschluss - Schlupf - Kennlinien erfasst, deren Basis die Interaktion Material / Fahrbahn nach Persson (1997) unter den gegebenen technischen Bedingungen am Fahrzeug darstellt. Der ABS-Bremsvorgang bei zeitabhaengigem Bremsmoment ist ein technisch hochdynamischer Systemzustand im Wechselspiel Material - Reifen - Fahrzeug-Fahrbahn. Auf der Sensorik basierende dynamische Systemerweiterungen, wie z.B. durch den Seitenwand-Torsions-Sensor der Continental AG, verbessern Fahrsicherheit, Komfort und Wirtschaftlichkeit durch die Kombination mit einem Fahrzeugmanagementsystem, das die Reifenkraefte und -verformungen als

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

    International Nuclear Information System (INIS)

    Sarkar, C; Hirani, H

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  6. 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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Che-Pin Chen

    2018-04-01

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

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

    Science.gov (United States)

    Tian, Tongfei; Nakano, Masami

    2017-03-01

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

  12. Identification of a biomarker of sleep deficiency-are we tilting windmills?

    Directory of Open Access Journals (Sweden)

    Quan SF

    2012-03-01

    Full Text Available No abstract available. Article truncated at 150 words. The amount of time spent asleep by adults in the United States and other developing countries is decreasing. It is estimated that over 40 years ago, adults slept in excess of 8 hours per night, but now sleep barely 7 hours per night (1 During this time frame, there has been a corresponding increase in obesity and diabetes mellitus which in part has been attributed to a reduction in time sleeping (2. In addition, sleep deficiency and other sleep disorders have been implicated as risk factors for hypertension, cardiovascular disease and cancer (3-5. Consequently, billions of excess health care dollars are spent on medical conditions associated with sleep deficiency or sleep disorders (6,7. Their impact also include substantial costs resulting from lost productivity as well as increased absenteeism, presenteeism and motor vehicle or industrial accidents (6,7. Thus, sleep disorders and sleep deficiency are significant threats to public health and productivity…

  13. Are You "Tilting at Windmills" or Undertaking a Valid Clinical Trial?

    Science.gov (United States)

    Zariffa, Jose; Kramer, John L.K.

    2011-01-01

    In this review, several aspects surrounding the choice of a therapeutic intervention and the conduct of clinical trials are discussed. Some of the background for why human studies have evolved to their current state is also included. Specifically, the following questions have been addressed: 1) What criteria should be used to determine whether a scientific discovery or invention is worthy of translation to human application? 2) What recent scientific advance warrants a deeper understanding of clinical trials by everyone? 3) What are the different types and phases of a clinical trial? 4) What characteristics of a human disorder should be noted, tracked, or stratified for a clinical trial and what inclusion /exclusion criteria are important to enrolling appropriate trial subjects? 5) What are the different study designs that can be used in a clinical trial program? 6) What confounding factors can alter the accurate interpretation of clinical trial outcomes? 7) What are the success rates of clinical trials and what can we learn from previous clinical trials? 8) What are the essential principles for the conduct of valid clinical trials? PMID:21786433

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

    Energy Technology Data Exchange (ETDEWEB)

    Leber, M.

    1998-11-01

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

  15. Multi-objective design optimization and control of magnetorheological fluid brakes for automotive applications

    Science.gov (United States)

    Shamieh, Hadi; Sedaghati, Ramin

    2017-12-01

    The magnetorheological brake (MRB) is an electromechanical device that generates a retarding torque through employing magnetorheological (MR) fluids. The objective of this paper is to design, optimize and control an MRB for automotive applications considering. The dynamic range of a disk-type MRB expressing the ratio of generated toque at on and off states has been formulated as a function of the rotational speed, geometrical and material properties, and applied electrical current. Analytical magnetic circuit analysis has been conducted to derive the relation between magnetic field intensity and the applied electrical current as a function of the MRB geometrical and material properties. A multidisciplinary design optimization problem has then been formulated to identify the optimal brake geometrical parameters to maximize the dynamic range and minimize the response time and weight of the MRB under weight, size and magnetic flux density constraints. The optimization problem has been solved using combined genetic and sequential quadratic programming algorithms. Finally, the performance of the optimally designed MRB has been investigated in a quarter vehicle model. A PID controller has been designed to regulate the applied current required by the MRB in order to improve vehicle’s slipping on different road conditions.

