Electro-Hydraulic Brake (EHB) System - Seminar Reports_PPT_PDF_DOC_Presentation_Free Download for Mechanical Engineering

1/28/13Electro-Hydraulic Brake (EHB) System - Seminar Reports| PPT| PDF| DOC| Presentation| Free Download for Mechanical Engineering Seminarsonly.com Home Applied Electronics IT Projects MBA Projects Computer Science Chemical Mechanical Projects PHP Projects Electronics Biomedical Java Projects VLSI Projects IT MBA .Net Projects Seminar Reports PPT Mechanical Project Ideas Software Projects IEEE Projects Electrical Science Computer Projects Electrical Projects Links Civil Electronics Projects Embedded Projects Contact us >> Bookmark this site (CTRL-D) Are you interested in this topic. Then mail to us immediately to get the full report. Electro-Hydraulic Brake (EHB) System Definition Electro-Hydraulic Brake (EHB) System is a system which senses the driver's will of braking through the pedal simulator and controls the braking pressures to each wheels. The system is also a hydraulic Brake by Wire system.Many of the vehicle sub-systems in E-mail :- contactv 2@ gm ail.com today’s modern vehicles are being converted into “by-wire” type systems. This normally ______________________________ implies a function, which in the past was activated directly through a purely mechanical device, is now implemented through electro-mechanical means by way of signal transfer to and from an Electronic Control Unit. Optionally, the ECU may apply additional “intelligence” based upon input from other sensors outside of the driver’s influence. ElectroHydraulic Brake is not a true “by-wire” system with the thought process that the physical wires do not extend all the way to the wheel brakes. However, in the true sense of the definition, any EHB vehicle may be braked with an electrical “joystick” completely independent of the traditional brake pedal. It just so happens that hydraulic fluid is used to transmit energy from the actuator to the wheel brakes. This configuration offers the distinct advantage that the current production wheel brakes may be maintained while an integral, manually applied, hydraulic failsafe backup system may be directly incorporated in the EHB system. The cost and complexity of this approach typically compares favorably to an Electro-Mechanical Brake (EMB) system, which requires significant investment in vehicle electrical failsafe architecture, with some needing a 42 volt power source. Therefore, EHB may be classified a “stepping stone” technology to full Electro-Mechanical Brakes A base brake event can be described as a normal or typical stop in which the driver maintains the vehicle in its intended direction at a controlled deceleration level that does not closely approach wheel lock. All other braking events where additional intervention may be necessary, such as wheel brake pressure control to prevent lock-up, application of a wheel brake to transfer torque across an open differential, or application of an induced torque to one or two selected wheels to correct an under- or over steering condition, may be classified as controlled brake performance. Statistics from the field indicate the majority of braking events stem from base brake applications and as such can be classified as the single most important function. From this perspective, it can be of interest to compare modernday Electro-Hydraulic Brake (EHB) hydraulic systems with a conventional vacuum-boosted brake apply system and note the various design options used to achieve performance and reliability objectives. Single Channel Complexity Comparison for Base Brakes: The conventional system utilizes a largely mechanical link all the way from the brake pedal through the vacuum booster and into the master cylinder piston. Proportional assist is provided by an air valve acting in conjunction with the booster diaphragm to utilize the stored vacuum energy. The piston and seal trap brake fluid and transmit the hydraulic energy to the wheel brake. www.seminarsonly.com/mech & auto/Electro-Hydraulic-Brake-System.php 1/3 and component selection. accumulator safety. and 2-wheel versus 4-wheel backup modes. circuit designs. Thus. As the apply and release valves open and close. which could include the addition of cooling fins. The extra components and the resulting software to control them. careful attention must be given to heat sinking. these few components are extremely robust in nature and thoroughly tested to exceed durability requirements. In the case of the electrohydraulic brake they center around increased electrical and mechanical complexity. Special consideration must be given to the ECU cover heat transfer properties.com/mech & auto/Electro-Hydraulic-Brake-System. In regards to the E-H pump and accumulator.seminarsonly. To prevent unwanted brake applications. closed recirculation system