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Viewing 91 to 120 of 11079
2017-09-17
Technical Paper
2017-01-2514
Wei Han, Lu Xiong, Zhuoping Yu, Haocheng Li
Abstract BBW (Brake-by-wire) can increase the electric and hybrid vehicles performance and safety. This paper proposes a novel mechatronic booster system, which includes APS (active power source), PFE (pedal feel emulator), ECU (electronic control unit). The system is easily disturbed when the system parameters and the outside conditions change. The system performance is weakened. The cascade control technique can be used to solve the problem. This paper develops an adaptive cascade optimum control (ACOC) algorithm based on the novel mechatronic booster system. The system is divided into main loop and servo loop, both of them are closed-loop system. The servo-loop system can eliminate the disturbance which exists in the servo loop. So the robustness of the cascade control system is improved than which of the general closed-loop control system. Different control object is respectively chosen. The control-oriented mathematical model is designed.
2017-09-17
Technical Paper
2017-01-2513
Haocheng Li, Zhuoping Yu, Lu Xiong, Wei Han
Abstract In this paper, an integrated electronic hydraulic brake(I-EHB) system is introduced, which is mainly composed of a motor, a worm gear, a worm, a gear, a rack etc. The friction leads the system to the creeping phenomenon and the dead zone. These phenomenon seriously affect the response speed and the hydraulic pressure control .In order to realize the accurate hydraulic pressure control of I-EHB system, a new friction compensation control method is proposed based on LuGre dynamic friction model. And the theoretical design of adaptive control method is designed based on the feedback of the master cylinder pressure and the operating state of the system. Then the stability of the control method is proved by Lyapunov theorem. A co-simulation model is built with Matlab/Simulink and AMESim, so as to prove the validity of the control method.
2017-09-17
Technical Paper
2017-01-2516
Xiong Yang, Jing Li, Hui Miao, Zheng Tang Shi
Abstract A general principle scheme of IEHB (Integrated Electro-Hydraulic Brake system) is proposed, and the working principle of the system is simply introduced in this paper. Considering the structure characteristics of the hydraulic control unit of the system, a kind of time-sharing control strategy is adopted to realize the purpose of independent and precise hydraulic pressure regulation of each wheel brake cylinder in various brake conditions of a vehicle. Because of the strong nonlinear and time varying characteristics of the dynamic brake pressure regulation processes of IEHB, its comprehensive brake performance is mainly affected by temperature, humidity, load change, the structure and control parameters of IEHB, and so on.
2017-09-17
Technical Paper
2017-01-2515
Christian Riese, Armin Verhagen, Simon Schroeter, Frank Gauterin
Abstract The ongoing changes in the development of new power trains and the requirements due to driver assistance systems and autonomous driving could be the enabler for completely new brake system configurations. The shift in the brake load collective has to be included in the systems requirements for electric vehicles. Many alternative concepts for hydraulic brake systems, even for decentralized configurations, can be found in the literature. For a decentralized system with all state of the art safety functionalities included, four actuators are necessary. Therefore, the single brake module should be as cost-effective as possible. Previous papers introduced systems which are for example based on plunger-like concepts, which are very expensive and heavy due to the needed gearing and design. In this paper a comparison between a state of the art hydraulic brake system using an electromechanical brake booster, and a completely new decentralized hydraulic brake concept is presented.
2017-09-17
Journal Article
2017-01-2529
Jae Seol Cho, JongYun Jeong, Hyoung Woo Kim, Hwa Sun Lee, Yang Woo Park, Junghwan Lim, Yoonjae Kim, Jinwoo Kim, Byung Soo Joo, Ho Jang
Abstract A semi-empirical index to evaluate the noise propensity of brake friction materials is introduced. The noise propensity index (NPI) is based on the ratio of surface and matrix stiffness of the friction material, fraction of high-pressure contact plateaus on the sliding surface, and standard deviation of the surface stiffness of the friction material that affect the amplitude and frequency of the stick-slip oscillation. The correlation between noise occurrence and NPI was examined using various brake linings for commercial vehicles. The results obtained from reduced-scale noise dynamometer and vehicle tests indicated that NPI is well correlated with noise propensity. The analysis of the stick-slip profiles also indicated that the surface property affects the amplitude of friction oscillation, while the mechanical property of the friction material influences the propagation of friction oscillation after the onset of vibration.
