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Viewing 271 to 300 of 8654
Article
2014-01-20
The system is a late step in Ford’s building-block approach to self-driving cars. Existing assistance systems will be integrated and use improved sensors, hardware, and software.
Article
2014-01-15
Acoustic performance has become a key competitive factor for off-highway equipment due to an increasing focus on operator comfort and noise pollution as well as continuing regulatory pressure.
Article
2014-01-12
The diagnostics of machinery requires analysis of the time series of sensor and control signals.
Standard
2014-01-10
This SAE Standard has been adopted to provide a basis for dynamometer determination of gross engine power and torque under reference conditions. It is intended for use primarily by engine manufacturers who supply engines for installation by others in applications where the engine manufacturer may not control the induction and exhaust system design or the speed at which the engine is run.
Article
2014-01-08
A widely used material for lightning strike protection of CFRP structures within the aerospace industry is expanded metal foil (EMF). An issue with EMF is micro cracking of the paint, which can result in corrosion of the metal foil and subsequent loss of conductivity. Boeing researchers examined the issues of stress and displacement in the composite structure layup, which contribute to paint cracking caused by aircraft thermal cycling.
Article
2014-01-07
Because its engineers have made faster progress than expected, Toyota will offer a fuel-cell car in the U.S. in 2015—earlier than it had planned—the company announced Jan. 6 at the Consumer Electronics Show in Las Vegas.
Article
2014-01-03
Liquid ring pumps are used in aircraft fuel systems in conjunction with main impeller pumps and are used for priming the pump system as well as to remove fuel vapor and air from the fuel.
Article
2014-01-02
After a 10-month selection process involving 25 proposals from 24 states, the U.S. FAA has chosen six unmanned aircraft systems (UAS) research and test site operators across the country. In selecting the six test site operators, the FAA considered geography, climate, location of ground infrastructure, research needs, airspace use, safety, aviation experience, and risk.
Article
2013-12-27
Macro Sensors CD series of subminiature LVDT position sensors features a lightweight, low-mass core, compact 0.375 in diameter, and accuracy necessary for many aerospace applications with tight space and weight restrictions.
Technical Paper
2013-12-20
Alexandre Schalch Mendes, Pablo Siqueira Meirelles
This work describes the development and use of the Hardware-in-the-Loop (HIL) technique to evaluate the dynamic behavior of a torsional vibration rubber damper (TVD) used in a spark ignition internal combustion engine. The TVD was adapted to a test bench designed for this research and the HIL technique was applied considering the simulated dynamic response of the crankshaft. The results of the torsional vibration amplitudes are compared with measured values in a steady-state well identified condition, to experimentally validate the proposed mathematical model and the possibility to use the HIL technique to evaluate dampers and crankshaft behavior in realistic long term tests, where the rubber degradation also affects the dynamic response of the system. Finally, it was concluded that simulated and measured signals presented a good correlation in some engine operational conditions, reaching the objectives of this study.
Technical Paper
2013-12-20
P A Lakshminarayanan
The passby noise is the net effect of the noise from the engine, tires, vehicle panels, the fan and the exhaust silencer. Exhaust noise is probably the loudest component of the passby noise in diesel trucks. The passby noise is measured when the vehicle is in transient condition according to the standards. A technique is developed to simulate the transient noise from the exhaust using 1-d simulation software AVL-Boost. It considers thermodynamics of combustion in the engine including the turbocharger, inertia of the engine and the vehicle. The technique helps in optimizing exhaust silencer, acceleration and in-cylinder parameters in transient conditions and the turbocharger fatigue. A 165 kW 6-cylinder turbocharged and intercooled engine is simulated. The transient performance of the engine in the vehicle is validated by comparing the predicted results with the observed fuel consumption on road, time to accelerate to 60 km h−1 and the fluctuations in the turbocharger speed. The Linear Acoustics model of the silencer in conjunction with this transient model of the engine is used to predict the insertion loss of the silencer and the vehicle passby noise.
Article
2013-12-19
The goal of the program, which began in 2007, is to advance development of new sensor and control technologies with the aim of applying them to the active safety systems of future vehicles.
