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Viewing 241 to 270 of 8657
Technical Paper
2014-04-01
Joe Serrano, Geoff Routledge, Norman Lo, Mark Shost, Vijay Srinivasan, Biswa Ghosh
Cylinder deactivation is a technology seeing increased automotive deployment in light of more demanding fuel economy and emissions requirements. Examples of current production systems include GM's Active Fuel Management and Chrysler's Multi-Displacement System, both of which provide one fixed level of deactivation. Dynamic Skip Fire (DSF), in which the number of fired cylinders is continuously varied to match the torque demand, offers significantly increased fuel savings over a wider operating range than the current production systems. One of the biggest challenges in implementing cylinder deactivation is developing strategies to provide acceptable Noise, Vibration and Harshness (NVH); this paper discusses those challenges and the methodologies developed. This work covers theoretical root causes; proposed metrics to quantify the NVH level; algorithmic and physical mitigation methods; and both subjective and objective evaluation results.
Technical Paper
2014-04-01
Hiroki Yamaura, Masao Ishihama, Kazuhide Togai
Engine torque profile shaping strategies have been proposed to reduce noise & vibration for passenger cars. However, it has not been sufficiently studied that feasible torque profile for vibration suppression is dependent on engine speed and target torque shape. On the other hand, combustion pressure profile shaping strategies have been proposed to reduce noise. However, there is almost no research of the quantitative evaluation of contribution of combustion pressure profile. First, the torque profile shaping was studied. Pre-compensated torque and 2-step torque were selected as typical target torque profiles. An effectiveness of vibration suppression by two torque profiles was evaluated by both drivetrain vibration model and engine torque profile model which have been established well. As a result of studying the torque profile shaping, timing of torque rise by the 2-step torque generation is delayed or advanced. Torque profile by the pre-compensation is deformed in steep change part.
Technical Paper
2014-04-01
Zhengfei Tang, Yongfu Chen, Jian Zeng, Yu Yang, Yunqing Zhang
NVH quality is one of the most important criteria by which people judge the design of a vehicle. The Powertrain Mounting System (PMS), which can reduce the vibration from engine to vehicle cab as well as the inside noise, has attained significant attention. Much research has been done on the isolation method for three- and four-point mounting. But the six-point mounting system, which is usually equipped in commercial vehicle, is seldom studied and should be paid more attention. In this paper, the support rod installed on the upside of the transmission case is considered as a flexible body. Thus a rigid-flexible coupling model of PMS is established and the necessity of the established model is analyzed by comparing the simulation results of the new model and those of the conventional model. Based on the traditional theory of energy decoupling and reasonable allocation of the natural frequencies, Adams and MATLAB are integrated into the optimization software iSIGHT to optimize the six-point PMS.
Technical Paper
2014-04-01
Jeremie Dernotte, John E. Dec, Chunsheng Ji
This article presents an investigation of the sources combustion-generated noise and its measurement in HCCI engines. Two cylinder-pressure derived parameters, the Combustion Noise Level (CNL) and the Ringing Intensity (RI), that are commonly used to establish limits of acceptable operation are compared along with spectral analyses of the pressure traces. This study focuses on explaining the differences between these two parameters and on investigating the sensitivity of the CNL to the ringing/knock phenomenon, to which the human ear is quite sensitive. Then, the effects of independently varying engine operating conditions such as fueling rate, boost pressure, and speed on both the CNL and RI are studied. Results show that the CNL is not significantly affected by the high-frequency components related to the ringing/knock phenomenon. In contrast, CNL is found to be sensitive to increasing energy in the 0.4 to 2.0 kHz frequency range generated by the combustion-induced uniform pressure rise.
WIP Standard
2014-03-25
This SAE Recommended Practice establishes the test procedure, environment, instrumentation, and data analyses for comparing interior sound level of passenger cars, multipurpose vehicles, and light trucks having gross vehicle weight rating (GVWR) of 4540 kg (10 000 lb) or less. The test procedure is characterized by having fixed initial conditions (specified initial vehicle speed and gear selection at the starting point on the test site) to obtain vehicle interior sound measurement during road load operation over various road surfaces at specified constant speeds. The measurement data so derived is useful for vehicle engineering development and analysis.
