WorldWideScience

Sample records for repair braking systems

  1. Bicycle Braking System

    OpenAIRE

    Brady, Noel

    2001-01-01

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

  2. Safety Braking System

    Directory of Open Access Journals (Sweden)

    Joseph Charles

    2016-10-01

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

  3. 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.

  4. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

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

  5. 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.

  6. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

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

  7. 49 CFR 570.56 - Vacuum brake assist unit and vacuum brake system.

    Science.gov (United States)

    2010-10-01

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

  8. Fireproof Brake Hydraulic System.

    Science.gov (United States)

    1981-09-01

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

  9. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

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

  10. 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.

  11. 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.

  12. 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.

  13. 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...

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

    Directory of Open Access Journals (Sweden)

    O. Je. Nishhenko

    2009-06-01

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

  15. 49 CFR 393.41 - Parking brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Parking brake system. 393.41 Section 393.41... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  16. 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.

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

    Science.gov (United States)

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

    2015-06-01

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

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

    National Research Council Canada - National Science Library

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

    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...

  19. 49 CFR 570.55 - Hydraulic brake system.

    Science.gov (United States)

    2010-10-01

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

  20. 49 CFR 570.58 - Electric brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Electric brake system. 570.58 Section 570.58... 10,000 Pounds § 570.58 Electric brake system. (a) Electric brake system integrity. The average brake... no fluctuation evidencing a short circuit or other interruption of current. (1) Inspection procedure...

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

    Directory of Open Access Journals (Sweden)

    Seth Daniel Oduro

    2013-02-01

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

  2. 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.

  3. 49 CFR 570.5 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ... lb. (a) Failure indicator. The brake system failure indicator lamp, if part of a vehicle's original... CFR 571.105, on every new passenger car manufactured on or after January 1, 1968, and on other types... vehicle manufacturer that the brake system failure indicator lamp is operable. (b) Brake system integrity...

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

    OpenAIRE

    松島, 徹; 泉井, 一浩; 西脇, 眞二

    2011-01-01

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

  5. 49 CFR 393.40 - Required brake systems.

    Science.gov (United States)

    2010-10-01

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

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

    Science.gov (United States)

    Lü, Hui; Yu, Dejie

    2014-12-01

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

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

    OpenAIRE

    Thuppal Vedanta, Srivatsan; Kora, Naga Vamsi Krishna

    2016-01-01

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

  8. Transient thermal behavior of a cylindrical brake system

    Energy Technology Data Exchange (ETDEWEB)

    Naji, M.; Al-Nimr, M.; Masoud, S. [Jordan Univ. of Science and Technology, Irbid (Jordan). Dept. of Mechanical Engineering

    2000-03-01

    A mathematical model is presented to describe the thermal behavior of a brake system which consists of shoe and drum. The model is solved analytically using Green's function method for any type of the stopping braking action. In terms of the obtained solutions, the transient temperature distribution of the brake is described. The thermal behavior is investigated for three specified braking actions which are the impulse, unit step and trigonometric stopping actions. (orig.)

  9. 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.

  10. Study on Braking Energy Regeneration System for City Bus

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

  11. Brake Fluid Compatibility Studies with Advanced Brake Systems

    Science.gov (United States)

    2016-01-16

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

  12. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

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

  13. 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

  14. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Science.gov (United States)

    2010-10-01

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

  15. The design of brake fatigue testing system

    OpenAIRE

    2015-01-01

    Brake is used to reduce the operating speed of the machinery equipment or to make it stop. It is essential for vehicles, climbing machines and many fixed equipment in their safety work. Brake tester is an experimental apparatus to measure and analyse the braking performance. Based on the PLC technology and for the purpose of testing brake shoe friction material’s life, this paper designed a virtual brake test platform. In it, inverter were used to control the motor, so that it can load automa...

  16. A high performance pneumatic braking system for heavy vehicles

    Science.gov (United States)

    Miller, Jonathan I.; Cebon, David

    2010-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

    黄志武; 杨迎泽; 王晶; 李赟

    2013-01-01

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

  18. 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.

  19. 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.

  20. 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.

  1. Linear Control Technique for Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    Chankit Jain

    2014-08-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Hou Youfu; Xie Fangwei; Huang Fei

    2011-01-01

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

  3. 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.

  4. RELIABILITY OF BRAKE SYSTEMS OF BUSES OF GROUP MAZ

    Directory of Open Access Journals (Sweden)

    A. Bessarab

    2013-01-01

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

  5. Brake subharmonic solutions of first order Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

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

  6. 49 CFR 232.103 - General requirements for all train brake systems.

    Science.gov (United States)

    2010-10-01

    ... pneumatic technology, the integrity of the train line shall be monitored by the brake control system. (c) A... straight air brake 30-50 (7) Self-lapping portion for electro-pneumatic brake (minimum full application... 49 Transportation 4 2010-10-01 2010-10-01 false General requirements for all train brake...

  7. Design and development of coil casing MRF brake system

    Directory of Open Access Journals (Sweden)

    Siti Lydia R.

    2017-01-01

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

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

    OpenAIRE

    Jiankun Peng; Hongwen He; Wei Liu; Hongqiang Guo

    2015-01-01

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

  9. Charging valve of the full hydraulic braking system

    Directory of Open Access Journals (Sweden)

    Jinshi Chen

    2016-03-01

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

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

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianlong; YIN Chengliang; ZHANG Jianwu

    2009-01-01

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

  11. 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.

  12. RELIABILITY OF BRAKE SYSTEMS OF BUSES OF GROUP MAZ

    OpenAIRE

    A. Bessarab

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  15. 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…

  16. 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...

  17. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

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

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

    Science.gov (United States)

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

    2013-02-01

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

  19. Slide Mode Control for Integrated Electric Parking Brake System

    OpenAIRE

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

    2013-01-01

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

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

    OpenAIRE

    Chen, J. P.

    2001-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mamun B.I. Reaz

    2011-01-01

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

  2. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

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

  3. Grey Repairable System Analysis

    Institute of Scientific and Technical Information of China (English)

    Renkuan Guo; Charles Ernie Love

    2006-01-01

    In this paper, we systematically discuss the basic concepts of grey theory, particularly the grey differential equation and its mathematical foundation, which is essentially unknown in the reliability engineering community. Accordingly,we propose a small-sample based approach to estimate repair improvement effects by partitioning system stopping times into intrinsic functioning times and repair improvement times. An industrial data set is used for illustrative purposes in a stepwise manner.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

    2017-08-28

    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.

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

    Directory of Open Access Journals (Sweden)

    R. M. Mohanty

    2013-09-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2011-01-01

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

  11. 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.

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

    OpenAIRE

    2016-01-01

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

  13. Performance requirements for locomotive braking systems

    CSIR Research Space (South Africa)

    Vermaak, P

    2000-02-01

    Full Text Available ; and • The compilation of mine Codes of Practice and Procedures. 2 Of all the equipment used to mine and transport ore, track bound haulage systems are most commonly overlooked provided that the production is not affected. In order to reduce incidents involving... MRAC guideline for the compilation of a mandatory code of practice for the operation of underground rail bound transport equipment............... 22 9.6 Suppliers’ specifications for new locomotives ............. 23 9.6.1 Battery locomotives...

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

    Science.gov (United States)

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

    2013-04-01

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

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

    Science.gov (United States)

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

    2017-02-01

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

  16. Dynamic Braking System of a Tidal Generator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-01

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

  17. 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.

  18. 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

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

    OpenAIRE

    Hongqiang Guo; Hongwen He; Xuelian Xiao

    2014-01-01

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

  20. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2010-03-30

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

  1. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

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

  2. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Science.gov (United States)

    2010-10-01

    ... vehicle is determined by measuring the stopping distance from a given initial speed. S6.5.3.2. Unless... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 135; Light vehicle brake systems. 571... Federal Motor Vehicle Safety Standards § 571.135 Standard No. 135; Light vehicle brake systems. S1. Scope...

  3. Slide Mode Control for Integrated Electric Parking Brake System

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2013-01-01

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

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

    Science.gov (United States)

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

    2007-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

    高燕; 宋胜涛; 王跃军; 韩美香; 郭太清

    2012-01-01

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

  6. 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

  7. Investigation of energy efficiency for electro-hydraulic composite braking system which is based on the regenerated energy

    National Research Council Canada - National Science Library

    Bin Ma; Muyi Lin; Yong Chen; Lian-xin Wang

    2016-01-01

      A novel structure of the combined braking system based on the regenerative braking energy has been proposed to achieve simplified structure and energy-saving capability simultaneously, which includes...

  8. Investigation of energy efficiency for electro-hydraulic composite braking system which is based on the regenerated energy

    National Research Council Canada - National Science Library

    Ma, Bin; Lin, Muyi; Chen, Yong; Wang, Lian-xin

    2016-01-01

    A novel structure of the combined braking system based on the regenerative braking energy has been proposed to achieve simplified structure and energy-saving capability simultaneously, which includes...

  9. 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…

  10. Cumulative asbestos exposure for US automobile mechanics involved in brake repair (circa 1950s-2000).

    Science.gov (United States)

    Finley, Brent L; Richter, Richard O; Mowat, Fionna S; Mlynarek, Steve; Paustenbach, Dennis J; Warmerdam, John M; Sheehan, Patrick J

    2007-11-01

    We analyzed cumulative lifetime exposure to chrysotile asbestos experienced by brake mechanics in the US during the period 1950-2000. Using Monte Carlo methods, cumulative exposures were calculated using the distribution of 8-h time-weighted average exposure concentrations for brake mechanics and the distribution of job tenure data for automobile mechanics. The median estimated cumulative exposures for these mechanics, as predicted by three probabilistic models, ranged from 0.16 to 0.41 fibers per cubic centimeter (f/cm(3)) year for facilities with no dust-control procedures (1970s), and from 0.010 to 0.012 f/cm(3) year for those employing engineering controls (1980s). Upper-bound (95%) estimates for the 1970s and 1980s were 1.96 to 2.79 and 0.07-0.10 f/cm(3) year, respectively. These estimates for US brake mechanics are consistent with, but generally slightly lower than, those reported for European mechanics. The values are all substantially lower than the cumulative exposure of 4.5 f/cm(3) year associated with occupational exposure to 0.1 f/cm(3) of asbestos for 45 years that is currently permitted under the current occupational exposure limits in the US. Cumulative exposures were usually about 100- to 1,000-fold less than those of other occupational groups with asbestos exposure for similar time periods. The cumulative lifetime exposure estimates presented here, combined with the negative epidemiology data for brake mechanics, could be used to refine the risk assessments for chrysotile-exposed populations.

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

    OpenAIRE

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2017-08-01

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

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

    Institute of Scientific and Technical Information of China (English)

    HUANGFU Shihui; BAO Xiangying

    2006-01-01

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

  14. Brake Pedal Displacement Measuring System based on Machine Vision

    Directory of Open Access Journals (Sweden)

    Chang Wang

    2013-10-01

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

  15. Motorcycle Repair.

    Science.gov (United States)

    Hein, Jim; Bundy, Mike

    This motorcycle repair curriculum guide contains the following ten areas of study: brake systems, clutches, constant mesh transmissions, final drives, suspension, mechanical starting mechanisms, electrical systems, fuel systems, lubrication systems, and overhead camshafts. Each area consists of one or more units of instruction. Each instructional…

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

    Institute of Scientific and Technical Information of China (English)

    孟国营; 徐志强; 霍森; 方佳雨

    1997-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Gao xiangqian; Zhou Yongxia

    1996-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    吴祥超; 赵运德; 鲁雄文

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Zhang Fengjiao

    2015-03-01

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

  20. Minimal period estimates for brake orbits of nonlinear symmetric Hamiltonian systems

    CERN Document Server

    Liu, Chungen

    2009-01-01

    In this paper, we consider the minimal period estimates for brake orbits of nonlinear symmetric Hamiltonian systems. We prove that if the Hamiltonian function $H\\in C^2(\\Bbb R^{2n}, \\Bbb R)$ is super-quadratic and convex, for every number $\\tau>0$, there exists at least one $\\tau$-periodic brake orbit $(\\tau,x)$ with minimal period $\\tau$ or $\\tau/2$ provided $H(Nx)=H(x)$.

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

    Directory of Open Access Journals (Sweden)

    Jingang Guo

    2014-10-01

    Full Text Available Traditional friction braking torque and motor braking torque can be used in braking for electric vehicles (EVs. A sliding mode controller (SMC based on the exponential reaching law for the anti-lock braking system (ABS is developed to maintain the optimal slip value. Parameter optimizing is applied to the reaching law by fuzzy logic control (FLC. A regenerative braking algorithm, in which the motor torque is taken full advantage of, is adopted to distribute the braking force between the motor braking and the hydraulic braking. Simulations were carried out with Matlab/Simulink. By comparing with a conventional Bang-bang ABS controller, braking stability and passenger comfort is improved with the proposed SMC controller, and the chatting phenomenon is reduced effectively with the parameter optimizing by FLC. With the increasing proportion of the motor braking torque, the tracking of the slip ratio is more rapid and accurate. Furthermore, the braking distance is shortened and the conversion energy is enhanced.

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

    Science.gov (United States)

    Suciu, Cornel; Mihai, Ioan

    2016-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

    XU Ming

    2009-01-01

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

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

    Science.gov (United States)

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

    2013-05-01

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

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

    Science.gov (United States)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Guo Lie

    2014-01-01

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

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Hui Lü

    2016-01-01

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

  9. Reward optimization of a repairable system

    Energy Technology Data Exchange (ETDEWEB)

    Castro, I.T. [Departamento de Matematicas, Facultad de Veterinaria, Universidad de Extremadura, Avenida de la Universidad, s/n. 10071 Caceres (Spain)]. E-mail: inmatorres@unex.es; Perez-Ocon, R. [Departamento de Estadistica e Investigacion Operativa, Facultad de Ciencias, Universidad de Granada, Avenida de Severo Ochoa, s/n. 18071 Granada (Spain)]. E-mail: rperezo@ugr.es

    2006-03-15

    This paper analyzes a system subject to repairable and non-repairable failures. Non-repairable failures lead to replacement of the system. Repairable failures, first lead to repair but they lead to replacement after a fixed number of repairs. Operating and repair times follow phase type distributions (PH-distributions) and the pattern of the operating times is modelled by a geometric process. In this context, the problem is to find the optimal number of repairs, which maximizes the long-run average reward per unit time. To this end, the optimal number is determined and it is obtained by efficient numerical procedures.

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

    OpenAIRE

    Zhang Fengjiao; Wei Minxiang

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Bobyr Maxim

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2014-01-01

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

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

    Science.gov (United States)

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

    2016-05-01

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

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

    Institute of Scientific and Technical Information of China (English)

    吴卫东; 尹用山

    2001-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    TANG Hua-ping; PENG Ya-qing

    2005-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Hongliang WANG

    2015-04-01

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

  18. Model-based fuzzy control solutions for a laboratory Antilock Braking System

    DEFF Research Database (Denmark)

    Precup, Radu-Emil; Spataru, Sergiu; Rǎdac, Mircea-Bogdan;

    2010-01-01

    This paper gives two original model-based fuzzy control solutions dedicated to the longitudinal slip control of Antilock Braking System laboratory equipment. The parallel distributed compensation leads to linear matrix inequalities which guarantee the global stability of the fuzzy control systems...

  19. 地铁微机控制直通电空制动系统研究%Research on Direct Acting Electro-pneumatic Braking System with Microcomputer Control of Metro

    Institute of Scientific and Technical Information of China (English)

    杨丰萍; 陈振华; 李玉庆

    2014-01-01

    介绍了地铁车辆微机控制直通电空制动系统的组成、制动模式和防滑控制功能。着重研究了制动过程中制动力计算与分配及不同阶段的制动响应。研究结果可为微机控制直通电空制动系统在性能检测试验台研制及我国地铁车辆应用检修中提供帮助。%This paper discusses the structure, braking mode and anti-skid control of direct acting electro-pneumat-ic braking system with microcomputer control. It mainly researches the braking force calculation, distribution, and the braking response at different stages in braking process. The results may provide some reference for test bench development of direct acting electro-pneumatic braking system and practical repairing of metro vehicles.

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

    Science.gov (United States)

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

    2016-01-01

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

  1. Remote control canard missile with a free-rolling tail brake torque system

    Science.gov (United States)

    Blair, A. B., Jr.

    1981-01-01

    An experimental wind-tunnel investigation has been conducted at supersonic Mach numbers to determine the static aerodynamic characteristics of a cruciform canard-controlled missile with fixed and free-rolling tail-fin afterbodies. Mechanical coupling effects of the free-rolling tail afterbody were investigated using an electronic/electromagnetic brake system that provides arbitrary tail-fin brake torques with continuous measurements of tail-to-mainframe torque and tail-roll rate. Results are summarized to show the effects of fixed and free-rolling tail-fin afterbodies that include simulated measured bearing friction torques on the longitudinal and lateral-directional aerodynamic characteristics.

  2. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ... signal or signals. Electric vehicle or EV means a motor vehicle that is powered by an electric motor... or control signals in an antilock brake system, or a total functional electrical failure in a... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 105; Hydraulic and electric...

  3. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2013-02-11

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

  4. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Science.gov (United States)

    2010-10-01

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

  5. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-15

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

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

    Science.gov (United States)

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

    2012-01-01

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

  8. Kvitebjoern gas pipeline repair - baptism of remote pipeline repair system

    Energy Technology Data Exchange (ETDEWEB)

    Gjertveit, Erling

    2010-07-01

    On the 1st of November 2007, severe anchor damage was discovered on the 30 inch Kvitebjoern gas export pipeline. The damage constituted a localised dent and a 17deg buckle, but no leakage. Statoil has invested in building an effective repair contingency structure for the large pipeline network on the Norwegian Continental shelf, with particular focus on the large gas export pipelines. The repair method for the Kvitebjoern pipeline was remotely operated using two Morgrip couplings and a spool. The installation used the purpose built Pipeline Repair System stored at Killingoey and couplings produced and tested back in 2005. This presentation will cover the initial damage investigations, the temporary operational phase, the repair preparations, the actual repair and lessons learned. (Author)

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

    Institute of Scientific and Technical Information of China (English)

    汪德成; 陈凌珊; 黄欣; 蒋培露

    2014-01-01

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

  10. Autonomous collision avoidance system by combined control of steering and braking using geometrically optimised vehicular trajectory

    Science.gov (United States)

    Hayashi, Ryuzo; Isogai, Juzo; Raksincharoensak, Pongsathorn; Nagai, Masao

    2012-01-01

    This study proposes an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents. The proposed system prevents the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside. In the proposed system, to avoid the predicted colliding position based on constant-velocity obstacle motion assumption, the avoidance trajectory is derived as connected two identical arcs. The system then controls the vehicle autonomously by the combined control of the braking and steering systems. In this paper, the proposed system is examined by real car experiments and its effectiveness is shown from the results of the experiments.

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

    Institute of Scientific and Technical Information of China (English)

    吕建刚; 郭劭琰; 李彦路; 滕飞; 宋彬

    2012-01-01

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

  12. Augmented Reality Repair Guidance System

    Directory of Open Access Journals (Sweden)

    Sidharth Bhatia

    2012-07-01

    Full Text Available The daily life of a common man revolves around various forms of appliances/gadgets he uses throughout the day such as a mobile phone, laptop, printer, microwave oven, washing machine, etc. Although these appliances/gadgets are taken by most of the people for granted, the problem occurs when any of these things do not work as they are expected to. Getting them to the repair shops for every small glitch is expensive as well as time consuming. Although most of the companies which produce these appliances/gadgets do supply them with basic manuals, which deal with how to solve these minor issues, but reading them and at the same time repairing the corresponding appliance/gadget can be a frustrating task at times. These problems can be reduced to a large extent if some kind of live guidance is available. In this paper we propose a method to do so with the help of an augmented reality based system that will guide the user to carry out small scale repair jobs on these gadgets. All that is required is a decent webcam and a computing device, with a processor of 1 GHz or more and a display screen.

  13. Active vibration control of multibody system with quick startup and brake based on active damping

    Institute of Scientific and Technical Information of China (English)

    TANG Hua-ping; TANG Yun-jun; TAO Gong-an

    2006-01-01

    A kind of active vibration control method was presented based on active damping and optimization design for driving load of multibody system with quick startup and brake. Dynamical equation of multibody system with quick startup and brake and piezoelectric actuators intelligent structure was built. The optimum driving load was calculated by applying the presented method. The self-sensing and self-tuning closed-loop active vibration control in quick startup and brake process was realized. The control algorithm, using local velocity negative feedback, i.e. the output of a sensor only affects the output of the actuator collocated, can induce damping effectively to actively suppress the system vibration. Based on the optimization design for driving load of multibody system with quick startup and bake, the active damping of piezoelectric actuators intelligent structure was used to farther suppress the vibration of system. Theoretical analysis and calculation of numerical show that the proposed method makes the vibration of system decrease more than the optimal design method for driving load of multibody system.

  14. [An automatic torque control system for a bicycle ergometer equipped with an eddy current brake].

    Science.gov (United States)

    Kikinev, V V

    2007-01-01

    The main elements of the loading device of a bicycle ergometer, including an eddy current brake and a torque sensor, are described. The automatic torque control system, which includes the loading device, is equipped with a stabilizing feedback controller that optimally approximates the closed-loop transfer function of the target model. The reduced transfer function model of the controller is of the fourth order. A method featuring a modulation-demodulation loop is suggested for implementation of the control system.

  15. Wheel slide protection control using a command map and Smith predictor for the pneumatic brake system of a railway vehicle

    Science.gov (United States)

    Lee, Nam-Jin; Kang, Chul-Goo

    2016-10-01

    In railway vehicles, excessive sliding or wheel locking can occur while braking because of a temporarily degraded adhesion between the wheel and the rail caused by the contaminated or wet surface of the rail. It can damage the wheel tread and affect the performance of the brake system and the safety of the railway vehicle. To safeguard the wheelset from these phenomena, almost all railway vehicles are equipped with wheel slide protection (WSP) systems. In this study, a new WSP algorithm is proposed. The features of the proposed algorithm are the use of the target sliding speed, the determination of a command for WSP valves using command maps, and compensation for the time delay in pneumatic brake systems using the Smith predictor. The proposed WSP algorithm was verified using experiments with a hardware-in-the-loop simulation system including the hardware of the pneumatic brake system.

  16. Development of Quasi-3DOF upper limb rehabilitation system using ER brake: PLEMO-P1

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T; Fukushima, K; Furusho, J; Ozawa, T [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: kikuchi@mech.eng.osaka-u.ac.jp

    2009-02-01

    In recent years, many researchers have studied the potential of using robotics technology to assist and quantify the motor functions for neuron-rehabilitation. Some kinds of haptic devices have been developed and evaluated its efficiency with clinical tests, for example, upper limb training for patients with spasticity after stroke. However, almost all the devices are active-type (motor-driven) haptic devices and they basically require high-cost safety system compared to passive-type (brake-based) devices. In this study, we developed a new practical haptic device 'PLEMO-P1'; this system adopted ER brakes as its force generators. In this paper, the mechanism of PLEMO-P1 and its software for a reaching rehabilitation are described.

  17. Modeling and Simulation of integrated steering and braking control for vehicle active safety system

    Directory of Open Access Journals (Sweden)

    Beibei Zhang

    2011-03-01

    Full Text Available Active chassis systems like braking, steering, suspension and propulsion systems are increasingly entering the market. In addition to their basic functions, these systems may be used for functions of integrated vehicle dynamics control. An experimental platform which aims to study the integration control of steering and braking is designed due to the research requirement of vehicle active safety control strategy in this paper. A test vehicle which is equipped with the systems of steer-by-wire and brake-bywire is provided and the Autobox, combined with Matlab/simulink and MSCCarsim, is used to fulfill the RCP (Rapid Control Prototyping and HIL (Hardware-in-loop. The seven-freedom vehicle model is constructed first and the approach of vehicle parameters estimation based on the Extended Kalman Filter (EKF is proposed. Testing the vehicle state through the sensor has its own disadvantage that the cost is high and easily affected by environment outside. To find a actual method of receiving the vehicle state using the ready-made sensors in vehicle, the researchers put forward various estimation method, of which have advantages and disadvantages. Based on the above, this paper applies the EKF to estimate the vehicle state, making the actual estimation come true. The primary control methods and controller designment is carried out to prove the validation of the platform.

  18. A SVM framework for fault detection of the braking system in a high speed train

    Science.gov (United States)

    Liu, Jie; Li, Yan-Fu; Zio, Enrico

    2017-03-01

    In April 2015, the number of operating High Speed Trains (HSTs) in the world has reached 3603. An efficient, effective and very reliable braking system is evidently very critical for trains running at a speed around 300 km/h. Failure of a highly reliable braking system is a rare event and, consequently, informative recorded data on fault conditions are scarce. This renders the fault detection problem a classification problem with highly unbalanced data. In this paper, a Support Vector Machine (SVM) framework, including feature selection, feature vector selection, model construction and decision boundary optimization, is proposed for tackling this problem. Feature vector selection can largely reduce the data size and, thus, the computational burden. The constructed model is a modified version of the least square SVM, in which a higher cost is assigned to the error of classification of faulty conditions than the error of classification of normal conditions. The proposed framework is successfully validated on a number of public unbalanced datasets. Then, it is applied for the fault detection of braking systems in HST: in comparison with several SVM approaches for unbalanced datasets, the proposed framework gives better results.

  19. Determination of minimum sample size for fault diagnosis of automobile hydraulic brake system using power analysis

    Directory of Open Access Journals (Sweden)

    V. Indira

    2015-03-01

    Full Text Available Hydraulic brake in automobile engineering is considered to be one of the important components. Condition monitoring and fault diagnosis of such a component is very essential for safety of passengers, vehicles and to minimize the unexpected maintenance time. Vibration based machine learning approach for condition monitoring of hydraulic brake system is gaining momentum. Training and testing the classifier are two important activities in the process of feature classification. This study proposes a systematic statistical method called power analysis to find the minimum number of samples required to train the classifier with statistical stability so as to get good classification accuracy. Descriptive statistical features have been used and the more contributing features have been selected by using C4.5 decision tree algorithm. The results of power analysis have also been verified using a decision tree algorithm namely, C4.5.

  20. Hardware simulation of automatic braking system based on fuzzy logic control

    Directory of Open Access Journals (Sweden)

    Noor Cholis Basjaruddin

    2016-07-01

    Full Text Available In certain situations, a moving or stationary object can be a barrier for a vehicle. People and vehicles crossing could potentially get hit by a vehicle. Objects around roads as sidewalks, road separator, power poles, and railroad gates are also a potential source of danger when the driver is inattentive in driving the vehicle. A device that can help the driver to brake automatically is known as Automatic Braking System (ABS. ABS is a part of the Advanced Driver Assistance Systems (ADAS, which is a device designed to assist the driver in driving the process. This device was developed to reduce human error that is a major cause of traffic accidents. This paper presents the design of ABS based on fuzzy logic which is simulated in hardware by using a remote control car. The inputs of fuzzy logic are the speed and distance of the object in front of the vehicle, while the output of fuzzy logic is the intensity of braking. The test results on the three variations of speed: slow-speed, medium-speed, and high-speed shows that the design of ABS can work according to design.

  1. 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.

  2. Probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP)

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, M.A. [Univ. of California, Los Angeles, CA (United States); Sargent, T.J. [Univ. of Chicago, IL (United States)]|[Stanford Univ., CA (United States). Hoover Institution

    1998-01-01

    In its most recent report on the annual probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP), the annual failure rate is calculated to be 1.3E({minus}7)(1/yr), rounded off from 1.32E({minus}7). A calculation by the Environmental Evaluation Group (EEG) produces a result that is about 4% higher, namely 1.37E({minus}7)(1/yr). The difference is due to a minor error in the US Department of Energy (DOE) calculations in the Westinghouse 1996 report. WIPP`s hoist safety relies on a braking system consisting of a number of components including two crucial valves. The failure rate of the system needs to be recalculated periodically to accommodate new information on component failure, changes in maintenance and inspection schedules, occasional incidents such as a hoist traveling out-of-control, either up or down, and changes in the design of the brake system. This report examines DOE`s last two reports on the redesigned waste hoist system. In its calculations, the DOE has accepted one EEG recommendation and is using more current information about the component failures rates, the Nonelectronic Parts Reliability Data (NPRD). However, the DOE calculations fail to include the data uncertainties which are described in detail in the NPRD reports. The US Nuclear Regulatory Commission recommended that a system evaluation include mean estimates of component failure rates and take into account the potential uncertainties that exist so that an estimate can be made on the confidence level to be ascribed to the quantitative results. EEG has made this suggestion previously and the DOE has indicated why it does not accept the NRC recommendation. Hence, this EEG report illustrates the importance of including data uncertainty using a simple statistical example.

  3. KGS Based Control for Parking Brake Cable Manufacturing System

    OpenAIRE

    Geeta Khare; R.S. Prasad

    2011-01-01

    In today’s competitive production environment, process industries, demand a totally integrated control and optimization solution that can increase productivity, reliability and quality while minimizing cost. Automation is a step beyond mechanization. For automation of production plant either centralized or distributed control system are used. There are standardized approaches and standard hardware & software available worldwide as per the requirement. Investment in process control system is a...

  4. Identification and Modeling of Automotive Electrical Parking Brake System for SiL Simulation

    Institute of Scientific and Technical Information of China (English)

    PENG Yi-qiang; LI Wei; ZHANG Jin-lei

    2008-01-01

    To evaluate the software behavior of the electronic control unit (ECU) of automotive electrical parking brake (EPB), a software-in-the-loop (SiL) simulation system is built. The EPB is simulated by ARX (auto-regressive with auxiliary input) model, ARMAX (auto-regressive moving average with auxiliary input) model, and NNARMAX (neural network ARMAX) model. By system identification, the ARX(3,4,2), ARX(4,4,2), ARMAX(3,3,1,1), and ARMAX(4,4,3,2) models are derived. Validation results show that the four-order ARMAX model and the NNARMAX model better simulate the actuator of the EPB.

  5. Stable and optimal fuzzy control of a laboratory Antilock Braking System

    DEFF Research Database (Denmark)

    Precup, Radu-Emil; Spataru, Sergiu; Petriu, Emil M.

    2010-01-01

    This paper discusse four new Takagi-Sugeno fuzzy controllers (T-S FCs) for the longitudinal slip control of an Antilock Braking System laboratory equipment. Two discretetime dynamic Takagi-Sugeno fuzzy models of the controlled plant are derived based on the parameters in the consequents...... conditions to the fuzzy control systems (FCSs) and the other two T-S FCs are tuned by the linear-quadratic regulator approach applied to each rule. Linear matrix inequalities are solved to guarantee the global stability of the FCSs. Real-time experimental results validate the original T-S FCs and design...

  6. Stochastic Modelling Of The Repairable System

    Directory of Open Access Journals (Sweden)

    Andrzejczak Karol

    2015-11-01

    Full Text Available All reliability models consisting of random time factors form stochastic processes. In this paper we recall the definitions of the most common point processes which are used for modelling of repairable systems. Particularly this paper presents stochastic processes as examples of reliability systems for the support of the maintenance related decisions. We consider the simplest one-unit system with a negligible repair or replacement time, i.e., the unit is operating and is repaired or replaced at failure, where the time required for repair and replacement is negligible. When the repair or replacement is completed, the unit becomes as good as new and resumes operation. The stochastic modelling of recoverable systems constitutes an excellent method of supporting maintenance related decision-making processes and enables their more rational use.

  7. NIU's Kinder, Gentler, Housing Repair System.

    Science.gov (United States)

    Tillis, Linda; Montgomery, Rogene

    1999-01-01

    Explains the effective use of a centralized housing-repair request system at Northern Illinois University that has improved customer service and increased fiscal accountability. Describes the system and assesses of its effectiveness. (GR)

  8. A Two-Unit Cold Standby Repairable System with One Replaceable Repair Facility and Delay Repair:Some Reliability Problems

    Institute of Scientific and Technical Information of China (English)

    WEI Ying-yuan; TANG Ying-hui

    2004-01-01

    This paper considers a two-unit same cold standby repairable system with a replaceable repair facility and delay repair .The failure time of unit is assumed to follow exponential distribution , and the repair time and delay time of failed unit are assumed to follow arbitrary distributions , whereas the failure and replacement time distributions of the repair facility are exponential and arbitrary . By using the Markov renewal process theory, some primary reliability quantities of the system are obtained.

  9. Research of Motorcycle Braking Parameters

    Directory of Open Access Journals (Sweden)

    Loreta Levulytė

    2016-12-01

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

  10. Simulation Research on Braking Performance of Tracked Vehicle Hydraulic Energy Storage Braking System%履带车辆液压储能式制动系统制动性能仿真研究

    Institute of Scientific and Technical Information of China (English)

    赵广俊; 吕建刚; 宋彬; 滕飞

    2011-01-01

    为了实现对履带车辆制动能量的回收利用,针对某型履带车辆建立其液压储能式制动系统,分析系统工作模式;在AMESim下建立液压储能式制动系统及车辆模型,在Matlab/Simulink下建立控制系统模型;提出基于踏板行程逻辑门限值的模糊控制策略;在驾驶员不同的制动意图和系统负荷能力条件下,对履带车辆的制动工况进行联合仿真研究.结果表明,在该控制策略下液压储能式制动系统实现了对履带车辆的稳定制动和对制动能量的有效回收.%In order to achieve the tracked vehicle braking energy recovery and utilization, a certain type of tracked vehicle hydraulic energy storage braking system was established, and the working mode was analyzed. The model of hydraulic energy storage braking system and the vehicle was established in AMESim, and the control system model was established in Matlab/Simulink. Fuzzy logic control strategy based on pedal opening threshold was proposed. Under the driver's different braking intention and conditions of system load capacity, the tracked vehicle's braking process was researched under co-simulation. The results show that with the control strategy in the hydraulic energy storage braking system, the stable braking of tracked vehicle and the effective recovery of braking energy were achieved.

  11. Integrated Electrical Wire Insulation Repair System

    Science.gov (United States)

    Williams, Martha; Jolley, Scott; Gibson, Tracy; Parks, Steven

    2013-01-01

    An integrated system tool will allow a technician to easily and quickly repair damaged high-performance electrical wire insulation in the field. Low-melt polyimides have been developed that can be processed into thin films that work well in the repair of damaged polyimide or fluoropolymer insulated electrical wiring. Such thin films can be used in wire insulation repairs by affixing a film of this low-melt polyimide to the damaged wire, and heating the film to effect melting, flow, and cure of the film. The resulting repair is robust, lightweight, and small in volume. The heating of this repair film is accomplished with the use of a common electrical soldering tool that has been modified with a special head or tip that can accommodate the size of wire being repaired. This repair method can furthermore be simplified for the repair technician by providing replaceable or disposable soldering tool heads that have repair film already "loaded" and ready for use. The soldering tool heating device can also be equipped with a battery power supply that will allow its use in areas where plug-in current is not available

  12. Magnetostrictive Brake

    Science.gov (United States)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

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

  13. 49 CFR 393.49 - Control valves for brakes.