Article
2013-12-19
As some features quiet children, others interfere with driver concentration on the road ahead, studies by AAA and MIT find. Toyota is testing transfer of tasks to passengers to relieve the driver of cognitive overload.
Article
2013-12-10
ExhaustTrak from Sierra-CP Engineering, the Automotive Test Division of Sierra, was designed in response to customer requirements for a rugged, accurate, and fast solution for direct exhaust mass flow measurement, and is specifically designed for transient cycle flow rate measurement.
Article
2013-12-06
If smaller and thinner particles can be aligned in a certain way, it may be possible for a battery to hold a charge 50% longer than current batteries can.
Article
2013-12-05
AEI is not a publication that would normally embrace road impressions of a vehicle: the extraordinary Volkswagen XL1 is a very rare exception.
Article
2013-12-04
While shifting the manufacturing process of a composite part from pre-impregnated to a new liquid resin injection process, the Composites Development team at Bombardier Aerospace had to redesign the component to a new set of design allowables. The Integrated Product Development Team was able to quickly provide a turnkey solution that resulted in a positive business case for both weight and cost.
Article
2013-12-02
Millbrook Proving Ground in the U.K. has introduced a Portable Emissions Measurement System (PEMS).
Technical Paper
2013-11-27
Ninad Pimpalkhare, Gaurav Gupta, Mugundaram Ravindran, Chetan Prakash Jain, Chiranjit Ghosh, Prince Shital
Structure borne noise is the major source of noise inside the vehicle compartment. Recently the quietness of the occupant cabin has become an important dimension to the quality of product. OEMs are finding it challenging to meet the customer expectations for “Powerful yet quiet” attribute. Several focused studies have been made to reduce the under hood component noise in automobiles. This paper summarizes the optimization of vibro-accoustic sensitivity (VAS) of the engine mounts in passenger car engine. The contribution of each engine mount on the structure-borne noise transfer inside the cabin is studied by conventional FRF and normal mode analysis using Nastran, along with physical testing validation. This paper emphasizes to reduce the structure borne noise with the focus on weight reduction of the body side engine mount.
Technical Paper
2013-11-27
Shantanu Rohidas Tathe, Kiran P Wani
Whole body vibration deals with the biodynamic responses of human body in various postures. Vertical vibration exposure in sitting posture is common situation encountered while driving vehicle or riding motorcycle. We have chosen Wan & Schimmel's 4 DOF biodynamic model for this study by referring the goodness of fit results for various models available in the literature. A single degree of freedom model of motorcycle is used for analysis of whole body vibration on two wheeler. We have neglected pitch, yaw movements of two wheeler for purpose of simplicity. Whole body vibration analysis for human body in sitting posture is described by three terms i.e. Seat to Head Transmissibility (STH), Driving point impendence (DPM) & apparent mass (AP). In order to analyze human response on motorcycle Road to head (RTH), Road to lower torso (RTLT), Road to viscera (RTV), Road to upper torso (RTUT) responses are calculated for different motorcycle suspension natural frequencies. Simulation of biodynamic model is carried in MATLAB which shows close match with experimental results from literature.
Technical Paper
2013-11-27
Chatterjee Joydeep, Chetan Prakash Jain, Deepak Kumar Panda
Road/Tire noise is an important product quality criterion for passenger cars which are driving customers to decide upon the selection of a vehicle. Reduced engine noise and improvement in road conditions has resulted into more road/tire noise problem as average vehicle speed has gone up. Excitations from road surface travelling through the tire/suspension to vehicle body (structure-borne path) and air-pumping noise caused by tread patterns (air-borne paths) are the main contributor to tire noise issue inside the vehicle cabin [1]. A lot of emphasis is put on the component level design as well as its compliance with vehicle structure to reduce the cabin noise. The objective of this work is to establish a methodology for evaluating structure-borne road/tire noise by evaluating the tire structural behavior and its interface with the vehicle body and its suspension system and identifying the contributing critical paths. NVH techniques like Modal Parameter Estimation and Transfer Path Analysis are used to characterize the contribution of noise from tires.