Article
2014-03-24
Massachusetts will be the home, and MIT the beneficiary, of a new FAA-designated unmanned aircraft test site just an hour and a half from campus. MIT classes and researchers developing unmanned aerial vehicles and their associated systems will be able to take advantage of the facility located at Joint Base Cape Cod, according to MIT Professor Jonathan How of the Department of Aeronautics and Astronautics.
Technical Paper
2014-03-24
Ulhas Mohite, Prashant Bhavsar
Abstract In this paper the approach to predict vibrations in motorcycles is presented. It can be divided mainly in two parts: prediction of engine forces using multi body dynamics (MBD) simulation and prediction of vibration response using FEA. Dynamic forces predicted at each engine mount through MBD simulation are used as input to FE analysis for vibration prediction. Single cylinder SI engine having primary balancer shaft is considered to develop this methodology. Flexibilities of important parts are considered for MBD simulation. Crankshaft ball bearing which is used in almost all two wheeler engine is modeled with 6×6 stiffness matrix. It provides coupling between radial, axial and tilting deflections of bearing and it also allows moment transfer from crankshaft to casing. This helps to predict realistic forces at each bearing and engine mounts. Distribution of primary and secondary forces at crank bearings and at different engine mounts is studied. Forces predicted from MBD simulation at each engine mounts are applied to full vehicle FE model.
Article
2014-03-12
DGE Inc.'s HMIts, which simulates a user’s speech and touch and then validates the response of the infotainment system, enables OEMs and Tier suppliers to perform repetitive testing on any HMI/infotainment system in a controlled environment, ensuring accurate results and eliminating the need for time-consuming and labor-intensive manual test plans.
Article
2014-03-12
dSPACE’s latest solution for electric motor testing combines SCALEXIO hardware-in-the-loop (HIL) simulation technology with an DS2655 FPGA base module and a scalable electronic load to enable users to test electric motor control systems in a more realistic environment by emulating the real motor and generator currents.
Article
2014-03-11
The Miniscan IRXpert analyzer from AMETEK Petrolab Co. is a portable multi-fuel analyzer for gasoline, diesel, and biodiesel blends incorporating mid-IR and near-IR spectroscopy to achieve accuracy of fuel properties. It will be displayed a the SAE 2014 World Congress in Detroit April 8-10.
Article
2014-03-10
Billing itself as the "first-ever open-source race team," Perrinn myTeam is inviting students, professional engineers, and others to contribute and share data for development of a possible sports car entry at Le Mans in 2015.
Article
2014-03-10
Engineers at NASCAR's Research & Development Center in Concord, NC, recently performed three separate window net and window net mounting tests and used them to design an improved window net mounting system for the 2013 season.
Article
2014-03-10
Jesse Garant & Associates (JG&A) Metrology Center offers industrial CT scanning focused on 3-D internal part inspection services using industrial computed tomography equipment.
Article
2014-03-10
CD-adpaco fills the design testing void with multidisciplinary design exploration (MDX), a methodology for automatically testing designs from early in the concept stage.
Article
2014-03-10
NanoFocus’ μsurf cylinder tool, which will be displayed at the SAE 2014 World Congress April 8-10 in Detroit, provides a nondestructive technique for high-resolution 3-D measurements of the inside of cylinder bores and liners.
WIP Standard
2014-03-06
To provide a method that accounts for the attenuation due to line-of-sight blockage of aircraft noise by terrain features.
WIP Standard
2014-03-06
To provide a method for modeling the noise directivity behind start-of-takeoff roll based on empirical data from modern jet aircraft. This method would replace the method described in Section 3.3.1 of SAE-AIR-1845A "Procedure for the Calculation of Airplane Noise in the Vicinity of Airports."
Magazine
2014-03-04
What's New at ConExpo/IFPE More new products and technologies that companies plan to showcase at this year's ConExpo-Con/Agg, which is co-located with the IFPE fluid-power event in Las Vegas from March 4-8, are previewed. Gearshift actuator dynamics in a dual clutch transmission The emergence of tougher environmental and fuel efficient legislations have triggered exploration and advance toward new and better vehicle transmission technologies. Software makes solid impact Programs are helping hydraulic systems do more while reducing operator workloads. Damping out booming noise NVH improvement techniques are gaining traction with the goal to improve the quality perception of off-highway equipment performance and operator comfort.