    Science.gov (United States)

    2010-10-01

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

  14. Pad-mode-induced instantaneous mode instability for simple models of brake systems

    Science.gov (United States)

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

    2015-10-01

    Automotive disc brake squeal is fugitive, transient and remains difficult to predict. In particular, instantaneous mode squeal observed experimentally does not seem to be associated with mode coupling and its mechanism is not clear. The effects of contact pressures, friction coefficients as well as material properties (pressure and temperature dependency and anisotropy) for brake squeal propensity have not been systematically explored. By analysing a finite element model of an isotropic pad sliding on a plate similar to that of a previously reported experimental study, pad modes have been identified and found to be stable using conventional complex eigenvalue analysis. However, by subjecting the model to contact pressure harmonic excitation for a range of pressures and friction coefficients, a forced response analysis reveals that the dissipated energy for pad modes is negative and becomes more negative with increasing contact pressures and friction coefficients, indicating the potential for instabilities. The frequency of the pad mode in the sliding direction is within the range of squeal frequencies observed experimentally. Nonlinear time series analysis of the vibration velocity also confirms the evolution of instabilities induced by pad modes as the friction coefficient increases. By extending this analysis to a more realistic but simple brake model in the form of a pad-on-disc system, in-plane pad-modes, which a complex eigenvalue analysis predicts to be stable, have also been identified by negative dissipated energy for both isotropic and anisotropic pad material properties. The influence of contact pressures on potential instabilities has been found to be more dominant than changes in material properties owing to changes in pressure or temperature. Results here suggest that instantaneous mode squeal is likely caused by in-plane pad-mode instabilities.

  15. Diverless pipeline repair system for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, Carlo M. [Eni Gas and Power, Milan (Italy); Fabbri, Sergio; Bachetta, Giuseppe [Saipem/SES, Venice (Italy)

    2009-07-01

    SiRCoS (Sistema Riparazione Condotte Sottomarine) is a diverless pipeline repair system composed of a suite of tools to perform a reliable subsea pipeline repair intervention in deep and ultra deep water which has been on the ground of the long lasting experience of Eni and Saipem in designing, laying and operating deep water pipelines. The key element of SiRCoS is a Connection System comprising two end connectors and a repair spool piece to replace a damaged pipeline section. A Repair Clamp with elastomeric seals is also available for pipe local damages. The Connection System is based on pipe cold forging process, consisting in swaging the pipe inside connectors with suitable profile, by using high pressure seawater. Three swaging operations have to be performed to replace the damaged pipe length. This technology has been developed through extensive theoretical work and laboratory testing, ending in a Type Approval by DNV over pipe sizes ranging from 20 inches to 48 inches OD. A complete SiRCoS system has been realised for the Green Stream pipeline, thoroughly tested in workshop as well as in shallow water and is now ready, in the event of an emergency situation.The key functional requirements for the system are: diverless repair intervention and fully piggability after repair. Eni owns this technology and is now available to other operators under Repair Club arrangement providing stand-by repair services carried out by Saipem Energy Services. The paper gives a description of the main features of the Repair System as well as an insight into the technological developments on pipe cold forging reliability and long term duration evaluation. (author)

  16. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXVI, I--CATERPILLAR LUBRICATION SYSTEMS AND COMPONENTS, II--LEARNING ABOUT BRAKES (PART I).

    Science.gov (United States)

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE FUNCTIONS OF DIESEL ENGINE LUBRICATION SYSTEMS AND COMPONENTS AND THE PRINCIPLES OF OPERATION OF BRAKE SYSTEMS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) THE NEED FOR OIL, (2) SERVICE CLASSIFICATION OF OILS, (3) CATERPILLAR LUBRICATION SYSTEM COMPONENTS (4)…

  17. Fundamentals of automotive and engine technology standard drives, hybrid drives, brakes, safety systems

    CERN Document Server

    2014-01-01

    Hybrid drives and the operation of hybrid vehicles are characteristic of contemporary automotive technology. Together with the electronic driver assistant systems, hybrid technology is of the greatest importance and both cannot be ignored by today’s car drivers. This technical reference book provides the reader with a firsthand comprehensive description of significant components of automotive technology. All texts are complemented by numerous detailed illustrations. Contents History of the automobile.- History of the Diesel engine.- Areas of use for Diesel engines.- Basic principles of the Diesel engine.- Basic principles of Diesel fuel-injection.- Basic principles of the gasoline engine.- Inductive ignition system.- Transmissions for motor vehicles.- Motor vehicle safety.- Basic principles of vehicle dynamics.- Car braking systems.- Vehicle electrical systems.- Overview of electrical and electronic systems in the vehicle.- Control of gasoline engines.- Control of Diesel engines.- Lighting technology.- Elec...

  18. The effectiveness of antilock braking systems in reducing accidents in Great Britain.

    Science.gov (United States)

    Broughton, Jeremy; Baughan, Chris

    2002-05-01

    Antilock braking systems (ABS) are fitted to many new cars with the aims of improving their ability to steer while braking heavily and of reducing stopping distances on some road surfaces. This paper presents the findings of a project that assessed the effectiveness of ABS in reducing accidents in Great Britain. A large postal survey was carried out of the owners of modern cars. asking for details of any accidents in which they had been involved during the previous year as well as factors that might influence their likelihood of being involved in an accident. Questions were also asked to test respondents' knowledge of ABS. ABS cars ditfered in several respects from non-ABS cars, as did the two groups of drivers. Consequently, a sophisticated statistical analysis was required to provide unbiased estimates of the effectiveness of ABS. Various results did not achieve statistical significance, but the overall stability of the results indicates that real effects have been measured. They confirm that ABS does have the potential to reduce the number of accidents, but show that this has not been fully achieved. One reason may be that many drivers have little or no knowledge of ABS.

  19. Systems Maintenance Automated Repair Tasks (SMART)

    Science.gov (United States)

    Schuh, Joseph; Mitchell, Brent; Locklear, Louis; Belson, Martin A.; Al-Shihabi, Mary Jo Y.; King, Nadean; Norena, Elkin; Hardin, Derek

    2010-01-01

    SMART is a uniform automated discrepancy analysis and repair-authoring platform that improves technical accuracy and timely delivery of repair procedures for a given discrepancy (see figure a). SMART will minimize data errors, create uniform repair processes, and enhance the existing knowledge base of engineering repair processes. This innovation is the first tool developed that links the hardware specification requirements with the actual repair methods, sequences, and required equipment. SMART is flexibly designed to be useable by multiple engineering groups requiring decision analysis, and by any work authorization and disposition platform (see figure b). The organizational logic creates the link between specification requirements of the hardware, and specific procedures required to repair discrepancies. The first segment in the SMART process uses a decision analysis tree to define all the permutations between component/ subcomponent/discrepancy/repair on the hardware. The second segment uses a repair matrix to define what the steps and sequences are for any repair defined in the decision tree. This segment also allows for the selection of specific steps from multivariable steps. SMART will also be able to interface with outside databases and to store information from them to be inserted into the repair-procedure document. Some of the steps will be identified as optional, and would only be used based on the location and the current configuration of the hardware. The output from this analysis would be sent to a work authoring system in the form of a predefined sequence of steps containing required actions, tools, parts, materials, certifications, and specific requirements controlling quality, functional requirements, and limitations.

  20. Optimization of actuator/sensor position of multi-body system with quick startup and brake

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new method was put forward to optimize the position of actuator/sensor of multi-body system with quick startup and brake. Dynamical equation was established for the system with intelligent structure of piezoelectric actuators. According to the property of the modes varying with time, the performance index function was developed based on the optimal configuration principle of energy maximal dissipation, and the relevant optimal model was obtained. According to its characteristic, a float-encoding genetic algorithm, which is efficient, simple and excellent for solving the global-optimal solution of this problem, was adopted. Taking the plane manipulator as an example, the result of numerical calculation shows that, after the actuator/sensor position being optimized,the vibration amplitude of the multi-body system is reduced by 35% compared with that without optimization.

  1. Improvement of Brake System of Yutong Bus%字通客车制动系统改进探究

    Institute of Scientific and Technical Information of China (English)

    张希望; 杨正中; 蒋清莲

    2012-01-01

    针对宇通客车经过多年使用后出现的刹车不良或失效进行探究,提出在制动系统加装一个空气干燥器的改进方案,效果良好。%After use of Yutong Buses many years, the authors make study on the bad brakes or failure and put for- ward the braking system with an air dryer improvement program. The results are good.

  2. Evaluation of an autonomous braking system in real-world PTW crashes.

    Science.gov (United States)

    Savino, Giovanni; Pierini, Marco; Rizzi, Matteo; Frampton, Richard

    2013-01-01

    Powered 2-wheelers (PTWs) are becoming increasingly popular in Europe. They have the ability to get around traffic queues, thus lowering fuel consumption and increasing mobility. The risk of rider injury in a traffic crash is however much higher than that associated with car users. The European project, Powered Two Wheeler Integrated Safety (PISa), identified an autonomous braking system (AB) as a priority to reduce the injury consequences of a PTW crash. The aim of this study was to assess the potential effectiveness of the AB system developed in PISa, taking into account the specific system characteristics that emerged during the design, development and testing phases. Fifty-eight PTW cases representing European crash configurations were examined, in which 43 percent of riders sustained a Maximum Abbreviated Injury Scale (MAIS) 2+ injury. Two of the most common crash types were a PTW impacting a stationary object (car following scenario) 16% and an object pulling across the PTW path (crossing scenario) 54%. An expert team analysed the in-depth material of the sample crashes and determined a posteriori to what extent the AB would have affected the crash. For those cases where the AB was evaluated as applicable, a further quantitative evaluation of the benefits was conducted by considering a set of different possible rider reactions in addition to that exhibited in the actual crash. In 67 percent of cases, the application of AB could have mitigated the crash outcome. Analysis of those real crash cases showed the potential for an expert rider to avoid the collision. An early reaction of the rider, associated with a correct application of the brakes would have avoided 18 of the 37 car following/crossing scenarios. Conversely, according to the analysis, an expert rider would not have been able to avoid 19 of the 37 cases. In 14 of those 19 cases, the AB would have contributed to mitigating the crash outcome. This study demonstrated significant potential for

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

    Science.gov (United States)

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

    2017-08-01

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

  4. New Method of Road Surface Identification in Anti-Lock Braking System

    Institute of Scientific and Technical Information of China (English)

    QI Zhi-quan; LIU Zhao-du; ZHANG Jing-bo; MA Yue-feng

    2005-01-01

    Based on the vehicle-road dynamic model, the road characteristic parameter, which depends on different types of road surfaces, is introduced and a new method of road surface identification for automotive anti-lock braking system (ABS) is proposed. According to the characteristics of vehicle-road dynamic model, a simple math resolution method of the model's factors is established. Only using the information of wheel speed, the vehicle reference velocity and the wheel slip ratio are estimated real-timely. And based on the wheel dynamic model, the road characteristic parameter is determined to identify the road surface for the determination of thresholds of ABS regulative parameters. With this new method, the road surface identification can be accurately obtained and calculation time is short that it can meet the ABS real time control need, and it also improves the performance of ABS.

  5. 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.

  6. 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.

  7. How does a collision warning system shape driver's brake response time? The influence of expectancy and automation complacency on real-life emergency braking.

    Science.gov (United States)

    Ruscio, Daniele; Ciceri, Maria Rita; Biassoni, Federica

    2015-04-01

    Brake Reaction Time (BRT) is an important parameter for road safety. Previous research has shown that drivers' expectations can impact RT when facing hazardous situations, but driving with advanced driver assistance systems, can change the way BRT are considered. The interaction with a collision warning system can help faster more efficient responses, but at the same time can require a monitoring task and evaluation process that may lead to automation complacency. The aims of the present study are to test in a real-life setting whether automation compliancy can be generated by a collision warning system and what component of expectancy can impact the different tasks involved in an assisted BRT process. More specifically four component of expectancy were investigated: presence/absence of anticipatory information, previous direct experience, reliability of the device, and predictability of the hazard determined by repeated use of the warning system. Results supply indication on perception time and mental elaboration of the collision warning system alerts. In particular reliable warning quickened the decision making process, misleading warnings generated automation complacency slowing visual search for hazard detection, lack of directed experienced slowed the overall response while unexpected failure of the device lead to inattentional blindness and potential pseudo-accidents with surprise obstacle intrusion. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Eddy current braking experiment using brake disc from aluminium series of A16061 and A17075

    Science.gov (United States)

    Baharom, M. Z.; Nuawi, M. Z.; Priyandoko, G.; Harris, S. M.

    2012-09-01

    The electromagnetic braking using eddy current was studied, focused on two series of aluminium as the brake disc which are A16061 and A17075. This paper presents the comparison for both series in a few varied parameters related to eddy current braking such as air-gap, number of turns and brake disc thickness. Optical tachometer has been used along with PULSE analyzer to capture the speed (rpm) and time (s). The findings shows that the smaller the air-gap, the larger of electromagnet turns and the thicker disc thickness is, will generate higher braking torque to stop the rotational motion of disc brake and give great performance for eddy current braking. Thos parameters that been evaluated also addressed a potential on expanding this knowledge to develop an electromagnetic braking system to replace the conventional braking system.

  9. An analysis of braking measures

    NARCIS (Netherlands)

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

    2010-01-01

    Braking to a full stop at a prescribed target position is a driving manoeuvre regularly used in experiments to investigate driving behaviour or to test vehicle acceleration feedback systems in simulators. Many different performance measures have been reported in the literature for analysing braking.

  10. 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.

  11. Design And Implementation of Dsp-Based Intelligent Controller For Automobile Braking System

    Directory of Open Access Journals (Sweden)

    S.N. Sidek and M.J.E. Salami

    2012-08-01

    Full Text Available An intelligent braking system has great potential applications especially, in developed countries where research on smart vehicle and intelligent highways are receiving ample attention. The system when integrated with other subsystems like automatic traction control, intelligent throttle, and auto cruise systems, etc will result in smart vehicle maneuver. The driver at the end of the day will become the passenger, safety accorded the highest priority and the journey optimized in term of time duration, cost, efficiency and comfortability. The impact of such design and development will cater for the need of contemporary society that aspires to a quality drive as well as to accommodate the advancement of technology especially in the area of smart sensors and actuators.  The emergence of digital signal processor enhances the capacity and features of universal microcontroller.  This paper introduces the use of TI DSP, TMS320LF2407 as an engine of the system. The overall system is designed so that the value of inter-vehicle distance from infrared laser sensor and speed of follower car from speedometer are fed into the DSP for processing, resulting in the DSP issuing commands to the actuator to function appropriately.Key words:  Smart Vehicle, Digital Signal Processor, Fuzzy Controller, and Infra Red Laser Sensor

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

    Science.gov (United States)

    Rossa, Carlos; Lozada, José; Micaelli, Alain

    2014-01-01

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

  13. Systems with randomly failing repairable components

    DEFF Research Database (Denmark)

    Der Kiureghian, Armen; Ditlevsen, Ove Dalager; Song, Junho

    2005-01-01

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in time and rep......, or reducing the mean duration of system downtime. Example applications to an electrical substation system demonstrate the use of the formulas developed in the paper....

  14. Method and apparatus for electromagnetically braking a motor

    Science.gov (United States)

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

    2011-01-01

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

  15. Research on temperature rise of hoisting machine disk brake

    Institute of Scientific and Technical Information of China (English)

    MA Jun; JANG Hai-bo

    2012-01-01

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

  16. Brake Test Bench Pneumatic Braking System Modeling and Simulation Based on MATLAB%基于MATLAB的制动器试验台气压制动系统建模与仿真

    Institute of Scientific and Technical Information of China (English)

    张雷

    2016-01-01

    结合某公司的项目“制动器试验台气动制动系统研究与应用”,对气压制动系统的的组成和工作原理进行了分析,通过MATLAB建立其数学模型。在此基础上利用MATLAB的Simulink对其仿真模型并进行仿真,实现对气压控制算法的改进,实现用模糊PID对气压制动系统的控制。通过仿真的结果表明使用模糊PID使得使系统输出响应具有的动静态性能。%Combined with a company project brake test pneumatic brake system research and application of the air brake system composition and working principle analysis,the mathematical model by MATLAB.On the basis of its use of MATLAB Simulink simulation model and simulation,to achieve improved pressure control algorithm,implemented using fuzzy PID control for air brake systems.

  17. Design of Mechanically Actuated Aerodynamic Braking System on a Formula Student Race Car

    Science.gov (United States)

    Muralidharan, Vivek; Balakrishnan, Abhijith; Vardhan, Vinit Ketan; Meena, Nikita; Kumar, Y. Suresh

    2017-05-01

    Every second in a racing competition counts the performance of a team against the other. Many innovative and sophisticated techniques are being employed to overcome loses in time and add to the performance of the vehicle. Especially in a car racing challenge there is more freedom to install these innovative systems to empower the car to maximum efficiency due to availability of more space. At the global spectrum there are few events which encourage such innovations. Formula Student Racing competitions are one of the global events organized by the Society of Automotive Engineers of different countries which gives opportunity to university students to build and race formula style cars. Like any other racing competitions in this high octane event having an inch over their opponents is always an advantage. Not just better acceleration and high velocities but also good deceleration is required to excel in the competition. Aerodynamic braking system is utilizing the aerodynamic drag force to create high deceleration. This mechanism can be installed on any car with spoilers with minimum modification. Being a student event great amount of care needs to be given to the safety concerns of the driver.

  18. Development and Verification of the Tire/Road Friction Estimation Algorithm for Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Jian Zhao

    2014-01-01

    Full Text Available Road friction information is very important for vehicle active braking control systems such as ABS, ASR, or ESP. It is not easy to estimate the tire/road friction forces and coefficient accurately because of the nonlinear system, parameters uncertainties, and signal noises. In this paper, a robust and effective tire/road friction estimation algorithm for ABS is proposed, and its performance is further discussed by simulation and experiment. The tire forces were observed by the discrete Kalman filter, and the road friction coefficient was estimated by the recursive least square method consequently. Then, the proposed algorithm was analysed and verified by simulation and road test. A sliding mode based ABS with smooth wheel slip ratio control and a threshold based ABS by pulse pressure control with significant fluctuations were used for the simulation. Finally, road tests were carried out in both winter and summer by the car equipped with the same threshold based ABS, and the algorithm was evaluated on different road surfaces. The results show that the proposed algorithm can identify the variation of road conditions with considerable accuracy and response speed.

  19. The Improvement of Hydraulic System in Press Brake%折弯机液压系统的改进

    Institute of Scientific and Technical Information of China (English)

    尹亮

    2011-01-01

    On the analysis of design faults in the hydraulic system for the 1000kN press brake, the design has been improved. The practice production shows that the improvement has a good effect.%在分析1000kN折弯机液压系统设计缺陷的基础上,进行了改进.经一段时间的生产表明,达到了预期效果.

  20. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

    ... and release of the brakes on the last car in the train; and (6) The communicating signal system is... that operating conditions pose a safety hazard to an inspector walking the brakes, brake indicators may be used to verify the set and release on cars so equipped. However, the observation of the brake...

  1. Performance Test of Countershaft Brake System for Commercial Vehicle AMT%商用车 AMT 中间轴制动器性能试验

    Institute of Scientific and Technical Information of China (English)

    范珊珊; 宁立群; 崔伟; 杨子轩

    2016-01-01

    商用车电控机械式自动变速器 AMT 升档时,通过中间轴制动器来同步待啮合的齿轮,以保证换档的平顺性,因而中间轴制动器的性能直接关系到 AMT 的换档品质。本文设计台架试验,对 AMT 中间轴制动器的制动力、密封性、一致性、寿命等性能进行测试。试验模拟实车升档情况,以16档商用车自动变速器为对象,采用 TTC200控制器,协调控制离合器和制动器,同时采用 CANalyser 实时监测制动器性能,最终提出制动器的改进方案。试验表明,该中间轴制动器可以满足自动变速器的使用需求。%In order to achieve shift comfort, automatic mechanical transmissions for commercial vehicles use a counter shaft brake system to synchronize the target gears when upshifting. Therefore the AMT shift quality depends largely on the performance of the countershaft brake system. A testbed for the countershaft brake system was built to analyze the braking force, sealing, consistency, durability etc. During the test, TTC200, a type of control unit which supports the rapid prototy ping, coordinately controled the clutch and brake system, simulating the actual upshift process. Meanwhile, CANalyser monitored the behavior of the brake system. Finally, improvements for brake system were proposed. In conclusion, the countershaft brake system could meet the requirements of AMT.

  2. 驻车制动器的自锁保护装置%Self-locking Protection System of Hand brake

    Institute of Scientific and Technical Information of China (English)

    蒋晓琴

    2013-01-01

    The working conditions of central braking systems used in most automobiles are discussed.The reasons of the automobile sliding accident are analyze.And a simple improved design is put forward by adding a self-locking protection system,which is consist of electro-hydraulic control devices on the hand brake.While the self-locking protection system is working,the hand brake can not be released unless the ignition switch is turned on.%通过对汽车中央制动器的工作状态进行研究,分析了带中央制动器的汽车倒溜下滑的原因;提出了一种简单的改进设计方法,即在驻车制动器上加装一个带自锁功能的电液控制辅助装置,使得汽车在点火开关断开后,司机可以拉出手柄制动,但因自锁不能推回手柄解除制动,若要解除制动,必须先闭合点火开关,辅助装置的作用是要解除制动必须要点火开关闭合.

  3. 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.

  4. Study on Braking Sensation Based on Urban Working Conditions

    Directory of Open Access Journals (Sweden)

    Abi Lanie

    2017-01-01

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

  5. Reduction of Noise from Disc Brake Systems Using Composite Friction Materials Containing Thermoplastic Elastomers (TPEs)

    Science.gov (United States)

    Masoomi, Mohsen; Katbab, Ali Asghar; Nazockdast, Hossein

    2006-09-01

    Attempts have been made for the first time to prepare a friction material with the characteristic of thermal sensitive modulus, by the inclusion of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation in order to the increase the damping behavior of the cured friction material. Styrene butadiene styrene (SBS), styrene ethylene butylene styrene (SEBS) and nitrile rubber/polyvinyl chloride (NBR/PVC) blend system were used as TPE materials. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and storage modulus (E‧) for the friction material, dynamic mechanical analyzer (DMA) were used. Natural frequencies and mode shapes of friction material and brake disc were determined by modal analysis. However, NBR/PVC and SEBS were found to be much more effective in damping behavior. The results from this comparative study suggest that the damping characteristics of commercial friction materials can be strongly affected by the TPE ingredients. This investigation also confirmed that the specimens with high TPE content had low noise propensity.

  6. Braking System for Domestic Low-floor Light Rail Transit Vehicles%国产低地板轻轨车辆制动系统方案

    Institute of Scientific and Technical Information of China (English)

    曹国利; 曾宪华; 刘睿

    2012-01-01

    描述了国产化低地板车制动系统的参数、组成和原理,本系统为电子液压制动系统,由电气指令直接控制液压基础制动装置,简化了制动系统,节省了车底空间,解决了低地板轻轨车辆底部空间小,无法容纳空气制动装置的问题,满足低地板轻轨车辆的要求.%The parameters,composition and principle of domestic low-floor hydraulic brake system are described. This system uses electronic signals to control the foundation braking gears directly,it simplifies the braking systems and occupies less space. It also solves the installation problem of pneumatic braking equipments under the floor in a lowfloor light rail vehicle. Consequently, the electric hydraulic braking system could meet the requirements of low-floor light rail vehicles, and help to establish a theoretical foundation for the future study of low-floor hydraulic brake system.

  7. Schedule Planning for Repairing Power Supply System

    OpenAIRE

    Kuo-Wei Lin; Chein-Jen Kang

    2012-01-01

    Problem statement: Taiwan is located in the tropical ocean areas. The strong typhoon in summer often causes the collapse of electric transmission towers and results in power outages that seriously affect peoples lives and industrial production. Approach: In light of this situation, this study aims to employ project management techniques of Theory of Constraints (TOC) to develop a practical TOC model to quickly repair the towers and restore power supplied system. Results: The actual applicatio...

  8. Structural Principle Analysis of SBC Braking System on BENZ%奔驰轿车SBC制动系统的结构原理分析

    Institute of Scientific and Technical Information of China (English)

    蔡北勤

    2012-01-01

    SBC which stands for sensotronic brake control is an electrically activated braking system equipped on BENZ. The author introduces its composition, analyzes its working principle and advantages.%SBC是奔驰轿车采用的一种电子感应制动系统,介绍SBC的结构组成,分析该系统的工作原理和优点。

  9. DESIGN OF ELECTRIC VEHICLE BRAKING ENERGY RECOVERY SYSTEM BASED ON THE COMPOSITE BRAKING%基于复合制动的电动汽车制动能量回收系统设计

    Institute of Scientific and Technical Information of China (English)

    彭闪闪; 赵雪松; 时培成

    2015-01-01

    以某国产品牌纯电动汽车为研究对象,以回收和利用汽车的制动能量为研究目标,综合考虑汽车制动动力学特性、电机发电特性和电池充电特性等多方面因素,对其制动能量回收及控制策略进行探讨和研究;提出了一种机械和电机复合制动的能量回收方案;并基于Simulink软件进行了详细的仿真分析,获得了一个较为理想的能量回收率,为进一步开发设计具体的制动能量回收系统控制器奠定了良好的基础。%A domestic brand of pure electric vehicles is taken as the research object and the recovering and using of car braking energy of automobile is taken as the research target. The braking energy recovery and control method is discussed with the consideration of the vehicle braking dynamics, electric power generation characteristics, battery charging characteristics and other factors. A mechanical and electrical composite braking plan of energy recovery is proposed, and using the Simulink to simulate. The simulation results show that the energy efficiency is higher. It laid a good foundation for further design of specific braking energy recovery system controller.

  10. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Science.gov (United States)

    2010-10-01

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

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

    Directory of Open Access Journals (Sweden)

    I. M. Biloborodova

    2009-04-01

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

  12. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Science.gov (United States)

    2010-10-01

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

  13. Utilization of a hardware-in-the-loop-system for controlling the speed of an eddy current brake

    Science.gov (United States)

    Kramer, V.; Mishra, R.; Brauneis, P.; Schmidt, K.

    2012-05-01

    Rapid prototyping with a hardware-in-the-loop (HiL) system significantly reduces the development time for controller-type testing and is widely used in various fields of engineering. In this discussion, a controller is developed for a speed control application utilizing a magnetic brake. A mathematical model is presented first that has been implemented in Matlab/ Simulink. The controller development steps are described that will form the basis of a control system for a wind turbine. A test is carried out that simulates the wind turbine inertial load.

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

    Institute of Scientific and Technical Information of China (English)

    沙永东; 李晓豁; 康晓敏; 侯静

    2012-01-01

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

  15. Design of Feed-forward Controller with Stick-slip Friction Modeling in Electro-mechanical Brake System

    Directory of Open Access Journals (Sweden)

    Park Giseo

    2016-01-01

    Full Text Available Electro-Mechanical Brake (EMB is expected to be one of the future brake system. Feedback controller with sensor measuring is commonly used for control of EMB. However, this controller has some issues like delayed response and extra cost about sensor installation. In this paper, Feed-forward controller in EMB is proposed for solving these problems of feedback control. Also, it is very necessary to describe dynamical phenomenon of friction in actual EMB system. The actual EMB system shows stick-slip friction of mechanical parts which is difficult to model and apply to design of controller. This research is focused on exquisitely describing this stick-slip friction. In order to do this, the experiment about EMB is proceeded in the open loop system with the motor current command and data from the experiment is used for identification of model parameters during stiction. Then, parameters during slip is estimated in the closed loop system. Finally, developed friction model of EMB is proposed and it is utilized for design of feed-forward controller. Matlab Simulink is used for design of EMB simulation model and EMB test bench is utilized for experiment. Performance of proposed control system is compared with that of feedback control system.

  16. Automatic braking system modification for the Advanced Transport Operating Systems (ATOPS) Transportation Systems Research Vehicle (TSRV)

    Science.gov (United States)

    Coogan, J. J.

    1986-01-01

    Modifications were designed for the B-737-100 Research Aircraft autobrake system hardware of the Advanced Transport Operating Systems (ATOPS) Program at Langley Research Center. These modifications will allow the on-board flight control computer to control the aircraft deceleration after landing to a continuously variable level for the purpose of executing automatic high speed turn-offs from the runway. A bread board version of the proposed modifications was built and tested in simulated stopping conditions. Test results, for various aircraft weights, turnoff speed, winds, and runway conditions show that the turnoff speeds are achieved generally with errors less than 1 ft/sec.

  17. Test and analysis of the reaction time of the automobile pneumatic braking system%某汽车气压制动系统制动反应时间的测试及分析

    Institute of Scientific and Technical Information of China (English)

    郭伟

    2014-01-01

    The braking reaction time is one of the important performance parameters of automobile braking system, is one of the main factors influencing the automobile braking distance. This paper tested the braking reaction time of pneumatic braking system of an automobile, and analyzes its braking system performance.%汽车制动反应时间是汽车制动系统的重要性能参数之一,是影响汽车制动距离的主要因素之一。本文对某汽车气压制动系统进行制动反应时间测试,并分析其制动系统特性。

  18. Optimal Strategy for Inspection and Repair of Structural Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Sørensen, John Dalsgaard

    1987-01-01

    A new strategy for inspection and repair of structural elements and systems is presented. The total cost of inspection and repair is minimized with the constraints that the reliability of elements and/or of the structural system are acceptable. The design variables are the time intervals between...... inspections and the quality of the inspections. Numerical examples are presented to illustrate the performance of the strategy. The strategy can be used for any engineering system where inspection and repair are required....

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

    Energy Technology Data Exchange (ETDEWEB)

    Reuter, M.; Spielmann, W.

    1996-01-01

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

  20. 混合动力汽车再生制动压力协调控制系统%Pressure Coordinated Control System for HEV Regenerative Braking

    Institute of Scientific and Technical Information of China (English)

    杨阳; 邹佳航; 杨洋; 秦大同; 刘永刚

    2014-01-01

    再生制动作为混合动力汽车中的一门关键技术,越来越受到大家的关注和重视,针对国内外混合动力汽车再生制动压力协调控制系统的局限性和复杂性,设计出一种基于 ABS 硬件的再生制动压力协调控制系统,该系统实现了再生制动与(Anti-lock braking system,ABS)制动功能下的压力协调控制。建立AMEsim与Simulink联合仿真模型并进行恒制动强度下、变制动强度下、纯ABS模式下和综合制动模式下的仿真分析,结果表明除纯ABS外各模式下的电池SOC(State of Charge)回收率分别为0.27%、0.33%和0.29%,仿真结果表明电机能将汽车制动时减少的能量进行一定程度的回收并提供制动力。因此,所设计系统能实现各制动模式下压力协调控制以满足汽车制动需求,仿真结果验证了该方案的有效性和可行性,为再生制动系统的设计与优化奠定了基础。%As a key technology of hybrid electric vehicles, regenerative braking is attracting more and more attention. In view of the limitations and complexity of pressure coordinated control system for the regenerative braking of hybrid electric vehicles, a new kind of pressure coordinated control system has been designed in the basis of appropriate transformation on anti-lock braking system (ABS). The system can realize the pressure coordinated control of the regenerative braking and the traditional ABS braking. Based on AMESim-simulink co-simulation, models have been established to make some simulation analysis under the conditions of constant braking intensity, variable braking intensity, pure ABS model and integrated braking model. The result is that the battery’s state of charge(SOC) recovery rates of them except pure ABS model are 0.27%, 0.33% and 0.29% respectively. It proves that motor can partly recover energy which is reduced in braking and provide part braking force. Consequently, the system can realize pressure

  1. Estimate of potential benefit for Europe of fitting Autonomous Emergency Braking (AEB) systems for pedestrian protection to passenger cars.

    Science.gov (United States)

    Edwards, Mervyn; Nathanson, Andrew; Wisch, Marcus

    2014-01-01

    The objective of the current study was to estimate the benefit for Europe of fitting precrash braking systems to cars that detect pedestrians and autonomously brake the car to prevent or lower the speed of the impact with the pedestrian. The analysis was divided into 2 main parts: (1) Develop and apply methodology to estimate benefit for Great Britain and Germany; (2) scale Great Britain and German results to give an indicative estimate for Europe (EU27). The calculation methodology developed to estimate the benefit was based on 2 main steps: 1. Calculate the change in the impact speed distribution curve for pedestrian casualties hit by the fronts of cars assuming pedestrian autonomous emergency braking (AEB) system fitment. 2. From this, calculate the change in the number of fatally, seriously, and slightly injured casualties by using the relationship between risk of injury and the casualty impact speed distribution to sum the resulting risks for each individual casualty. The methodology was applied to Great Britain and German data for 3 types of pedestrian AEB systems representative of (1) currently available systems; (2) future systems with improved performance, which are expected to be available in the next 2-3 years; and (3) reference limit system, which has the best performance currently thought to be technically feasible. Nominal benefits estimated for Great Britain ranged from £119 million to £385 million annually and for Germany from €63 million to €216 million annually depending on the type of AEB system assumed fitted. Sensitivity calculations showed that the benefit estimated could vary from about half to twice the nominal estimate, depending on factors such as whether or not the system would function at night and the road friction assumed. Based on scaling of estimates made for Great Britain and Germany, the nominal benefit of implementing pedestrian AEB systems on all cars in Europe was estimated to range from about €1 billion per year for

  2. Assessment of Integrated Pedestrian Protection Systems with Autonomous Emergency Braking (AEB) and Passive Safety Components.

    Science.gov (United States)

    Edwards, Mervyn; Nathanson, Andrew; Carroll, Jolyon; Wisch, Marcus; Zander, Oliver; Lubbe, Nils

    2015-01-01

    Autonomous emergency braking (AEB) systems fitted to cars for pedestrians have been predicted to offer substantial benefit. On this basis, consumer rating programs-for example, the European New Car Assessment Programme (Euro NCAP)-are developing rating schemes to encourage fitment of these systems. One of the questions that needs to be answered to do this fully is how the assessment of the speed reduction offered by the AEB is integrated with the current assessment of the passive safety for mitigation of pedestrian injury. Ideally, this should be done on a benefit-related basis. The objective of this research was to develop a benefit-based methodology for assessment of integrated pedestrian protection systems with AEB and passive safety components. The method should include weighting procedures to ensure that it represents injury patterns from accident data and replicates an independently estimated benefit of AEB. A methodology has been developed to calculate the expected societal cost of pedestrian injuries, assuming that all pedestrians in the target population (i.e., pedestrians impacted by the front of a passenger car) are impacted by the car being assessed, taking into account the impact speed reduction offered by the car's AEB (if fitted) and the passive safety protection offered by the car's frontal structure. For rating purposes, the cost for the assessed car is normalized by comparing it to the cost calculated for a reference car. The speed reductions measured in AEB tests are used to determine the speed at which each pedestrian in the target population will be impacted. Injury probabilities for each impact are then calculated using the results from Euro NCAP pedestrian impactor tests and injury risk curves. These injury probabilities are converted into cost using "harm"-type costs for the body regions tested. These costs are weighted and summed. Weighting factors were determined using accident data from Germany and Great Britain and an independently

  3. 风轮机液压制动控制系统的研究%Research on Hydraulic Braking Control System of Wind Turbine

    Institute of Scientific and Technical Information of China (English)

    张文亭

    2015-01-01

    该文分析了风轮机常用的制动系统和控制系统,设计了基于紧急情况下的风轮机液压制动系统,并通过实验进行了测试,最后进行了紧急情况下的数据仿真研究,指出本制动器在不同最大设置压力和初始转速条件下的制动性能。%This paper analyses common braking system and control system in wind turbine, designs the hydraulic brake system of wind tur-bine based on emergency cases,and verified by experiment, also studies on the data simulation in case of emergency, points out the brake performance at different maximum set pressure and initial speed conditions.