2017-09-17
Journal Article
2017-01-2521
Stacey Scherer
Abstract Wheel bearing friction torque (“drag”) directly contributes to vehicle fuel economy and CO2 emissions. At the same time, one of the most important factors for long-term durability of wheel bearings is effective seal performance. Since these two factors are often in conflict, it is important to balance the desire for low friction with the need for optimal sealing. One factor that affects wheel bearing sealing performance is the distortion of the outer ring that occurs when the bearing is mounted to the steering knuckle with fasteners. Minimizing this distortion is not just important for sealing, however. This paper explores the relationship between the outer ring distortion and the resulting friction torque. A design of experiments (DOE) approach was used in order to study the effects of the fastening bolt torque, constant velocity joint (CVJ) fastening torque, and outer ring distortion on component-level drag.
2017-09-17
Journal Article
2017-01-2502
David B. Antanaitis, Matthew Robere
Abstract The purchase of a new automobile is unquestionably a significant investment for most customers, and with this recognition, comes a correspondingly significant expectation for quality and reliability. Amongst automotive systems -when it comes to considerations of reliability - the brakes (perhaps along with the tires) occupy a rarified position of being located in a harsh environment, subjected to continuous wear throughout their use, and are critical to the safe performance of the vehicle. Maintenance of the brake system is therefore a fact of life for most drivers - something that almost everyone must do, yet given the potentially considerable expense, it is something that of great benefit to minimize.
2017-09-17
Journal Article
2017-01-2511
Toshikazu Okamura
Abstract The most fundamental function of an automobile brake system is assuring stable braking effectiveness under various conditions. In a previous paper (2004-01-2765), the author et al. confirmed that the friction behavior of disc brakes during running-in depends on both the friction materials and discs’ friction-surface textures. Various friction pairs were tested by combining discs finished with roller-burnishing and grinding and five friction materials including NAO and low-steel. Some NAO material exhibited large effects on the difference in friction behaviors between the discs’ surface textures. A disc finished with roller-burnishing needed a longer running-in period than that with grinding. In another paper (2011-01-2382), a further experiment was conducted by combining eight surface textures (finished under four turning conditions with and without additional roller-burnishing), two NAO materials, and two rotational directions.
2017-09-17
Journal Article
2017-01-2498
David B. Antanaitis, E Lloyd
Abstract This paper describes the development work that went into the creation of the SAE J3052 “Brake Hydraulic Component Flow Rate Measurement at High Delta Pressure”, and also shows some example applications. The SAE J3052 recommended practice is intended to measure flow characteristics through brake hydraulic components and subsystems driven by pressure differentials above 1 bar, and was anticipated by the task force to be invoked for components and subsystems for which pressure response characteristics are critical for the operation of the system (such as service brake pressure response and stopping distance, or pressure rise rate of a single hydraulic circuit in response to an Electronic Stability Control command). Data generated by this procedure may be used as a direct assessment of the flow performance of a brake hydraulic component, or they may be used to build subsystem or system-level models.
2017-09-17
Journal Article
2017-01-2501
ByeongUk Jeong, Hyong Tae Ryu, Kwang Ki Jung, Chang Jin Kim
Abstract Owing to the enhanced performance of engines these days, more heat should be dissipated in the braking system. Success of doing this properly causes more heat to the disc in the brake system which results in the deformation or scratches on the surface of it and a reduction in the appearance of the product. A study for detailed factors to aggravate this was done as a solution to prevent these from happening. In this paper, we present our work based on experiments to study MPU (Metal Pick Up) of the pad and the scoring(scratching) of the disc. MPU of which the main component is “Fe”, is formed through the process of fusing the separated materials from the disc by friction with the pad, and by local heat generation to the pad. [1,2,3,4,5] The occurrence of MPU and the possibility of the disc scoring resulting from this were studied by noting “Fe” which was transferred to the surface of the pad to different extent and degree of segregation according to the roughness of the disc.
2017-09-17
Journal Article
2017-01-2527
Dejie Huang, Xu Zhou, Peiqing Qian, Chao Wen, Yu Liu
Abstract The seal structure and key parameters of wheel bearing were introduced. Research on sealing failure diagnosis, abrasive scratch analysis, residual interference, and abrasion reconstruction was carried out for a typical seal structure. Based on these methods of scientific failure analysis, eight causes of seal failure were summarized systematically, which were important for the guidance of seal design and failure analysis of wheel bearings.
