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Viewing 211 to 240 of 8727
2014-04-16
Article
The latest release of the MapleSim toolbox from Maplesoft expands control design capabilities and supports parameterized controllers for improved flexibility.
2014-04-16
Article
The all-new sports car poses a crucial question: Is it too clever by half? Dr. Andre Ebner, who heads the company’s development of onboard systems, argues very strongly that it is not.
2014-04-15
Article
With its i3 slated to reach U.S. customer hands in early May, BMW is ramping up production of its first mass-produced all-electric vehicle.
2014-04-14
Article
Customers want quieter cabins, but industry trends are working against the engineers who strive to reduce noise, vibration, and harshness.
2014-04-14
Article
Backed by the world’s fifth-fastest computer, Argonne’s new VERIFI service combines unique test facilities along with focused expertise to help engine developers.
2014-04-09
Article
Misfire detection is most difficult, SAE Congress panel tells attendees, and overall emissions diagnosis is harder than with passenger cars and light-duty trucks.
2014-04-07
Article
Atego Vantage is an integrated solution combining model-based systems and software engineering with asset-based modular design.
2014-04-07
Article
Elysium’s CADfeature 11.3 is a feature-based program for repairing, migrating, and reporting on product engineering data in manufacturing.
2014-04-07
Article
Meggitt Sensing Systems introduces a line of Endevco general purpose isotron IEPE accelerometers designed to meet the needs of various test applications.
2014-04-07
Article
Multiquip recently chose Exa to evaluate and reduce noise propagation from its containerized power generators.
2014-04-07
Article
The Maulflex conduit system from TE Connectivity is a lightweight, flexible, customizable shielded electrical conduit system for rugged environments.
2014-04-07
Article
XCal-View software from Renishaw offers improved functionality and flexibility for laser calibration data analysis.
2014-04-04
Article
According to CD-adapco's Frederick Ross, the first, and most difficult, stage in the construction of a virtual prototype is the process of pulling together all of the individual CAD parts that define a vehicle.
2014-04-01
Article
Palmer Wahl Instrumentation Group’s Wahl DST500-FM temperature indicator with fixed probes is a high-accuracy, wide-range thermometer designed for hazardous locations where accurate and reliable temperature monitoring is critical.
2014-04-01
Article
Dakota Instruments’ 6A03 acrylic flow meters are offered with interchangeable direct reading scales for air, water, argon, oxygen, carbon dioxide, nitrogen, helium, and hydrogen.
2014-04-01
Technical Paper
2014-01-0895
Hiroyuki Tanaka, Hisashi Ihara, Akira Satomura, Yasuhiko Wada, Hideto Momii, Tatsuya Suma
Abstract In order to enhance product attraction, it is important to reduce the impact noise when a vehicle go over bumps such as bridge joints. Vehicle performance to transitional noise phenomena is not yet analyzed well. In this paper, a prediction method is established by vector composition and inverse Fourier transform with the combination of Multibody Dynamics (MBD) and FEM. Also, a root cause analysis method is established with the following three mechanism analysis methods; transfer path analysis, mode contribution analysis, and panel contribution analysis.
2014-04-01
Technical Paper
2014-01-0892
Eric Frank, Peter Jacobsen
Abstract As the demand for Sound Quality improvements in vehicles continues to grow, robust analysis methods must be established to clearly represent end-user perception. For vehicle sounds which are tonal by nature, such as transmission or axle whine, the common practice of many vehicle manufacturers and suppliers is to subjectively rate the performance of a given part for acceptance on a scale of one to ten. The polar opposite of this is to measure data and use the peak of the fundamental or harmonic orders as an objective assessment. Both of these quantifications are problematic in that the former is purely subjective and the latter does not account for the presence of masking noise which has a profound impact on a driver's assessment of such noises. This paper presents the methodology and results of a study in which tonal noises in the presence of various level of masking noise were presented to a group of jurors in a controlled environment.