  16. Optimal design of a new 3D haptic gripper for telemanipulation, featuring magnetorheological fluid brakes

    International Nuclear Information System (INIS)

    Nguyen, Q H; Choi, S B; Lee, Y S; Han, M S

    2013-01-01

    In this research work, a new configuration of a 3D haptic gripper for telemanipulation is proposed and optimally designed. The proposed haptic gripper, featuring three magnetorheological fluid brakes (MRBs), reflects the rolling torque, the grasping force and the approach force from the slave manipulator to the master operator. After describing the operational principle of the haptic gripper, an optimal design of the MRBs for the gripper is performed. The purpose of the optimization problem is to find the most compact MRB that can provide a required braking torque/force to the master operator while the off-state torque/force is kept as small as possible. In the optimal design, different types of MRBs and different MR fluids (MRFs) are considered. In order to obtain the optimal solution of the MRBs, an optimization approach based on finite element analysis (FEA) integrated with an optimization tool is used. The optimal solutions of the MRBs are then obtained and the optimized MRBs for the haptic gripper are identified. In addition, discussions on the optimal solutions and performance of the optimized MRBs are given. (paper)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

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

  18. 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.

  19. Plasma Jet Braking: Energy Dissipation and Nonadiabatic Electrons

    International Nuclear Information System (INIS)

    Khotyaintsev, Yu. V.; Cully, C. M.; Vaivads, A.; Andre, M.; Owen, C. J.

    2011-01-01

    We report in situ observations by the Cluster spacecraft of wave-particle interactions in a magnetic flux pileup region created by a magnetic reconnection outflow jet in Earth's magnetotail. Two distinct regions of wave activity are identified: lower-hybrid drift waves at the front edge and whistler-mode waves inside the pileup region. The whistler-mode waves are locally generated by the electron temperature anisotropy, and provide evidence for ongoing betatron energization caused by magnetic flux pileup. The whistler-mode waves cause fast pitch-angle scattering of electrons and isotropization of the electron distribution, thus making the flow braking process nonadiabatic. The waves strongly affect the electron dynamics and thus play an important role in the energy conversion chain during plasma jet braking.

  20. Syntegra: complete integration of traction, bogie and brake systems

    Energy Technology Data Exchange (ETDEWEB)

    Loewenstein, L.; Wangelin, F. von [Siemens AG, Transportation Systems, Erlangen (Germany). Group Technology TS GT; Teichmann, M.; Hoffmann, T. [Siemens TS, Graz (Austria); Joeckel, A. [Siemens Automation and Drives, Nuernberg (Germany)

    2007-07-01

    With Syntegra {sup registered} technology, Siemens has developed an approach to the complete integration of traction, bogie and brake systems, and this has initially been put into practice for metro, underground and S-Bahn (urban regional express) trains. Syntegra constitutes a fundamentally new approach, achieving a greater intensity of integration compared with the types of drive system that have been in use up until now. With Syntegra, the bogie, transmission and brake components are all brought together as part of one and the same system. The integration and, more especially, the technological advances within the three named areas bring about numerous synergies. The new generation of powered bogie features a combination of high efficiency, low dead weight and reduced emissions. A Syntegra drive system achieves a performance which is markedly better than that of conventional systems. (orig.)

  1. 49 CFR 232.305 - Single car air brake tests.

    Science.gov (United States)

    2010-10-01

    ... from a train or when placed on a shop or repair track, as defined in § 232.303(a); (2) A car is on a shop or repair track, as defined in § 232.303(a), for any reason and has not received a single car air... 49 Transportation 4 2010-10-01 2010-10-01 false Single car air brake tests. 232.305 Section 232...