2017-09-17
Journal Article
2017-01-2532
David B. Antanaitis, Michael Shenberger, Max Votteler
Abstract The high performance brake systems of today are usually in a delicate balance - walking the fine line between being overpowered by some of the most potent powertrains, some of the grippiest tires, and some of the most demanding race tracks that the automotive world has ever seen - and saddling the vehicle with excess kilograms of unsprung mass with oversized brakes, forcing significant compromises in drivability with oversized tires and wheels. Brake system design for high performance vehicles has often relied on a very deep understanding of friction material performance (friction, wear, and compressibility) in race track conditions, with sufficient knowledge to enable this razor’s edge design.
2017-09-17
Journal Article
2017-01-2525
Seungpyo Lee, Mincheol Park
Abstract The primary functions of bearing seals are to prevent lubrication from escaping and foreign material from entering, the effectiveness of which is determined by the design of the seal lips. Bearings with low friction rotation are in great demand in the automotive market as a direct result of enforced vehicle fuel economy and reduced CO2 emissions regulations. Therefore, bearings with good sealing function and low friction rotation are required. This makes designing a seal challenging as the ideologies of high seal-ability and low friction rotation tend to be contradictory. Current estimations of bearing seal friction or rotational torque require significant time and cost through empirical methods of trial and error. Research into the estimation of bearing rotational torque through numerical analysis, based on finite element methods, is the focal point of this paper.
2017-09-17
Journal Article
2017-01-2526
Robert G. Sutherlin
Abstract As material cleanliness and bearing lubrication have improved, wheel bearings are experiencing less raceway spalling failures from rotating fatigue. Warranty part reviews have shown that two of the larger failure modes for wheel bearings are contaminant ingress and Brinell damage from curb and pothole impacts. Warranty has also shown that larger wheels have higher rates of Brinell warranty. This paper discusses the Brinell failure mode for bearings. It reviews a vehicle test used to evaluate Brinell performance for wheel bearings. The paper also discusses a design of experiments to study the effects of factors such as wheel size, vehicle loading and vehicle position versus the bearing load from a vehicle side impact to the wheel. As the trend in vehicle styling is moving to larger wheels and low profile tires, understanding the impact load can help properly size wheel bearings.
2017-09-17
Journal Article
2017-01-2522
Chao Wen, Lu Zhang, Tong Luo, Dejie Huang, Yu Liu
Abstract The actual installed conditions of 1st, 2nd and 3rd generation of wheel bearing were introduced. The theoretical factors of the axial fastening force for the axle (or CVJ bolts) and nuts were analyzed and the requirements for building up a precise axial force test system were given out. Four testing plans were discussed for the requirements. Based on the cases, the axial force test system was built up, and the axial force test was successfully carried out for the front wheel bearing of a car.
2017-09-17
Journal Article
2017-01-2524
Sebastiano Rizzo, Stefano Pagliassotto
Abstract Wheel bearings are safety-critical automotive components. For this application, the steel rolling elements are subjected to fatigue failure and therefore play a key role in overall bearing fatigue life performance. This performance is influenced by metallurgical, mechanical, and physical properties obtained by precise manufacturing process parameters. These properties are continuously analyzed and are evolving at all bearing manufacturing companies. Last year, the Precision Bearing Components (PBC) Group of NN Inc., a global supplier of steel rolling elements for wheel bearings, developed a non-conventional heat treatment process for 100Cr6 (SAE 52100) rolling element steel for improved fatigue performance. The results of wheel bearing rolling contact fatigue (RCF) tests showed the importance of rolling element dimensional stability. As retained austenite transformed to the martensite phase, rolling element volume increase occurred, leading to fatigue failure.
2017-09-17
Journal Article
2017-01-2520
Vincenzo Ricciardi, Dzmitry Savitski, Klaus Augsburg, Valentin Ivanov
Abstract The brake architecture of hybrid and full electric vehicle includes the distinctive function of brake blending. Known approaches draw upon the maximum energy recuperation strategy and neglect the operation mode of friction brakes. Within this framework, an efficient control of the blending functions is demanded to compensate external disturbances induced by unpredictable variations of the pad disc friction coefficient. In addition, the control demand distribution between the conventional frictional brake system and the electric motors can incur failures that compromise the frictional braking performance and safety. However, deviation of friction coefficient value given in controller from actual one can induce undesirable deterioration of brake control functions.