  4. 新款三轮运动车制动系统设计%Design of Brake System of New Three-wheel Sports Car

    Institute of Scientific and Technical Information of China (English)

    田锐; 李桂华

    2012-01-01

    Through the braking performance analysis for new three-wheel sports car,the paper designed and calculated the structure of floating type disc brake in braking system and fully hydraulic braking drive system by human power.According to GB 7258-2004"safety specification for power-driven vehicles operating on road",its performance is verified,and the design result is good.And so the braking requirements of three-wheel sports car in ideal pavement is also met.%通过对新款三轮运动车制动性能要求进行分析,设计计算了制动系统的浮钳形盘式制动器结构和采用人力操纵的全液压制动驱动系统,并根据《机动车运行安全技术条件》(GB 7258-2004)进行了验证,达到了设计效果,满足了三轮运动车在理想路面上的制动要求。

  5. CFD Analysis Of Straight Ventilated Disc Brake

    Directory of Open Access Journals (Sweden)

    Nikhil K

    2016-05-01

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

  6. Schedule Planning for Repairing Power Supply System

    Directory of Open Access Journals (Sweden)

    Kuo-Wei Lin

    2012-01-01

    Full Text Available Problem statement: Taiwan is located in the tropical ocean areas. The strong typhoon in summer often causes the collapse of electric transmission towers and results in power outages that seriously affect peoples lives and industrial production. Approach: In light of this situation, this study aims to employ project management techniques of Theory of Constraints (TOC to develop a practical TOC model to quickly repair the towers and restore power supplied system. Results: The actual application had verified that the research model could not only shorten the duration of work but also save the manpower and material expenses. Conclusion: It once again proved the excellent results of reparation operations by applying TOC to project management.

  7. Application Research on Urban Rail Transit EP2002 Brake System%城市轨道交通 EP2002制动系统应用研究

    Institute of Scientific and Technical Information of China (English)

    陶敏; 张帆; 杨颖; 高亮彰

    2015-01-01

    In this paper,the EP2002 brake control logic and pneumatic principle were analyzed by intro-duced EP2002 brake system structure and the type and function of EP2002 valve.The advantages of EP2002 brake control system in urban rail vehicle applications were given.%介绍 EP2002制动系统构成和 EP2002阀的种类及作用,分析 EP2002制动控制逻辑及其气动原理,说明EP2002制动控制系统在城轨车辆中应用的优势。

  8. 球车制动系统寿命试验机的设计%Design of System Life Tester of Ball Vehicle Braking Mechanism

    Institute of Scientific and Technical Information of China (English)

    柳金梅; 朱晓杰

    2012-01-01

    根据球车的制动踏板和加速踏板的联动运动原理,设计一种气动试验机,通过它模拟人在驾驶车辆时加速踏板和制动踏板的往复运动,来检验联动机构的耐久性,从而考察其制动系统的寿命。%According to link motion principle of brake pedal and accelerator pedal, a pneumatic tester is designed which simulates the reciprocating motion of brake and accelerator pedal when people driving the car. The durability of link gear is tested and the system life of brake system is tested.

  9. 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, ...

  10. Incidence of systemic inflammatory response syndrome after endovascular aortic repair

    DEFF Research Database (Denmark)

    De La Motte, L; Vogt, K; Jensen, Leif Panduro;

    2011-01-01

    The aim of this study was to estimate the incidence of the post-implantation syndrome/systemic inflammatory response syndrome (SIRS) after endovascular aortic repair.......The aim of this study was to estimate the incidence of the post-implantation syndrome/systemic inflammatory response syndrome (SIRS) after endovascular aortic repair....

  11. Closed loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; van Ommeren, Jan C.W.; Zijm, Willem H.M.

    In this paper we consider closed loop two-echelon repairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  12. Design and optimazation of braking system on FSAE racing car%FSAE赛车制动系统的设计及其优化

    Institute of Scientific and Technical Information of China (English)

    李栋新; 黄光绪; 包耳

    2014-01-01

    按照FSAE规定,赛车制动系统要求简单控制,必须有两条液压回路而且每条液压回路必须有独立的储液罐,不允许采用带有助力的制动装置。将制动系统全部采用液压动力制动系统。这种方式作用滞后时间较短、工作压力高,因而主缸尺寸小,使制动器结构简单、质量小、机械效率高。假定附地面附着系数为0.8的情况下,赛车以20km/h制动的情况下计算了赛车的最大减速度和制动距离。对于制动系统的设计和优化具有指导性的意义。%According to the FSAE competition rules, the braking system of racing cars should be easily controlled, two hydraulic circuits and two independent resevoirs for each circuit are required, and no power assisting device is allowed. We put hydraulic power braking system into practice, by this mean we have short delay time and high working pressure so that the size of the master cylinder could be small. In this case the brake is constructed easily, having less mass and much more efficient. Assume adhension coefficient was 0.8 and initial speed of braking was 20 km/h, maximum deceleration and braking distance was calculated. This study is helpful for the braking system design of racing car.

  13. A Reduced-Order Model for Complex Modes of Brake Squeal Model and Its Application to a Flexible Pin-on-Disc System

    Directory of Open Access Journals (Sweden)

    Lijun Zhang

    2015-01-01

    Full Text Available Brake squeal is often analytically studied by a complex eigenvalue analysis of linearized models of the brake assembly that is usually quite large. In this paper, a method for determining those frequencies having the most effect on the pair of coupling frequencies that saves much time is put forward and a reduced-order model is presented based on the complex modes theory. The reduced-order model is proved to be effective when applied to a flexible pin-on-disc system; even damping and nonlinearity are taken into consideration. This reduced-order model can predict the onset of squeal as well as the squeal frequency with sufficient accuracy and largely reduced amount of calculation and gives us a practical guide to perform design optimization in order to reduce brake squeal.

  14. 液压蓄能器制动能量回收系统建模与仿真%Hydraulic Accumulator Brake Energy Recovery System Modeling and Simulation

    Institute of Scientific and Technical Information of China (English)

    殷允朝

    2016-01-01

    本文分析了液压蓄能器混合动力制动回收系统基本组成和工作原理并建立力学模型,重点研究了基于Matlab/simulink仿真和传动比的匹配。结果表明:在最高转速变化允许范围内合理选择传动比的参数匹配,能缩短制动时间和获取较高的制动回收率。%Hydraulic accumulator hybrid brake recovery system basic composition and working principle are analyzed,Based on Matlab/simulink and the ratio of matching is key research, The results show that:In the range of allowable maximum speed change the rational selection of parameters matching ratio, Braking time is shortened and Brake recovery rate was improved.

  15. The strength of the hybrid braking calipers analysis

    Institute of Scientific and Technical Information of China (English)

    Li Weitao; Yu Haiqing; Jiang Xiaoyan

    2015-01-01

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

  16. Reliability analysis of two unit parallel repairable industrial system

    Directory of Open Access Journals (Sweden)

    Mohit Kumar Kakkar

    2015-09-01

    Full Text Available The aim of this work is to present a reliability and profit analysis of a two-dissimilar parallel unit system under the assumption that operative unit cannot fail after post repair inspection and replacement and there is only one repair facility. Failure and repair times of each unit are assumed to be uncorrelated. Using regenerative point technique various reliability characteristics are obtained which are useful to system designers and industrial managers. Graphical behaviors of mean time to system failure (MTSF and profit function have also been studied. In this paper, some important measures of reliability characteristics of a two non-identical unit standby system model with repair, inspection and post repair are obtained using regenerative point technique.

  17. 49 CFR 236.712 - Brake pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake pipe. 236.712 Section 236.712 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.712 Brake pipe. A pipe...

  18. Targeting DNA-repair systems brings hopes to cancer patients

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ CAS researchers have recently raised a hypothesis to circumvent tumor resistance to radio- and chemo-therapy and to enhance the efficacy of DNAdamaging agents by interfering with DNA repair. "There are emerging anticancer therapeutic opportunities in targeting DNA-repair systems," they asserted.

  19. Incidence of systemic inflammatory response syndrome after endovascular aortic repair

    DEFF Research Database (Denmark)

    De La Motte, L; Vogt, K; Jensen, Leif Panduro;

    2011-01-01

    AIM: The aim of this study was to estimate the incidence of the post-implantation syndrome/systemic inflammatory response syndrome (SIRS) after endovascular aortic repair. METHODS: All patients, undergoing elective primary endovascular repair of an asymptomatic infrarenal abdominal aortic aneurysm...

  20. Capacitated two-indenture models for repairable item systems

    NARCIS (Netherlands)

    Zijm, Willem H.M.; Avsar, Zeynep Müge

    2003-01-01

    A two-indenture maintenance system is considered for a number of identical installations, in use at a single site. The installations are considered as assemblies that are made up of a number of repairable components. A component repair center and an assembly facility are both modeled as product form

  1. Capacitated two-indenture models for repairable item systems

    NARCIS (Netherlands)

    Zijm, Willem H.M.; Avsar, Z.M.; van Houtum, Geert-Jan

    2001-01-01

    A two-indenture maintenance system is considered for a number of identical installations, in use at a single site. The installations are considered as assemblies that are made up of a number of repairable components. A component repair center and an assembly facility are both modeled as product form

  2. Capacitated two-echelon inventory models for repairable item systems

    NARCIS (Netherlands)

    Avsar, Z.M.; Zijm, Willem H.M.; Gershwin, S.B.; Dallery, Y.; Papadopoulos, C.; Smith, J.M.

    2002-01-01

    In this paper, we consider two-echelon maintenance systems with repair facilities both at a number of local service centers (called bases) and at a central location. Each repair facility may be considered to be a job shop and is modeled as a (limited capacity) open queuing network, while any

  3. Control Circuit Design for Electronic Parking Brake System%电子驻车制动系统控制电路设计

    Institute of Scientific and Technical Information of China (English)

    郑婷; 王洪亮; 王显会; 皮大伟

    2014-01-01

    Based on the research status of electronic parking brake system at home and abroad and the function analysis of electronic parking brake system ,the overall design of a cable-type electronic parking brake system was carried out .The gradient sensor ,motor speed sensor and parking pulling sensor were selected ,and each module circuit was designed .The real vehicle matching and the parking/removing function debugging in variable drive conditions were completed .The results show that the static and dynamic characteristics of the electronic parking brake system can meet the design requirements .%在结合目前国内外电子驻车制动系统研究现状以及对其功能要求分析的基础之上,针对钢索牵引式电子驻车制动系统进行整体设计。依次对倾角传感器、电机转速传感器和拉力传感器等进行选型并完成各模块的电路设计;完成实车匹配并根据驾驶员实际操作以及各种车况进行驻车制动或解除的功能调试,结果表明其静态特性和动态特性均满足设计要求。

  4. Performance experiment of integrated system with car electromagnetic and frictional brakes%轿车电磁制动与摩擦制动集成系统的性能试验

    Institute of Scientific and Technical Information of China (English)

    刘存香; 何仁; 胡春花

    2012-01-01

    At the test bench of integrated system with electromagne-tic and frictional brakes, the blend brake torque comparison was conducted with various air gap, maximum supplying current, electromagnetic brake coil turns and brake disc material. The relationship among blend brake torque, electromagnetic brake torque and frictional brake torque, and the influence of different parameters on the blend brake torque were investigated. The results show that air gap, supplying current of electromagnetic brake coil, electromagnetic brake coil turns and brake disc material all have influences on the total torque of integrated system. With consideration of two factors of performance and installation, the optimum air gap and maximum supplying current of electromagnetic brake coil are 2 mm and 15 A with electromagnetic brake coil turns of 820 x4 for copper brake disc. For those vehicles with gross mass more than 1 200 kg, the maximum supplying current of electromagnetic brake coil can be increased to 25 A.%利用所研制的电磁制动与摩擦制动集成系统试验台,进行了不同空气间隙、不同最大通电电流、不同电磁制动器线圈匝数以及不同制动盘材料时的集成系统联合制动力矩对比试验,研究了联合制动力矩、电磁制动力矩与摩擦制动力矩三者关系以及各参数对电磁制动与摩擦制动集成系统的影响.结果表明:气隙、电磁线圈通电电流、电磁线圈匝数以及制动盘材料等均对集成系统总制动力矩大小造成影响;综合考虑性能、安装2方面因素,可以选择的参数为气隙2 mm,电磁制动器线圈的最大通电电流为15 A,电磁线圈匝数为820×4,制动盘材料采用铜材质;对于整车总质量超过1200 kg的车辆,线圈最大通电电流可以增大至25 A.

  5. Mathematical Model of Asynchronous Motor with Embedded Combined Braking Device

    Directory of Open Access Journals (Sweden)

    V. Solencov

    2013-01-01

    Full Text Available The paper presents a conclusion of a mathematical model pertaining to asynchronous motor with embedded combined braking device on the basis of electromechanical brake and electromagnetic slip coupling. The mathematical model has been obtained in an orthogonal coordinate system a, b, which is fixed with respect to the asymmetric part of the asynchronous motor with embedded combined braking device. The model makes it possible to investigate transient processes in various asynchronous motors with embedded braking devices.

  6. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Science.gov (United States)

    2010-10-01

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

  7. An analysis of the annual probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP)

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, M.A. [Univ. of California, Los Angeles, CA (United States); Sargent, T.J.

    1995-11-01

    The Environmental Evaluation Group (EEG) previously analyzed the probability of a catastrophic accident in the waste hoist of the Waste Isolation Pilot Plant (WIPP) and published the results in Greenfield (1990; EEG-44) and Greenfield and Sargent (1993; EEG-53). The most significant safety element in the waste hoist is the hydraulic brake system, whose possible failure was identified in these studies as the most important contributor in accident scenarios. Westinghouse Electric Corporation, Waste Isolation Division has calculated the probability of an accident involving the brake system based on studies utilizing extensive fault tree analyses. This analysis conducted for the U.S. Department of Energy (DOE) used point estimates to describe the probability of failure and includes failure rates for the various components comprising the brake system. An additional controlling factor in the DOE calculations is the mode of operation of the brake system. This factor enters for the following reason. The basic failure rate per annum of any individual element is called the Event Probability (EP), and is expressed as the probability of failure per annum. The EP in turn is the product of two factors. One is the {open_quotes}reported{close_quotes} failure rate, usually expressed as the probability of failure per hour and the other is the expected number of hours that the element is in use, called the {open_quotes}mission time{close_quotes}. In many instances the {open_quotes}mission time{close_quotes} will be the number of operating hours of the brake system per annum. However since the operation of the waste hoist system includes regular {open_quotes}reoperational check{close_quotes} tests, the {open_quotes}mission time{close_quotes} for standby components is reduced in accordance with the specifics of the operational time table.

  8. Improvement of Brake System of XJ-650 Workover Rig%XJ-650型修井机绞车制动系统改进

    Institute of Scientific and Technical Information of China (English)

    赵有清

    2015-01-01

    The working principle of hydraulic disc brake system of the hydraulic disc brake system is described in this paper.The problem of the existence of the pneumatic control belt brake for the XJ-650 type of the well is put forward.The hydraulic disc brake system of the workover rig is a-dapted for technological reformation,which is suitable for workover operation in deep and com-plex well conditions,and the construction of the labor intensity is decreased,security is obviously enhanced.%简述了修井机液压盘式刹车系统的工作原理。指出现有 XJ-650型修井机的气控带式刹车存在的问题。采用液压盘式刹车系统对该修井机进行技术改造,适应深井、复杂工况井等修井作业要求,并且使施工的劳动强度下降,安全性明显增强。

  9. 燃料电池汽车线控串行复合制动系统的开发%Development of BBW Series Hybrid Brake System for FCV

    Institute of Scientific and Technical Information of China (English)

    刘清河; 刘涛; 孙泽昌

    2011-01-01

    A brake-by-wire (BBW) hydraulic brake valve with mechanical backup is developed and its control performance is tested and analyzed. Based on BBW, a series hybrid brake system for a fuel-cell vehicle is built with corresponding control algorithm for electro-hydraulic braking designed. A hardware-in-the-loop simulation on series hybrid braking process is conducted. The results show that the system achieves the series application of motor regenerative braking and hydraulic friction braking, effectively enhancing braking energy recovery rate.%开发了具备机械备份的线控液压制动阀并对其控制性能进行了试验和分析.以线控制动系统为基础,建立了燃料电池汽车线控串行复合制动系统,并设计了与之相适应的电液复合制动控制算法.对串行复合制动过程进行了硬件在环仿真.结果表明,该系统实现了电机再生制动与液压摩擦制动的串行施加,有效提高了制动能量回收率.

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

    OpenAIRE

    Dong-Chan Lee; Chul-Goo Kang

    2015-01-01

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

  11. Research of the Brake Parking Problem of Industrial Sewing Machine System%工业缝纫机系统制动停车问题研究

    Institute of Scientific and Technical Information of China (English)

    边淳; 郗晓田; 文小琴; 游林儒

    2012-01-01

    order to improve the efficiency of industrial sewing machine system based on brushless dc motor control, simplified brake method and simplify the brake method, this paper put forward a new kind of reversing lock brake parking control method about the brushless dc motor control industrial sewing machine system. This method analyzed from the two aspects of speed and braking, PI speed control method is used, detecting needle position signal for reversing locking brake, and demonstrated the feasibility of this control method in theory. Finally, presents a practical control rendering. Practice proves that the method has achieved good effect, met the control requirements of the industrial sewing machine system and improves the dynamic performance of the system.%为提高基于直流无刷电机控制的工业缝纫机系统的制动效率、简化制动方法,提出了一种新型的基于无刷直流电机控制的工业缝纫机系统换向锁定制动停车控制方法.该方法从调速、制动两方面人手,采用PI调节降速,通过检测停针位信号进行换向锁定制动.同时从理论方面分析论证了该控制方法的可行性,并给出了实际的控制效果图.实践证明:该方法取得了良好的控制效果,完全满足工缝机系统的控制要求,提高了系统的性能.

  12. Design and Simulation on Electric Braking System of Pure Electric Vehicle%纯电动汽车电制动系统设计与仿真

    Institute of Scientific and Technical Information of China (English)

    王系朋; 潘盛辉

    2016-01-01

    In order to improve the utilization of electrical energy and more efficient pure electric vehicles, electric braking system can be installed on pure electric vehicles. Electric brake system can recover kinetic energy during braking and convert it into electrical energy. This paper presents an electrical braking system. The basic idea of the design is to rectify AC during braking is-sued by the AC motor into DC, and DC-DC converter converts the rectified voltage DC to appropriate size and charge it to the battery pack. According to the simulation results, electric energy 17 267 J can be recovered with the recovery efficiency 49. 1%. The sim-ulation results show that the designed electric braking system can recover kinetic energy during braking, and convert it into electrical energy to re-use, improving utilization of electrical energy, and effectively extending the pure electric vehicle mileage.%为了提高电能的利用率,让纯电动汽车在行驶过程中更加节能,可以为纯电动汽车安装电制动系统,电制动系统可以回收纯电动汽车在制动过程中的部分动能,并将其转换成为电能再次利用。本文设计了一种电制动系统,设计的基本思路是先将制动过程中电机发出的交流电整流,然后通过DC-DC直流变换器把整流后的直流电的电压值转换为合适的大小并充入电池组。根据仿真结果求得本文设计的电制动系统在测试的工况下,可以回收电能17267 J,回收效率为49.1%。仿真结果表明,本文设计的电制动系统可以将纯电动汽车制动过程中的部分动能被转化成为了电能再次利用,提高了电能的利用率,可以有效地延长纯电动汽车的续航里程。

  13. 基于混合系统理论的串联式再生制动控制策略分析%Analysis on the Control Strategy for Series Regenerative Braking Based on Hybrid System Theory

    Institute of Scientific and Technical Information of China (English)

    宋士刚; 李小平; 孙泽昌

    2015-01-01

    With series regenerative braking system of electric vehicle as the object of study, by the analyses on braking energy and braking regulations, the safe operation range of electro-hydraulic hybrid regenerative braking is theoretically determined, and with concurrent consideration of motor regenerative braking and battery charging power, a mathematical model for the optimization of regenerative braking is established. Based on the theory of hy-brid system and the model for hybrid automata, the regenerative braking system is visually described and a regenera-tive braking control strategy is proposed with coordinated control between motor regenerative braking force and the hydraulic braking forces on front and rear wheels, and a simulation is conducted on control model. The results indi-cate that the regenerative braking control strategy proposed increases the proportion of motor regenerative braking and thus enhance the recovery rate of vehicle braking energy in braking process.%以电动汽车串联式再生制动系统为研究对象,通过对制动能量和制动法规的分析,从理论上确定了电液复合再生制动的安全运行范围,并综合考虑电机再生制动和电池充电功率,建立了再生制动优化问题的数学模型。基于混合系统理论,利用混合自动机模型,直观描述了再生制动系统,提出了电机再生制动力和前后轮液压制动力协调控制的再生制动控制策略,并对控制模型进行了仿真分析。结果表明,该再生制动控制策略在制动过程中增加了电机再生制动的比例,从而提高了汽车制动能量的回收率。

  14. Reliability Analysis of Repairable Systems Using Stochastic Point Processes

    Institute of Scientific and Technical Information of China (English)

    TAN Fu-rong; JIANG Zhi-bin; BAI Tong-shuo

    2008-01-01

    In order to analyze the failure data from repairable systems, the homogeneous Poisson process(HPP) is usually used. In general, HPP cannot be applied to analyze the entire life cycle of a complex, re-pairable system because the rate of occurrence of failures (ROCOF) of the system changes over time rather thanremains stable. However, from a practical point of view, it is always preferred to apply the simplest methodto address problems and to obtain useful practical results. Therefore, we attempted to use the HPP model toanalyze the failure data from real repairable systems. A graphic method and the Laplace test were also usedin the analysis. Results of numerical applications show that the HPP model may be a useful tool for the entirelife cycle of repairable systems.

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

    Science.gov (United States)

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

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

  16. Improvement of control strategy in hybrid brake system of electric vehicle%电动汽车混合制动系统控制策略的改进

    Institute of Scientific and Technical Information of China (English)

    何仁; 俞剑波; 王润才

    2013-01-01

    针对电动汽车混合制动系统,通过对整车制动动力学和ECE R13法规的分析,理论上确定了混合制动系统的安全制动区域.在此区域内,以充分回收车辆制动能量为目标,在满足ECE R13制动法规和整车制动稳定性的前提下,对于前后轴机械制动力分配固定的混合制动系统,提出了一种电动机制动力与摩擦制动力分配的优化方法.以工作模式切换点的坐标及制动力分配曲线的斜率为优化对象进行优化.此外,基于制动力分配影响因素多变的特点,设计了一种3参数输入的制动力分配模糊控制策略.分别建立新的制动控制策略模型嵌入到ADVISOR2002中进行仿真分析,从而验证改进控制策略的有效性.结果表明2种新的控制策略能够有效改善电动汽车的制动能量回收率.%The safe area of braking force distribution was established theoretically by analyzing braking dynamics and the ECE R13 rule for hybrid braking system of electric vehicles. In the safe area, to obtain maximum energy of regenerative braking and meet the requirements of ECE R13 and braking stability, an optimization method of motor regenerative braking force and friction braking force distribution was proposed for the hybrid braking system with friction braking force distribution to front and rear axle. The point coordinate of switching operation mode and the rake ratio of braking force distribution were optimized. According to the changeable effect factors of braking force distribution, a novel control strategy of braking force distribution was designed based on fuzzy logic with three parameters-input. The new models of braking control strategy were simulated in ADVISOR2002 to verify the improved control strategy. The results show that the two new control strategies can effectively improve the rate of braking energy recovery in electric vehicle.

  17. Composites materials for friction and braking application

    Science.gov (United States)

    Crăciun, A. L.; Pinca-Bretotean, C.; Birtok-Băneasă, C.; Josan, A.

    2017-05-01

    The brake pads are an important component in the braking system of automotive. Materials used for brake pads should have stable and reliable frictional and wear properties under varying conditions of load, velocity, temperature and high durability. These factors must be satisfied simultaneously which makes it difficult to select effective brake pads material. The paper presents the results of the study for characterisation of the friction product used for automotive brake pads. In the study it was developed four frictional composites by using different percentages of coconut fibres (0%, 5%, 10%, 15%) reinforcement in aluminium matrix. The new composites tested in the laboratory, modelling appropriate percentage ratio between matrix and reinforcement volume and can be obtained with low density, high hardness properties, good thermal stability, higher ability to hold the compressive force and have a stable friction coefficient. These characteristics make them useful in automotive industry.

  18. Research on control strategy of regenerative braking system based on HEV%HEV再生制动控制策略的研究

    Institute of Scientific and Technical Information of China (English)

    仇秋飞; 朱伟; 赵云飞; 吴叶青

    2011-01-01

    Regenerative braking is not only a significant characteristic of EV, but also can improve its economic efficiency. The constraints are analyzed in the course of braking energy recovery. Then by designing the vehicle structure and the control strategy of regenerative braking system to resolve or weaken the problem that limits the braking energy recovery, meeting the design' s objective. At last, the test is done on the road, and the result indicates: 25% power can be recovered, and the mileage is prolonged.%制动能量回收是电动汽车的一个重要特性,也是电动汽车能实现经济性的重要方面.分析了制动能量回收过程中的限制因素,然后通过对整车系统结构以及再生制动控制策略的设计,削弱并解决了这些因素对制动能量回收的限制,以达到设计目的.最后进行道路试验,试验结果表明:在多模式驱动下该新型混合动力的再生制动系统可以回收总能量的25%,延长了续驶里程.

  19. Effect of surface roughness on amalgam repair using adhesive systems.

    Science.gov (United States)

    Giannini, Marcelo; Paulillo, Luis Alexandre Maffei Sartini; Ambrosano, Gláucia Maria Bovi

    2002-01-01

    The objective of this in vitro study was to evaluate the effect of three surface treatments and two adhesive systems on the shear bond strength of old and freshly placed amalgam. The results suggested that the intact amalgam showed a significantly higher strength than repaired groups and the strongest repaired specimens were made when the amalgam surfaces were roughened with a diamond bur or microetcher. The adhesive systems showed no significant differences on bond strength with the same superficial texture.

  20. Repair bond strength of resin composite to a novel CAD/CAM hybrid ceramic using different repair systems.

    Science.gov (United States)

    Elsaka, Shaymaa E

    2015-01-01

    This study evaluated the repair bond strength of a nanohybrid resin composite to a novel CAD/CAM hybrid ceramic based on four intraoral ceramic repair systems. Vita Enamic (VE) CAD/CAM hybrid ceramic was used in this study. Specimens were divided into five test groups according to the repair method performed on the ceramic surface: Gr C (No treatment; control); Gr CZ (Cimara Zircon); Gr PR (Porcelain Repair); Gr CR (Clearfil Repair); and Gr CS (CoJet system). Nanohybrid resin composite (GrandioSO) was packed onto treated ceramic surfaces for adhesion testing using microtensile bond strength test. Debonded specimens were examined with a stereomicroscope and SEM to determine the fracture mode. Data were analyzed using ANOVA and Tukey's HSD test. PR and CZ repair systems significantly enhanced the bond strength of nanohybrid resin composite to VE CAD/CAM hybrid ceramic when compared with the other tested repair systems.

  1. Stability analysis of automotive disc brake system with random parameters%随机参数汽车盘式制动器的稳定性分析

    Institute of Scientific and Technical Information of China (English)

    吕辉; 于德介

    2014-01-01

    针对不确定性参数汽车制动器噪声的抑制问题,基于随机参数分析理论,将响应面法与有限元复特征值技术相结合,提出了一种随机参数汽车制动器系统稳定性的分析方法。该方法用随机参数对制动器系统的不确定性进行描述,系统的摩擦系数、制动压力、制动盘厚度、制动片厚度和支撑背板的厚度参数分别采用随机变量表示;为提高分析效率,建立了包含随机变量的制动器不稳定特征值的响应面近似模型,进而根据系统特征值的随机特性对系统稳定性进行分析。用该方法对某车的浮钳盘式制动器系统进行研究,采用蒙特卡洛方法分析了随机参数正态分布假设下系统特征值的概率统计特性和参数灵敏度。结果表明:通过修改制动器支撑背板的厚度以提高支撑刚度,可有效改善制动器系统的稳定性,减小制动噪声的产生。%To suppress the brake noises of an automotive disc brake system with uncertain parameters ,a stability analysis method of automotive brake systems is presented in this paper .The essential idea of this method is to combine the RSM (Re-sponse Surface Method) and complex eigenvalue analysis techniques with random parameters introduced to describe such uncer-tainties in the brake system as friction coefficients ,brake pressure ,disc thickness ,pad thickness and backplate thickness .In order to improve the analysis efficiency ,RSM is used to build up the approximation models to express the functional relation-ships between the unstable eigenvalues and the system parameters ,which makes it available to study the stability of the brake system according to the random characteristics of the unstable eigenvalues .The stability analysis of a float caliper disc brake system is carried out by the proposed method with the random parameters assumed to follow normal distributions .The statisti-cal characteristics and the sensitivities

  2. Optimization Design of Control Strategy with Electro+EHB Braking System%电-液复合制动系统的控制策略多目标优化

    Institute of Scientific and Technical Information of China (English)

    李玉芳; 吴炎花

    2013-01-01

    Based on the design of electric car with electric + EHB braking system, the design put forward the control strategy of ideal braking force distribution. The constraint conditions of braking were analysed as: the constraint of braking regulations, the constraint of motor characteristics, braking stability and braking comfortable. And the optimum design was made by ISIGHT software. The dynamics and control models were established by SIMLINK software, then the Shanghai typical city bus driving cycle was selected. Compared with the parallel braking control strategy, the ideal braking force distribution strategy can not only greatly enhance the braking energy recovery efficiency, but also greatly improve braking efficiency and comfort.%研究电动汽车电机制动+EHB复合制动系统性能优化问题,提出理想制动力分配控制策略.分析制动时各环节的约束条件:制动法规的约束、电机特性的约束、制动稳定性的约束以及制动舒适性的约束条件,然后运用ISIGHT软件进行优化设计.再运用SIMLINK软件建立动力学和控制模型,选取上海典型城市公交循环工况,进行仿真.与并行制动控制策略比较,优化后的理想制动力分配策略不仅很大程度上提高制动能量回收效率,而且大大提高制动效能和制动平顺性.

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

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2016-07-01

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

  4. Effectiveness of forward collision warning and autonomous emergency braking systems in reducing front-to-rear crash rates.

    Science.gov (United States)

    Cicchino, Jessica B

    2017-02-01

    The objective of this study was to evaluate the effectiveness of forward collision warning (FCW) alone, a low-speed autonomous emergency braking (AEB) system operational at speeds up to 19mph that does not warn the driver prior to braking, and FCW with AEB that operates at higher speeds in reducing front-to-rear crashes and injuries. Poisson regression was used to compare rates of police-reported crash involvements per insured vehicle year in 22 U.S. states during 2010-2014 between passenger vehicle models with FCW alone or with AEB and the same models where the optional systems were not purchased, controlling for other factors affecting crash risk. Similar analyses compared rates between Volvo 2011-2012 model S60 and 2010-2012 model XC60 vehicles with a standard low-speed AEB system to those of other luxury midsize cars and SUVs, respectively, without the system. FCW alone, low-speed AEB, and FCW with AEB reduced rear-end striking crash involvement rates by 27%, 43%, and 50%, respectively. Rates of rear-end striking crash involvements with injuries were reduced by 20%, 45%, and 56%, respectively, by FCW alone, low-speed AEB, and FCW with AEB, and rates of rear-end striking crash involvements with third-party injuries were reduced by 18%, 44%, and 59%, respectively. Reductions in rear-end striking crashes with third-party injuries were marginally significant for FCW alone, and all other reductions were statistically significant. FCW alone and low-speed AEB reduced rates of being rear struck in rear-end crashes by 13% and 12%, respectively, but FCW with AEB increased rates of rear-end struck crash involvements by 20%. Almost 1 million U.S. police-reported rear-end crashes in 2014 and more than 400,000 injuries in such crashes could have been prevented if all vehicles were equipped with FCW and AEB that perform similarly as systems did for study vehicles. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Study on the Integrated Control for Vehicle Stability Based on Two-wheeled Motor Regenerative Braking System%基于双轮式电机再生制动车辆稳定性集成控制研究

    Institute of Scientific and Technical Information of China (English)

    陈庆樟; 许广举; 孟杰; 焦洪宇

    2014-01-01

    Taking two-wheeled motor front drive electric vehicle regenerative braking system as the research object, the regenerative braking system coordinated controller was developed by integrating the dual-motor regenerative braking, hydraulic brake and the stability system. The vehicle braking mode and the allocation of braking torque were determined according to the vehicle's braking demand, vehicle status and energy storage system state, and the stability control torque was provided by the two-wheeled motor regenerative braking system according to the real-time vehicle stability condition. The results show that, compared with the motor unilateral independent control strategy, the integrated coordinated controller has better stability effect on vehicle braking in the process of turning.%以双轮式电机前驱电动汽车制动系统为研究对象,把双电机再生制动、液压制动、稳定性控制集成在一起,开发了再生制动系统协调控制器。根据车辆制动需求、车辆状态、系统储能状态等确定车辆制动模式及分配制动力矩,并根据车辆实时稳定性状况由双轮式电机再生制动提供车辆稳定性控制力矩。仿真和试验结果表明,在车辆转弯制动工况中采用所述集成协调控制器比采用电机单边独立控制稳定性控制效果更好。

  6. Design and Analysis of Hydraulic System of Disc Brake for Downward Belt Conveyor%下运带式输送机盘式制动器液压系统设计与分析

    Institute of Scientific and Technical Information of China (English)

    刘灿杰; 贾跃虎; 刘志奇

    2011-01-01

    通过分析下运带式输送机制动工况的特点以及盘式制动器的优点,设计出适合各制动工况要求的新型盘式制动器液压系统.该液压系统具有松闸、保压、正常停车制动、超速制动、紧急制动和系统突然断电制动等功能.建立了系统的数学模型,将数学模型线性化后推导出了系统传递函数,分析了各元件参数对系统响应性的影响,为设计压力精细调节的制动器提供了理论基础.%The characteristics of braking condition of downward belt conveyor and advantages of disc brake were analyzed. A new hydraulic system of disc brake which met each braking condition requirement was designed. This hydraulic system have functions of loose braking, the normal parking braking, emergency braking and suddenly lose power braking. The mathematical model of this hydraulic system was established. The transfer function of this hydraulic system was deduced by the mathematical model linearization. The influences of the parameters to the response of the system were analyzed. The research work lays theory foundation for the design of brake with pressure fine adjustment.