  2. Thulium fiber laser lithotripsy using a muzzle brake fiber tip

    Science.gov (United States)

    Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

    2017-02-01

    The Thulium fiber laser (TFL) is being explored as an alternative to Holmium:YAG laser for lithotripsy. TFL beam profile allows coupling of higher power into smaller fibers than multimode Holmium laser beam, without proximal fiber tip degradation. A smaller fiber provides more space in ureteroscope working channel for increased saline irrigation and allows maximum ureteroscope flexion. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback, but increased retropulsion. In this study, a "fiber muzzle brake" was tested for reducing fiber burnback and stone retropulsion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-OD, 360-μm-ID tube with 275-μm thru hole located 250-μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed, ex vivo. Small stones with a mass of 40 +/- 4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 +/- 4 s (n=10), without distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers. The muzzle brake fiber tip provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

  3. Carbon nanotube torsional springs for regenerative braking systems

    International Nuclear Information System (INIS)

    Liu, Sanwei; Martin, Corbin; Livermore, Carol; Lashmore, David; Schauer, Mark

    2015-01-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg −1   ±  1.2 kJ kg −1 and 3.4 kJ kg −1   ±  0.4 kJ kg −1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg −1 and 0.67 kW kg −1 , respectively, with maximum measured values of up to 4.7 kJ kg −1 and 1.2 kW kg −1 , respectively. A slightly lower energy density of up to 1.2 kJ kg −1 and a 0.29 kW kg −1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism. (paper)

  4. 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.

  5. A novel technique for optimal integration of active steering and differential braking with estimation to improve vehicle directional stability.

    Science.gov (United States)

    Mirzaeinejad, Hossein; Mirzaei, Mehdi; Rafatnia, Sadra

    2018-06-11

    This study deals with the enhancement of directional stability of vehicle which turns with high speeds on various road conditions using integrated active steering and differential braking systems. In this respect, the minimum usage of intentional asymmetric braking force to compensate the drawbacks of active steering control with small reduction of vehicle longitudinal speed is desired. To this aim, a new optimal multivariable controller is analytically developed for integrated steering and braking systems based on the prediction of vehicle nonlinear responses. A fuzzy programming extracted from the nonlinear phase plane analysis is also used for managing the two control inputs in various driving conditions. With the proposed fuzzy programming, the weight factors of the control inputs are automatically tuned and softly changed. In order to simulate a real-world control system, some required information about the system states and parameters which cannot be directly measured, are estimated using the Unscented Kalman Filter (UKF). Finally, simulations studies are carried out using a validated vehicle model to show the effectiveness of the proposed integrated control system in the presence of model uncertainties and estimation errors. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Tilting toward windmills

    International Nuclear Information System (INIS)

    McGowan, J.G.

    1993-01-01

    Emerging from the shadow of an energy crisis in the 1970s, a wind-power industry flourished briefly in the US. Part of an ambitious US government program to support research and development on renewable energy sources, the Department of Energy and the National Aeronautic and Space Agency sponsored the construction of a wide variety of large wind turbines-most accompanied by exaggerated claims by the promoters. But by the 1980s, US interest in wind power almost disappeared due to a drop in world oil prices, the Reagan administrations curtailment of funding, and the disappointing results of the initial wind turbines. The problems with the initial wind turbines was overly optimistic economic projections, siting snags, difficulties connecting wind-generated electricity to utility power grids. Today, however the wind farms in California are a highly productive, inexpensive source of energy. The author presents arguments dispelling the following four widely-believed myths about wind energy: (1) Wind power is not a significant energy source; (2) Wind-generated electricity is expensive and unreliable; (3) New and improved machine designs are needed to make wind power feasible; and (4) The technology is impractical for use by utilities because of problems connecting wind machines to the electricity grid, and because wind itself is intermittent. A study at Battelle Pacific Northwest Lab estimates that turbine technology could supply 20% of the country's electrical needs. Investor-owned wind-power plants in California generate electricity at a rate ranging from 4.7 to 7.2 cents per kilowatt-hour. The reality is that wind-produced electricity is now less expensive that electricity produced by conventional fossil- or nuclear-powered generating plants in many parts of the world. And unlike some of the proposed renewable electric-power sources like photovoltaics, wind power's future is not dependent on further breakthroughs in engineering or materials technology

  7. Windmills, Butter, and Bacon

    DEFF Research Database (Denmark)

    Hjermitslev, Hans Henrik

    2015-01-01

    In spite of ideological concerns due to N.F.S. Grundtvig’s reservations about the natural sciences and the traditional education of his day, the Grundtvigian movement and, especially, teachers at the People’s High Schools and the agricultural schools played an important role in the dissemination...... of scientific knowledge to the rural population in the decades around 1900. The diffusion of technological innovations such as a decentralized electricity supply system and an automatic cream separator for cooperative dairies had a profound and lasting impact on the development of modern Denmark. Hence......, the Grundtvigian movement contributed not only to political and cultural nation building but also to technological modernization and economic growth in late nineteenth- and early twentieth-century Denmark....