2017-09-17
Journal Article
2017-01-2496
Enrico Galvagno, Antonio Tota, Alessandro Vigliani, Mauro Velardocchia
Abstract Brake systems represent important components for passenger cars since they are strictly related to vehicle safety: Anti-lock Braking Systems (ABS) and Electronic Stability Control (ESC) are the most well-known examples. The paper is focused on the characterization of the braking hydraulic plant and on the design of a pressure following control strategy. This strategy is aimed at pursuing performances and/or comfort objectives beyond the typical safety task. The low-level logic (focus of the paper) consists of a Feedforward and Proportional Integral controller. A Hardware In the Loop (HIL) braking test bench is adopted for pressure controller validation by providing some realistic reference pressure histories evaluated by a high-level controller. Results prove that innovative control strategies can be applied to conventional braking systems for achieving targets not limited to braking issues, i.e., comfort or NVH tasks.
2017-09-17
Technical Paper
2017-01-2533
Thomas J. Hall
Abstract As Pure Electric Vehicles have become a recent entrant to the higher end Passenger Vehicle Market, general interest in the overall technology has expanded beyond the environmental interest into the pure performance opportunities associated with electrically driven vehicles. Recently a new Racing Series has formed that is dedicated to Electric Vehicle Racing. Specifically the Formula-E® series has emerged as a venue for competition for Pure Electric open wheel race cars competing on Road Courses throughout the world. Success in the race series is influenced by the available energy that can be stored in the battery along with the applicable electrical efficiencies associated with the drive and control of the Propulsion Motors. The Race series also allows Regenerative Braking.
2017-09-17
Technical Paper
2017-01-2534
Silvia Faria Iombriller, Wesley Bolognesi Prado
Summary Considering that the most part of commercial vehicles are equipped with air brakes it is very important assure specific technical requirements for air brake system and its components. In addition, the effects of brake system failure are more critical for commercial vehicles which require more attention on their requirements details. Historically, the development of air brakes technology started on North America and Europe and consequently two strong and distinct resolutions were structured: FMVSS 121 and ECE R.13, respectively. For passenger cars were developed the ECER.13H to harmonize North American and European resolutions. However, for commercial vehicles regional applications, culture and implementation time must be considered. These commercial vehicles peculiarities must be understood and their specific requirements harmonized to attend the global marketing growth.
2017-09-17
Journal Article
2017-01-2482
Meechai Sriwiboon, Nipon Tiempan, Kritsana Kaewlob, Seong K Rhee, Donald Yuhas
Abstract Disc pad physical properties are believed to be important in controlling brake friction, wear and squeal. Thus these properties are carefully measured during and after manufacturing for quality assurance. For a given formulation, disc pad porosity is reported to affect friction, wear and squeal. This investigation was undertaken to find out how porosity changes affect pad natural frequencies, dynamic modulus, hardness and compressibility for a low-copper formulation and a copper-free formulation, both without underlayer, without scorching and without noise shims. Pad natural frequencies, modulus and hardness all continuously decrease with increasing porosity. When pad compressibility is measured by compressing several times as recommended and practiced, the pad surface hardness is found to increase while pad natural frequencies and modulus remain essentially unchanged.
2017-09-17
Journal Article
2017-01-2481
Vishal Mahale, Jayashree Bijwe, Sujeet Sinha
Abstract Potassium titanate (KT) fibers/whiskers are used as a functional filler for partial replacement of asbestos in NAO friction materials (FMs). Based on little information reported in open literature; its exact role is not well defined since some papers claim it as the booster for resistance to fade (FR), or wear (WR) and sometimes as damper for friction fluctuations. Interestingly, KT fibers and whiskers (but not powder) are proved as carcinogens by the International Agency for Research on Cancer (IARC). However, hardly any efforts are reported on exploration of influence of KT powder and its optimum amount in NAO FMs (realistic composites) in the literature. Hence a series of five realistic multi-ingredient compositions in the form of brake-pads with similar parent composition but varying in the content of KT powder from 0 to 15 wt% (in the steps of 3) were developed. These composites were characterized for physical, mechanical, chemical and tribological performance.