  7. DNA Repair Systems: Guardians of the Genome

    Indian Academy of Sciences (India)

    2016-10-01

    The 2015 Nobel Prize in Chemistry was awarded jointly to Tomas Lindahl, Paul Modrich and Aziz Sancar to honour their accomplishments in the field of DNA repair. Ever since the discovery of DNA structure and their importance in the storage of genetic information, questions about their stability became pertinent. A molecule which is crucial for the development and propagation of an organism must be closely monitored so that the genetic information is not corrupted. Thanks to the pioneering research work of Lindahl, Sancar, Modrich and their colleagues, we now have an holistic awareness of how DNA damage occurs and how the damage is rectified in bacteria as well as in higher organisms including human beings. A comprehensive understanding of DNA repair has proven crucial in the fight against cancer and other debilitating diseases.

  8. Web-ADARE: A Web-Aided Data Repairing System

    KAUST Repository

    Gu, Binbin

    2017-03-08

    Data repairing aims at discovering and correcting erroneous data in databases. In this paper, we develop Web-ADARE, an end-to-end web-aided data repairing system, to provide a feasible way to involve the vast data sources on the Web in data repairing. Our main attention in developing Web-ADARE is paid on the interaction problem between web-aided repairing and rule-based repairing, in order to minimize the Web consultation cost while reaching predefined quality requirements. The same interaction problem also exists in crowd-based methods but this is not yet formally defined and addressed. We first prove in theory that the optimal interaction scheme is not feasible to be achieved, and then propose an algorithm to identify a scheme for efficient interaction by investigating the inconsistencies and the dependencies between values in the repairing process. Extensive experiments on three data collections demonstrate the high repairing precision and recall of Web-ADARE, and the efficiency of the generated interaction scheme over several baseline ones.

  9. Muzzle brakes and their performance

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal

    1958-01-01

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

  10. 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.

  11. Braking Energy Recovery System for Electric Vehicle%电动汽车制动能量回收系统研究

    Institute of Scientific and Technical Information of China (English)

    王猛; 孙泽昌; 卓桂荣; 程鹏

    2012-01-01

    In order to further improve the energy efficiency of electric vehicles, thus to improve the driving range economy, a braking energy recovery system for electric vehicles with simple structure, high reliability and fail-safe function was developed. Meanwhile, considering performance parameters of motor and battery, the efficient regenerative braking control strategy with strong portability was developed. Based on the proposed system and control strategy, hardware-in-loop tests were accomplished. Test results showed that friction braking force and regenerative braking force could be well integrated and braking energy recovery efficiency was high. Finally, experimental data of a FCV on CYC Japan-1015 proved the performance and feasibility of the proposed system. Braking energy recovery efficiency reached to 59. 15%.%为进一步提高电动汽车的能量利用效率以改善其续驶里程,开发了一套电动汽车制动能量回收系统.系统结构简单,可靠性高,并具有机械制动备份功能.同时,考虑到电动汽车电动机和电池性能参数,开发了高效的再生制动控制策略,算法具有较强的移植性.采用硬件在环的方式对系统的控制效果和制动能量回收效率进行了仿真测试.结果表明,再生制动力和摩擦制动力可以很好地协调运作,同时有效地回收制动能量.最后,在燃料电池汽车上进行转鼓实验,很好地完成了Japan-1015循环工况,能量回收效率高达59.15%.

  12. ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE

    Directory of Open Access Journals (Sweden)

    Özgür IRMAK

    2017-10-01

    Full Text Available Purpose: This study evaluated the effects of different adhesive systems on repair bond strength of aged resin composites. Materials and Methods: Ninety composite discs were built and half of them were subjected to thermal aging. Aged and non-aged specimens were repaired with resin composite using three different adhesive systems; a two-step self-etch adhesive, a two-step total-etch adhesive and a one-step self-etch adhesive; then they were subjected to shear forces. Data were analyzed statistically. Results: Adhesive type and aging significantly affected the repair bond strengths (p<0.0001. No statistical difference was found in aged composite groups repaired with two-step self- etch or two-step total-etch adhesive. One-step self-etch adhesive showed lower bond strength values in aged composite repair (p<0.0001. Conclusion: In the repair of aged resin composite, two-step self-etch and two-step total-etch adhesives exhibited higher shear bond strength values than that of one-step self-etch adhesive.

  13. 汽车EPB系统控制原理研究%Researches on Control Principles of Automotive Electric Parking Brake EPB System

    Institute of Scientific and Technical Information of China (English)

    刘峰

    2016-01-01

    汽车电子技术的不断进步,令驻车制动系统即手制动系统从过去机/液式的,逐渐变成电子式的。电子驻车制动可在行车前自动释放或在熄火后自动拉紧,省去了忘记解除驻车制动或“坡起”溜车等情况的困扰与风险;由于电子驻车制动系统即EPB系统的结构较为复杂,需要对其控制原理进行分析研究,本文主要包括EPB的组成及工作原理等。%With the automobile’s and electrical technology constantly development, the parking brake system is changing from the primary mechanical, hydraulic into electrical. Electric parking brake (EPB) system is able to release it before ignoring or strain it after stopping the engine automatically, and cuts the dififculties and dangerous rates of forgetting to be released or the slide on the slope; Because of the automotive EPB frame is so complex, the electrical brake system needs to analysis. This thesis is mainly contains the EPB structures and working principles.

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

    Directory of Open Access Journals (Sweden)

    Joni Dewanto

    2010-01-01

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

  15. Analysis of contaminated field failure data for repairable systems

    DEFF Research Database (Denmark)

    Hansen, Christian Kornerup; Thyregod, Poul

    1991-01-01

    A simple model for electronic systems with repair, and a method for analyzing recorded field failure data for such systems are presented. The work performed has resulted in analytical results that may be used for assessing the product reliability. The method was originally developed for use under...

  16. Closed loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; van Ommeren, Jan C.W.; Zijm, Willem H.M.; Liberopoulos, G.; Papadopoulos, C.T.; Tan, B.; MacGregor Smith, J.; Gershwin, S.B.

    2006-01-01

    In this paper we consider closed loop two-echelon epairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  17. 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

  18. 纯电动轻型卡车再生制动系统的仿真与控制策略%Modeling and simulation of regenerative braking system for pure electric light truck

    Institute of Scientific and Technical Information of China (English)

    宋百玲; 周学升; 李佳; 王兴; 程崇; 孙世磊

    2015-01-01

    为保证纯电动轻型货车在具有最佳制动力分配的前提下多回收制动能量,仿真模拟了双能量源再生制动系统,设计了理想制动力分配再生制动控制策略。以东风EQ5030轻型货车为原型,根据纯电动轻型货车对能量和功率的双重要求,组成超级电容+蓄电池的双能量源储能结构。利用Matlab/Sumilink软件,建立再生制动系统仿真模型。在典型的道路循环工况下,对两种控制策略进行仿真对比。结果表明:本文设计的理想制动力分配再生制动控制策略比传统并联再生制动控制策略能量回收率提高了37.33%,增加了汽车的续驶里程。%A dual-energy-source regenerative braking-system simulation model was established to ensure an electric light-truck recover braking-energy as much as possible within a best braking force distribution. A dual energy source regenerative braking system was simulated to design an ideal braking force distribution of regenerative braking control strategy. A light truck named Dongfeng EQ5030 was taken as the prototype with a super capacitor being introduced into a pure electric-vehicle energy-storage-system to meet the demand of energy and power for a pure electric vehicle light truck. An ideal braking force distribution of regenerative braking control strategy was designed. A simulation model of regenerative braking system was established using the Matlab/Sumilink software to simulate and contrast two different control strategies under typical road cycle. The results show that the energy recovery rate increases by 37.33% than that of the traditional paralel control strategy for the ideal braking force distribution of regenerative braking control strategy designed. It causes electric cars increase travel distance.

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

    Institute of Scientific and Technical Information of China (English)

    岑耀东; 陈林

    2012-01-01

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

  20. 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.

  1. Optimal inspection and Repair Strategies for Structural Systems

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Faber, Michael Havbro

    1992-01-01

    A model for reliability-based repair and maintenance strategies of structural systems is described. The total expected costs in the lifetime of the structure are minimized with the number of inspections, the number and positions of the inspected points, the inspection efforts, the repair criteria...... to be inspected and to select the location of the points to be inspected. It is shown how information obtained through inspections and through the periods of normal operating of the structure can be used to update the inspection and maintenance planning. Finally, a small example is given illustrating...

  2. Lubrication System. Teacher's Guide. Small Engine Repair Series. First Edition.

    Science.gov (United States)

    Hill, Pamela

    This teacher's guide accompanies three student manuals and together with them comprises an instructional package on the lubrication system in the Small Engine Repair Series for handicapped/special needs students. The first section, "Notes to the Instructor," covers equipment needs, preparation before teaching the instructional package,…

  3. UV Radiation Damage and Bacterial DNA Repair Systems

    Science.gov (United States)

    Zion, Michal; Guy, Daniel; Yarom, Ruth; Slesak, Michaela

    2006-01-01

    This paper reports on a simple hands-on laboratory procedure for high school students in studying both radiation damage and DNA repair systems in bacteria. The sensitivity to ultra-violet (UV) radiation of both "Escherichia coli" and "Serratia marcescens" is tested by radiating them for varying time periods. Two growth temperatures are used in…

  4. Randomized trial comparing the Prolene Hernia System, mesh plug repair and Lichtenstein method for open inguinal hernia repair.

    NARCIS (Netherlands)

    Nienhuijs, S.W.; Oort, I.M. van; Keemers-Gels, M.E.; Strobbe, L.J.; Rosman, C.

    2005-01-01

    BACKGROUND: Most surgeons favour the use of a mesh for open inguinal hernia repair as it has a low recurrence rate. Procedures used most frequently are the Lichtenstein method, mesh plug repair and the Prolene Hernia System. The choice of technique may be influenced by the effects on postoperative p

  5. Effective Measurement of Reliability of Repairable USAF Systems

    Science.gov (United States)

    2012-09-01

    Hansen presented a course, Concepts and Models for Repairable Systems Reliability, at the 2009 Centro de Investigacion en Mathematicas (CIMAT). The...defines MTBF in Technical Order 00-2-2, Maintenance Documentation ., Mean Time Between Failure (Inherent). Inherent refers to a Type 1 failure or...The USAF uses maintenance data to document the system failures. There is no method within that data system to define specific failure modes

  6. Availability, reliability and downtime of systems with repairable components

    DEFF Research Database (Denmark)

    Kiureghian, Armen Der; Ditlevsen, Ove Dalager; Song, J.

    2007-01-01

    Closed-form expressions are derived for the steady-state availability, mean rate of failure, mean duration of downtime and lower bound reliability of a general system with randomly and independently failing repairable components. Component failures are assumed to be homogeneous Poisson events in ......, or reducing the mean duration of system downtime. Example applications to an electrical substation system demonstrate the use of the formulas developed in the paper....

  7. Catecholamines, cardiac natriuretic peptides and chromogranin A: evolution and physiopathology of a 'whip-brake' system of the endocrine heart.

    Science.gov (United States)

    Tota, Bruno; Cerra, Maria Carmela; Gattuso, Alfonsina

    2010-09-15

    In the past 50 years, extensive evidence has shown the ability of vertebrate cardiac non-neuronal cells to synthesize and release catecholamines (CA). This formed the mindset behind the search for the intrinsic endocrine heart properties, culminating in 1981 with the discovery of the natriuretic peptides (NP). CA and NP, co-existing in the endocrine secretion granules and acting as major cardiovascular regulators in health and disease, have become of great biomedical relevance for their potent diagnostic and therapeutic use. The concept of the endocrine heart was later enriched by the identification of a growing number of cardiac hormonal substances involved in organ modulation under normal and stress-induced conditions. Recently, chromogranin A (CgA), a major constituent of the secretory granules, and its derived cardio-suppressive and antiadrenergic peptides, vasostatin-1 and catestatin, were shown as new players in this framework, functioning as cardiac counter-regulators in 'zero steady-state error' homeostasis, particularly under intense excitatory stimuli, e.g. CA-induced myocardial stress. Here, we present evidence for the hypothesis that is gaining support, particularly among human cardiologists. The actions of CA, NP and CgA, we argue, may be viewed as a hallmark of the cardiac capacity to organize 'whip-brake' connection-integration processes in spatio-temporal networks. The involvement of the nitric oxide synthase (NOS)/nitric oxide (NO) system in this configuration is discussed. The use of fish and amphibian paradigms will illustrate the ways that incipient endocrine-humoral agents have evolved as components of cardiac molecular loops and important intermediates during evolutionary transitions, or in a distinct phylogenetic lineage, or under stress challenges. This may help to grasp the old evolutionary roots of these intracardiac endocrine/paracrine networks and how they have evolved from relatively less complicated designs. The latter can also be used

  8. 自行车碟刹制动距离测试系统的设计与实现%Design and implementation of bicycle disc braking distance test system

    Institute of Scientific and Technical Information of China (English)

    陈梦群; 杨成忠

    2012-01-01

    随着碟刹的使用越来越普及,刹车的可靠性测试显得尤为重要,而国内市场上尚没有针对碟刹的测试系统.针对这一问题,设计了一套自行车碟刹制动距离测试系统.首先建立了自行车的刹车模拟装置,然后在模拟装置上安装了拉力传感器和速度传感器对其进行实时监测,传感器信号由数据采集卡采集并上传至上位机,上位机软件分析数据后下发命令控制模拟装置的刹车过程,并实时显示拉力值、速度值和制动距离等.通过多次制动距离测试,求平均值,确定了碟刹的制动距离,最后进行了试验验证.研究结果表明,该测试系统能够较准确地测量出自行车的制动距离,并且性能稳定,简单易操作,实用性强,具有良好的实际应用价值.%As the bicycle disc brake is getting more and more popular,the reliability testing is very important. But in the domestic market, there is no test system for the disc brake. Aiming at this problem,a system was designed to test the braking distance of the bicycle disc brake. The bicycle simulator was firstly created to simulate bicycle braking. Then a tension sensor and a speed sensor were installed on the braking simulator. The tension sensor was used to indirectly measure the power of gripping on the handlebar when the bicycle simulator was braking. The speed sensor was used to measure the speed of the inertial disc throughout the braking process. The signals of the two sensors were collected by the data acquisition card. The data of the sensors from the data acquisition card was gotten and analyzed, the commands were sent to control of the braking process, the data was real-time displayed,including tension value, velocity,the braking distance and so on. The braking distance of a bicycle disc brake was determined by the average of multiple test results. Finally the verification experiment was done in a factory producing Bicycle disc brakes. The results indicate that the

  9. Research on New Automobile Power Hydraulic Braking System by Vibratory Energy%新型振动能量主缸助力式汽车液压制动系统研究

    Institute of Scientific and Technical Information of China (English)

    李滟泽; 丁志华

    2013-01-01

    介绍了一种新型振动能量回收式液压减振系统,研究了一种振动能量主缸助力式汽车液压制动系统,油液在储液罐、减振器、蓄能器和制动液压元件之间循环流动.所述的振动能量助力式汽车液压制动系统能回收部分汽车的振动能量转化为液压能用于汽车助力制动,减小制动踏板力,降低驾驶疲劳度,缩短制动滞后时间,提高汽车制动安全性能.所述振动能量回收式液压减振系统申报了国家发明专利(CN102152778A),振动能量助力式汽车液压制动系统申报了国家实用新型专利(ZL 2011 20101080.1).%A new vibratory energy-recovery hydraulic damping system is introduced, and an automobile power hydraulic braking system by vibratory energy is researched. The oil is circulated between storage tank, energy accumulator, vibratum dampers and hydraulic components. The braking system can recycle some vibratory energy and convert to hydraulic energy which is used for automobile power braking system.It can reduce brake pedal force, lower fatigue of drive, shorten retardation time of braking, and enhance safety of braking. The vibratory energy-recovery hydraulic damping system has reported the national invention patent (CN102152778A), and the vibratory energy power-assisted automobile hydraulic braking system also has reported the national practical new patent(ZL 2011 2 0101080.1).

  10. Evaluation and dynamic forecast of reliability on vehicle brake system based on time-dependent theory%基于时变理论的车辆制动系统可靠性评估及动态预测

    Institute of Scientific and Technical Information of China (English)

    石博强; 唐歌腾

    2014-01-01

    为了研究整车制动系统的使用可靠性,以某越野车的盘式制动器为研究对象,针对制动系统在使用过程中会受到温度、车速、磨损等随时间变化的不确定性因素的影响,建立了基于时变理论的制动系统可靠性评估及动态预测模型,并应用模糊综合评判对各不确定性因素的影响程度进行了定量化,最后对此款越野车的制动系统可靠性进行了动态预测。结果表明,模型制动距离预测误差为2.1%,误差较小,该模型预测结果有效可行;同时该模型又可对未来t时刻的制动系统可靠性进行预测,可为整车制动安全性的主动预警提供有效参考数据。%As one of the most important sub-systems ensuring vehicle’s driving safety, the brake system, whose work reliability greatly determines the safety of car running in a large extent, is usually taken as an important object in studies of vehicle’s braking reliability. While for brake system, the use reliability is related to the allowable braking distance, braking deceleration and other relevant parameters prescribed by travel safety regulations. The intention of this paper is to establish a model of evaluation and dynamic forecast on brake system’s reliability based on time-dependent theory. Therefore the vehicle’s braking performance was studied to analyze the use reliability of brake system and the uncertain factors (such as temperature, speed and wear) which can cause the fluctuation of braking performance and exist in brake system’s whole lifetime were also analyzed. In addition, the impact extent of uncertain factors was quantified by fuzzy comprehensive evaluation method in this paper as well. Combined with the study of vehicle braking distances under different conditions, the model can not only assess the reliability of brake system in current time, but also dynamically predict that in future time. The evaluation and dynamic forecast model was

  11. Low-impact friction materials for brake pads

    OpenAIRE

    2016-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    XIAO Wen-yong; WANG Feng; ZHUO Bin

    2008-01-01

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

  13. 重型内燃牵引车双回路制动系统的设计和研究%Design and Research of Two-Circuit Braking System in Heavy Motor Tractor

    Institute of Scientific and Technical Information of China (English)

    张瑜

    2015-01-01

    介绍了双回路气制动系统在内燃牵引车如何有效地应用。该系统通过使用液压元件和气压元件,保证当一个制动回路失灵后,第二个制动回路能正常工作。同时在两套管路中设置比例阀,分别调节前后制动器分泵压力,使每个车轮有合适的制动力,充分利用整车附着力,使得工程车辆既能达到最大的制动力,保证整车安全可靠性。气源通过气制动控制系统与制动泵相连接,能够实现牵引的挂车制动的远程集中控制。同时利用重型卡车成熟的气制动控制元件和叉车成熟的液压制动执行元件,满足了港口牵引车的制动安全性、结构的紧凑性,又能够实现牵引的挂车制动的远程集中控制,具有很好的拓展性。%This article introduces the effective implication of two-circuit braking system in internal combustion tractor. This system uses hydraulic components and pneumatic components to make sure the second circuit braking system is in working or-der when the first fails. Meanwhile, proportional valves are installed in both circuits to adjust the pressure of front and rear brakes. Therefore, each wheel has appropriate brake force. By taking advantages of friction, the vehicle can achieve the maxi-mum braking force which ensures safety and reliability. Air source is connected with the brake pump through air braking con-trol system, thus to realize the remote centralized control of the braking of trailer. Moreover, it applies mature air brake com-ponents of heavy truck and mature hydraulic components of forklift truck. So that it satisfies braking safety and structural com-pactness, which has favorable expansibility.

  14. Control of start-up and dynamic braking of conveyors used for downhill transport in surface mines

    Energy Technology Data Exchange (ETDEWEB)

    Rosseger, A.; Borczyk, Z.; Kwater, M. (POLTEGOR Instytut, Wroclaw (Poland))

    1992-04-01

    Presents the structure of a microprocessor-aided control system for conveyors used in surface mines for downhill transport. Control of motor start-up and braking is performed in 8 speed stages. Permissible starting time duration is taken into consideration. The procedure of direct current braking is described. The microprocessor activates emergency braking by disc brakes if direct current braking is not sufficient. The system was implemented on four conveyors and has been used successfully since 1990.

  15. Analysis of contaminated field failure data for repairable systems

    OpenAIRE

    Hansen, Christian Kornerup; Thyregod, Poul

    1991-01-01

    A simple model for electronic systems with repair, and a method for analyzing recorded field failure data for such systems are presented. The work performed has resulted in analytical results that may be used for assessing the product reliability. The method was originally developed for use under ideal circumstances, but it has been adapted for use with contaminated data (i.e., data where the failure times are observed embedded by noise). A simple model for the noise that enables an analytica...

  16. Design and Simulation of Electronically Controlled Brake System for Heavy Off-Road Vehicle%重型越野汽车电控制动系统的设计与仿真

    Institute of Scientific and Technical Information of China (English)

    张堃; 黄茂; 刘保国; 虎忠

    2014-01-01

    For reducing the braking response time and improving the braking performance of heavy off-road vehicle, an electronically controlled brake system ( EBS) for pneumatic braking is designed. Based on the perform-ance parameters of target vehicle and EBS control algorithm with Matlab/Simulink as simulation platform, models for target vehicle and control alroithm are built to simulate the braking performance of EBS designed in different working conditions, which are then compared with the test data of conventional ABS system, verifying the rationality of sys-tem designed. The results show that the EBS designed has obvious advantages in reducing brake response time and enhancing braking safety.%为缩短重型越野汽车的制动响应时间,提高制动性能,设计了基于气压制动的电控制动系统( EBS)。依据目标车型的性能参数及EBS控制算法,以Matlab/Simulink为仿真平台,建立了目标车型的整车模型及控制算法模型。仿真研究了所设计的EBS系统在不同工况下的制动性能,并通过与常规ABS制动系统试验数据的对比,验证了系统设计的合理性。结果表明,所设计的EBS系统在减少制动响应时间和提高制动安全性方面具有明显的优势。

  17. Materials directed to implants for repairing Central Nervous System

    Energy Technology Data Exchange (ETDEWEB)

    Canillas, M.; Moreno-Burriel, B.; Chinarro, E.

    2014-07-01

    Central Nervous System (CNS) can be damaged by a wide range of injuries and disorders which entail permanent disability in some cases. Moreover, CNS repairing process presents some complications. The natural repair mechanism, which consists on the glial scar formation, is triggered by the inflammatory process. Molecules delivered during these processes, inflammation and glial scar formation as well as oxygen and glucose deficiencies due to the injury, create an inhibitory environment for axon regeneration and remyelination which is known as secondary injury. Biomaterials are taking up an even more important role in repairing CNS. Physicochemical properties of some ceramic materials have inspired different applications to repair CNS as substrates, electrodes or molecule vehicles. Based on their biocompatibility, capability to neutralize reactive species involved in the inflammatory processes and their versatile processing to obtain scaffolds with different shapes and sizes, ceramics are a succulent offer in nervous tissue engineering. Furthermore, their possibilities have been increased with polymeric-ceramics composites development, which have given rise to new interesting horizon. (Author)

  18. 飞机数字化全电刹车系统的设计%Design of Aircraft Digital Electric Braking System

    Institute of Scientific and Technical Information of China (English)

    施建洪; 漆云海; 李建海; 辛庆伟

    2014-01-01

    设计的飞机全电刹车系统,以四无刷直流电机驱动四滚珠丝杠布局的机电作动机架,取代了原来液压刹车的活塞阀门作动机架,电机通过传动装置驱动滚珠丝杠松刹刹车盘实现飞机的刹车。在硬件设计上,刹车控制器的CPU采用TI公司的电机及运动控制专用DSP2407,以满足对控制系统的性能要求;4台无刷直流电机的换相信号由可编程逻辑器件完成;对电机的驱动采用了MOSFET与栅极驱动芯片IR2130组成的功率驱动电路,实现了无刷直流电机的高效驱动。%The structure and aircraft electric braking system was presented. The piston and valve actuated housing for hy-draulic braking system was replaced by electro-mechanical actuated housing, which consisted of four motors and four ball screws. The ball screw, driven by the motor through gearing, put pressure to braking carbon stack. The CPU of digital con-troller used DSP TMS320F2407, which was designed for motor and motion control applications. The control signal for brushless DC motor was produced by programmable logic device. The motor driving circuit comprised by MOSFET IR 2130 was used to drive the motor efficiently.

  19. 气压式电子驻车制动电磁阀控制特性%Characteristics of solenoid valve in electronic parking brake system control

    Institute of Scientific and Technical Information of China (English)

    黄涤; 王洪亮; 皮大伟; 石秉良; 李楠

    2016-01-01

    In order to realize the automatic control of a pneumatic parking brake system,the charging and discharging characteristics of the parking control valves and its control method is studied. Analysing the structure and working principle of a heavy duty car parking brake system,this paper designs an overall scheme of the pneumatic electronic parking brake system. The mechanical properties of the spring brake cylinder is analyzed. The charging and discharging characteristics of the electromagnetic valve is studied and compared with the traditional manual valve. The control method of the pulse width modulation( PWM) is analyzed. The relationship between the inflation rate and the PWM duty ratio of the control valve is studied. The experimental results show that the solenoid valve can preserve pressure according to the demand and can adjust the aeration rate of the solenoid valve by changing the PWM signal duty ratio.%为实现气压式驻车制动系统的自动控制,研究了驻车控制阀的充放气特性及控制方法.通过分析重型车驻车制动系统的结构及工作原理,设计了气压式电子驻车制动系统的总体方案. 分析了弹簧制动缸的力学性能,对电磁阀的快速充放气特性进行了研究,并与传统手动阀做了比较. 分析了脉冲宽度调制( Pulse width modulation,PWM)的控制方法,研究了驻车制动系统控制阀在PWM控制下占空比与充气速率的关系. 实验结果证明电磁阀可按需求保压并且可通过改变PWM信号占空比调节电磁阀充气速率.

  20. Design of Online Detection System for Natural Frequency of Brake Discs%制动盘固有频率在线检测系统的设计

    Institute of Scientific and Technical Information of China (English)

    褚志刚; 周亚男; 蒋忠翰; 张昌福

    2012-01-01

    In order to obtain the natural frequency of brake discs rapidly and accurately,an online detection system is designed and developed in this paper.The system is composed of sensors,data acquisition hardware,data acquisition and analysis software module,online detection software module and controlled circuit.The design principle and the implementation method of the system are introduced.The application results show that the detection system has good performances and can detect the natural frequency of brake discs rapidly and accurately,and display the judgment results intuitively.%为了快速准确的完成对制动盘固有频率的检测,开发了一套在线检测系统。该系统由传感器、数据采集硬件、数据采集及分析软件模块、在线检测软件模块及控制电路构成。详细介绍了系统的设计,论述了系统的检测原理和实现方法。应用结果表明:本系统性能稳定,能快速准确地完成对制动盘固有频率的在线检测,并直观给出制动盘合格性的判定结果。

  1. Reliability Analysis of Partially Repairable Systems%部分可修系统的可靠性分析

    Institute of Scientific and Technical Information of China (English)

    苏保河

    2005-01-01

    The reliability analysis of a system with repairable failures and non-repairable failures is presented. It is assumed that the system has n repairable failure modes and m non-repairable failure modes. As one repairable failure mode takes place, the system will be repaired after the failure mode is detected, otherwise, it would never work again when attaining one non-repairable failure mode. Thus, the system brings about new reliability indices for having both repairable failures and non-repairable failures. The definitions of the new reliability indices are given, and the calculating methods for them are derived by using probability analysis and the supplementary variable technique.

  2. Nonlinear Mixed-Effects Models for Repairable Systems Reliability

    Institute of Scientific and Technical Information of China (English)

    TAN Fu-rong; JIANG Zhi-bin; KUO Way; Suk Joo BAE

    2007-01-01

    Mixed-effects models, also called random-effects models, are a regression type of analysis which enables the analyst to not only describe the trend over time within each subject, but also to describe the variation among different subjects. Nonlinear mixed-effects models provide a powerful and flexible tool for handling the unbalanced count data. In this paper, nonlinear mixed-effects models are used to analyze the failure data from a repairable system with multiple copies. By using this type of models, statistical inferences about the population and all copies can be made when accounting for copy-to-copy variance. Results of fitting nonlinear mixed-effects models to nine failure-data sets show that the nonlinear mixed-effects models provide a useful tool for analyzing the failure data from multi-copy repairable systems.

  3. 49 CFR 393.52 - Brake performance.

    Science.gov (United States)

    2010-10-01

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

  4. The Application of Hydraulic Braking-system for Light Proof Tire Vehicle%全液压制动系统在轻型防爆胶轮车上的应用

    Institute of Scientific and Technical Information of China (English)

    赵瑞萍

    2013-01-01

    介绍了轻型防爆胶轮车的制动系统,着重介绍了全液压制动系统的组成、特点,详细分析了全液压制动系统各元部件在设计过程中的选型,实践证明,全液压制动系统在轻型防爆胶轮车上的应用是可行及可靠的.%The braking systems in light type vehicle with the rubber wheeles are introduced, introduced the instructures and features of the hydraulic braking system, details how to select the parts in the design. Application shows that the application of hydraulic braking system in light type vehicle with the rubber wheeles is reasonable and reliable.

  5. Negative Effect of Disc Thickness Variation on the Performance of Anti-lock Braking System and Its Control Method%制动盘厚薄差对ABS性能的负面影响及控制方法

    Institute of Scientific and Technical Information of China (English)

    张立军; 黄平宇

    2013-01-01

    A nonlinear braking dynamics model for a quarter car is established, which consists of a rigid-ring-based transient tire model and a disc brake model with consideration of disc thickness variation ( DTV). Based on the model and by using MATLAB/Simulink, the negative effects of DTV on the braking performance of ABS system with slip rate threshold control are analyzed, and a set of adaptive control parameters based on the degrees of DTV are proposed on the basis of optimization to suppress the negative effects of DTV. The results indicate that DTV has negative effects on wheel motion, braking performance and braking comfort, while the use of DTV adaptive control parameters though may deteriorate braking comfort, but can effectively improve wheel motion and braking performance.%建立了包含瞬态刚性圈轮胎模型、考虑制动盘厚薄差(DTV)的制动器模型的1/4车非线性制动动力学模型.基于该模型,利用MATLAB/Simulink软件分析了DTV对滑移率门限值控制下ABS制动性能的负面影响,并提出了一套抑制DTV影响的适应性控制参数.结果表明:DTV会对车轮运动状态、制动效能和制动舒适性产生负面影响,而采用DTV适应性ABS控制参数虽会恶化舒适性,但可改善车轮运动状态,提高制动效能.

  6. ACTIVE FRONT STEERING DURING BRAKING PROCESS

    Institute of Scientific and Technical Information of China (English)

    CHEN Deling; CHEN Li; YIN Chengliang; ZHANG Yong

    2008-01-01

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

  7. 飞机数字电传防滑刹车系统污染控制方法研究%Study on the Pollution Control Method for Aircraft Digital Telex Antiskid Brake System

    Institute of Scientific and Technical Information of China (English)

    刘忠平; 亢敏; 韩亚国; 赵文庆

    2015-01-01

    The work principles, using requirements and pollution control requirements for high precision electro⁃hydraulic servo valve were discussed from a view of solving oil pollution problem synthetically in braking control system. The pollution control methods and ways were proposed. Through controlling pollution in the aspects of design, utility and maintenance of the braking control system, braking wheels and hydraulic tubes, holding brake pressure in air and braking failures caused by hydraulic oil pollution could be effec⁃tively avoided.%从刹车系统污染综合治理角度出发,论述了飞机刹车控制系统中高精度电液伺服阀的工作原理、选用要求及污染度控制要求,提出了飞机刹车系统油液污染控制的方法和途径。通过在刹车系统、刹车机轮、刹车管路的设计、使用、维护等方面进行污染控制,能够有效避免飞机刹车系统在使用中由于污染问题导致着陆过程中出现空中带压、刹车失效现象。

  8. LQG Control of Acceleration/Braking System Based on Wheelbase Preview%预瞄信息空气悬架汽车在加速/制动工况下的LQG控制

    Institute of Scientific and Technical Information of China (English)

    潘公宇; 黄宇

    2012-01-01

    A mathematic model of one second vehicle about acceleration/braking system based on air suspension is established. By applying wheelbase preview control to forecast the road surface roughness at the front wheel, the optimal controller based on wheelbase preview control theory is designed. Then the simulation is implemented in the MATLAB/Simulink environment. The simulation results show that the performance of the active air suspension acceleration/braking system with a LQG controller based on wheelbase preview can effectively suppress vehicle vibration compared with the passive air suspension acceleration/braking system; and compared with the optimal air suspension acceleration/braking system, the active air suspension acceleration/braking system does well in improving the ride comfort of acceleration/braking system.%建立了基于空气悬架的1/2车辆加速/制动系统模型,通过轴距预瞄在后轮处提前预测路面不平度;设计了基于轴距预瞄控制算法的加速/制动最优控制器;进行了白噪声仿真分析.仿真结果表明:与被动空气悬架加速/制动系统相比,基于轴距预瞄控制的主动空气悬架加速/制动系统能有效降低车辆振动.与最优控制空气悬架加速/制动系统相比,质心加速度和后轮对应处的车身加速度、悬架动行程、轮胎动载均有显著减小,较好的改善了车辆在加速/制动时的平顺性和操纵稳定性.

  9. STRATOS™ system for the repair of pectus excavatum.

    Science.gov (United States)

    Stefani, Alessandro; Nesci, Jessica; Morandi, Uliano

    2013-12-01

    Open techniques represent a valid repair option for severe asymmetric pectus excavatum in adults. The use of metal supports is recommended to reduce the risk of recurrence. A wide variety of metal supports have been proposed, with pre-, trans- or retrosternal fixation. A novel open technique using titanium bars fixed to the ribs with clips has been recently introduced (STRATOS™ system) for chest wall reconstruction, rib fracture fixation and chest wall malformation repair. We employed this technique in two adult patients with severe asymmetric pectus excavatum: after sternal mobilization, one bar is passed below the body of the sternum and secured with clips bilaterally to two ribs. In the first case, the results remained excellent 5 years after surgery. In the second case, the initial results were satisfying but the bar ruptured after 30 months: removal of the bars and clips was performed and a subsequent recurrence of the deformity occurred. The experiences reported in literature are still too limited to draw firm conclusions about the use of the STRATOS™ system in pectus excavatum repair, but it seems that the use of two bars may reduce the risk of rupture. At present, we are the only ones who reported long-term results.