  8. Using robotics in kinematics classes: exploring braking and stopping distances

    Science.gov (United States)

    Brockington, Guilherme; Schivani, Milton; Barscevicius, Cesar; Raquel, Talita; Pietrocola, Maurício

    2018-03-01

    Research in the field of physics teaching has revealed high school students’ difficulties in establishing relations between kinematic equations and real movements. Moreover, there are well-known and significant challenges in their comprehension of graphic language content. Thus, this article explores a didactic activity which utilized robotics in order to investigate significant aspects of kinematics, gathering data and performing analyses and descriptions via graphs and mathematical equations which were indispensable for the analysis of the phenomena in question. Traffic safety appears as a main theme, with particular emphasis on the distinction between braking and stopping distances in harsh conditions, as observed in the robot vehicle’s tires and track. This active-learning investigation allows students to identify significant differences between the average value of the initial empirical braking position and that of the vehicle’s programmed braking position, enabling them to more deeply comprehend the relations between mathematical and graphic representations of this real phenomenon and the phenomenon itself, thereby providing a sense of accuracy to this study.

  9. Stellar rotation, dynamo, electromagnetic braking, age an lithium burning

    International Nuclear Information System (INIS)

    Schatzmann, E.

    1989-01-01

    After an introduction describing the problem and the observational tests of the theory a consistant model of the dynamo mechanism in rotating star is presented. This provides for the electromagnetic braking a law Ω ∼ (1.t/t c har) -3 / 4 , in good agreement with the observations. This rests on the hypothesis that the main contribution to the EM braking is due to the magnetic field present in bipolar magnetic spots at the surface of the stellar disk. The premain sequence EM braking provides an initial angular velocity on arrival on the main sequence which is slightly smaller than the angular velocity when the dynamo turns on. Starting the dynamo takes place when the level at which the (αΩ) dynamo number becomes larger than one drops below the ionization level of hydrogen. Before that time, the surface dynamo mechanism would take place in a region of low ionization, where the magnetic Reynods number is so small that dissipation overtakes the building of the magnetic field. Turbulent mixing with a turbulent diffusion coefficient proportional to Ω 2 provides a consistant picture of the time and mass dependance of the surface abundance of Lithium. When the level of Li-burning is sufficiently far from the bottom of the convective zone an asymptotic value of lithium abundance is reached. This can explain the anomalous Li abundance of pop.II stars. (author). 40 refs

  10. 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.

  11. 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.

  12. 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.

  13. An evaluation of short-term exposures of brake mechanics to asbestos during automotive and truck brake cleaning and machining activities.

    Science.gov (United States)

    Richter, Richard O; Finley, Brent L; Paustenbach, Dennis J; Williams, Pamela R D; Sheehan, Patrick J

    2009-07-01

    Historically, the greatest contributions to airborne asbestos concentrations during brake repair work were likely due to specific, short-duration, dust-generating activities. In this paper, the available short-term asbestos air sampling data for mechanics collected during the cleaning and machining of vehicle brakes are evaluated to determine their impact on both short-term and daily exposures. The high degree of variability and lack of transparency for most of the short-term samples limit their use in reconstructing past asbestos exposures for brake mechanics. However, the data are useful in evaluating how reducing short-term, dust-generating activities reduced long-term exposures, especially for auto brake mechanics. Using the short-term dose data for grinding brake linings from these same studies, in combination with existing time-weighted average (TWA) data collected in decades after grinding was commonplace in rebuilding brake shoes, an average 8-h TWA of approximately 0.10 f/cc was estimated for auto brake mechanics that performed arc grinding of linings during automobile brake repair (in the 1960s or earlier). In the 1970s and early 1980s, a decline in machining activities led to a decrease in the 8-h TWA to approximately 0.063 f/cc. Improved cleaning methods in the late 1980s further reduced the 8-h TWA for most brake mechanics to about 0.0021 f/cc. It is noteworthy that when compared with the original OSHA excursion level, only 15 of the more than 300 short-term concentrations for brake mechanics measured during the 1970s and 1980s possibly exceeded the standard. Considering exposure duration, none of the short-term exposures were above the current OSHA excursion level.

  14. 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.