Article
2014-03-03
One of the subject areas garnering the most attention at the SAE 2014 World Congress is aerodynamics because of its effect on vehicle efficiency through drag reduction and the potential for real-world fuel economy gains.
Magazine
2014-03-01
The future for electric and hybrid vehicles in India Technical and political challenges alike have held back the electric and hybrid market, but there are signs of hope. Flex-fuel snowmobile challenge results in improved efficiency and lower emissions Noise and exhaust emissions of recreational snowmobiles have come under increased scrutiny by the U.S. federal government. Students from Kettering University take on the design challenges of meeting or exceeding such regulations. Actuator dynamics in a dual clutch transmission The emergence of tougher environmental and fuel efficient legislations have triggered exploration and advance toward new and better vehicle transmission technologies.
Article
2014-02-26
Technical sessions focused on interiors at the SAE 2014 World Congress span the designated technology areas, including electronics, materials, and safety/testing. One example in the electronics area, to take place April 8 at 9:30 a.m., covers multi-media systems. As part of the discussion, Takata researchers will present new touchscreen concepts such as a smart display surface that could benefit steering-wheel design.
Article
2014-02-17
The four-year, $15 million development program with UW-Madison and Wayne State University aims to achieve diesel levels of efficiency and torque, with lower emissions and cost—in an advanced gasoline-fueled engine.
Article
2014-02-12
A new approach is presented for wind tunnel calibrations based on a limited number of dynamic pressure measurements and a predictive technique using Neural Network (NN).
Article
2014-02-12
The methodology enables material selection and design optimization of energy absorbers for pedestrian protection based on a simple laboratory test and FE model, eliminating the need for extensive vehicle testing.
Article
2014-02-04
In teaming with Honda, Subaru, Jaguar Land Rover, MIT AgeLab, and Touchstone Evaluations to do basic research, Denso's Doug Patton says objective is "toolkit" for developing new HMIs.
WIP Standard
2014-02-04
This Hydrospace Information Report (HIR) identifies the general environmental considerations for the design, development, evaluation, and testing of advanced surface craft, submersible vehicles, and other marine craft. This HIR provides criteria on the environmental limits within which marine vehicles, related components, and associated equipment should operate satisfactorily and reliably. This HIR is intended for use as a guide for the development of specific environmental requirements to be included in detailed specifications for marine vehicles and associated equipment. Specific requirements are in a state of continual change as our knowledge of the ocean environment increases. The ocean environment varies with location and time. Changes in the ocean environment can occur not only on a seasonal basis but also monthly, weekly, daily, and in some cases even hourly.
Article
2014-01-30
BYD and the New York Metropolitan Transportation Authority (MTA) recently announced some findings from a two-month pilot test on a 40-ft BYD battery-electric bus conducted in Manhattan from Aug. 25 to Oct. 25 of last year. The electric bus maker also recently completed the first phase of a 10-month trial, which commenced this past summer in Gatineau, Quebec, and Ottawa, Ontario, again using a 40-ft BYD-supplied electric bus.
Article
2014-01-30
Dana Holding Corp. on Jan. 28 dedicated an 8000-m² (86,000-ft²) technology center in Pune, India. Its 240-plus engineers there do work for OEMs in the light-vehicle, commercial-vehicle, and off-highway markets in India and in the region.
Article
2014-01-30
Battery behemoth Johnson Controls and Lawrence Technological University in Southfield, MI, announced Jan. 29 that they will team to identify and validate new energy-storage technologies for vehicles. Johnson Controls says it will donate and install state-of-the-art test equipment and deploy technical resources to the university to propel academic and applied research into optimizing vehicle and battery design.
Article
2014-01-28
High-contrast IR wire grid polarizers from Edmund Optics are suited for broadband infrared applications that require high transmission and contrast, including spectroscopy and thermal imaging.
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