Technical Paper
2013-11-27
Marco Mammetti, Juan Garcia, Marina Roche Arroyos
Reduction of CO2 emission is a mandatory objective for every actor in the field of automotive transport, and electric vehicles (EV's) are increasingly becoming an effective option for both OEMs and customers. However, components development and vehicle integration for EV's present new challenges that must be faced and new issues which need to be solved. In particular electric motor control systems are developed to achieve the same comfort conditions as in conventional vehicles. IDIADA developed a prototype electric commercial vehicle in which both the motor and driveline were integrated. The electric motor output shaft delivers the torque to the transmission under a certain level of load variation and with torque irregularities that must be smoothed out in the transmission components. This paper studies the results of the testing of the prototype vehicle carried out to improve the overall NVH behavior of the powertrain. The test results revealed that abrupt change in frequency content must be limited in order to avoid torque irregularities from the motor to the transmission.
Technical Paper
2013-11-27
Aditya Palsule, Nagasuresh Inavolu, M Jaganmohan Rao, Kalyan Hatti
The present work focusses on the Noise &Vibration refinement carried out on a Heavy commercial vehicle (HCV). In a heavy commercial 4×4 vehicle the existence of an auxiliary gearbox (AGB) is primarily for switching between the multiple drive options. The AGB can become an additional source of noise from the drive train. In this particular vehicle the overall noise from the vehicle has particularly been dominated by the noise from the AGB in specific drive options and conditions as experienced during the subjective assessment of the vehicle initially. First assessment was made by modifying the gear tooth geometry and then the gears were changed from spur to helical as a part of the AGB refinement process. The results of both these assessments were compared. A considerable improvement in the AGB noise was thereby achieved.
Technical Paper
2013-11-27
Kalyan S. Hatti, Vijay Antony John Britto, Sai sankaranarayana
In the automotive industry several attributes needs to be considered for the development of a new vehicle which are important for the customer, such as vehicle dynamics, driveability, fuel consumption, emissions, durability and NVH among many others. Sometimes these characteristics are conflicting and often need is to create a robust trade-off where the design space is sufficient to fit all of them in a vehicle that rhymes with the brand image and is appealing to the intended customer. Automobile manufacturers try to meet the requirements with respect to quality and comfort and often, emotional, aspects supercede the previous objective, pragmatic demands. The satisfaction of the demands by the customers concerning comfort, driving pleasure, design appears dominant and functionality criteria sometimes takes a back seat. NVH is considered to be one of the key buy in factor among the above mentioned attributes. This paper discusses on how the NVH aspect plays an vital role to get a competitive advantage over other vehicle aspects Moving from traditional approach of - ‘Test -Analyse -Fix’ to ‘Design Right First Time’ has been experienced.
Technical Paper
2013-11-27
Kishore Chittilla, Yogesh Yeola, Ashish Tiwari, Ramkumar Rajamanickam
Tire modal performance plays an important role in passenger car NVH refinement which includes road induced noise. Work done in the past, enumerates testing methods, excitation technique applied and boundary conditions. It also includes Mode shapes, analysis results and study of variables affecting the modal performance of passenger car Tire. Here, in this paper an attempt is made to compare the experimental modal analysis results, obtained using two different excitation techniques for exciting tire. In the experimental modal analysis under discussion, the passenger car tire of type 175/65R14, was inflated up to 2.2 bar (32psi) pressure in free-free condition. Impact Hammer and Electro-dynamic shaker were used to excite the tire structure in radial direction. Single Input Multiple Output technique was used for excitation and response signal acquisition. Modal parameters of the tested tire were identified in the frequency domain with curve fitting technique and modal parameter estimation technique.
Technical Paper
2013-11-27
Chandra Sekhar J, Ramkumar Rajamanickam, E Ramachandran, Nagesh Voderahobli Karanth
Modal analysis is a specialized tool which has been used for many years to reliably estimate various parameters such as natural frequency, mode shape and damping. Since these parameters have direct relevance to the behavior of any component or structure and the resultant vibrations, the methods used for evaluation of these have been taken up as a part of this project. MATLAB is a platform that serves analysis purpose and offers many advantages over dedicated, menu driven systems. Open function assure flexibility and possibility to modify functions for specific needs and also providing traceability and quality assurance. The current paper targets to make a comparative evaluation of various modal parameter estimators using existing MATLAB tools for determining modal parameters for simple structures. FRF measurements on simple structures are carried out and the data is processed using MATLAB run parameter estimators. The computed results are compared and advantages and limitations of the estimators are discussed.