  15. Mechanism analysis and evaluation methodology of regenerative braking contribution to energy efficiency improvement of electrified vehicles

    International Nuclear Information System (INIS)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Yuan, Ye

    2015-01-01

    Highlights: • The energy flow of an electric vehicle with regenerative brake is analyzed. • Methodology for measuring the regen brake contribution is discussed. • Evaluation parameters of regen brake contribution are proposed. • Vehicle tests are carried out on chassis dynamometer. • Test results verify the evaluation method and parameters proposed. - Abstract: This article discusses the mechanism and evaluation methods of contribution brought by regenerative braking to electric vehicle’s energy efficiency improvement. The energy flow of an electric vehicle considering the braking energy regeneration was analyzed. Then, methodologies for measuring the contribution made by regenerative brake to vehicle energy efficiency improvement were introduced. Based on the energy flow analyzed, two different evaluation parameters were proposed. Vehicle tests were carried out on chassis dynamometer under typical driving cycles with three different control strategies. The experimental results the difference between the proposed two evaluation parameters, and demonstrated the feasibility and effectiveness of the evaluation methodologies proposed

  16. The effects of porosity in friction performance of brake pad using waste tire dust

    Directory of Open Access Journals (Sweden)

    İbrahim Mutlu

    2015-10-01

    Full Text Available Abstract This research is focused on the effect of porosity on the friction-wear properties of automotive brake pads. Waste Tire Dust (WTD was used as a new friction material in brake pads. Newly formulated brake pad materials with five different components have been produced by conventional techniques. In the experimental studies, the change of the friction coefficient, the temperature of the friction surface, the specific wear rate, and the hardness, density and porosity were measured. In addition, the micro-structural characterizations of brake pads are determined using Scanning Electron Microscopy (SEM. The mean coefficient of friction, porosity and specific wear are increased due to a WTD rate increases, on the other hand, hardness and density are decreased. As a result, WTD can be considered as an alternative to revalorize this kind of waste products in the brake pads and the amount of porosity of the brake pad affected the friction coefficient and wear behavior of the pad.

  17. Research on squeal noise of tread brake system in rail freight vehicle

    Science.gov (United States)

    Zhang, Jun; Li, Yong-hua; Fang, Ji; Zhao, Wen-zhong

    2017-07-01

    Brake squeal is a result of a unstable flutter from brake system, it results to the noise pollution in railway side and excessive wear of wheel tread. A finite element model of brake system for rail freight vehicle is set up, the contact and friction between the brake shoe and wheel tread is considered, the complex modals of brake system are calculated, the possibility of happening chatter and squeal noise are analyzed. The results show that the pressure angle or the brake force direction have a important influence on the unstable chatter and squeal noise, the more greater the pressure angle deviates from the wheel center, the more greater the possibility of happening chatter and squeal noise is, and the possibility of happening chatter and squeal noise is also increased along with the addition of friction factor.

  18. 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.

  19. Anti-lock braking system (ABS) and regenerative braking system (RBS) in hybrid electric vehicle for smart transportation system

    Science.gov (United States)

    Evuri, Geetha Reddy; Rao, G. Srinivasa; Reddy, T. Ramasubba; Reddy, K. Srinivasa

    2018-04-01

    Pulse width modulation (PWM) based (a non-consistent) breaking system is used to keep the wheels from being bolted in the proposed antilock breaking system (ABS). Using this method a better hold of the street by wheels is possible and halting separations likewise diminish essentially particularly on precarious street surfaces like frosty or wet streets. The active vitality of the wheel is by and large lost amid braking as warmth because of grinding among brake cushions. This vitality can be recuperated using regenerative braking systems (RBS). In this strategy, the overabundance vitality is put away incidentally in capacitor banks before it gets changed over to warm vitality and is squandered. This framework delays the battery life by reviving the battery utilizing the put away vitality. Subsequently the mileage of the electric vehicle likewise increments as it can travel more separation in a solitary battery charge. These two techniques together help make electric vehicle vitality productive and more secure and less demanding to utilize subsequently anticipating and diminishing the quantity of mischance's.

  20. Investigation into the use of water based brake fluid for light loads ...

    African Journals Online (AJOL)

    The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus· of University of Uyo and the· braking effiqiency obtained at test to its suitability for light loads. Keywords·: Water-based, Brake fluid properties, Light loads ...