  10. Bone repair: Effects of physical exercise and LPS systemic exposition.

    Science.gov (United States)

    Nogueira, Jonatas E; Branco, Luiz G S; Issa, João Paulo M

    2016-08-01

    Bone repair can be facilitated by grafting, biochemical and physical stimulation. Conversely, it may be delayed lipopolysaccharide (LPS). Physical exercise exerts beneficial effects on the bone, but its effect on bone repair is not known. We investigated the effect of exercise on the LPS action on bone healing through bone densitometry, quantitative histological analysis for bone formation rate and immunohistochemical markers in sedentary and exercised animals. Rats ran on the treadmill for four weeks. After training the rats were submitted to a surgical procedure (bone defect in the right tibia) and 24h after the surgery LPS was administered at a dose of 100μg/kg i.p., whereas the control rats received a saline injection (1ml/kg, i.p.). Right tibias were obtained for analysis after 10days during which rats were not submitted to physical training. Physical exercise had a positive effect on bone repair, increasing bone mineral density, bone mineral content, bone formation rate, type I collagen and osteocalcin expression. These parameters were not affected by systemic administration of LPS. Our data indicate that physical exercise has an important osteogenic effect, which is maintained during acute systemic inflammation induced by exposure to a single dose of LPS.

  11. Evaluation of Precast Panels for Airfield Pavement Repair. Phase 1: System Optimization and Test Section Construction

    Science.gov (United States)

    2013-06-01

    panel repair system for repair of rigid airfield pavements in contingency situations. Design criteria were provided by AFCEC to assist with the...dimensions limit repair versatility, since they do not align with typical rigid airfield pavement slab sizes. The Air Force prototype system design consists...at the joint. The original Air Force panel design used 0.75-in.-wide joints that were backfilled with a rapid-setting rigid pavement repair material

  12. 49 CFR 238.313 - Class I brake test.

    Science.gov (United States)

    2010-10-01

    ... side of each car's brake system responds properly to application and release signals; (2) The brake... occurs first, that the train remains in continuous passenger service. (c) Each passenger car and each... performed on the car within the previous calendar day and the car has not been disconnected from a source of...

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

    Science.gov (United States)

    Wolny, Stanisław

    2017-06-01

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

  14. Simulation analysis of hydraulic regenerative braking system for pure electric vehicle based on AMESim%基于AMESim的纯电动汽车液压再生制动系统的研究

    Institute of Scientific and Technical Information of China (English)

    徐耀挺; 宁晓斌; 王秋成

    2012-01-01

    为提高纯电动汽车制动时的再生制动能量回收率与汽车起步加速的动力性能,通过比较各种再生制动能量回收方案与储能方式,提出了在纯电动汽车的蓄电池回收制动能量的基础上加设液压制动能量回收系统.应用PID控制,在ECE-15循环工况下进行了仿真,并分析了整车的动力性能与能量的回收利用率.研究结果表明,在纯电动汽车上利用液压再生制动系统能够显著地提高整车的起步加速能力,并增加汽车的续驶里程28%左右.%In order to increase the regenerative braking energy recovery and the dynamic performance of vehicle start and acceleration in the stage of brake,the hydraulic braking energy recovery system was used with the storage battery braking energy recovery system after comparing kinds of regenerative braking recovery plan and energy storage method. The system was used to do simulation and analysis in vehicle dynamic performance and energy recovery efficiency under the PID control and ECE-15 cycle. The system simulation and analysis results show that, using hydraulic regenerative braking system in pure electric vehicle.it can significantly improve the ability of vehicle's start-acceleration and increase the vehicle driving range around 28%.

  15. Study on the Optimum Service Braking System for Low-speed Goods Vehicle%低速货车配备行车制动系统的研究

    Institute of Scientific and Technical Information of China (English)

    马恩; 杨博竣

    2016-01-01

    Current condition of service braking system for low-speed goods vehicle in China are discussed. Service brake safety properties of low-speed goods vehicle are affected directly by service brake system. To ex-plore the optimum designs of service braking system for low-speed goods vehicle, tests were carried out in ac-cordance with GB7258-2012 safety specifications for power-driven vehicles operating on roads. Research and practice in a long period proves the optimum designs are service manual hydraulic braking system for load less than one ton low-speed goods vehicle, but are service power pneumatic braking system for load more than one ton low-speed goods vehicle.%论述了我国低速货车配备行车制动系统的现状,低速货车行车制动系统直接影响其行车安全,试验按照强制性国家标准GB7258-2012《机动车运行安全技术条件》进行,经过研究人员长期研究和实践证明,得到最佳方案是:载重量小于1t的低速货车配备行车人力液压制动系统;载重量大于1t的低速货车配备行车动力气压制动系统。

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

    Science.gov (United States)

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

    2009-06-01

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

  17. 直流无刷电机再生制动系统试验台的设计与验证%Design and Verification of Brushless DC Motor Regenerative Braking System Test Bench

    Institute of Scientific and Technical Information of China (English)

    隋妮; 王广萍; 李仲兴; 张德望; 顾剑波

    2011-01-01

    基于再生制动理论,以电动汽车用轮毂电机为主体,搭建了直流无刷电机再生制动试验台.以回收能量最大化为目标,提出了相应的再生制动控制策略.结合电机的输出特性和工作原理,利用SIMULINK软件建立了再生制动系统模型.通过模型仿真和试验台试验结果的对比分析,验证了再生制动试验台设计方案的可行性和控制策略的合理性.%Basod on theory of regenerative braking, with electric vehicle hub motor as subject, a brushless DC motor regenerative braking test bench is built. To maximize energy recovery, regenerative braking control strategy is proposed in the paper. In accordance with output characteristic and working principle of motor,regenerative braking system is established with software SIMULINK.By modeling simulation and contrastive analysis of the test result, feasibility of design program of regenerative braking test bench and rationality of control strategy are validated.

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

    Science.gov (United States)

    2010-10-01

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

  19. 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

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

    Science.gov (United States)

    Xu, Ai Qun

    2016-06-01

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

  1. Theoretical approach of disc brake system optimum design for drilling rigs%钻机盘式刹车系统优化设计的理论探讨

    Institute of Scientific and Technical Information of China (English)

    吕瑞典; 伍开松; 罗井泉

    2001-01-01

    The applied forces to braking disc and braking plier for discbrake system of drilling rigs are analyzed.Then the basic relationships of the consuming energy on the friction faces, forces and other factors are deduced.The expressions of energy transformation for disc brake system of drilling rigs are derived on the basis of the principle of energy conservation. By further analysis of the operating requirements of the disc brake system and main failure forms during braking periods, the theoretical curves of temperature change and consuming power changes are proposed.At case the optimum design model of the disc brake system for drilling rigs is established, and also some things related to the model are discussed.%分析了钻机盘式刹车系统中刹车盘和刹车钳的受力状态,导出了其受力和摩擦面上耗散功率等因素之间的基本关系式。根据能量守恒原理又推导了钻机盘式刹车系统的能量转换表达式。通过进一步分析盘式刹车系统的使用要求和刹车过程中失效的主要形式,提出了刹车盘摩擦表面温度变化的理想曲线和耗散功率变化的理想曲线。建立了钻机盘式刹车系统的优化设计模型,并进行了分析讨论。

  2. 电动汽车再生制动系统仿真与分析%The simulation and analysis of electric vehile brake system

    Institute of Scientific and Technical Information of China (English)

    孙凯

    2016-01-01

    According to vehicle dynamics theory, The deeply theoretical researching and simulation are completed. the braking system is also analyzed entirely and thoroughly,including in the principle of energy recovery. the conformation of the regenerative-friction system、controltheory,innuencing factors and so on.Creating simulation data and curves show that regenerative braking distribution control strategy can assure high effcient energy recover.Gives some suggestion for the experiments and tests.%以电动汽车为研究对象,对其再生制动系统进行了深入的理论分析和仿真研究。从能量回馈的原理、再生-摩擦制动系统的结构、控制理论、影响因素等几个方面入手。对制动系统进行了全面、详细、深入的剖析,搭建了仿真模型。在此基础上进行了一系列仿真数据和曲线进行分析,为实车综合控制策略的制定提供参考。

  3. Development and construction of a controlled rail brake for diesel and battery-powered trolleys; Entwicklung und Bau einer gesteuerten und / oder geregelten Schienenbremse fuer Diesel- und Batteriekatzen

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J. [Deutsche Montan Technologie GmbH, Bochum (Germany). Car Synergies Division

    2003-07-01

    A new rail brake system for diesel and battery-driven trolleys was developed which reduces the overall dynamics in case of emergency braking operations. Further, the new brake was to permit the use of DZ2000 trolleys on I 140 E rail systems with 12 brake clasps.

  4. 车辆制动能量回收模拟系统设计与仿真%Design and Simulation of Vehicle Braking Energy Recovery Analog System

    Institute of Scientific and Technical Information of China (English)

    蔡普; 林慕义; 王连新; 郑鑫

    2016-01-01

    目前国内液压节能汽车试验平台结构复杂,管路繁多,液压泵/马达、飞轮等的动态参数不确定,无法满足多种工况下的实验配合问题。新型车辆制动能量回收模拟系统,使用电液比例控制系统代替传统的液压泵/马达,可实现能量回收过程多种复杂工况的动态模拟。设计车辆制动能量回收模拟系统,运用MATLAB/Simulink软件,建立了车辆制动能量回收模拟系统的仿真模型,通过仿真得到了该模拟系统在充、放液过程中的动态特性,并设计了试验台架,为后续车辆制动能量回收系统的实验研究提供了平台。%At present, domestic hydraulic energy⁃saving automobile test platform structure is complex, the pipe is various, and the hydraulic pump/motor, flywheel and other dynamic parameters are uncertainty, so it can not meet the experiments with a variety of conditions. In the new type of vehicle braking energy recovery simulation system, the electro⁃hydraulic proportional control system was used to replace the traditional hydraulic pump/motor. It could realize dynamic simulations of a variety of complex working conditions in energy recovery process. The system of vehicle braking energy recovery was designed, and the simulation model of this system was es⁃tablished by using MATLAB/Simulink software. The dynamic characteristics of the simulation system during charging and discharging hydraulic fluid were figured out, and the test bench was designed initially. It provides platform for subsequent experimental verification of vehicle braking energy recovery simulation system.

  5. A discounted model for a repairable system with continuous state space

    NARCIS (Netherlands)

    Bruns, P.B.

    2000-01-01

    We examine repairable systems with a continous state space and partial repair options, carried out at fixed times $n=1,2,...$. Every time interval $[n,n+1)$ there is a manufacturing cost and a repair cost. These cost functions are not restricted to the class of bounded functions in this study. Condi

  6. Bond strength durability of a resin composite on a reinforced ceramic using various repair systems

    NARCIS (Netherlands)

    Ozcan, Mutlu; Valandro, Luiz Felipe; Amaral, Regina; Leite, Fabiola; Bottino, Marco Antonio

    2009-01-01

    Objectives. This study compared the durability of repair bond strength of a resin composite to a reinforced ceramic after three repair systems. Methods. Alumina-reinforced feldspathic ceramic blocks (Vitadur-alpha(R)) (N=30) were randomly divided into three groups according to the repair method: PR-

  7. Heat distribution in disc brake

    Science.gov (United States)

    Klimenda, Frantisek; Soukup, Josef; Kampo, Jan

    2016-06-01

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

  8. GUIDES TO POLLUTION PREVENTION: THE AUTO REPAIR INDUSTRY

    Science.gov (United States)

    Automotive maintenance and repair shops generate a variety of waste streams during activities such as replacing fluids (e.g., motor oil, radiator coolant, transmission fluid, brake fluid), replacing non-repairable parts (e.g., brake shoes/pads, shocks, batteries, belts, mufflers,...

  9. 东风EQ1166G车制动系统介绍及常见故障排除%Introduction of DongFeng EQ1166G brake system and its common trouble shooting.

    Institute of Scientific and Technical Information of China (English)

    蒋显斌; 王涛

    2001-01-01

    介绍了EQ1166G车制动系统部分制动阀类的功用,针对制动系统较容易出现的故障,进行分析判断,找出引起故障的原因,结合实际提出故障排除的具体方法。%Use of brake valves for brake system in DongFeng EQ1166G isintroduced and its common troubles are analyzed、 diagnosed and removed

  10. Reliability Design of the City Rail Train Brake System Based on the Axis Control%基于轴控的城轨列车制动系统的可靠性设计

    Institute of Scientific and Technical Information of China (English)

    赵文文; 姚恩涛; 游有鹏; 王辉

    2013-01-01

    压电比例阀是一种新型气动阀,轴控是以列车单轴作为基本控制对象.为提高系统的可靠性,从系统架构出发,分析了轴控制动系统的冗余设计方案;以制动单元为对象,建立了车控制动单元和轴控制动单元的广义随机Petri网(GSPN)的可靠性模型,对两个系统稳态的可靠性进行了对比,为制动系统的进一步完善提供了可靠的数学模型.%The piezoelectric proportional valve is a new type of pneumatic valve, axle control regards the single axle as the basic control object. From the architecture of the system, the redundant design of the axle control brake system is analyzed to improve the system reliability. Based on the brake unit, the reliability model of the vehicle control and axle control brake system of generalized stochastic Petri net( GSPN) is established and the reliability of the system steadiness is compared, which provides reliable mathematical model to improve the brake control system.

  11. 提升机盘形闸摆动分析及其检测技术%Analysis on swing of disk brakes of hoists and its detection technology

    Institute of Scientific and Technical Information of China (English)

    樊兆峰

    2011-01-01

    In view of great error in detecting clearance of the disk brake of the hoist in collieries, the fault operating status of swinging disk brakes is proposed. After the analysis on the working principle of the disc brake, main swing causes of the disc brake are pointed out, and the parameter A indicating swing amplitude of the disc brake is defined. In addition, after the detection system being designed, the swing of the disc brake is tested, and the variation curve of brake shoe position with the time is offered. The detection technology offers references for the repair and maintenance of the disc brake, and is beneficial to the safe operation of the hoisting system.%针对提升机盘形闸的闸间隙在检测中存在误差较大的问题,提出了盘形闸摆动的故障运行状态。通过对盘形闸工作原理的分析,指出了盘形闸摆动的主要原因,并定义了表征盘形闸摆动幅度的参数6。设计了检测系统,对盘形闸的摆动进行了测试,给出了闸瓦位置随时间的变化曲线。该检测技术对盘形闸的检修及维护提供了参考依据,有利于提升系统的安全运行。

  12. Successful repair of a ventricular assist system percutaneous lead.

    Science.gov (United States)

    Pantalos, G M; Marks, J D; Richardson, E E; Nelson, K E; Long, J W

    1999-01-01

    A patient with an implanted, electrically powered, ventricular assist device (Thermo Cardiosystems VE HeartMate) experienced a partial break of the percutaneous lead 5 months after implantation. The break (limited to the Silicone rubber tube) occurred at the junction of the lead with the Y-connector to the controller and vent, leaving approximately 5 cm of exposed lead from the skin exit site to the connector. Electronic and pumping functions of the pump continued, but the opening in the lead (which went more that half way around the circumference) prevented the use of pneumatic actuation as a back-up mode for pump operation, and placed the pump at risk for contamination. Repair of the lead without surgical intervention was desirable, with ease of repair and minimal risk to the patient being the top priorities. The use of multiple layers of heat-shrink tubing or external metal stents was ruled out in favor of a three stage repair procedure. The first stage involved the removal of the Dacron velour in-growth material from the lead to expose the underlying Silicone rubber tube. While the opening in the tube was held shut, a coating of medical grade Silicone rubber adhesive was applied to the tube, then wrapped with a woven Dacron mesh, followed by two layers of plastic wrapping material to protect the adhesive. This initial layer was secured by an external stent of tubing with cable ties. After several days to allow for complete curing of the adhesive, the adhesive coating with mesh was repeated. The final step involved a double layer wrap of a 1 mm thick Silicone rubber sheeting with mesh incorporation and adhesive secured in place with cable ties. After completion of the repair and verification of the ability to operate the device with pneumatic actuation, the patient was discharged with no recurrence of the problem after 8 months of weekly follow-up. This experience demonstrates the need to clinically anticipate component repair or replacement without total device

  13. 刹车系统的摩擦自激振动和控制%FRICTION-INDUCED SELF-EXCITED VIBRATION AND CONTROL OF A BRAKE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    贾尚帅; 丁千

    2012-01-01

    The non-linear dynamics and control of friction-induced vibration in a brake system are investigated. Adopting the LuGre friction model, the dynamical equations of a 2-DOF disc brake system are derived by considering the friction force between the disc and the pad. The critical speed of Hopf bifurcation of the equilibrium is obtained through stability analysis. The design method based on differential geometry and linear quadratic optimal control for SISO nonlinear system controller is used to reduce the chatter phenomena during deceleration-type braking by postponing the critical speed of Hopf bifurcation. At last, the influences of the controller and the system parameters are analyzed. The simulation result shows that the method based on differential geometry and linear quadratic optimal is effective to control the self-excited vibration.%研究刹车系统的摩擦自激振动和控制问题。采用LuGre模型计算摩擦力,建立了两自由度盘式刹车系统的动力学模型。通过平衡点的稳定性分析,给出Hopf分岔失稳的临界速度。应用基于微分几何法和线性二次型最优控制相结合的方法,设计单输入单输出的非线性系统控制器,以便通过推迟系统的分岔临界速度,减少减速型刹车过程中的摩擦颤振,避免刹车啸叫。最后分析了控制器和系统参数对控制效果的影响。仿真表明,该控制器能有效的抑制刹车系统中的摩擦自激振动。

  14. Inducible repair system in Haemophilus influenzae unaccompanied by mutation. [uv

    Energy Technology Data Exchange (ETDEWEB)

    Notani, N.K.; Setlow, J.K.

    1980-07-01

    Weigle reactivation of ultraviolet-irradiated HPlc1 phage was observed after ultraviolet or mitomycin C treatment of Haemophilus influenzae cells. The amount of reactivation was considerably increased when the treated cells were incubated in growth medium before infection. The presence of chloramphenicol during this incubation abolished the reactivation. No mutation of this phage accompanied the reactivation. When cells were treated so as to produce a maximal reactivation of phage, neither reactivation nor mutation of cells was observed. It is concluded that H. influenzae has an inducible repair system that is not accompanied by mutation.

  15. Research on Recovering System of Braking Energy in Hydraulic Excavator%液压挖掘机制动能量的回收系统

    Institute of Scientific and Technical Information of China (English)

    吴文海; 郑辉; 邓斌; 刘桓龙

    2013-01-01

    针对传统液压挖掘机回转系统能量损失严重的问题,提出并设计一套液压挖掘机回转制动能量回收系统.分析该系统工作原理,以及液压蓄能器的参数匹配,通过AMESim软件建立模型,并进行仿真分析.仿真结果表明:该回转制动能量回收系统使挖掘机回转系统的节能效率达到50%左右,蓄能器进行能量回收的效率达到66.9%,回收能量再利用效率为50.3%,实现了节能减排的目的.%The paper proposes a recovering system of swing braking energy, which is designed to reduce the energy loss in hydraulic excavators swing system. Furthermore, the principle of the recovering system and the parameters of hydraulic accumulator are introduced. The simulation model is built by AMESim, Simulation results shown that the hydraulic excavator equipped with the recovering system of swing braking energy can save about 50% energy compared with the traditonal hydraulic excavator. The energy recovery efficiency can reach to 66. 9% with the hydraulic accumulator. The recovery energys utilization efficiency also can achieve 50. 3%. Thus, the recovering system meets the goal of energy-saving and emission-reduction.

  16. Mechanism and Durability of Repair Systems in Polymer-Modified Cement Mortars

    Directory of Open Access Journals (Sweden)

    Ru Wang

    2015-01-01

    Full Text Available This paper investigated the mechanism and durability of repair systems made of ordinary cement-based repair mortar and three kinds of polymer-modified repair mortars with old concrete, SBR dispersion, SAE dispersion, and SAE powder. By comparing the bonding properties of mortars before and after erosion, it was found that polymers could effectively improve the durability of the repair system and SAE powder had the best improvement. Micromorphology study of the repair mortar and the interface of repair mortar with old concrete through SEM showed that the polymer film formed from SAE powder whatever in the mortar or at the interface was dense and tough, the film formed from SAE dispersion was loose and weak, while the film formed from SBR dispersion was in between them, which explained the difference in the tensile bond strength and the durability of the repair systems.

  17. Modeling and Analysis on Braking Hydraulic System for LHD Based on Automation Studio%基于Automation Studio地下铲运机制动液压系统建模分析

    Institute of Scientific and Technical Information of China (English)

    张楠; 韩飞

    2016-01-01

    该文以CY-6型地下铲运机的重要单元之一制动液压系统为研究对象,该系统采用的是SAHR型制动器系统,其为全液压单回路式的制动形式,分析其工作原理,并对动作执行机构及所受载荷进行研究,在此基础之上,应用Automation Studio仿真分析软件搭建整机制动液压系统的仿真分析模型,对其动态工作过程进行仿真分析,获取了系统的充液过程和制动过程的性能曲线和相关参数,为实现该种车辆制动液压系统的优化设计获得理论参考和技术支撑,具有一定的工程应用价值。%In this paper, CY-6-type LHD braking hydraulic system as the research object, the system uses the SAHR type braking system, which is single-loop hydraulic braking system. Analyze the working principle of the system, and the action actuator and suffered payload. On this basis, the application of Automation Studio simulation software to build a model of braking hydraulic system. Simulation dynamic working process. And get the performance curve of filling process and the braking system and related parameters. To achieve optimal design this kind of vehicle hydraulic steering system to obtain a theoretical reference and technical support, with some engineering value.

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

    Science.gov (United States)

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

    2009-07-01

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

  19. Robust Clamping Force Control of an Electro-Mechanical Brake System for Application to Commercial City Buses

    Directory of Open Access Journals (Sweden)

    Sangjune Eum

    2017-02-01

    Full Text Available This paper proposes a sensor-less robust force control method for improving the control performance of an electro-mechanical brake (EMB which is applicable to commercial city buses. The EMB generates the accurate clamping force commanded by a driver through an independent motor control at each wheel instead of using existing mechanical components. In general, an EMB undergoes parameter variation and a backdrivability problem. For this reason, the cascade control strategy (e.g., force-position cascade control structure is proposed and the disturbance observer is employed to enhance control robustness against model variations. Additionally, this paper proposed the clamping force estimation method for a sensor-less control, i.e., the clamping force observer (CFO. Finally, in order to confirm the performance and effectiveness of a proposed robust control method, several experiments are performed and analyzed.

  20. Analysis of the Temperature Thresholds of Medium-sized T ruck’s Drum Brake System Based on Simulative Continuous Brake in the Continuous Long Dow nhill%模拟长下坡连续制动的中型货车鼓式刹车系统温度阈值分析

    Institute of Scientific and Technical Information of China (English)

    薛刚; 胡立伟; 孙亚南; 祁首铭; 李耀平

    2015-01-01

    Medium‐sized trucks need to be braked constantly when they are driven in the continuous long dow nhill and large trucks are more frequent .Because of the frequent braking ,the temperature of the braking system will rise sharply and the thermal fade will happen .This article analyzes the tem‐perature changes of full loaded medium‐sized trucks’ braking friction surface ,top of the brake shoe , inside of the brake shoe based on the data of the relevant experiment .It deduces the relationship be‐tween the highest temperatures of the three parts considering safety and comes to the conclusion that the temperature of the three parts will be higher when the trucks have the bigger initial velocities .It can prevent traffic accidents from happening by reminding the drivers before the thermal fade .%中型货车在连续长下坡路段行驶通常需不断制动,大型载重车辆制动更为频繁。由于频繁制动,会导致刹车系统温度急剧上升,从而出现热衰退现象。文中依据模拟中型货车满载状态连续长下坡鼓式制动器制动实验,通过实验数据分析,中型货车满载状态连续长下坡时鼓式制动器摩擦片表面、制动蹄顶部和制动蹄内侧3个部位的温度变化规律,推导出摩擦片失效温度与制动蹄顶部及内侧危险温度阈值之间对应关系,得到当初速度不断上升的过程中,摩擦片表面失效温度和制动蹄顶部和内侧的拟合危险温度阈值在一定范围内也同时上升的结论,在热衰退出现之前向驾驶员发出温度预警,有效控制因刹车系统热衰退导致交通事故的发生。

  1. Direct Self-Repairing Control for Quadrotor Helicopter Attitude Systems

    Directory of Open Access Journals (Sweden)

    Huiliao Yang

    2014-01-01

    Full Text Available A quadrotor helicopter with uncertain actuator faults, such as loss of effectiveness and lock-in-place, is studied in this paper. An adaptive fuzzy sliding mode controller based on direct self-repairing control is designed for such nonlinear system to track the desired output signal, when any actuator of this quadrotor helicopter is loss of effectiveness or stuck at some place. Moreover, using the Lyapunov stability theory, the stability of the whole system and the convergence of the tracking error can be guaranteed. Finally, the availability of the proposed method is verified by simulation on 3-DOF hover to ensure that the system performance under faulty conditions can be quickly recovered to its normal level. And this proposed method is also proved to be better than that of LQR through simulation.

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

    Science.gov (United States)

    Sawczuk, Wojciech

    2017-06-01

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

  3. 城市公交车机电复合制动能量回收系统研究%Study on Electro-mechanical Braking Energy Regeneration System for City Bus

    Institute of Scientific and Technical Information of China (English)

    邹政耀; 陈晓东; 金佳骏

    2012-01-01

    Aiming at the city bus characteristics of low speed operation and frequent start and stop conditions,an electro-mechanical braking energy regeneration system was proposed in this paper,which adopted a high-speed flywheel and a battery to recover the braking energy and achieve the secondary traction for the auxiliary start function.The system was designed and the braking simulation validated its feasibility.The experiment results show that the system can effectively recover the braking energy,improve the starting performance of the bus and it will be applied to city bus engineering in the future.%城市公交车辆运行工况复杂,需频繁启停,大量的能量浪费于车辆的制动。针对该现象,提出了采用高速飞轮和蓄电池组合的机电复合制动能量回收及二次牵引理论;进行了系统设计和制动工况仿真实验,验证了方案的可行性。实验证明:该系统能有效地回收利用城市公交车制动能量,改善起步性能,并具有成本低、易实现的特点。

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

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2013-01-01

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

  5. Regenerative braking control technology for wheel-side electric driving system%轮边电力驱动系统再生制动控制技术研究

    Institute of Scientific and Technical Information of China (English)

    卞永明; 兰皓; 蒋佳; 李生博; 吴昊; 金晓林

    2011-01-01

    轮边电力驱动系统中的再生制动系统主要涉及制动能量分配控制技术和再生制动能量回收控制技术.轮边电力驱动工程机械采用双向DC/DC变换器,结合电压电流双闭环控制实现超级电容的储能,从而控制再生制动能量的回收.通过MATLAB建模仿真表明,在满足安全制动的前提下,能够实现最大化的能量回收.%The regenerative braking system of wheel-side electric driving system mainly comprises the control technologies for braking energy distribution and regenerative energy recovery. To control the regenerative braking energy recovery, a bi-directional DC/DC converter, together with a double closedloop voltage-current control, is applied for super-capacitor energy storage of relevant construction machinery. By employing MatlabTM modeling and simulation, it is indicated that the energy recovery maximization could be realized to meet the demand on braking safety.

  6. A deteriorating two-system with two repair modes and sojourn times phase-type distributed

    Energy Technology Data Exchange (ETDEWEB)

    Montoro-Cazorla, Delia [Departamento de Estadistica e I.O., Escuela Politecnica de Linares, Universidad de Jaen, 23700 Linares, Jaen (Spain); Perez-Ocon, Rafael [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)]. E-mail: rperezo@ugr.es

    2006-01-01

    We study a two-unit cold standby system in steady-state. The online unit goes through a finite number of stages of successive degradation preceding the failure. The units are reparable, there is a repairman and two types of maintenance are considered, preventive and corrective. The preventive repair aims to improve the degradation of a unit being operative. The corrective repair is necessary when the unit fails. We will assume that the preventive repair will be interrupted in favour of a corrective repair in order to increase the availability of the system. The random operational and repair times follow phase-type distributions. For this system, the stationary probability vector, the replacement times, and the involved costs are calculated. An optimisation problem is illustrated by a numerical example. In this, the optimal degradation stage for the preventive repair of the online unit is determined by taking into account the system availability and the incurred costs.

  7. REPAIRABLE SYSTEM AVAILABILITY MODEL WITH RESPECT TO LIFE DISTRIBUTION OF SPARE PARTS

    Institute of Scientific and Technical Information of China (English)

    WU Yueming

    2008-01-01

    The failed components of repairable systems are replaced with spare parts that may have different failure distributions from those of the components that have failed. The spare parts may be either the same as new, better than new, or worse than new. This is the reality in maintenance engineering. Repair with better spare parts is defined as "super repair". The failure distributions of the spare parts affect the availability of the components and their systems. A novel model is proposed to describe the availability of repairable systems across their operating time, at the level of their components, on the assumption that the failed components are immediately replaced. The model functions with arbitrary failure distributions of spare parts. It can be used to compute the availability of components and systems not only under perfect and imperfect repair but also under super repair.

  8. 轻型电动汽车新型制动能量回收系统的研究%Research of a new brake energy recovery system of the light electric car

    Institute of Scientific and Technical Information of China (English)

    王新彦; 赵培; 桂天; 张胜文; 李忠国

    2013-01-01

      针对目前电动汽车制动能量回收效率偏低的问题,采用制动能量回收与利用并举的方法,以长安奔奔mini为样车,设计了一种新型制动能量回收系统,使再生制动时一部分电流为车载电池充电,一部分电流经整流转换后提供给开启的车用电器;建立该系统的动力学模型,得到了再生制动时功率Pe 与电机转速n的对应关系;并搭建了该新型制动能量回收系统的模拟实验平台,采用并行制动控制策略,测得了再生制动时回收利用的功率及其电机转速的时间历程曲线,通过计算得出了回收利用的制动能量及其效率.实验结果表明:当电机(2830 r· min-1)开始制动时,新型制动能量回收系统的效率提高了5.01%,验证了该设计方案的可行性与有效性.%In order to solve the problem of the low efficiency of braking energy recovery systems , a method of re-covering and utilizing braking energy was used to design a new braking energy recovery system based on the Chang'an Benben mini car .One part of the electric current was used for the recharge of the battery , while the other part of the current supplied the electrical devices of the car after current rectifier .The dynamic model of the new braking energy recovery system was established , the corresponding relations of the regenerative braking pow-er ( Pe ) and the motor speed ( n) with time were obtained and the simulative experiment device of the new bra-king energy recovery system was developed .The power and corresponding rotating speed of the electric engine with time were measured by the experiment with parallel control strategy , and then the energy and the efficiency of regenerative braking were calculated .The experimental results show that when the motor begins to brake from the speed of 2 830 r· min -1 , the efficiency of the new braking energy recovery system is increased by 5.01%compared with that of

  9. Loss of Thiol Repair Systems in Human Cataractous Lenses

    Science.gov (United States)

    Wei, Min; Xing, Kui-Yi; Fan, Yin-Chuan; Libondi, Teodosio; Lou, Marjorie F.

    2015-01-01

    Purpose. The purpose of this study was to investigate the thiol repair systems of thioltransferase (TTase) and thioredoxin (Trx) and oxidation-damaged proteins in human cataractous lenses. Methods. Cataractous lenses in humans (57–85 years of age) were classified into cortical, nuclear, mixed, mature, and hypermature cataract types by using a lens opacity classification system, and were obtained by extracapsular cataract extraction (ECCE) procedure. Cortical and nuclear cataracts were grouped by decreasing order of visual acuity into optical chart reading (R), counting fingers (CF), hand motion (HM), and light perception (LP). ECCE lens homogenate was analyzed for glutathione (GSH) level and enzyme activities of TTase, glutathione reductase (GR), Trx, and thioredoxin reductase (TR). Cortical and nuclear cataractous lenses (8 of each) with visual acuity better than HM were each dissected into cortical and nuclear portions for measurement of glyceraldehyde 3-phosphate dehydrogenase (G3PD) activity. Clear lenses (in humans 49–71 years of age) were used as control. Results. Compared with control, all cataractous lenses lost more than 80% GSH and 70% GR; TR and Trx activity; and 40% to 70% TTase activity, corroborated with the loss in visual acuity. Among cataracts with R and CF visual acuity, cortical cataract lost more cortical G3PD activity (18% of control) than that of nuclear cataract (50% of control), whereas GSH depletion and TTase inactivation were similar in both cataracts. Conclusions. Thiol repair systems were damaged in all types of cataracts. Cortical and nuclear cataracts showed differential G3PD inactivation in the cortex, implying those 2 type of cataracts might be formed through different mechanisms. PMID:25537203

  10. 无模型自适应控制在飞机防滑刹车中的应用%Application of Model Free Control Technology on the Aircraft Anti-skid Brake Systems

    Institute of Scientific and Technical Information of China (English)

    时伟; 刘文胜; 陈建群

    2012-01-01

    Considering the complexity and nonlinear of aircraft antiskid braking system, by analyzing the principle of aircraft anti -skid braking system, an aircraft anti-skid brake control algorithm based on model free adaptive control is presented. Not need to establish accurate dynamic model, the method can achieve optimal slip ratio control by using the information of braking system input and output. Simulation results show that the control scheme based on model free adaptive control achieve stable slip rate within five seconds, and provides a new way of improving the efficiency of the aircraft brake.%针对飞机防滑刹车系统的复杂性和非线性,在分析滑移率控制式飞机防滑刹车系统的工作原理基础上,提出了一种基于无模型自适应控制的飞机防滑刹车控制算法;该算法无需精确的动力学模型,直接利用输入输出信息实现飞机防滑刹车的最佳滑移率控制;仿真结果表明:采用无模自适应防滑刹车控制算法,在5s之内就能获得稳定的滑移率,为提高飞机刹车的效率提供了一条新的思路.

  11. Study of Hydraulic Regenerative Braking System in Electrical Vehicle%基于CPS的新型电动汽车液压再生制动能量回收系统研究

    Institute of Scientific and Technical Information of China (English)

    周翎霄

    2015-01-01

    In order to improve efficiency of recovering braking energy in electrical vehicle, a constant pressure hydraulic regenerative braking system with flywheel has been designed after comparing several hydraulic regenerative braking schemes. Then the joint braking and CEC-15 driving condition simulation based are processed. The results of simulation indicate positive correlation between displacement of pump/motor and efficiency of energy recovering under a certain value of displacement and driving range of electrical has been prolonged by 24%.%针对纯电动汽车能量利用率低的问题,提出对电动汽车进行制动能量回收,通过比较多种液压制动能量回收方案与储能方式,认为定压源飞轮液压再生制动系统较合理,且对该系统分别进行汽车联合制动工况和城市循环工况仿真,分析系统制动能量回收利用率和节能效果,仿真结果显示,泵/马达排量在一定范围内,制动能量回收效率与排量大小呈正相关,续驶里程能提高24%左右。

  12. 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

  13. Repair and degradation systems in irradiated animal cells

    Energy Technology Data Exchange (ETDEWEB)

    Ivannik, B.P.; Proskuryakov, S.Ya.; Ryabchenko, N.I. (Akademiya Meditsinskikh Nauk SSSR, Obninsk. Nauchno-Issledovatel' skij Inst. Meditsinskoj Radiologii)

    It was shown that primary radiosensitivity of DNA depends on the rate of DNA repair. In Zajdela hepatoma cells, cycloheximide administered immediately or 2 h before irradiation of animals does not influence DNA repair. Cycloheximide administered 4 h before irradiation of rats with a dose of 30 Gy arrests DNA repair in thymocytes and Zajdela hepatoma cells. At the same time, in cells of rat lymph nodes and spleen, under similar conditions, cycloheximide does not influence DNA repair and inhibits the secondary DNA degradation.