became the de facto standard.php 2/3 . This stored energy is created by pressurizing brake fluid from the reservoir with an electro-hydraulic pump into a suitable pre-charged vessel. As with any new technology. In the ECU design. On the mechanical side there is redundancy in valves and wheel brake sensors in that the vehicle may still be braked with two or three boosted channels. From the mid 80’s through the latter part of the 1990’s numerous ABS configurations ranging from hydraulically boosted open systems. Thermal robustness must also carefully be designed into the unit. to four valve flow control designs. and cost viewpoint. However. as duty cycles for valves and motors will be higher than in add-on type system. backup components are not typically considered practical from a size. to modulators based upon ball screws and electric motors came to market before the 8-valve.Seminar Reports| PPT| PDF| DOC| Presentation| Free Download for Mechanical Engineering Compare this to the basic layout of the typical EHB system. multiple processors and internal circuit isolation for critical valve drivers. component redundancy is used throughout. two of the three inputs must be detected to initiate base brake pressure. the driver’s input is normally interpreted by up to three different devices: a brake switch. there are concerns and tradeoffs to be dealt with. The backup master cylinder is subsequently locked out of the main wheel circuit using isolation solenoid valves. It is obvious the EHB system is significantly more complex in nature. First. Similar to the days of early ABS introduction. a travel sensor. numerous steps have been taken to eliminate the possibility of boost failure due to electronic or mechanical faults. does add a small level of additional complexity in itself. The “bywire” characteristics now come into play as the driver’s braking intent signals are sent to the ECU. www. This includes multiple wire feeds. Here an algorithm translates the dynamically changing voltage input signals into the corresponding solenoid valve driver output current waveforms.1/28/13 Electro-Hydraulic Brake (EHB) System . multiple EHB hydraulic design configurations have emerged. mass. To address this concern. The accumulator pressure is regulated by a separate pressure sensor or other device. so all wheel brake pressure must come from a high-pressure accumulator source. failsafe braking performance. a pressure sensor at each wheel continuously “closes the loop” by feeding back information to the ECU so the next series of current commands can be given to the solenoid valves to assure fast and accurate pressure response. materials. and a pressure sensor while an emulator provides the normal pedal “feel”. The configuration adopted in Delphi’s EHB development has included use of four-wheel failsafe with individual isolation pistons and utilization of mechanical pedal feel lockout. Elliott.mando. Ultimately.htm Like 0 Tw eet 2 0 5 You may also like this : Whiplash Protection System.php 3/3 . inherent accumulator precharge isolation. This particular design allows system flexibility. Safety Air Bags in Cars. http://www. Disk Brake.Seminar Reports| PPT| PDF| DOC| Presentation| Free Download for Mechanical Engineering braking performance. Brighton Technical Center. Microbial Fuel Cells. Full Authority Digital Engine Control. accumulator safety. Reference 1). Reuter. Automatic Air Suspension.contactv2@gmail. M/C C-86 2). Hybrid solar Desiccant Cooling System. Application of Nitrous Oxide in Automobiles. Pulse Detonation Engine.Dayton Technical Center.com/eng/technique_safetyehb. Virtual Manufacturing Systems. Four-Wheel Steering System. Micromachining. Wave Energy Converter. Each of these concerns has been answered by prudent designs and incorporation of new component technologies. Joseph A.seminarsonly. Hydroforming Techniques. Aerogel. Atomic Battery. Non-Destructive Testing. Electro-Hydraulic Brake (EHB) System.com www. ”Delphi Corporation”. Blended Wing Body. Noise Control in IC Engine. M/C 483-3DB210 3). and 2-wheel versus 4-wheel backup modes. David F. no matter which final configuration is selected for a specific vehicle platform. Wear Debris Analysis. and the ability to tune for optimum failed system stopping performance for all vehicle classes. Cryogenic Hardening.1/28/13 Electro-Hydraulic Brake (EHB) System . A carefully de-signed and implemented EHB system holds the promise of enabling the new brake-by-wire features while still reliably performing the everyday task of stopping the vehicle. IC Engine <<back copyright © 2006 V2 C om pute rs E-m ail :. Plastic Injection Molding. Antimatter. Ejection Seat. ”Delphi Corporation” . Ceramic Disc Brakes.com/mech & auto/Electro-Hydraulic-Brake-System. it will have to undergo the rigors of full brake system validation. Robotic Car.