2017-09-17
Journal Article
2017-01-2523
Seonho Lee, Yoongil Choi, Kyuntaek Cho, Hyounsoo Park
Abstract Raceway Brinell damage is one major cause of wheel bearing (hub unit) noise during driving. Original Equipment Manufacturer (OEM) customers have asked continuously for its improvement to the wheel bearing supply base. Generally, raceway Brinelling in a wheel hub unit is a consequence of metallic yielding from high external loading in a severe environment usually involving a side impact to the wheel and tire. Thus, increasing the yielding strength of steel can lead to higher resistance to Brinell damage. Both the outer ring and hub based on Generation 3 (Gen. 3) wheel unit are typically manufactured using by AISI 1055 bearing quality steel (BQS); these components undergo controlled cooling to establish the core properties then case hardening via induction hardening (IH). This paper presents a modified grade of steel and its IH design that targets longer life and improves Brinell resistance developed by ILJIN AMRC (Advanced Materials Research Center).
2017-09-05
Article
The ITT Smart Pad is a brake pad technology concept from ITT Inc. that offers an approach to friction designed to empower the entire brake system with real-time data.
CURRENT
2017-09-05
Standard
J2704_201709
This SAE Recommended Practice describes a test method for determining the vertical force and deflection properties of a non-rolling tire and the associated contact patch length and width. The method applies to any tire so long as the equipment is properly scaled to conduct the measurements for the intended test tire. The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development. NOTE: Herein, road load models are models for predicting forces applied to the vehicle spindles during operation over irregular pavements. Within the context of this Recommended Practice, forces applied to the pavement are not considered.
CURRENT
2017-09-05
Standard
J2718_201709
This SAE Recommended Practice describes application of two closely related test procedures, which together determine the linear range longitudinal and lateral stiffnesses of a statically loaded non-rotating tire. The procedures apply to any tire so long as the equipment is properly sized to correctly conduct the measurements for the intended test tire. The data are suitable for use in determining parameters for road load models and for comparative evaluations of the measured properties in research and development. NOTE: Herein, road load models are models for predicting forces applied to the vehicle spindles during operation over irregular pavements. Within the context of this document, forces applied to the pavement are not considered.
2017-08-31
Magazine
New vision @ Gentex Creating a vital ADAS partner through home-grown R&D and manufacturing in (of all places) western Michigan. Positioning for hybrid growth BorgWarner "modularizes" to provide OEMs optimal electrified-driveline flexibility. Editorial: Beleaguered diesel could use a break-or a breakthrough SAE Standards News Kickoff to begin testing program to validate SAE J2954 wireless charging Recommended Practice Supplier Eye Will you be an active participant or passive bystander? The Navigator For future vehicles, communication equals trust Tenneco readies new semi-active digital suspension for 2020 New 90-degree turbo V6 leads Audi's hybridization blitz GKN using modular control algorithms for added systems integration U of M students engineer new autonomous shuttle system Jaguar's 2018 E-Pace shares Land Rover bones Ford pumps powertrains for 2018 F-150 2018 Subaru Crosstrek moves to new global platform Nissan's Ponz Pandikithura on EV lifecycle value
2017-08-22
Article
The wheel rim consists of two aluminium (Al) parts, the inner Al carrier star with the Al brake disk and the outer Al rim well with the tyre. Unlike a conventional disc brake, the New Wheel Concept brake engages the Al disk from the inside. This allows it to have a particularly large diameter, enhancing braking performance.
2017-08-21
Article
The Activac system debuted on 2017MY Ford F-150s powered by the second-generation 3.5-L EcoBoost V6. Weighing 1.82 lb, the vacuum-generation system, including hoses, replaced a 2.27 lb cam-driven mechanical pump.
2017-08-17
Journal Article
2017-01-9683
Rui Ma, John B. Ferris, Alexander A. Reid, David J. Gorsich
Abstract Computationally efficient tire models are needed to meet the timing and accuracy demands of the iterative vehicle design process. Axisymmetric, circumferentially isotropic, planar, discretized models defined by their quasi-static constraint modes have been proposed that are parameterized by a single stiffness parameter and two shape parameters. These models predict the deformed shape independently from the overall tire stiffness and the forces acting on the tire, but the parameterization of these models is not well defined. This work develops an admissible domain of the shape parameters based on the deformation limitations of a physical tire, such that the tire stiffness properties cannot be negative, the deformed shape of the tire under quasi-static loading cannot be dominated by a single harmonic, and the low spatial frequency components must contribute more than higher frequency components to the overall tire shape.
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