  14. 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.

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

    Science.gov (United States)

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

    2015-03-01

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

  16. 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...

  17. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

    NARCIS (Netherlands)

    Lukovic, M.; Ye, G.

    2015-01-01

    In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio

  18. MUTYH and the mismatch repair system: partners in crime?

    Science.gov (United States)

    Niessen, Renée C; Sijmons, Rolf H; Ou, J; Olthof, Sandra G M; Osinga, Jan; Ligtenberg, Marjolijn J; Hogervorst, Frans B L; Weiss, Marjan M; Tops, Carli M J; Hes, Frederik J; de Bock, Geertruida H; Buys, Charles H C M; Kleibeuker, Jan H; Hofstra, Robert M W

    2006-03-01

    Biallelic germline mutations of MUTYH-a gene encoding a base excision repair protein-are associated with an increased susceptibility of colorectal cancer. Whether monoallelic MUTYH mutations also increase cancer risk is not yet clear, although there is some evidence suggesting a slight increase of risk. As the MUTYH protein interacts with the mismatch repair (MMR) system, we hypothesised that the combination of a monoallelic MUTYH mutation with an MMR gene mutation increases cancer risk. We therefore investigated the prevalence of monoallelic MUTYH mutations in carriers of a germline MMR mutation: 40 carriers of a truncating mutation (group I) and 36 of a missense mutation (group II). These patients had been diagnosed with either colorectal or endometrial cancer. We compared their MUTYH mutation frequencies with those observed in a group of 134 Dutch colorectal and endometrial cancer patients without an MMR gene mutation (0.7%) and those reported for Caucasian controls (1.5%). In group I one monoallelic MUTYH mutation was found (2.5%). In group II five monoallelic germline MUTYH mutations were found (14%), four of them in MSH6 missense mutation carriers (20%). Of all patients with an MMR gene mutation, only those with a missense mutation showed a significantly higher frequency of (monoallelic) MUTYH mutations than the Dutch cancer patients without MMR gene mutations (P = 0.002) and the published controls (P = 0.001). These results warrant further study to test the hypothesis of mutations in MMR genes (in particular MSH6) and MUTYH acting together to increase cancer risk.

  19. Optimization method of frictional braking force distribution for integrated system of electromagnetic and frictional braking of car%轿车电磁与摩擦制动集成系统摩擦制动力分配优化方法

    Institute of Scientific and Technical Information of China (English)

    何仁; 赵强; 胡东海

    2015-01-01

    分析了轿车电磁与摩擦制动集成系统的结构与工作原理,推导了轿车前后轴利用附着系数的计算公式。以 ECE R13制动法规与电磁制动器设计要求为约束条件,以轿车前后轴实际利用附着系数与理想状态制动强度差值的平方和最小为目标函数,以 MATLAB 优化工具箱为计算工具,建立了轿车电磁与摩擦制动集成系统摩擦制动力分配优化方法,计算了不同工况下的摩擦制动力分配最优值。计算结果表明:当制动强度分别为0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8时,优化前的目标函数值分别为0.03、0.05、0.07、0.07、0.08、0.07、0.06、0.04,优化后的的目标函数值分别为0.00、0.00、0.00、0.00、0.00、0.00、0.01、0.01,优化后,目标函数值明显减小,轿车前后轴利用附着系数曲线更靠近理想曲线,且均在 ECE R13制动法规控制曲线的下方,因此,提出的优化方法满足ECE R13制动法规的要求,轿车制动稳定性得到提高。%The structure and working principle of integrated system of the electromagnetic and frictional braking for car were analyzed.The calculation formula of utilization adhesion coefficient for front and rear axles was derived.The ECE R13 braking regulation and the design requirement of electromagnetic braking were taken as constraint conditions,the minimum square sum of differences between the actual curve of utilization adhesion coefficient and the braking strength of ideal condition for front and rear axles was taken as objective function,MATLAB optimization toolbox was employed,the optimization method of frictional braking force distribution for the integrated system of electromagnetic and frictional braking was established,and the optimal values of frictional braking force distribution under different conditions were calculated. Calculation result indicates when the braking strength is 0

  20. Reliability analysis of repairable systems using system dynamics modeling and simulation

    Science.gov (United States)

    Srinivasa Rao, M.; Naikan, V. N. A.

    2014-07-01

    Repairable standby system's study and analysis is an important topic in reliability. Analytical techniques become very complicated and unrealistic especially for modern complex systems. There have been attempts in the literature to evolve more realistic techniques using simulation approach for reliability analysis of systems. This paper proposes a hybrid approach called as Markov system dynamics (MSD) approach which combines the Markov approach with system dynamics simulation approach for reliability analysis and to study the dynamic behavior of systems. This approach will have the advantages of both Markov as well as system dynamics methodologies. The proposed framework is illustrated for a standby system with repair. The results of the simulation when compared with that obtained by traditional Markov analysis clearly validate the MSD approach as an alternative approach for reliability analysis.

  1. Materials directed to implants for repairing Central Nervous System

    Directory of Open Access Journals (Sweden)

    Canillas, M.

    2014-12-01

    Full Text Available Central Nervous System (CNS can be damaged by a wide range of injuries and disorders which entail permanent disability in some cases. Moreover, CNS repairing process presents some complications. The natural repair mechanism, which consists on the glial scar formation, is triggered by the inflammatory process. Molecules delivered during these processes, inflammation and glial scar formation as well as oxygen and glucose deficiencies due to the injury, create an inhibitory environment for axon regeneration and remyelination which is known as “secondary injury”. Biomaterials are taking up an even more important role in repairing CNS. Physicochemical properties of some ceramic materials have inspired different applications to repair CNS as substrates, electrodes or molecule vehicles. Based on their biocompatibility, capability to neutralize reactive species involved in the inflammatory processes and their versatile processing to obtain scaffolds with different shapes and sizes, ceramics are a succulent offer in nervous tissue engineering. Furthermore, their possibilities have been increased with polymeric-ceramics composites development, which have given rise to new interesting horizon.Existen diferentes tipos de lesiones o desordenes del Sistema Nervioso Central (SNC que pueden provocar graves secuelas e incluso en algunos casos una discapacidad permanente. Además, el proceso de reparación del SNC tiene algunas complicaciones. El mecanismo natural de reacción a una lesión, el cual consiste en la formación de una cicatriz glial, es desencadenado por un proceso inflamatorio. Las moléculas liberadas durante estos procesos, la inflamación y formación de la cicatriz glial, así como la deficiencia en oxígeno y glucosa debidos a la lesión, crean un ambiente que inhibe la regeneración axonal creando la llamada “lesión secundaria”. Los biomateriales están adquiriendo un papel cada vez más importante en la reparación de SNC. Las

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

    Institute of Scientific and Technical Information of China (English)

    刘宁霞; 罗哉

    2012-01-01

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

  3. CCBII制动机系统模式追踪与多故障诊断技术%Mode Tracking and Multiple Faults Diagnosis of CCBII Brake System

    Institute of Scientific and Technical Information of China (English)

    黄志武; 宾睿; 杨迎泽; 刘伟荣

    2014-01-01

    由于CCBII制动机具有多种工作模式,工况复杂,工作部件繁多且耦合性强等特点,经常有多故障并发。传统的故障诊断技术难以对其进行多故障诊断。本文在基于解析冗余关系的诊断技术上,引入差分进化算法进行多故障检测与定位。首先构建制动机各工作模式模型,并推导系统的扩展全局解析冗余关系以获得模式转变特征表和系统故障特征表,再引入一致性向量比较特征表,实现系统的模式追踪。当模式追踪失败后,构建候选故障假设集,对每个候选故障设计基于差分进化算法参数估计器,通过比较候选故障参数的平均适应函数值,定位同时发生的多个故障,实现制动机系统多故障实时在线检测。最后通过仿真实验和实际应用验证本文方法的有效性。%Due to the fact that the CCBII brake system is characterized by multiple operation modes,complex working environments and mutiple number of components with strong coupling,multiple faults may often hap-pen simultaneously.It is difficult to carry out multiple faults diagnosis for the CCBII brake system using the traditional fault diagnosis techniques.In this paper,the differential evolution algorithm was introduced into the diagnosis technique based on the analytical redundancy relations to implement multiple faults detection and lo-cation.Firstly,the models of working modes were established and the augmented global analytical redundancy relations(AGARRs)for the system were deduced to obtain the mode-change signature matrix and fault signa-ture matrix.Mode tracking was done by comparing the two signature matrixes with coherence vectors.Once mode tracking failed,the candidate fault assumption sets were established correspondingly.Furthermore,fault parameter estimators were designed on the basis of the differential evolution algorithm.Multiple faults were i-dentified among the hypothesis sets by calculating the

  4. Design of brake pedal displacement measuring system based on Hall sensor%基于霍尔传感器的制动踏板行程测量系统设计

    Institute of Scientific and Technical Information of China (English)

    刘东辉; 吴初娜

    2012-01-01

    To solve the requirements of collecting the brake pedal displacement data in the driving simulator and locate the brake pedal position accurately,a brake pedal displacement measuring system which consists of two Hall sensors,seven small magnets,one SCM control system was presented,its working principle and realizing method were introduced.The Hall effect principle was used to locate the brake pedal position.The pulse signal was detected and output by Hall sensors,and was sent to the SCM control system after phase reverse and demodulation.The SCM calculated the brake pedal displacement based on the pulse signal.The result proves that the measurement error of the system is less than ±3%,and the measuring performance is stable.It also has the advantages of small dimension and low cost.It can fulfill the requiring of measuring the brake pedal displacement.9 figs,6 refs.%为了解决驾驶模拟器中对制动踏板行程的数据采集需求,使其能精确判断出制动踏板所处的位置,设计了一种由2个霍尔传感器、7个小磁块和1个单片机控制系统组成的制动踏板行程测量系统,并介绍了其原理与实现方法。采用霍尔效应原理来测量制动踏板的行程,通过霍尔传感器感应到磁块后输出脉冲信号,将脉冲信号进行反向和相位解调处理后输入单片机控制系统;单片机控制系统根据脉冲信号计算得到制动踏板行程。结果表明,该测量系统的测量误差小于等于±3%,测量性能稳定,且具有体积小、成本低等优点,可以满足对制动踏板行程进行测量的需要。

  5. In-Space Repair and Refurbishment of Thermal Protection System Structures for Reusable Launch Vehicles

    Science.gov (United States)

    Singh, M.

    2007-01-01

    Advanced repair and refurbishment technologies are critically needed for the thermal protection system of current space transportation systems as well as for future launch and crew return vehicles. There is a history of damage to these systems from impact during ground handling or ice during launch. In addition, there exists the potential for in-orbit damage from micrometeoroid and orbital debris impact as well as different factors (weather, launch acoustics, shearing, etc.) during launch and re-entry. The GRC developed GRABER (Glenn Refractory Adhesive for Bonding and Exterior Repair) material has shown multiuse capability for repair of small cracks and damage in reinforced carbon-carbon (RCC) material. The concept consists of preparing an adhesive paste of desired ceramic with appropriate additives and then applying the paste to the damaged/cracked area of the RCC composites with an adhesive delivery system. The adhesive paste cures at 100-120 C and transforms into a high temperature ceramic during reentry conditions. A number of plasma torch and ArcJet tests were carried out to evaluate the crack repair capability of GRABER materials for Reinforced Carbon-Carbon (RCC) composites. For the large area repair applications, Integrated Systems for Tile and Leading Edge Repair (InSTALER) have been developed and evaluated under various ArcJet testing conditions. In this presentation, performance of the repair materials as applied to RCC is discussed. Additionally, critical in-space repair needs and technical challenges are reviewed.

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

    Directory of Open Access Journals (Sweden)

    Dong-Chan Lee

    2015-11-01

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

  7. 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

  8. Recovering system of swing braking energy in hydraulic excavator%液压挖掘机回转制动能量回收系统

    Institute of Scientific and Technical Information of China (English)

    管成; 徐晓; 林潇; 王守洪

    2012-01-01

    为了回收液压挖掘机在回转阶段的制动能量,提出一种基于回转马达进/出口压力差自动识别回转过程所处阶段,决策能量回收的全液压自动控制回转制动能量回收系统.引入一正态分布函数,以蓄能器压力状态(SOP)、液压泵出口压力以及负流量反馈压力为输入信号,根据负载的实时需求功率,提出一种以复合恒功率-负流量动力控制决策发动机和蓄能器主辅动力源的能量分配方法,保证回转机构的正常高效运转.仿真结果表明,当回转系统作为单独执行机构时,采用该回收系统的液压挖掘机,能够实现高达50.0%的再生制动能量用于驱动回转的能量回收利用效率,在相同工况下比同吨位液压挖掘机节能16.3%,不影响操作习惯和操作性能.%In order to recover the braking energy from the hydraulic excavator during swing phase,an automatic hydraulic-controlled braking energy recovery system was proposed which can automatically identify the swing stage by the pressure difference between inlet and outlet of the swing pump and determining distribution algorithm of the recovering energy. One normal school function was introduced. State of pressure (SOP) of the accumulator, the outlet pressure of the hydraulic pump and the feedback pressure from negative-flow control were considered as input signals. According to the real-time required power of the load, the energy distribution algorithm was proposed based on the comprehensive constant-power negative-flow control between the main power source and the auxiliary power source (that is engine and accumulator) , which ensures the normal operation of the swing mechanism. Simulation results show that the hydraulic excavator equipped with the swing recovery system can achieve 16. 3% energy saving compared with the baseline under the same working condition, and the overall chain efficiency from the total braking energy to the terminal swing mechanism is as

  9. THE OPTIMAL SYSTEM FOR SERIES SYSTEMS WITH WARM STANDBY COMPONENTS AND A REPAIRABLE SERVICE STATION

    Directory of Open Access Journals (Sweden)

    M. Salah EL-Sherbeny

    2009-01-01

    Full Text Available This paper deals with the reliability and availability characteristics of three different series system configurations with warm standby components and a repairable service station. The failure time of the primary and warm standby are assumed to be exponentially distributed with parameters and respectively. The repair time distribution of each server is also exponentially distributed with parameter . The breakdown time and the repair time of the service station are also assumed exponentially distributed with parameters and respectively. We derive the reliability dependent on time, availability dependent on time, the mean time to failure, , and the steady-state availability for three configurations and perform comparisons. Comparisons are made for specific values of distribution parameters and of the cost of the components. The three configurations are ranked based on: , and where is either or .

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

    Directory of Open Access Journals (Sweden)

    R. Jegadeeshwaran

    2015-03-01

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

  11. A modelling study of drying shrinkage damage in concrete repair systems

    NARCIS (Netherlands)

    Lukovic, M.; Savija, B.; Schlangen, E.; Ye, G.; van Breugel, K.

    2014-01-01

    Differential shrinkage between repair material and concrete substrate is considered to be the main cause of premature failure of repair systems (Martinola, Sadouki et al. 2001, Beushausen and Alexander 2007). Magnitude of induced stresses depends on many factors, for example the amount of restraint,

  12. Design of Energy Recovery Strategy and Simulation Analysis of Rotary Drill Hydraulic Braking System%牙轮钻机静液压制动系统仿真分析及能量回收方案设计

    Institute of Scientific and Technical Information of China (English)

    齐九龙; 张志壮; 赵静一; 王智勇; 唱荣蕾

    2016-01-01

    Hydraulic braking is used on rotary drill, to avoid the impact on the pump caused by the system pressure fluctuations is necessary, and the kinetic or potential energy can be recycled for use of the rotary drill when braking.Through the calculation and simulation analysis of the hydraulic braking system, the pressure relief valve of parameters of the closed pump was adjusted, and the system pressure impact was reduced.Energy recovery strategy of the braking system was proposed, and the mathematical model was es-tablished and the energy recovery system was simulation analyzed.The relationship of the pressure increasing of the accumulator gas chamber along with time was obtained, and the relationship between the size of the throttle opening and the braking time was revealed. The efficiency of energy recovery braking system was calculated.The correctness of the using of hydraulic braking system on rotary drill and the feasibility of energy recovery strategy are verified.Energy recovery is implemented which tranforms the kinetic or potential ener-gy of the rotary drill to pressure energy of the accumulator, and a reference for energy recovery braking system on large vehicle is pro-vided.%牙轮钻机采用静液压制动,需要避免系统压力波动对泵产生的冲击,同时钻机的动能或者势能可以回收再利用。通过对静液压制动系统的计算与仿真分析,对闭式泵高压溢流阀参数进行调整,减小系统压力冲击;提出了制动系统能量回收方案,并对能量回收系统进行了数学建模与仿真分析,获得了蓄能器气腔压力随时间的增长关系,揭示了节流阀开度大小与制动时间的关系;对制动系统能量回收效率进行了计算。证明了牙轮钻机采用静液压制动系统的正确性以及能量回收方案的可行性,实现了将钻机动能或者势能转换为蓄能器压力能的能量回收,为大型车辆制动系统能量回收提供了参考。

  13. Investigation of aerodynamic braking devices for wind turbine applications

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

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

    Science.gov (United States)

    Lv, Chen; Zhang, Junzhi; Li, Yutong

    2014-11-01

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

  15. 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.

  16. Shear Bond Strength of Repair Systems to New CAD/CAM Restorative Materials.

    Science.gov (United States)

    Üstün, Özlem; Büyükhatipoğlu, Işıl Keçik; Seçilmiş, Aslı

    2016-11-23

    To evaluate the bond strength of repair systems (Ceramic Repair, Clearfil Repair) to computer-aided design/computer-assisted machining (CAD/CAM) restorative materials (IPS e.max CAD, Vita Suprinity, Vita Enamic, Lava Ultimate). Thermally aged CAD/CAM restorative material specimens (5000 cycles between 5°C and 55°C) were randomly divided into two groups according to the repair system: Ceramic Repair (37% phosphoric acid + Monobond-S + Heliobond + Tetric N Ceram) or Clearfil Repair (40% phosphoric acid + mixture of Clearfil Porcelain Bond Activator and Clearfil SE Bond Primer + Clearfil SE Bond + Filtek Z250). The resin composite was light-cured on conditioned specimens. All specimens were stored in distilled water at 37°C for 24 hours and then additionally aged for 5000 thermal cycles. The shear bond strength test was performed using a universal testing machine (0.5 mm/min). Two-way ANOVA was used to detect significance differences according to the CAD/CAM material and composite repair system factors. Subgroup analyses were conducted using the least significant difference post-hoc test. The results of two-way ANOVA indicated that bond strength values varied according to the restorative materials (p CAD/CAM restorative materials (p > 0.05), except in the Vita Suprinity group (p < 0.05). Moreover, no differences were observed between the repair systems. Both the Clearfil and Ceramic repair systems used in the study allow for successful repairs. © 2016 by the American College of Prosthodontists.

  17. Characteristic Analysis and Control of a Hybrid Excitation Linear Eddy Current Brake

    Directory of Open Access Journals (Sweden)

    Baoquan Kou

    2015-07-01

    Full Text Available In this paper, a novel hybrid excitation linear eddy current brake is presented as a braking system for high-speed road and rail vehicles. The presence of the permanent magnets (PMs, whose flux lines in the primary core are oppositely directed with respect to the flux lines by the excitation windings, has the effect of mitigating the saturation of the iron in the teeth of the primary core. This allows the brake to be fed with more intense currents, improving the braking force. First, using the magnetic equivalent circuit method and the layer theory approach, the analytical model of the hybrid excitation linear eddy current brake was developed, which can account for the saturation effects occurring in the iron parts. The saturation effects make the design and control of eddy current brakes more difficult. Second, the relationship between the braking force characteristics and the design parameters were analyzed to provide useful information to the designers of eddy current brakes. Then, the controller of the hybrid excitation linear eddy current brake was designed to control the amplitude of the braking force. Finally, experimental measurements were conducted to verify the validity of the theoretical analysis.

  18. 纯电动汽车电液复合制动系统联合仿真%Co-simulation Study of Electro-hydraulic Compound Brake System of Electric Vehicle

    Institute of Scientific and Technical Information of China (English)

    王晖; 陈燎; 盘朝奉

    2014-01-01

    The study described the braking energy recovery system principle and structure. And then, according to the stroke simulator,high-pressure accumulator and hydraulic principles were established AMEsim based model,simulink-based vehicle dynamics model to establish a vehicle,motor,super capacitors and DC / DC converter models. The joint simulation of AMEsim-Simulink model was estab-lished based on all the above established model. In the vehicle initial condition of 36 km/ h,the brake pedal force size 30 N(small strength brake),50 N(small and medium strength brake)was simula-ted,and the simulation results were analyzed. In city conditions(low intensity brake),brake energy recovery rate was about 40% ,and the results showed the recovery effect is better.%介绍了制动能量回收系统的原理和结构,然后根据行程模拟器、高压蓄能器和液压泵的原理分别建立了以上部件基于 AMEsim 的模型,并应用 Simulink 建立了车辆整车动力学模型和电机、超级电容、DC / DC 变换器模型。以此为基础建立了 AMEsim-Simulink 联合仿真模型。在车辆初始行驶速度为36 km/ h 的工况下,分别选取制动踏板力为30 N(小强度制动)和50 N (中小强度制动)进行仿真,并对仿真结果进行了分析。结果表明:在城市工况下(小强度制动),制动能量回收率在40%左右,回收效果较好。

  19. Improvement of Wheeled Excavator JYL621E's Travelling and Braking System%JYL621E型轮式挖掘机行走制动系统改进

    Institute of Scientific and Technical Information of China (English)

    张建; 邹俊辉

    2013-01-01

    该文针对公司产品JYL621E在试验中出现的坡道不能起步和制动缓慢的问题,通过对JYL621E行走制动伺服控制系统进行分析,找出问题症结所在,并提出合理改进意见,经试验证明改进措施有效,问题得以解决,提高了主机的安全性能,进一步完善了产品.%This paper aimed at the problems of JYL621E appeared in test including can't start in ramp and brake slow,found out the reasons through analysis about its travelling and braking servo control system,gave reasonable suggestions proved effective for improvement,improved the safety performance of the product.

  20. Plasma Braking Due to External Magnetic Perturbations

    Science.gov (United States)

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

    2010-11-01

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

  1. Simulation research of the auto anti-lock braking system based on simulink%基于simulink的汽车防抱死制动系统的仿真研究

    Institute of Scientific and Technical Information of China (English)

    李少廷; 徐家川

    2016-01-01

    在 simulink环境下对汽车防抱死制动系统进行数学建模,采用基于车轮加、减速度门限值及参考滑移率的控制策略,控制器以车轮的角加、减速度和滑移率的大小为输入,根据输入值的大小控制器输出相应的信号给制动模型,进而对轮速和滑移率进行调节,使其在理想范围内。对汽车ABS模型进行仿真研究,通过得出的仿真曲线,验证了 ABS 制动系统拥有良好的制动性和操纵性。%Mathematical modeling to the automotive anti-look braking system was built based on simulink.It adopted the wheel add,substract speed threshold method and referenced slip ratio control strategy.The size of the wheel angular velocity and slip ratio study were input into the controler,the corresponding signal was output to the model of the brake based on the size of the input value to adj ust the wheel speed and slip ratio.Simulation was carried out on the automobile ABS model and simulation curve was obtained.The results confirmed that the ABS braking sys-tem has good brake and maneuverability.

  2. Simulation and analysis of electric vehicle regenerative braking system with multiplex power supply%复合电源电动车再生制动系统的仿真与分析

    Institute of Scientific and Technical Information of China (English)

    戚思良; 盘朝奉; 陈昆山; 陈龙; 马跃超

    2013-01-01

    针对以蓄电池为单一车载电源的纯电动汽车存在着功率密度低、能量密度低、使用寿命短等缺点,将超级电容引入到纯电动汽车的储能系统中,组成了超级电容—蓄电池的复合电源结构.在MATLAB/SIMULINK环境下建立复合电源储能系统和驱动系统的仿真模型.基于搭建的实验平台参数,以可能多地利用电机再生制动力、最大程度实现制动能量的回收为目的制定制动力分配控制策略,根据标准市区循环工况进行再生制动仿真实验.结果表明,此再生制动系统回收了24%的制动能量,可以很好地弥补了蓄电池的低功率密度和低能量密度等缺陷,提高车载能量的利用率和车辆的动力性能,延长电动车的续驶里程.%Because storage battery used for driving the electric vehicle only has low power density, low energy density and other disadvantages, supercapacitor was applied to the energy storage system in battery electric vehicle to form a multiple energy supply system with battery. The multiple energy supply system model and driving system model were established via simulation environment of MATLAB/SIMULINK. In order to use more motor regenerative braking force and maximize braking energy recovery module, the braking force distribution control strategy was developed based on experiment platform parameter. The regenerative simulation test was conducted according to the power demands under standard urban driving cycle. The result shows that the regenerative braking system can recycled 24% braking energy. The multiple energy supply system can make up for the low power density, low energy density and other defects of car battery very well. It can improve the energy utilization ratio and the dynamic performance of the vehicle, and extend the driving range of electric cars.

  3. Infrared characterization of thermal gradients on disc brakes

    Science.gov (United States)

    Panier, Stephane; Dufrenoy, Philippe; Bremond, Pierre

    2003-04-01

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

  4. Extravehicular Activity Probabilistic Risk Assessment Overview for Thermal Protection System Repair on the Hubble Space Telescope Servicing Mission

    Science.gov (United States)

    Bigler, Mark; Canga, Michael A.; Duncan, Gary

    2010-01-01

    The Shuttle Program initiated an Extravehicular Activity (EVA) Probabilistic Risk Assessment (PRA) to assess the risks associated with performing a Shuttle Thermal Protection System (TPS) repair during the Space Transportation System (STS)-125 Hubble repair mission as part of risk trades between TPS repair and crew rescue.

  5. Modeling the induced mutation process in bacterial cells with defects in excision repair system

    Science.gov (United States)

    Bugay, A. N.; Vasilyeva, M. A.; Krasavin, E. A.; Parkhomenko, A. Yu.

    2015-12-01

    A mathematical model of the UV-induced mutation process in Escherichia coli cells with defects in the uvrA and polA genes has been developed. The model describes in detail the reaction kinetics for the excision repair system. The number of mismatches as a result of translesion synthesis is calculated for both wild-type and mutant cells. The effect of temporal modulation of the number of single-stranded DNA during postreplication repair has been predicted. A comparison of effectiveness of different repair systems has been conducted.

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  7. 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.

  8. On-Orbit Health Monitoring and Repair Assessment of Thermal Protection Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project delivers On-orbit health MoNItoring and repair assessment of THERMal protection systems (OMNI_THERM). OMNI_THERM features impedance-based...

  9. Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage

    NARCIS (Netherlands)

    Rutgers, M.; van Pelt, M.J.; Dhert, W.J.A.; Creemers, L.B.; Saris, D.B.F.

    2010-01-01

    Osteoarthritis and Cartilage Volume 18, Issue 1, January 2010, Pages 12-23 -------------------------------------------------------------------------------- Review Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage M. Rutgers†, M.J.P. van Pelt†, W.

  10. Current state in tracking and robotic navigation systems for application in endovascular aortic aneurysm repair

    NARCIS (Netherlands)

    De Ruiter, Quirina M B; Moll, Frans L.; Van Herwaarden, Joost A.

    2015-01-01

    Objective This study reviewed the current developments in manual tracking and robotic navigation technologies for application in endovascular aortic aneurysm repair (EVAR). Methods EMBASE and MEDLINE databases were searched for studies reporting manual tracking or robotic navigation systems that are

  11. Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage

    NARCIS (Netherlands)

    Rutgers, M.; van Pelt, M.J.; Dhert, W.J.A.; Creemers, L.B.; Saris, D.B.F.

    2010-01-01

    Osteoarthritis and Cartilage Volume 18, Issue 1, January 2010, Pages 12-23 -------------------------------------------------------------------------------- Review Evaluation of histological scoring systems for tissue-engineered, repaired and osteoarthritic cartilage M. Rutgers†, M.J.P. van Pelt†,

  12. Current state in tracking and robotic navigation systems for application in endovascular aortic aneurysm repair

    NARCIS (Netherlands)

    De Ruiter, Quirina M B; Moll, Frans L.|info:eu-repo/dai/nl/070246882; Van Herwaarden, Joost A.|info:eu-repo/dai/nl/304814733

    2015-01-01

    Objective This study reviewed the current developments in manual tracking and robotic navigation technologies for application in endovascular aortic aneurysm repair (EVAR). Methods EMBASE and MEDLINE databases were searched for studies reporting manual tracking or robotic navigation systems that are

  13. Self-Repairing Flight Control System for Online Health Monitoring and Recovery Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR project, a reliable self-repairing Flight Control System (FCS) will be developed. To achieve this goal, an artificial Neural Network based Sensor...

  14. WELL-POSEDNESS OF THE MODEL DESCRIBING A REPAIRABLE, STANDBY, HUMAN & MACHINE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Geni Gupur

    2003-01-01

    By using the strong continuous semigroup theory of linear operators we prove the existence of a unique positive time-dependent solution of the model describing a repairable, standby, human & machine system.

  15. 液压蓄能式车辆制动能量回收系统的AMESim仿真研究%Simulation Study of Hydraulic Regenerative Braking Energy System of Vehicles by AMESim

    Institute of Scientific and Technical Information of China (English)

    刘天豪; 刘海朝; 祝昌洪

    2011-01-01

    The simulation model of hydraulic recovery braking energy system was built using AMESim. The energy loss and the factors affecting the braking performance were simulated. The simulation results show that in the braking process, energy loss made by vehicle resistance accounts for 16% of the total vehicle kinetic energy which is the main aspect of energy loss; the method to improve the efficiency of energy recovery is to increase the accumulator pre-charge pressure or to decrease the volume of accumulator; there is little influence on the energy recovery efficiency when changing the hydraulic pump/motor displacement, but it has a significant impact on the vehicle's starting and braking time.%建立车辆液压蓄能式制动能量回收装置的AMESim仿真模型,对其工作过程中的能量损耗情况和制动性能的影响因素进行仿真研究.仿真结果表明:能量回收制动过程中,由于车辆行驶阻力造成的损失占车辆总动能的16%,是能量损失的主要方面;提高能量回收效率的办法是提高蓄能器预充气压力或减小蓄能器体积;改变液压泵/马达排量对提高能量回收效率的影响不大,但可显著影响车辆的起动和制动时间.

  16. 基于 LabVIEW 的电动汽车制动能量回收测试系统%Braking Energy Recovery Test System of Electromobile Based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    周全

    2014-01-01

    In this paper, we use the virtual instrument technology to design the test system in upper monitor for the brake ener-gy recovery whit automobile which can realize the test with or without braking energy recovery of electric vehicles , and obtain the test curve on recovery effect.Moreover, it can get the continue driving mileage, the total mileage in braking energy recovery. Therefore, it has certain practical significance.%采用虚拟仪器技术,设计了基于LabVIEW的电动汽车制动能量回收的上位机测试系统,可实现对电动汽车在有、无制动能量回收时进行测试,得到回收效果测试曲线,及制动回收对续驶里程及总里程的估算等功能,具有一定的实际意义。

  17. Research on the On-site Training Exam System of Automotive Braking Machine%机车制动机现场培训考试系统的研究

    Institute of Scientific and Technical Information of China (English)

    张玲

    2015-01-01

    针对目前普遍存在机车司机培养时间短、 经验不足, 对机车操纵的熟练程度及对现象判断的准确性不高的问题, 采用气动技术、 依据流体力学理论, 设计开发了机车制动机现场培训考试系统. 经过在乘务员培训中的应用, 取得明显的效果, 提高了乘务员的制动机操作水平和对列车管判断的准确性.%The on-site training exam system of automotive braking machine was devised and developed with the pneumatic technology on the basis of liquid mechanics theory aimed at the problems such as short time of cultivation for the locomotive drivers, insufficient experience, and unskilled degree of controlling the locomotive, low accuracy to the estimation of the phenomenon. It was applied in the training of steward and achieved distinct effect, enhanced the level for steward to operate braking machine and judge the train braking pipe accurately.

  18. MUTYH and the mismatch repair system: partners in crime?

    NARCIS (Netherlands)

    Niessen, R.C.; Sijmons, R.H.; Ou, J.; Olthof, S.G.; Osinga, J.; Ligtenberg, M.J.L.; Hogervorst, F.B.L.; Weiss, M.M.; Tops, C.M.; Hes, F.J.; Bock, G.H. de; Buys, C.H.C.M.; Kleibeuker, J.H.; Hofstra, R.M.

    2006-01-01

    Biallelic germline mutations of MUTYH-a gene encoding a base excision repair protein-are associated with an increased susceptibility of colorectal cancer. Whether monoallelic MUTYH mutations also increase cancer risk is not yet clear, although there is some evidence suggesting a slight increase of r

  19. MUTYH and the mismatch repair system : partners in crime?

    NARCIS (Netherlands)

    Niessen, RC; Sijmons, RH; Ou, J; Olthof, SGM; Osinga, J; Ligtenberg, MJ; Hogervorst, FBL; Weiss, MM; Tops, CMJ; Hes, FJ; de Bock, GH; Buys, CHCM; Kleibeuker, JH; Hofstra, RMW

    2006-01-01

    Biallelic germline mutations of MUTYH-a gene encoding a base excision repair protein-are associated with an increased susceptibility of colorectal cancer. Whether monoallelic MUTYH mutations also increase cancer risk is not yet clear, although there is some evidence suggesting a slight increase of r

  20. Damage induced by continued corrosion in concrete repair systems

    NARCIS (Netherlands)

    Luckovic, M.; Savija, B.; Schlangen, E.

    2014-01-01

    Corrosion of steel reinforcement is the main cause of deterioration in reinforced concrete structures. After the repair, corrosion of the steel might continue and even accelerate. While the development of the corrosion cell depends on many parameters and is difficult to control, the occurrence of vi

  1. Mesenteric ischemia after abdominal aortic aneurysm repair : a systemic review

    NARCIS (Netherlands)

    Bruggink, J. L. M.; Tielliu, I. F. J.; Zeebregts, C. J.; Pol, R. A.

    2014-01-01

    Mesenteric ischemia after abdominal aneurysm repair is a devastating complication with mortality rates up to 70%. Incidence however is relatively low. The aim of this review was to provide an overview on current insights, diagnostic modalities and on mesenteric ischemia after abdominal aortic aneury

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

    Science.gov (United States)

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

    2012-11-01

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

  3. Application of Interfacial Propagation and Kinking Crack Concept to ECC/Concrete Overlay Repair System

    Directory of Open Access Journals (Sweden)

    Yaw ChiaHwan

    2014-01-01

    Full Text Available Research on the application of ultraductile engineered cementitious composite (ECC as overlay in the repair of deteriorated concrete structures is performed in this paper. Also, interfacial crack kinking and trapping mechanism experimentally observed in ECC/concrete overlay repair system are described by comparison of toughness and energy release rate. The mechanism involves cycles of extension, kinking, and arrest of interfacial crack into the overlay. Experimental testing of overlay repair system reveals significant improvements in load carrying capacity and ductility over conventional concrete overlay. The commonly observed overlay system failure mode of delamination or spalling is eliminated when ECC is applied. These failure modes are suppressed when ECC is used as an ideal and durable candidate overlay repair material.