Technical Paper
2013-11-27
Sivapriya Balasubramanian, Santosh Gosavi
Vehicle floor vibration is the resultant of different road inputs damped through various transfer paths. Seat comfort, which depends on these floor vibrations, can be evaluated with a single input signal “Pink noise”; which constitutes various road inputs. Transmissibility of seat structure on a vibration shaker with pink noise input includes all possible responses of road inputs. Still, transmissibility profile at vehicle end and component level varies. This is due to the utilization of “dummy” on component level testing on vibration shaker, which acts as a dead weight with dissimilar damping characteristics of human. A transmissibility correlation between human and dummy is attained by replacing the dummy in place of human and actuating it to find the difference in contribution between them for different class of vehicles. This contribution extrapolation from the damping effects of human and dummy is applied on dummy transmissibility. This results in a complete solution for attaining real time vehicle level seat structure transmissibility at component level testing.
Technical Paper
2013-11-27
Ammar Ali, Aditya S. Luktuke, E. Ramachandran, N.V. Karanth
Greater customer awareness is driving the automotive industry to constantly look to innovate and ensure that greater time, efforts and considerable resources are spent in developing a better vehicle. As we move away from noisy vehicles, the differentiating parameter in vehicles is the perception of quality in the vehicle noise or sound. As the masking effect due to overall vehicle noise level abates, many low noise sources gain prominence, which directly influences the perception of noise refinement. Hence, the concept of vehicle interior noise is not only limited to lower noise levels but has also extended to better sound quality (SQ). SQ technique involves use of relevant parameters for quantifying a subjective quality into an objective quantity. This paper will look at parameters relevant to subjective perception of vehicle interior noise and consider a benchmarking methodology targeting vehicle sound quality. A few vehicle test conditions relevant for vehicle SQ perception were identified.
Technical Paper
2013-11-27
Ankit Pant, Chetan Prakash Jain, Deepak Kumar Panda
For any new vehicle development, NVH target setting is crucial activity. Structural modification are to be done in early design phase to improve cabin comfort by identifying the sensitive paths and taking appropriate countermeasures for reduction of noise or vibrations transmission to cabin. A benchmark vehicle is taken to define the target areas for next model development. Numerical computations with suitably modified virtual model are carried out to accelerate the development cycle. Transfer path analysis (TPA) is an established technique for estimation and ranking of individual low-frequency noise or vibration contributions via the different structural transmission paths from point coupled powertrain or wheel-suspensions to the vehicle body [1]. TPA technique can also be used to define the improvement targets for future vehicles. This paper presents the methodology of carrying out the “Target Setting” using TPA for numerical model development for new model prior actual prototyping which will result into achieving desired NVH level in cabin.
Technical Paper
2013-11-27
Arpan Nagar, Venkatesan Chokkalingam, Nithiyanandam Umashankar, S Ravi Shankar
The crankshaft twist is of great concern for heavy duty engines. In order to have a longer B10 life and better NVH characteristics, it is desired to have minimum Torsional vibrations (TV) in the crank shaft. To keep the crankshaft twist in check - TV dampers are used. Aneasier approach is to use a Viscous TV damper which keeps TV below acceptable limit for entire speed range. But this is a very costly approach. In this paper, the design of rubber TV damper for multi-cylinder engine was optimized to have lower TV characteristics. The optimized rubber damper has been developed with AEM - VAMAC™ grade rubber. This material provides advantages of better TV attenuation, higher thermal resistance, oil resistance higher durability and a much longer life than other rubber compositions. Besides rubber profile was also optimized to obtain higher slip torque. The TV amplitudes with existing rubber compound (EPDM -Ethylene Propylene Diene Monomer) were measured in the engine testbed. The optimized TV damper with AEM - VAMAC™ rubber compound clearly indicates a reduction of about 50% in TV amplitudes for the critical orders of a multi-cylinder diesel engine.
Viewing 271 to 300 of 8654

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