  4. Non-parametric estimation of the availability in a general repairable system

    Energy Technology Data Exchange (ETDEWEB)

    Gamiz, M.L. [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)], E-mail: mgamiz@ugr.es; Roman, Y. [Departamento de Estadistica e I.O., Facultad de Ciencias, Universidad de Granada, Granada 18071 (Spain)

    2008-08-15

    This work deals with repairable systems with unknown failure and repair time distributions. We focus on the estimation of the instantaneous availability, that is, the probability that the system is functioning at a given time, which we consider as the most significant measure for evaluating the effectiveness of a repairable system. The estimation of the availability function is not, in general, an easy task, i.e., analytical techniques are difficult to apply. We propose a smooth estimation of the availability based on kernel estimator of the cumulative distribution functions (CDF) of the failure and repair times, for which the bandwidth parameters are obtained by bootstrap procedures. The consistency properties of the availability estimator are established by using techniques based on the Laplace transform.

  5. Magnetic Braking Revisited

    CERN Document Server

    Taam, R E

    2003-01-01

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

  6. Squeal analysis of ventilated disc brake using ansys

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  7. Squeal analysis of ventilated disc brake using ansys

    Directory of Open Access Journals (Sweden)

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

    2012-01-01

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

  8. Analysis of brake condition and parameter matching of hybrid energy storage system for hybrid electric vehicles%混合动力车制动工况分析与储能装置参数匹配

    Institute of Scientific and Technical Information of China (English)

    王伟达; 王言子; 项昌乐; 刘辉

    2014-01-01

    为提高混合动力系统整体性能,实现高效能量回收,分析某重型越野车辆驾驶循环工况中制动过程的功率与能量分布,从制动能量回收率与电机参数出发讨论对储能装置的性能要求。提出电池组-超级电容复合储能装置的参数匹配方法,针对21 t级试验样车混合动力系统进行实例计算,论证锂离子电池组与超级电容组成的复合储能装置的性能。实例计算与道路试验结果表明:匹配的复合储能装置符合车辆整体性能与制动能量回收的要求,体积、重量满足总体设计约束;匹配超级电容后,储能装置的瞬时功率能力大幅提升,可显著提高车辆的制动能力和制动能量回收率。%According to the driving cycle of heavy off-road vehicles, the brake power and energy permutation is analyzed, and the performance requirement for the hybrid energy storage system( HESS) is achieved based on the brake energy recovery rate and motor parameters. The parameter matching method for the HESS is proposed and by which the instance calculation for the hybrid propulsion system of 21 tons class vehicles is carried out, and the performance of the HESS with Li-ion cells and ultra capacitors is discussed too. The instance calculation and the test results indicate that the designed HESS can meet the requirement of the total performance of the HEV and the brake energy recovery, the volume and weight answer for the restriction of the top design of the HEV. The designed HESS with ultra capacitors can increase the transient power volume greatly and the brake performance and the brake energy recovery rate are enhanced remarkably.

  9. In Vitro Comparison of the Bond Strength between Ceramic Repair Systems and Ceramic Materials and Evaluation of the Wettability.

    Science.gov (United States)

    Kocaağaoğlu, Hasan; Manav, Taha; Albayrak, Haydar

    2017-04-01

    When fracture of an all-ceramic restoration occurs, it can be necessary to repair without removing the restoration. Although there are many studies about the repair of metal-ceramic restorations, there are few about all-ceramic restorations. The aim of this study was to evaluate the shear bond strength between ceramic repair systems and esthetic core materials and to evaluate the wettability of all-ceramic core materials. Disk-like specimens (N = 90) made of three dental ceramic infrastructure materials (zirconia ceramic, alumina ceramic, glass ceramic) were polished with silicon carbide paper, prepared for bonding (abrasion with 30 μm diamond rotary cutting instrument). Thirty specimens of each infrastructure were obtained. Each infrastructure group was divided into three subgroups; they were bonded using 3 repair systems: Bisco Intraoral Repair Kit, Cimara & Cimara Zircon Repair System, and Clearfil Repair System. After 1200 thermocycles, shear bond strength was measured in a universal testing machine at a 0.5 mm/min crosshead speed. In addition, the contact angle values of the infrastructures after surface treatments were examined for wettability. Data were analyzed by using ANOVA and Tukey post hoc tests. Although there were no significant differences among the repair systems (p > 0.05) in the glass ceramic and zirconia groups, a significant difference was found among the repair systems in alumina infrastructure (p 0.05); however, a statistically significant difference was found among the repair systems (p < 0.05). No difference was found among the infrastructures and repair systems in terms of contact angle values. Cimara & Cimara Zircon Repair System had higher bond strength values than the other repair systems. Although no difference was found among the infrastructures and repair systems, contact wettability angle was decreased by surface treatments compared with polished surfaces. © 2015 by the American College of Prosthodontists.

  10. The reliability assessment of the electromagnetic valve of high-speed electric multiple units braking system based on two-parameter exponential distribution

    Directory of Open Access Journals (Sweden)

    Jianwei Yang

    2016-06-01

    Full Text Available In order to solve the reliability assessment of braking system component of high-speed electric multiple units, this article, based on two-parameter exponential distribution, provides the maximum likelihood estimation and Bayes estimation under a type-I life test. First of all, we evaluate the failure probability value according to the classical estimation method and then obtain the maximum likelihood estimation of parameters of two-parameter exponential distribution by performing and using the modified likelihood function. On the other hand, based on Bayesian theory, this article also selects the beta and gamma distributions as the prior distribution, combines with the modified maximum likelihood function, and innovatively applies a Markov chain Monte Carlo algorithm to parameters assessment based on Bayes estimation method for two-parameter exponential distribution, so that two reliability mathematical models of the electromagnetic valve are obtained. Finally, through type-I life test, the failure rates according to maximum likelihood estimation and Bayes estimation method based on Markov chain Monte Carlo algorithm are, respectively, 2.650 × 10−5 and 3.037 × 10−5. Compared with the failure rate of a electromagnetic valve 3.005 × 10−5, it proves that the Bayes method can use a Markov chain Monte Carlo algorithm to estimate reliability for two-parameter exponential distribution and Bayes estimation is more closer to the value of electromagnetic valve. So, by fully integrating multi-source, Bayes estimation method can preferably modify and precisely estimate the parameters, which can provide a certain theoretical basis for the safety operation of high-speed electric multiple units.

  11. Stability Control of Vehicle Emergency Braking with Tire Blowout

    Directory of Open Access Journals (Sweden)

    Qingzhang Chen

    2014-01-01

    Full Text Available For the stability control and slowing down the vehicle to a safe speed after tire failure, an emergency automatic braking system with independent intellectual property is developed. After the system has received a signal of tire blowout, the automatic braking mode of the vehicle is determined according to the position of the failure tire and the motion state of vehicle, and a control strategy for resisting tire blowout additional yaw torque and deceleration is designed to slow down vehicle to a safe speed in an expected trajectory. The simulating test system is also designed, and the testing results show that the vehicle can be quickly stabilized and kept in the original track after tire blowout with the emergency braking system described in the paper.

  12. Thermal Modeling of Disc Brake Rotor in Frictional Contact

    Science.gov (United States)

    Ali, Belhocine; Ghazaly, Nouby Mahdi

    2013-01-01

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

  13. Theoretical and experimental study of magneto-rheological fluid disc brake

    Directory of Open Access Journals (Sweden)

    E.M. Attia

    2017-06-01

    The fluid is inserted between the rotating and fixed discs and a magnetic field is imposed on the fluid. In this paper, a complete test rig for an MR fluid disc brake is introduced. Experiments are conducted to measure the braking torque and speed of shaft during braking process and the results are presented at different voltage input to the brake. Also theoretical analysis for both MR brake and the mechanical system is developed and is solved numerically using finite difference method and Matlab software. Effect of current input to the MR brake, viscosity of fluid and design parameters is taken into consideration. A validation of the theoretical results with CFD model is introduced. The experimental results are performed and both angular velocity and the braking torque are obtained as responses during the braking process. A comparison between braking torques obtained from theoretical and experimental work shows agreement when voltage is 2 V at speed of 150 rpm and also agreement when voltage is 2 and 3 V at speed of 250 rpm.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-01

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

  15. Stochastic behavior of a cold standby system with maximum repair time

    Directory of Open Access Journals (Sweden)

    Ashish Kumar

    2015-09-01

    Full Text Available The main aim of the present paper is to analyze the stochastic behavior of a cold standby system with concept of preventive maintenance, priority and maximum repair time. For this purpose, a stochastic model is developed in which initially one unit is operative and other is kept as cold standby. There is a single server who visits the system immediately as and when required. The server takes the unit under preventive maintenance after a maximum operation time at normal mode if one standby unit is available for operation. If the repair of the failed unit is not possible up to a maximum repair time, failed unit is replaced by new one. The failure time, maximum operation time and maximum repair time distributions of the unit are considered as exponentially distributed while repair and maintenance time distributions are considered as arbitrary. All random variables are statistically independent and repairs are perfect. Various measures of system effectiveness are obtained by using the technique of semi-Markov process and RPT. To highlight the importance of the study numerical results are also obtained for MTSF, availability and profit function.

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

    Institute of Scientific and Technical Information of China (English)

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

    2013-01-01

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

  17. Magnetic braking in ultracompact binaries

    CERN Document Server

    Farmer, Alison

    2010-01-01

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

  18. Development of structural health monitoring systems for composite bonded repairs on aircraft structures

    Science.gov (United States)

    Galea, Stephen C.; Powlesland, Ian G.; Moss, Scott D.; Konak, Michael J.; van der Velden, Stephen P.; Stade, Bryan; Baker, Alan A.

    2001-08-01

    The application of bonded composite patches to repair or reinforce defective metallic structures is becoming recognized as a very effective versatile repair procedure for many types of problems. Immediate applications of bonded patches are in the fields of repair of cracking, localized reinforcement after removal of corrosion damage and for reduction of fatigue strain. However, bonded repairs to critical components are generally limited due to certification concerns. For certification and management of repairs to critical structure, the Smart Patch approach may be an acceptable solution from the airworthiness prospective and be cost effective for the operator and may even allow some relaxation of the certification requirements. In the most basic form of the Smart Patch in-situ sensors can be used as the nerve system to monitor in service the structural condition (health or well-being) of the patch system and the status of the remaining damage in the parent structure. This application would also allow the operator to move away from current costly time-based maintenance procedures toward real-time health condition monitoring of the bonded repair and the repaired structure. TO this end a stand-alone data logger device, for the real-time health monitoring of bonded repaired systems, which is in close proximity to sensors on a repair is being developed. The instrumentation will measure, process and store sensor measurements during flight and then allow this data to be up-loaded, after the flight, onto a PC, via remote (wireless) data access. This paper describes two in-situ health monitoring systems which will be used on a composite bonded patch applied to an F/A-18. The two systems being developed consists of a piezoelectric (PVDF) film-based and a conventional electrical-resistance foil strain gauge-based sensing system. The latter system uses a primary cell (Lithium- based battery) as the power source, which should enable an operating life of 1-2 years. The patch

  19. 30 CFR 56.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

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

  20. Braking performance of aircraft tires

    Science.gov (United States)

    Agrawal, Satish K.

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

  1. Mountain Braking Test Venue Study

    Science.gov (United States)

    2013-12-12

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

  2. Lubrication System. Introduction: Things for You to Know. Student Manual. Small Engine Repair Series. First Edition.

    Science.gov (United States)

    Hill, Pamela

    This student manual introducing the lubrication system is the first of three in an instructional package on the lubrication system in the Small Engine Repair Series for handicapped students. The stated purpose of the booklet is to help students learn about the lubrication system and safe and good work habits. Informative material and diagrams are…

  3. Parameter Interval Estimation of System Reliability for Repairable Multistate Series-Parallel System with Fuzzy Data

    Science.gov (United States)

    2014-01-01

    The purpose of this paper is to create an interval estimation of the fuzzy system reliability for the repairable multistate series–parallel system (RMSS). Two-sided fuzzy confidence interval for the fuzzy system reliability is constructed. The performance of fuzzy confidence interval is considered based on the coverage probability and the expected length. In order to obtain the fuzzy system reliability, the fuzzy sets theory is applied to the system reliability problem when dealing with uncertainties in the RMSS. The fuzzy number with a triangular membership function is used for constructing the fuzzy failure rate and the fuzzy repair rate in the fuzzy reliability for the RMSS. The result shows that the good interval estimator for the fuzzy confidence interval is the obtained coverage probabilities the expected confidence coefficient with the narrowest expected length. The model presented herein is an effective estimation method when the sample size is n ≥ 100. In addition, the optimal α-cut for the narrowest lower expected length and the narrowest upper expected length are considered. PMID:24987728

  4. 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.)

  5. ALLOCATING REPAIRABLE SYSTEM'S RELIABILITY SUBJECT TO MINIMAL TOTAL COST - AN INTEGER PROGRAMMING APPROACH

    Institute of Scientific and Technical Information of China (English)

    Ahmad A. Moreb

    2007-01-01

    Reliability allocation problem is commonly treated using a closed-form expression relating the cost to reliability. A recent approach has introduced the use of discrete integer technique for un-repairable systems. This research addresses the allocation problem for repairable systems. It presents an integer formulation for finding the optimum selection of components based on the integer values of their Mean Time to Failure (MTTF) and Mean Time to Repair (MTTR). The objective is to minimize the total cost under a system reliability constraint, in addition to other physical constraints. Although, a closed-form expression relating the cost to reliability may not be a linear; however, in this research, the objective function will always be linear regardless of the shape of the equivalent continuous closed-form function. An example is solved using the proposed method and compared with the solution of the continuous closed-form version. The formulation for all possible system configurations, components and subsystems are also considered.

  6. Analysis to Regenerative Braking System Based on Maximum Energy Recuperation%基于最大化能量回收策略的再生制动系统分析

    Institute of Scientific and Technical Information of China (English)

    李岩; 张伟

    2012-01-01

    The author elaborates the basic principle of regenerative breaking, the hydraulic braking decoupling principle and the control strategy to realize maximum energy recovery through the typical regenerative breaking system.%阐述再生制动的基本原理;通过典型的再生制动系统结构,说明再生制动与液压制动解耦原理.以及实现最大化能量回收的控制策略。

  7. Inducible SOS Response System of DNA Repair and Mutagenesis in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Celina Janion

    2008-01-01

    Full Text Available Chromosomal DNA is exposed to continuous damage and repair. Cells contain a number of proteins and specific DNA repair systems that help maintain its correct structure. The SOS response was the first DNA repair system described in Escherichia coli induced upon treatment of bacteria with DNA damaging agents arrest DNA replication and cell division. Induction of the SOS response involves more than forty independent SOS genes, most of which encode proteins engaged in protection, repair, replication, mutagenesis and metabolism of DNA. Under normal growth conditions the SOS genes are expressed at a basal level, which increases distinctly upon induction of the SOS response. The SOS-response has been found in many bacterial species (e.g., Salmonella typhimurium, Caulobacter crescentus, Mycobacterium tuberculosis, but not in eukaryotic cells. However, species from all kingdoms contain some SOS-like proteins taking part in DNA repair that exhibit amino acid homology and enzymatic activities related to those found in E. coli. but are not organized in an SOS system. This paper presents a brief up-to-date review describing the discovery of the SOS system, the physiology of SOS induction, methods for its determination, and the role of some SOS-induced genes.

  8. 纯电动汽车电—液复合制动系统控制算法的多边界条件优化设计%Optimization Design of EV Electro—Hydraulic Composite Braking System Control Algorithm with Multi—boundary Conditions

    Institute of Scientific and Technical Information of China (English)

    李玉芳; 周丽丽

    2012-01-01

    According to the characteristics of pure EV power system, an optimization design method of brake force control algorithm of electro-hydraulic composite brake system with multi - boundary conditions was proposed. And based on the analysis of boundary conditions, including the braking strength requirements, ECE regulations, and motor/battery characteristics etc, a reasonable range of brake force distribution ratio was achieved. And braking force distribution approach between the front and rear axles was brought out by considering such factors as the braking strength of demand and using frequency of the various adhesion coefficient roads. And the simulation analysis verifies the rationality and effectiveness of the brake force distribution algorithm.%根据纯电动汽车动力系统的特点,提出电—液复合制动系统控制算法的多边界条件优化设计方法.基于对制动强度需求、ECE法规和电机/蓄电池特性等多边界条件的分析,得出制动力分配比例的合理取值范围,以此为基础,提出根据制动强度需求和不同附着系数路面的使用频率等因素确定前后轴制动力分配系数的方法.仿真分析验证了制动力分配算法的有效性和合理性.

  9. Composite Energy Storage Control System Application on the Rig Braking Energy Recovery%复合储能控制系统在钻机制动能量回收中的应用

    Institute of Scientific and Technical Information of China (English)

    董兴华; 栾苏; 魏培静; 李洪波; 刘晶晶; 乌买尔·达吾提

    2016-01-01

    石油钻机在工作过程中由于制动能量无法回收利用,造成了能量的巨大浪费。采用储能单元可以在电机制动时回收能量,在电机负载增加时作为辅助动力源进行电能补充。然而,这类设备的储能单元易损坏、整体采购成本高,不利于在石油钻井行业推广应用。鉴于此,对钻机原有电控系统进行扩展,加入控制单元和储能单元,提出制动能量回收利用方案和复合储能单元的改良设计,并设计了该系统的控制策略、保护策略和储能单元的模糊控制。通过实际应用证明该系统可以改善电能的质量和降低生产成本,对制动能量的有效回收利用效果明显。最后指出该复合储能控制系统在石油钻井行业的应用前景十分广阔。%The unrecoverable braking energy of oil rig during operation often results in huge waste of energy. The energy storage unit can recover the energy during braking and supply as an auxiliary power source when the mo⁃tor load increases. However, the energy storage units are easily damaged and the overall procurement costs are high, which makes it not preferable to promote application in the oil drilling industry. In view of this, the original rig electric control system can be extended to integrate the control unit and the storage unit. The braking energy re⁃covery program and a modified design of composite energy storage unit have been proposed. The system’s control strategy, protection strategy and the energy storage unit fuzzy control have been designed. The practical application shows that the system can improve the quality of electricity and reduce production costs, presenting efficient recov⁃ery of braking energy. The developed composite energy storage control system has a broad application prospects in the oil drilling industry.

  10. 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.

  11. Effect of surface roughness and adhesive system on repair potential of silorane-based resin composite

    Directory of Open Access Journals (Sweden)

    Enas H. Mobarak

    2012-07-01

    Full Text Available This study was performed to evaluate the influence of surface roughness and adhesive system on the repair strength of silorane-based resin composite. Twenty-four substrate discs from silorane-based FiltekP90 were made and stored for 24 h. Half of the discs were roughened against 320 grit SiC paper while the other half was polished against 4000 grit SiC paper. All discs were etched with phosphoric acid. Repair resin composite, FiltekP90 or FiltekZ250, was bonded to the treated surfaces using their corresponding adhesive; P90 System Adhesive (SA or Adper Scotchbond Multipurpose (SBMP ending up with four repair groups. The groups were as follows: G1: Smooth + SA + FiltekP90; G2: Roughened + SA + FiltekP90; G3: Smooth + SBMP + FiltekZ250; G4: Roughened + SBMP + FiltekZ250. Additional six unrepaired discs from each resin composite (G5 and G6 were prepared to test the cohesive strength. After 24 h, discs (n = 6/group were serially sectioned to obtain sticks (n = 30/group for microtensile bond strength (μTBS testing. Scanning electron microscopic (SEM evaluation of substrates that received different treatments as well as representative substrate-repair sticks from each group were performed. Modes of failure were also determined. Two-way ANOVA with Repeated-Measures revealed that surface treatment and repair material had no significant effect on repair bond strength of silorane-based composite material. Paired t-test showed that all repair strength values were significantly lower than the cohesive strength of FiltekP90. Adhesive failure was the predominant mode of failure which was confirmed by SEM. Surface treated FiltekP90 composite showed different textures under SEM whereas phosphoric acid did not produce clear changes. An interaction layer between SBMP adhesive and FiltekZ250 repairing composite was detected. Repair of the silorane composite was successful irrespective of the surface roughness and chemistry of the repair

  12. Aircraft Brake Systems Testing Handbook.

    Science.gov (United States)

    1981-05-01

    INOX)*YIINOXI) 1 CONTINUE sOsMx=supxr*suPx CELTA -NPTJS*SUMXX-SQSMX A=( l.0/DELTA)*( SUMXX*SUMY-S)UMX*SUPXYJ 1(. 0/01 LTA) *4NPTS*SUMXY-SUMX* SUPY) RE...20 REIURN 30 YNY*0.5 CELTA =( (1.0/2. 0**YI*ICOFF-COEFFI) SAuS8 DS A OS8 COFF-COEFF COEFF-COEF GO TO 10 END 44 Program COFS Program COFS calculates the

  13. 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.

  14. RESTART simulation of non-Markov consecutive-k-out-of-n: F repairable systems

    Energy Technology Data Exchange (ETDEWEB)

    Villen-Altamirano, Jose, E-mail: jvillen@eui.upm.e [Departamento de Matematica Aplicada (E.U. Informatica), Universidad Politecnica de Madrid, Calle Arboleda s/n, 28031 Madrid (Spain)

    2010-03-15

    The reliability of consecutive-k-out-of-n: F repairable systems and (k-1)-step Markov dependence is studied. The model analyzed in this paper is more general than those of previous studies given that repair time and component lifetimes are random variables that follow a general distribution. The system has one repair service which adopts a priority repair rule based on system failure risk. Since crude simulation has proved to be inefficient for highly dependable systems, the RESTART method was used for the estimation of steady-state unavailability, MTBF and unreliability. Probabilities up to the order of 10{sup -16} have been accurately estimated with little computational effort. In this method, a number of simulation retrials are performed when the process enters regions of the state space where the chance of occurrence of a rare event (e.g., a system failure) is higher. The main difficulty for the application of this method is to find a suitable function, called the importance function, to define the regions. Given the simplicity involved in changing some model assumptions with RESTART, the importance function used in this paper could be useful for dependability estimation of many systems.

  15. Pattern recognition receptors and central nervous system repair.

    Science.gov (United States)

    Kigerl, Kristina A; de Rivero Vaccari, Juan Pablo; Dietrich, W Dalton; Popovich, Phillip G; Keane, Robert W

    2014-08-01

    Pattern recognition receptors (PRRs) are part of the innate immune response and were originally discovered for their role in recognizing pathogens by ligating specific pathogen associated molecular patterns (PAMPs) expressed by microbes. Now the role of PRRs in sterile inflammation is also appreciated, responding to endogenous stimuli referred to as "damage associated molecular patterns" (DAMPs) instead of PAMPs. The main families of PRRs include Toll-like receptors (TLRs), Nod-like receptors (NLRs), RIG-like receptors (RLRs), AIM2-like receptors (ALRs), and C-type lectin receptors. Broad expression of these PRRs in the CNS and the release of DAMPs in and around sites of injury suggest an important role for these receptor families in mediating post-injury inflammation. Considerable data now show that PRRs are among the first responders to CNS injury and activation of these receptors on microglia, neurons, and astrocytes triggers an innate immune response in the brain and spinal cord. Here we discuss how the various PRR families are activated and can influence injury and repair processes following CNS injury.

  16. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

    Directory of Open Access Journals (Sweden)

    Mladena Lukovic

    2015-12-01

    Full Text Available In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c. This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d, the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning. From reconstructed images, different phases in the repair system (repair material, substrate, voids can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

  17. EFFECT OF GENDER DIFFERENCE ON BRAKE REACTION TIME

    Directory of Open Access Journals (Sweden)

    Ashok

    2016-02-01

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

  18. PROTOBINARY EVOLUTION DRIVEN BY MAGNETIC BRAKING

    Science.gov (United States)

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

    2014-01-01

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

  19. 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...

  20. Systemic Inflammatory Response and Severe Thrombocytopenia after Endovascular Thoracic Aortic Aneurysm Repair

    Directory of Open Access Journals (Sweden)

    Valentina Silvestrin

    2017-01-01

    Full Text Available After Endovascular repair of thoracic aortic aneurysm, a systemic inflammatory response, named postimplantation syndrome, can develop. This syndrome is characterized by fever, leukocytosis, and elevated CRP plasma levels and its pathogenetic mechanisms are still unknown. Although this syndrome generally resolves within few days, some patients develop a persisting severe inflammatory reaction leading to mild or severe complications. Here we describe the case of a male patient who developed postimplantation inflammatory syndrome and severe thrombocytopenia after endovascular repair of thoracic aortic aneurysm. Treatment with prednisone (50 mg/bid for two weeks did not improve the clinical and laboratory findings. We utilized danazol, a weak androgen that has been shown to be effective in the treatment of immune and idiopathic thrombocytopenic purpura, and after 12 days of treatment with danazol (200 mg/bid, the patient improved progressively and platelet number increased up to 53,000/μL. Patients undergoing endovascular repair of thoracic aortic aneurysm should be carefully monitored for the development of postimplantation syndrome. This clinical condition is relatively common after the endovascular repair of aortic aneurysm but is rarely observed after endovascular repair of thoracic aortic aneurysms. The different known therapeutical approaches are still empiric, with reported beneficial effects with the use of NSAID, corticosteroids, and danazol.

  1. Systemic Inflammatory Response and Severe Thrombocytopenia after Endovascular Thoracic Aortic Aneurysm Repair

    Science.gov (United States)

    Silvestrin, Valentina; Bonvini, Stefano; Antonello, Michele; Grego, Franco; Vettor, Roberto

    2017-01-01

    After Endovascular repair of thoracic aortic aneurysm, a systemic inflammatory response, named postimplantation syndrome, can develop. This syndrome is characterized by fever, leukocytosis, and elevated CRP plasma levels and its pathogenetic mechanisms are still unknown. Although this syndrome generally resolves within few days, some patients develop a persisting severe inflammatory reaction leading to mild or severe complications. Here we describe the case of a male patient who developed postimplantation inflammatory syndrome and severe thrombocytopenia after endovascular repair of thoracic aortic aneurysm. Treatment with prednisone (50 mg/bid) for two weeks did not improve the clinical and laboratory findings. We utilized danazol, a weak androgen that has been shown to be effective in the treatment of immune and idiopathic thrombocytopenic purpura, and after 12 days of treatment with danazol (200 mg/bid), the patient improved progressively and platelet number increased up to 53,000/μL. Patients undergoing endovascular repair of thoracic aortic aneurysm should be carefully monitored for the development of postimplantation syndrome. This clinical condition is relatively common after the endovascular repair of aortic aneurysm but is rarely observed after endovascular repair of thoracic aortic aneurysms. The different known therapeutical approaches are still empiric, with reported beneficial effects with the use of NSAID, corticosteroids, and danazol. PMID:28154580

  2. Prediction of Repair Work Duration for Gas Transport Systems Based on Small Data Samples

    DEFF Research Database (Denmark)

    Lesnykh, Valery; Litvin, Yuri; Kozin, Igor

    2016-01-01

    Prediction of the duration of a repair and maintenance project of a gas transport system is an important part of planning activities. There exist numerous sources of uncertainties that may result in time overruns possibly leading to multiple negative consequences. Our experience in planning...... this work suggests that accepting the stochastic nature of the project duration is a constructive step towards the preparedness to contingencies and defining penalties for repair companies. To support this approach, one needs to construct probability distributions of the durations of the projects...

  3. Things for You to Know. Fuel System. Student Manual--Introduction. Small Engine Repair Series. First Edition.

    Science.gov (United States)

    Hill, Pamela

    This student manual, part of a small-engine repair series on servicing fuel systems, is designed for use by special needs students in Texas. Information covered in this manual is considered to be the minimum that students need to know about fuel systems in order to get small-engine repair jobs. The manual introduces students to small-engine fuel…

  4. Lubrication System 2. Service the Crankcase Breather. Student Manual. Small Engine Repair Series. First Edition.

    Science.gov (United States)

    Hill, Pamela

    This student manual on servicing the crankcase breather is the third of three in an instructional package on the lubrication system in the Small Engine Repair Series for handicapped students. The stated purpose for the booklet is to help students learn what tools and equipment to use and all the steps of the job. Informative material and…

  5. Superficial fascial system repair: an abdominoplasty technique to reduce local complications after caesarean delivery.

    Science.gov (United States)

    Al-Benna, Sammy; Al-Ajam, Yazan; Tzakas, Elias

    2009-05-01

    Abdominal incision complications are a major source of morbidity after caesarean delivery. Repair of the superficial fascial system may avert local complications after caesarean delivery by minimising tension to the skin and increasing the initial biomechanical strength of wound which has the potential to decrease early wound dehiscence and as a by-product correct suprapubic bulging.

  6. Optimal Repair And Replacement Policy For A System With Multiple Components

    Science.gov (United States)

    2016-06-17

    probabilistic life-cycle maintenance mod- els for deteriorating civil infrastructure. Probabilistic Enginering Mechanics 19 345– 359. Zhang, Y.L. 2002. A...Repair, Replace, Multiple Component Models, Maintenance Models, Markov Decision Process 15. NUMBER OF PAGES 83 16. PRICE CODE 17. SECURITY...Parametric Analysis of the Fuel System . . . . . . . . . . . . . . 39 6 Conclusions and Future Work 45 6.1 Conclusions

  7. Semiconservative replication, genetic repair, and many-gened genomes: Extending the quasispecies paradigm to living systems

    Science.gov (United States)

    Tannenbaum, Emmanuel; Shakhnovich, Eugene I.

    2005-12-01

    Quasispecies theory has emerged as an important tool for modeling the evolutionary dynamics of biological systems. We review recent advances in the field, with an emphasis on the quasispecies dynamics of semiconservatively replicating genomes. Applications to cancer and adult stem cell growth are discussed. Additional topics, such as genetic repair and many-gene genomes, are covered as well.

  8. Bond strength durability of direct and indirect composite systems following surface conditioning for repair

    NARCIS (Netherlands)

    Passos, Sheila Pestana; Ozcan, Mutlu; Vanderlei, Aleska Dias; Leite, Fabiola Pessoa Pereira; Kimpara, Estevao Tomomitsu; Bottino, Marco Antonio

    2007-01-01

    Purpose: This study evaluated the effect of surface conditioning methods and thermocycling on the bond strength between a resin composite and an indirect composite system in order to test the repair bond strength. Materials and Methods: Eighteen blocks (5 x 5 x 4 mm) of indirect resin composite (Sin

  9. Injecting a liquid bacteria-based repair system to make porous network conrete healed

    NARCIS (Netherlands)

    Sangadji, S.; Wiktor, V.A.C.; Jonkers, H.M.; Schlangen, H.E.J.G.

    2013-01-01

    Bacteria induced calcite precipitation has been proven to be effective in making concrete structure self-healing. In Microlab TU Delft, the concept has been enhanced by developing a liquid bacteria-based concrete repair system. The solution contains calcite precipitating bacteria, nutrients and buff

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

    Science.gov (United States)

    Szczypiński-Sala, W.; Lubas, J.

    2016-09-01

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

  11. 运行中动车组制动系统故障原因分析及处理%An Analysis on The Fault Causes in Braking System of Bullet Train During Operatqion and Processing

    Institute of Scientific and Technical Information of China (English)

    尹凤伟

    2015-01-01

    Since the 6th national railway speed upgrade in April 18th 2007 and the first time to run multiple units at the speed of 200km/h in China,the CRH series which is called "Harmony",in general has become a symbol marking that China' railway has stepped on the club of high-speed railway.As for multiple units,the braking system is related to safety,and it is also an important factor for railway speed upgrade.The speed-up of railway need high-power traction and besides, the braking capacity shall be completely powerful.%我国铁路自2007年4月18日进行第六次大提速,并在国内首次开行时速200km动车组以来,统称为"和谐号"的CRH系列动车组即成为我国铁路迈入高速铁路俱乐部的象征.对于动车组来说,制动系统既关系到安全问题,也是列车提速的重要因素.列车的提速,除了要有大功率牵引外,还必须有足够强大的制动能力.

  12. 高速动车组制动系统用中继阀改型设计分析%Redesign and Analysis of Relay Valve for High-speed Electric Multiple Unit Braking System

    Institute of Scientific and Technical Information of China (English)

    刘元清; 程国军; 庄国明; 汪枫

    2015-01-01

    In order to improve the pressure surge of brake system and the characteristic curve between AC pressure and BC pressure when brake pressure is high, this paper proposes that relay valve are redesigned and developed for its fast dynamic response and stability. Reduc-ing effective action area and changing throttle hole diameter are introduced to improve the dynamic performance by designing calculation, utilizing AMESim simulation software and testing verification. It aslso contributes to the new design and optimization of pneumatic valve.%为改善高速列车制动系统中出现的BC压力较大时压力波动的现象,避免AC压力和BC压力特性曲线交叉现象,开展中继阀优化设计,提高中继阀的跟随性和稳定性。通过设计计算,利用AMESim软件进行仿真分析以及实物试验对比验证分析,得出改变中继阀AC腔的作用面积和节流孔孔径可以提高中继阀动态性能。同时,为气动阀类产品的设计优化提供指导意义。

  13. 基于AVR单片机的飞机刹车控制盒仿真器的控制系统%Design of Control System for Aircraft Brake Control Box Emulator Based on AVR Microcontroller

    Institute of Scientific and Technical Information of China (English)

    雒名佳; 谢利理; 汪楚锟

    2012-01-01

    对于现代航空刹车数字控制盒的性能及功能要求,提出基于AVR单片机的仿真器控制系统的实现.本系统以AVR单片机为控制核心,通过模数转换器采集刹车电流信号,检测各通道的故障信号.通过控制真实负载和模拟通道的转换完成仿真实验,并实时上传数据作记录.%A new type of the actuator control system based on AVR microcontroller is proposed for the performance and the function of the modern aircraft braking digital box. AVR microcontroller is adopted as the control core, through ADC converter collecting braking current signal, the fault signals of every channel are detected. Simulation is completed by controlling the real load and transforming the analog channels. Meanwhile, the test data are uploaded and recorded in real time

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

    Directory of Open Access Journals (Sweden)

    Xinhua Liu

    2017-07-01

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

  15. Transnet regenerative braking concept definition

    CSIR Research Space (South Africa)

    Giesler, Achmed

    2015-09-01

    Full Text Available have the added advantage that they can be housed in temperature and controlled buildings in a relatively clean environment. Technologies being used and researched Energy regenerated during braking can either be fed back into the grid or stored... Body of Knowledge: http://sebokwiki.org/wiki/Concept_Definition Halligan, R. J. (2011, October 6). Operational Concept Description. Operational Concept Description. Melbourne: Project Performance International. Jaafar, A., Akli, C. S., Roboam, X...

  16. What brakes the Crab pulsar?

    Science.gov (United States)

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

    2016-03-01

    Context. Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. Aims: The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. Methods: We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. Results: From our analysis, we demonstrate that the power law index undergoes "instantaneous" changes at the time of observed jumps in rotational frequency (glitches). We find that the phase evolution of the Crab pulsar is dominated by a series of constant braking law episodes, with the braking index changing abruptly after each episode in the range of values between 2.1 and 2.6. Deviations from such a regular phase description behave as oscillations triggered by glitches and amount to fewer than 40 turns during the above period, in which the pulsar has made more than 2 × 1010 turns. Conclusions: Our analysis does not favor the explanation that glitches are connected to phenomena occurring in the interior of the pulsar. On the contrary, timing irregularities and changes in slow down rate seem to point to electromagnetic interaction of the pulsar with the surrounding environment.

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  18. 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.

  19. DNA repair. [UV radiation

    Energy Technology Data Exchange (ETDEWEB)

    Setlow, R.

    1978-01-01

    Some topics discussed are as follows: difficulty in extrapolating data from E. coli to mammalian systems; mutations caused by UV-induced changes in DNA; mutants deficient in excision repair; other postreplication mechanisms; kinds of excision repair systems; detection of repair by biochemical or biophysical means; human mutants deficient in repair; mutagenic effects of UV on XP cells; and detection of UV-repair defects among XP individuals. (HLW)

  20. Defective dental restorations: to repair or not to repair? Part 2: All-ceramics and porcelain fused to metal systems.

    Science.gov (United States)

    Blum, Igor R; Jagger, Daryll C; Wilson, Nairn H F

    2011-04-01

    With the increasing use of ceramics in restorative dentistry, and trends to extend restoration longevity through the use of minimal interventive techniques, dental practitioners should be familiar with the factors that may influence the decision either to repair or replace fractured metal-ceramic and all-ceramic restorations and, also, the materials and techniques available to repair these restorations. This second of two papers addresses the possible modes of failure of ceramic restorations and outlines indications and techniques in this developing aspect of restoration repair in clinical practice. The repair of metal-ceramic and all-ceramic restorations is a reliable low-cost, low-risk technique that may be of value for the management of loss or fracture of porcelain from a crown or bridge in clinical practice.

  1. 基于VC++和ADAMS/Car的汽车制动性能仿真分析系统%Simulation and analysis of automotive braking system based on VC++ and ADAMS/Car

    Institute of Scientific and Technical Information of China (English)

    张杰; 孙虎; 杨波; 王斌

    2012-01-01

    To speed up the virtual development of the automobile braking system, VC++6.0 programming environment and the Junction of ADAMS are applied to execute the batch files based on the ADAMS/ CAR software,and the simulation and analysis system for automotive braking system is developed as well. Then a friendly convenient and the flexible man-machine conversation interface are developed by VC++ foreground.When the software is used,the user only is required to input the vehicle parameters and set the simulation parameters, which will be obtained from the backstage of the system and transformed to the ADAMS operating commands and encapsulated in acar.cmd file.ADAMS will automatically create a virtual model and simulate after executing the acar.cmd file, so that the data of the simulation is got.With the application of the system the modeling efficiency for virtual model is improved,which reduce the work load on study and design of braking system greatly.%为了提高汽车制动系统的虚拟研发速度,利用VC++6.0的编程环境和ADAMS可执行批处理文件的功能,以ADAMS/CAR软件为基础平台,开发了汽车制动性能仿真分析系统.通过VC++前台开发出友好、方便、易用的人机交互界面,用户在使用此软件时,只需在此界面中输入整车结构参数及仿真设置参数,系统在后台获取这些参数并转换为需要对ADAMS进行的操作命令后封装入acar.cmd文件中,ADAMS调用此文件后即可自动实现整车虚拟模型建立及计算仿真,并获取仿真试验数据.设计人员利用此系统,可提高虚拟模型的建模效率,大大减少汽车制动系统研究与设计的工作量.

  2. Chain of impact of the development of hot spots and hot rubbing in disk brakes of passenger cars; Wirkungskette der Entstehung von Hotspots und Heissrubbeln in Pkw-Scheibenbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Sarda, Angelo

    2009-07-01

    Aspects coupled with brake comfort represent challenges with the development of brake systems. During the brake process, so-called hot spots on the surface of brake disks are developed under certain conditions. These hot spots result in an irregular thermal expansion and deformation of the brake disk. This results in vibrations impacting the comfort and being known as 'hot rubbing'. The author of the contribution under consideration describes the most important results from extensive benchmark tests and supplies experimentally secured realizations to the chain of impact of the development of hot spots and 'hot rubbing' in a disc brake.

  3. 3-Unit System Comprising Two Types of Units with First Come First Served Repair Pattern Except When Both Types of Units are Waiting for Repair

    Directory of Open Access Journals (Sweden)

    Amit Goyal

    2010-01-01

    Full Text Available Problem statement: In this study we investigated the probabilistic analysis of a three unit system working in a sugar Mill, wherein one unit is big and the other two units are small and identical, is examined. Upon failure of the big unit, both small units are made operative and failed unit is undertaken for repair immediately. Priority for operation is given to the big unit. Priority for repair is given to big unit if both types (i.e., big and small of units are in queue to get the repair done. System is able to work with full capacity only if big unit or both small units are in good condition. If only one small unit is operable, the system works at reduced capacity. The system under consideration goes to rest during the non-seasonal period. Approach: System was analyzed by making use of semi-Markov processes and regenerative point technique and various measures of the system effectiveness are obtained including the profit incurred to the system. Results: Graphs had been plotted to depict the behavior of the profit with respect to failure rate for different values of repair rate and with respect to revenue per unit up time for which system is working at full capacity for different values of cost for PM/CM. Conclusion: The profit increases with the decrease in the values of the failure rate and with the increase in the values of revenue per unit up time. It has lower (higher values on increasing the values of cost (repair rate. Cut-off points obtained for failure rate help decide about having the system with failure rate lesser than that the value at cut-off point. Also, the price of the product should be fixed in such a way so as to get the revenue greater than the value at cut-off point.

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

    Science.gov (United States)

    2008-05-20

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

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

    Institute of Scientific and Technical Information of China (English)

    YANG Zhiyong; HAN Jianmin; LI Weijing; WANG Jinhua

    2007-01-01

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

  6. Verification of pneumatic railway brake models

    Science.gov (United States)

    Piechowiak, Tadeusz

    2010-03-01

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

  7. [The correlations between aging of the human body, oxidative stress and reduced efficiency of repair systems].

    Science.gov (United States)

    Michalak, Aleksandra; Krzeszowiak, Jakub; Markiewicz-Górka, Iwona

    2014-12-15

    The article presents an current knowledge overview about the importance of oxidative stress and reduced efficiency of repair processes during the aging process of the human body. Oxidative damage to cellular macromolecules (proteins, lipids, nucleic acids), are formed under the influence of reactive oxygen species (ROS). They are the part of important mechanism which is responsible for the process of aging and the development of many diseases. The most important effects result from DNA damage, due to the mutations formation, which can lead to the development of tumors. However, a well-functioning repair systems (i.a. homologous recombination) remove the damage and prevent harmful changes in the cells. Lipid peroxidation products also cause oxidative modification of nucleic acids (and proteins). Proteins and fats also have repair systems, but much simpler than those responsible for the repair of nucleic acids. Unfortunately, with increasing age, they are more weakened, which contributes to increase numbers of cell damage, and consequently development of diseases specific to old age: cancer, neurodegenerative diseases or atherosclerosis.

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

    Directory of Open Access Journals (Sweden)

    Adel A. obed

    2016-06-01

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

  9. A decision dependent stochastic process model for repairable systems with applications

    Directory of Open Access Journals (Sweden)

    Paul F. Zantek

    2015-12-01

    This paper mathematically formalizes the notion of how management actions impact the functioning of a repairable system over time by developing a new stochastic process model for such systems. The proposed model is illustrated using both simulated and real data. The proposed model compares favorably to other models for well-known data on Boeing airplanes. The model is further illustrated and compared to other models on failure time and maintenance data stemming from the South Texas Project nuclear power plant.

  10. Repair, Evaluation, Maintenance, and Rehabilitation Research Program: Elements of Floating-Debris Control Systems

    Science.gov (United States)

    1988-09-01

    a variety of materials from plastic bottles to sage brush, but it is t’quialy wood in soiw shape or form--from whole trees to lawn furniture. The...REPAIR, EVALUATION, MAINTENANCE, AND REHABILITATION’RESEARCH PROGRAM TECHNICAL REPORT REMVR-HY-3 ELEMENTS O F FLOATING- DEBRIS CONTROL SYSTEMS’ by...TITLE (Include Security Classification) Elements of Floating- Debris Control Systems 12. PERSONAL AUTHOR(S) Perham, Roscoe E. 13a. TYPE OF REPORT 13b TIME

  11. Inspection-Repair based Availability Optimization of Distribution Systems using Teaching Learning based Optimization

    Science.gov (United States)

    Tiwary, Aditya; Arya, L. D.; Arya, Rajesh; Choube, S. C.

    2016-09-01

    This paper describes a technique for optimizing inspection and repair based availability of distribution systems. Optimum duration between two inspections has been obtained for each feeder section with respect to cost function and subject to satisfaction of availability at each load point. Teaching learning based optimization has been used for availability optimization. The developed algorithm has been implemented on radial and meshed distribution systems. The result obtained has been compared with those obtained with differential evolution.

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Directory of Open Access Journals (Sweden)

    A. S. Dorosh

    2015-06-01

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

  14. Design and Application of Hydraulic Brake System for Mega-watt Graded Wind Turbine%兆瓦级风力发电机组液压制动系统的设计与应用

    Institute of Scientific and Technical Information of China (English)

    董连俊

    2015-01-01

    阐述了风力发电机组液压制动系统的工作原理,针对兆瓦级风力发电机组对液压制动系统的高集成化、高可靠性的要求,对液压制动系统进行深入研究探讨;针对现场实际应用中容易出现的问题进行了分析,并提出相应的解决方案。%For the purpose of high integration and high reliability, this paper introduces principle of hydraulic brake system for wind turbine, and conducts in-depth research of this system. According to problems during application, proposes corresponding resolving scheme.

  15. 制动力作用下车辆-车站结构耦合系统分析%Analysis method for a vehicle structure coupled system under braking force

    Institute of Scientific and Technical Information of China (English)

    张楠; 夏禾; 程潜; G.De Roeck

    2011-01-01

    研究制动力作用下车辆-结构耦合系统的分析方法.以刚体动力学方法建立车辆子系统模型,以振型叠加法建立结构子系统模型,以给定的制动加速度时程、简化的Kalker蠕滑理论和轮轨密贴假定分别定义纵向、横向和竖向轮轨间相互作用力,采用时程积分和时间步内的力一运动状态迭代方式求解运动方程.作为算例,研究了深圳地铁4号线、6号线列车制动于深圳北站时车辆-结构动力耦合系统的动力响应,并对车站结构关键郎位的振动状态做出了分析和评价.%The analysis method for a vehicle-structure coupled system under braking force was studied. The vehicle subsystems were modeled using the rigid-body dynamics method, the structure subsystems were modeled with the modal superposition method. The longitudinal, lateral and vertical wheel-rail interacting forces were defined with the given braking acceleration time-history, the simplified Kalker creep theory and the wheel-rail osculation assumption,respectively. The equations of motion of the system were solved using the time-history integral method and the force-motion state iterations within time steps. As a case study, the dynamic responses of the vehicle-structure coupled system for Shenzhen North Station under brakings of Metro Line 4 and Line 6 trains were computed, and the vibration properties of some key structural parts of the station building were analyzed and evaluated.

  16. Driving style recognition method using braking characteristics based on hidden Markov model

    National Research Council Canada - National Science Library

    Chao Deng; Chaozhong Wu; Nengchao Lyu; Zhen Huang

    2017-01-01

    .... Firstly, braking impulse and the maximum braking unit area of vacuum booster within a certain time are collected from braking operation, and then general braking and emergency braking characteristics...

  17. Multisensor robotic system for autonomous space maintenance and repair

    Science.gov (United States)

    Abidi, M. A.; Green, W. L.; Chandra, T.; Spears, J.

    1988-01-01

    The feasibility of realistic autonomous space manipulation tasks using multisensory information is demonstrated. The system is capable of acquiring, integrating, and interpreting multisensory data to locate, mate, and demate a Fluid Interchange System (FIS) and a Module Interchange System (MIS). In both cases, autonomous location of a guiding light target, mating, and demating of the system are performed. Implemented visio-driven techniques are used to determine the arbitrary two-dimensional position and orientation of the mating elements as well as the arbitrary three-dimensional position and orientation of the light targets. A force/torque sensor continuously monitors the six components of force and torque exerted on the end-effector. Both FIS and MIS experiments were successfully accomplished on mock-ups built for this purpose. The method is immune to variations in the ambient light, in particular because of the 90-minute day-night shift in space.

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

    Directory of Open Access Journals (Sweden)

    Bela Vincze

    2006-01-01

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

  19. XJ250修井机液压盘式刹车液压控制系统仿真分析%Simulation Analysis of the Hydraulic Control System of the Hydraulic Disc Brake on the X J250 Workover Rig

    Institute of Scientific and Technical Information of China (English)

    张连业; 吴文秀; 刘威

    2012-01-01

    Taking as the object of study the hydraulic control system of the hydraulic disc brake on the XJ250 workover rig, the mathematical model on the basis of global flow and hydraulic cylinder piston motion equation was established by analyzing the structure of the control system. The AMESim simulation model for the hydraulic control system of the braking system was constructed and the model parameters and simulation parameters were set. The var- iation of the typical sine curve hydraulic source signal and excitation electromagnetic valve signal was used to carry out a simulation study of the response system of the operating brake hydraulic control system. The sudden opening of the step switch signal was used to conduct a simulation analysis of the urgency brake hydraulic system response. The hydraulic dynamic response curve of the main valve port of the hydraulic control system in the process of operating brake and urgency brake was derived. The simulation result is in agreement with the practical operation. The simulation analysis offers a reference for the improvement of the performance of the hydraulic control system of the workover rig disc brake.%以XJ250修井机液压盘式刹车的液压控制系统为研究对象,通过分析液压盘式刹车的液压控制系统结构,建立了基于全局流量与液压缸活塞运动方程的数学模型;构建了液压控制系统的AMESim仿真模型,设置了模型参数及仿真参数。以典型的正弦曲线液压源信号及激励电磁阀信号变化仿真研究工作制动液压控制系统响应性能,以阶跃开关信号突然开启模拟分析紧急制动液压系统响应。得到了工作制动及紧急制动过程中液压控制系统主要阀口处液压动态响应曲线,仿真结果与实际运行情况相符。该仿真分析为修井机液压盘式刹车液压控制系统性能的改进与完善提供了参考。

  20. Service the Two-Piece Flo-Jet Carburetor. Fuel System. Student Manual 3. Small Engine Repair Series. First Edition.

    Science.gov (United States)

    Hill, Pamela

    This student manual, part of a small-engine repair series on servicing fuel systems, is designed for use by special needs students in Texas. The manual explains in pictures and short sentences, written on a low reading level, the job of servicing two-piece flo-jet carburetors. Along with the steps of this repair job, specific safety and caution…

  1. Analysis and Design of Circular Plate MR Fluids Brake

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

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

    Science.gov (United States)

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

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

  3. Homomorphic Self-repairing Codes for Agile Maintenance of Distributed Storage Systems

    CERN Document Server

    Oggier, Frederique

    2011-01-01

    Distributed data storage systems are essential to deal with the need to store massive volumes of data. In order to make such a system fault-tolerant, some form of redundancy becomes crucial, incurring various overheads - most prominently in terms of storage space and maintenance bandwidth requirements. Erasure codes, originally designed for communication over lossy channels, provide a storage efficient alternative to replication based redundancy, however entailing high communication overhead for maintenance, when some of the encoded fragments need to be replenished in news ones after failure of some storage devices. We propose as an alternative a new family of erasure codes called self-repairing codes (SRC) taking into account the peculiarities of distributed storage systems, specifically the maintenance process. SRC has the following salient features: (a) encoded fragments can be repaired directly from other subsets of encoded fragments by downloading less data than the size of the complete object, ensuring ...

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

    Science.gov (United States)

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

    2013-02-01

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

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

    CERN Document Server

    Magalhaes, N S; Frajuca, C

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

  7. Corrosion inhibitors and other protective systems in concrete repair concepts or misconcepts

    Institute of Scientific and Technical Information of China (English)

    XuKe

    2009-01-01

    The paper concludes that as long as one continues to blindly use protection methods applicable for newly constructed structures for concrete repairs,the business of "repairing the repairs"will be on the rise.A broader understanding of the electrochemical differences between new and repaired concrete is necessary for effective protection of reinforcement in repaired structures.

  8. 公交客车制动能量回收系统起步仿真研究%Bus Braking Energy Recovery System Simulation Research

    Institute of Scientific and Technical Information of China (English)

    殷允朝

    2015-01-01

    建立公交客车液压蓄能器回收起步数学模型,并在MATLAB/Simulink进行了仿真分析,结果表明:在水平良好道路上,以40km/h下的制动车速,蓄能器回收的能量使得公交客车起步行驶了20.96m。%Bus hydraulic accumulator started recycling mathematical model is established, In MATLAB/Simulink simulation analysis. The results show that:In horizontal well on the road, At 40 km/h speed is braking, Bus started driving the 20.96 m by accumulator recycling of energy.

  9. Study on Cooperative Control Method of Vehicle Steering/Anti-lock Braking System%汽车转向/防抱死制动系统的协调控制研究

    Institute of Scientific and Technical Information of China (English)

    李果; 刘华伟; 王旭

    2012-01-01

    A new cooperative control system was proposed for the vehicle's steering antilock braking stability fields.The cooperative control architecture is composed with the execution layer and the cooperation layer.On the execution layer,based on the optimum slip ratio,the vehicle adjustable sliding mode controller was designed for the robustness of vehicles.Moreover,the adaptor was designed to adjust the gain of sliding mode control parameters,so as to reduce the chatter.On the other hand,the yaw moment and the front wheel angle controllers based on the robust adaptive control law were designed to improve the respond,adaptive robustness and stability of vehicles.On the cooperation layer,the brake force distribution policy applicable to the complex work condition and a new cooperative control method were proposed to solve the problems of steering and braking systems.Finally,the stability and the validity of the control algorithm were validated by simulation results.%协同控制结构由执行级和协调级组成。在执行级中,设计基于最佳滑移率的汽车防抱死制动可调节滑模控制器。针对滑模控制中固有抖振缺陷,自动适时调节控制参数增益以消弱抖振。此外,设计基于鲁棒自适应控制的横摆力矩控制器和主动前轮转向控制器力求改善汽车动态响应、鲁棒自适应性和稳定性。在协调级中,设计适用于复杂工况的制动力分配策略,并提出一种协调控制转向系统和制动系统的新方法。最后用仿真结果验证所设计控制算法的稳定性和有效性。

  10. The Refrigeration System; Appliance Repair--Advanced: 9027.01.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This course outline provides students with an understanding of the observation of basic refrigeration system components, the techniques used in working with copper tubing, and practice demonstrations to show what they have learned. Course content includes specific block objectives, orientation, refrigeration components (evaporator, compressor,…

  11. Rotator cuff repair in the Brazilian Unified Health System: Brazilian trends from 2003 to 2015.

    Science.gov (United States)

    Malavolta, Eduardo Angeli; Assunção, Jorge Henrique; Beraldo, Rodrigo Alves; Pinto, Gustavo de Mello Ribeiro; Gracitelli, Mauro Emilio Conforto; Ferreira Neto, Arnaldo Amado

    2017-01-01

    To assess the historical trend of rotator cuff repairs in Brazil between 2003 and 2015, using the database of the Brazilian Unified Health System's (Sistema Único de Saúde [SUS]) Department of Informatics (DataSUS). Historical series using DataSUS. Surgeries performed between 2003 and 2015 were included and data relating to cuff tear repair were assessed, including decompression procedures were included. The numerator was the total number of rotator cuff repair and the denominator, the total population of the assessed locality. Population data were based on information from the Instituto Brasileiro de Geografia e Estatística (IBGE). During the period, 50,207 surgeries were performed. The rate was presented as number of procedures per 100,000 inhabitants, and increased from 0.83 to 2.81, a growth of 238%. In 2015, the South region had the highest rate, 6.32, followed by the Southeast, 3.62, while the North had the lowest rate, 0.13. The growing trend can be observed in the Southeast, South, and Midwest, while the rate is stable in the North and Northeast. The rate of rotator cuff repairs in Brazil performed through the SUS increased from 0.83 to 2.81 between 2003 and 2015, representing a growth of 238%, but remains lower than that of developed countries. A trend of growth can be observed in the Southeast, South, and Midwest, while the rate is stable in the North and Northeast.

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

    Directory of Open Access Journals (Sweden)

    Perrenoud Alain

    2009-11-01

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

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

    Directory of Open Access Journals (Sweden)

    J. GLIŠOVIĆ

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Guoshun Wang

    2013-01-01

    Full Text Available Utilizing ABAQUS finite element software, the study established the relationship between a brake pad structure and distributions of temperature and thermal stress on brake disc. By introducing radial structure factor and circular structure factor concepts, the research characterized the effect of friction block radial and circumferential arrangement on temperature field of the brake disc. A method was proposed for improving heat flow distribution of the brake disc through optimizing the position of the friction block of the brake pad. Structure optimization was conducted on brake pads composed of 5 or 7 circular friction blocks. The result shows that, with the same overall contact area of friction pair, an appropriate brake pad structure can make the friction energy distribute evenly and therefore lowers peak temperature and stress of the brake disc. Compared with a brake pad of 7 friction blocks, an optimized brake pad of 5 friction blocks lowered the peak temperature of the corresponding brake disc by 4.9% and reduced the highest stress by 10.7%.

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  17. Low velocity impact response and damage evolution in unreinforced resin systems and self-repairing polymer matrix composites

    Science.gov (United States)

    Motuku, Molefi

    The low velocity impact response and damage evolution in unreinforced polymer matrices, conventional polymer matrix composites, and self-repairing polymer matrix composites was investigated. The impact response study of unreinforced matrices and conventional laminates was undertaken because the failure initiation energies, threshold energy levels, failure characteristics and damage evolution in both the matrix material (unreinforced resin plaques) and the composite are intrinsic to proper design of a self-repairing composite. The self-repairing concept was investigated due to its attractive potential to alleviate damage problems in polymer matrix composites. Self-repairing composites, which fall under the category of passive smart polymer composites, have the potential to self repair both micro- and macro-damage resulting from impacts as well as non-impact loading. The self-repairing mechanism is achieved through the incorporation of hollow fibers in addition to the normal solid reinforcing fibers. The hollow fibers store the damage-repairing solution or chemicals that are released into the matrix or damaged zone upon fiber failure to repair and/or arrest damage progression. The room temperature low velocity impact response and damage evolution in DERAKANE 411-350 and 411-C50 vinyl ester unreinforced resin systems was investigated as a function of impact energy level, sample thickness, matrix material and catalyst system. The low velocity impact response of conventional and self-repairing glass reinforced polymer composites was investigated by addressing the fabrication and some of the parameters that influence their response to low velocity impact loading. Specific issues addressed by this study include developing a process to fabricate self-repairing laminates, processing quality; selection of storage material for the repairing solution; release and transportation of repairing solution; the effect of the number, type and spatial distribution of the repairing

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

  19. 14 CFR 29.735 - Brakes.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

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

    Institute of Scientific and Technical Information of China (English)

    褚志刚; 叶方标; 蒋忠翰; 张昌福; 周亚男

    2014-01-01

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

  1. Uncertain multiobjective redundancy allocation problem of repairable systems based on artificial bee colony algorithm

    Institute of Scientific and Technical Information of China (English)

    Guo Jiansheng; Wang Zutong; Zheng Mingfa; Wang Ying

    2014-01-01

    Based on the uncertainty theory, this paper is devoted to the redundancy allocation problem in repairable parallel-series systems with uncertain factors, where the failure rate, repair rate and other relative coefficients involved are considered as uncertain variables. The availability of the system and the corresponding designing cost are considered as two optimization objectives. A crisp multiobjective optimization formulation is presented on the basis of uncertainty theory to solve this resultant problem. For solving this problem efficiently, a new multiobjective artificial bee colony algorithm is proposed to search the Pareto efficient set, which introduces rank value and crowding distance in the greedy selection strategy, applies fast non-dominated sort procedure in the exploitation search and inserts tournament selection in the onlooker bee phase. It shows that the proposed algorithm outperforms NSGA-II greatly and can solve multiobjective redundancy allocation problem efficiently. Finally, a numerical example is provided to illustrate this approach.

  2. Tribomaterial factors in space mechanism brake performance

    Science.gov (United States)

    Hawthorne, H. M.

    1990-01-01

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

  3. Recommendations for optimised repair welding operations in steam systems exposed to creep; Rekommendationer foer optimering av svetsreparationer i kryppaakaenda aangsystem

    Energy Technology Data Exchange (ETDEWEB)

    Storesund, Jan; Samuelson, Aake; Klasen, Bjoern; Jensen, Carsten

    2002-03-01

    Recommendations for optimised repair welding in creep exposed steam systems have been produced on basis of different parts of the project which involve a literature survey, case studies, metallographical investigations and finite element simulations. The separate parts are compiled in the present report where the results also are coupled to each other. Two of the project parts are reported in appendices in the present report and the other ones in three separate work reports. The studies have shown evidence of the complexity associated with repair welding and many alternatives may be offered for a given situation. The importance of the factors which may influence the life time of the repair have been investigated and are described in order to facilitate the decision-making process for the given situation. From the obtained results there are also more general recommendations to be given: Make sure that system stresses not are acting at the repair. Avoid welding methods that could result in strongly creep soft HAZs. Select a weld metal for the repair which is slightly creep hard compared to the remaining aged material. Selection of a wide and 'medium' deep excavation geometry as well as a repair around the whole circumference is to be preferred. Repairs of welds that not include excavation of the whole width of the original weld should be avoided. Replica testing is recommended in addition to the common practice in the quality and condition-monitoring control of the repair.

  4. Simple facet joint repair with dynamic pedicular system: Technical note and case series

    OpenAIRE

    Ali Fahir Ozer; Tuncer Suzer; Mehdi Sasani; Tunc Oktenoglu; Phillip Cezayirli; Hosein Jafari Marandi; Deniz Ufuk Erbulut

    2015-01-01

    Simple facet joint repair with dynamic pedicular system: Technical note and case series Ali Ozer, Tuncer Suzer, Mehdi Sasani, Tunc Oktenoglu, Phillip Cezayirli and Hosein Marandi Journal of Craniovertebral Junction and Spine. 6.2 (April-June 2015): p65. Copyright: COPYRIGHT 2015 Medknow Publications and Media Pvt. Ltd. http://www.jcvjs.com/ Full Text: Byline: Ali. Ozer, Tuncer. Suzer, Mehdi. Sasani, Tunc. Oktenoglu, Phillip. Cezayirli, Hosein. Marandi, Deniz. Erbulut Purpose: Facet joints are...

  5. An application of modulated poisson processes to the reliability analysis of repairable systems

    Energy Technology Data Exchange (ETDEWEB)

    Saldanha, Pedro L.C. [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Coordenacao de Reatores]. E-mail: saldanha@cnen.gov.br; Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear]. E-mail: frutuoso@con.ufrj.br; Noriega, Hector C. [Universidad Austral de Chile (UACh), Valdivia (Chile). Faculdad de Ciencias de la Ingeniaria]. E-mail: hnoriega@uach.cl

    2005-07-01

    This paper discusses the application of the modulated power law process (MPLP) model to the rate of occurrence of failures of active repairable systems in reliability engineering. Traditionally, two ways of modeling repairable systems, in what concerns maintenance policies, are: a pessimistic approach (non-homogeneous process - NHPP), and a very optimistic approach (renewal processes - RP). It is important to build a generalized model that might consider characteristics and properties both of the NHPP and of the RP models as particular cases. In practice, by considering the pattern of times between failures, the MPLP appears to be more realistic to represent the occurrence of failures of repairable systems in order to define whether they can be modeled by a homogeneous or a non-homogeneous process. The study has shown that the model can be used to make decisions concerning the evaluation of the qualified life of plant equipment. By controlling and monitoring two of the three parameters of the MPLP model during the equipment operation, it is possible to check whether and how the equipment is following the basis of its qualification process, and so identify how the effects of time, degradation and operation modes are influencing the equipment performance. The discussion is illustrated by an application to the service water pumps of a typical PWR plant. (author)

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

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-07-01

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

  7. What brakes the Crab pulsar?

    CERN Document Server

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

    2015-01-01

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

  8. 混合动力挖掘机回转制动能量回收系统建模与试验研究%Modeling and experimentalresearch on rotary braking energy recovery system of hybrid excavator

    Institute of Scientific and Technical Information of China (English)

    刘昌盛; 何清华; 龚俊; 赵喻明; 李赛白

    2016-01-01

    为了回收液压挖掘机回转阶段的制动能量,对挖掘机典型作业工况及能耗进行分析,设计一种以液压马达+电机为回收方式、超级电容为储能元件的回转制动能量回收方案。构建回转制动能量回收系统中发动机、电机、回收马达、超级电容等关键元件数学模型,在对回转运动状态确认与能量回收模式切换、回收电机力矩输出控制和超级电容SOC判断的基础上,建立能量回收系统的仿真模型,以挖掘机实际载荷谱为输入对系统能量回收效果进行仿真分析。搭建挖掘机回转制动能量回收系统试验平台,对该试验系统的能量回收效果和回转驱动性能进行试验研究。研究结果表明:该能量回收方案可行,在不影响挖掘机回转驱动性能的同时,平台回转制动能量回收效率可达到40%以上。%In order to recover the braking energy from the hydraulic excavator during rotary phase, the typical working condition and energy losses were analyzed, and a rotary braking energy recovery program for hybrid excavator was proposed based on hydraulic motor and electric motor as recovery method and capacitor as energy storage element. The mathematical model of key components such as engine, electric motor, hydraulic motor and capacitor was established. For the rotary braking energy recovery system, the simulation model was established based on rotary motion state recognition and energy recovery mode switching, electric motor torque output control and capacitor SOC judgment, and the effect of energy recovery system was analyzed by simulation based on the actual load spectrum of hydraulic excavator as input signal. At last the recovery effect and rotary drive performance was studied by building test platform of rotarybrakingenergyrecoverysystem. The results showthatnotonlytherecoveryprogramisfeasible,buttherotary braking energy recovery efficiency can reach above 40%without affecting

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

    Science.gov (United States)

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

    2017-01-01

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

  10. 液压同步系统和液压制动系统在行走马达上的应用%Application of Hydraulic Synchronization System and Hydraulic Brake System on Walking Motor

    Institute of Scientific and Technical Information of China (English)

    张帅君; 赖雨薇; 刘会涛; 高伟航; 张庆勇; 苏伟民

    2015-01-01

    A new kind of loop was introduced in which hydraulic synchronization and hydraulic brake could be realized. How to realize synchronization and braking functions was illustrated through example. And the loop has simple structure, practicality and safety utmostly.%介绍一种可同时实现液压同步和液压制动的回路,通过具体实例说明如何实现同步和制动的功能,并且最大可能实现结构简单、经济实用和安全可靠。

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

    Directory of Open Access Journals (Sweden)

    V. V. Solencov

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jiusheng Bao

    2015-01-01

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

  13. Operator Semi-group of Density Evolution Equation for a Repairable Redundnt System with Two Same Components

    Institute of Scientific and Technical Information of China (English)

    史定华; 徐洪; 等

    2002-01-01

    For a repairable redundant system consisting of two same components with exponential lifetime and general repair time distribution,the probability densities of the system in some state at time t were determined by a group of ordinary and partial differential equations,called density evolution equations.It was proved that the time-dependent solution of the density evolution equations uniquely exists and strongly converges to its steady state density solution by a semi-group method.In this proof,it is not necessary to suppose that the repair rate function is bounded.The technique of the proof is valuable for many density evolution equatons.

  14. A New Approach for Analyzing the Reliability of the Repair Facility in a Series System with Vacations

    Directory of Open Access Journals (Sweden)

    Renbin Liu

    2012-01-01

    Full Text Available Based on the renewal process theory we develop a decomposition method to analyze the reliability of the repair facility in an n-unit series system with vacations. Using this approach, we study the unavailability and the mean replacement number during (0,t] of the repair facility. The method proposed in this work is novel and concise, which can make us see clearly the structures of the facility indices of a series system with an unreliable repair facility, two convolution relations. Special cases and numerical examples are given to show the validity of our method.

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

    OpenAIRE

    Bu, Fanping; Tan, Han-Shue

    2007-01-01

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

  16. THE WORK SIMULATION OF FLOW RATE FOR CARRIAGES' REPAIR AS A MULTIPHASE, MULTIPLEX AND MULTIDISCIPLINARY SYSTEM OF MASS SERVICE

    Directory of Open Access Journals (Sweden)

    V. V. Myamlin

    2011-04-01

    Full Text Available The algorithm of computer simulation of the flexible flow for repair of cars as a multiphase polychannel manyobject queuing system is presented. The basic operators of the model are given and their work is described.

  17. Incisional, epigastric and umbilical hernia repair using the Prolene Hernia System: describing a novel technique.

    Science.gov (United States)

    Khera, Goldie; Berstock, David A

    2006-08-01

    The Prolene Hernia System (PHS) is already widely in use in the United Kingdom for inguinal hernias. We describe the novel technique of using the three-in-one design of the PHS (Ethicon Endo-Surgery, Bracknell, UK) for repairing incisional, epigastric and umbilical herniae. This is a three-dimensional device and consists of an onlay patch, a tubular connector and an underlay patch. We recommend a four 'corner' suturing of the underlay patch under vision (and then) through the full thickness of abdominal wall layers to ensure a flat underlay mesh. These four sutures flatten out the underlay patch and can be tied or removed with equal effect. The sutures are placed at 3, 6, 9 and 12 o'clock, which simplifies the procedure and ensures that the underlay lays correctly and is corrugation-free and tension-free, thereby providing a two-layer repair for those herniae with a high rate of recurrence.

  18. Prediction of Repair Work Duration for Gas Transport Systems Based on Small Data Samples

    DEFF Research Database (Denmark)

    Lesnykh, Valery; Litvin, Yuri; Kozin, Igor

    2016-01-01

    Prediction of the duration of a repair and maintenance project of a gas transport system is an important part of planning activities. There exist numerous sources of uncertainties that may result in time overruns possibly leading to multiple negative consequences. Our experience in planning...... this work suggests that accepting the stochastic nature of the project duration is a constructive step towards the preparedness to contingencies and defining penalties for repair companies. To support this approach, one needs to construct probability distributions of the durations of the projects...... of concurrently running subprojects. Following this, guidance is provided on how to decide about what duration should define the deadline for completion of the whole work. A simple example is provided....

  19. 49 CFR 238.317 - Class II brake test.

    Science.gov (United States)

    2010-10-01

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

  20. 49 CFR 236.701 - Application, brake; full service.

    Science.gov (United States)

    2010-10-01

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