2014-04-01
Technical Paper
2014-01-0893
Adarsh Venkata Padmanabhan, Hariram Ravichandran, Lokendra Pavan Kumar Pappala, Rangaraj Ramanan Durai
Abstract This paper will discuss information extraction from sound signals obtained using acoustic sensors which are strategically placed on the automotive body. The sound signal obtained contains useful information such as vehicle and road surface characteristics. The aforementioned information was spread out at different frequencies in the spectral distribution of the signal. Well defined filters for the corresponding frequency bands were used to isolate these characteristics and patterns pertaining to the identified useful information from the signal. The obtained information can be used as inputs for systems such as vehicle safety systems, power train systems and NVH (Noise, Vibration and Harshness) systems.
2014-04-01
Technical Paper
2014-01-0890
Shuming Chen, Dengzhi Peng, Dengfeng Wang
Abstract Automobile cabin acoustical comfort is one of the main features that may attract customers to purchase a new car. The acoustic cavity mode of the car has an effect on the acoustical comfort. To identify the factors affecting computing accuracy of the acoustic mode, three different element type and six different element size acoustic finite element models of an automobile passenger compartment are developed and experimentally assessed. The three different element type models are meshed in three different ways, tetrahedral elements, hexahedral elements and node coupling tetrahedral and hexahedral elements (tetra-hexahedral elements). The six different element size models are meshed with hexahedral element varies from 50mm to 75mm. Modal analysis test of the passenger car is conducted using loudspeaker excitation to identify the compartment cavity modes.
2014-04-01
Technical Paper
2014-01-0888
V. Jadon, G. Agawane, A. Baghel, Venkatesham Balide, R. Banerjee, A. Getta, H. Viswanathan, A. Awasthi
Abstract With significant decrease in the background noise in present day automobiles, liquid slosh noise from an automotive fuel tank is considered as a major irritant during acceleration and deceleration. All major international OEMs and their suppliers try to reduce sloshing noise by various design modifications in the fuel tank. However, most major activities reported in open literature are primarily based on performing various CAE and experimental studies in isolation. However, noise generation and its propagation is a multiphysics phenomenon, where fluid mechanics due to liquid sloshing affects structural behaviour of the fuel tank and its mountings which in turn affects noise generation and propagation. In the present study a multiphysics approach to noise generation has been used to predict liquid sloshing noise from a rectangular tank.
2014-04-01
Technical Paper
2014-01-0221
John Morello
Abstract As automotive and commercial vehicle OEM's continue their quest to reduce cost, product selection, quality, and reliability must be maintained. On-engine and wheel located connection systems create the greatest challenges due to the extreme levels of vibration. In the past, devices were fewer, and there where less direct connects in high vibration locations (Engine/ wheel sensors, electronic controllers, fuel injectors). Instead, small wire harnesses (“pigtails”) were commonly used. These pigtails can dampen the effect of the environment which includes mild to severe vibration by keeping the environmental effect away from the electrical connection contact point. Electrically connecting directly to the device creates new challenges in the connection system with the increased threat of fretting corrosion. Suppliers supporting OEM's are attempting to meet these direct connect requirements with lubrication, precious metal plating, and high contact force contacts.
2014-04-01
Technical Paper
2014-01-0439
Xingyu Liang, Kang Sun, Yuesen Wang, Gequn Shu, Lin Tang, Lei Ling, Xu Wang
Abstract Like outside scenery, the car interior noise and road condition will affect the driver's mental state when driving. In order to explore the influence of external visual and auditory factors on the driver's mood in the driving process based on research of traffic soundscape, this paper has selected four backbone roads of Tianjin city (China) to test and drive a gasoline passenger vehicle at different speeds. Near Acoustic Holographic was used to scan interior acoustic field distribution, while the tracking shot of the driver's location was recorded by a Sony camera. People with different characteristics were invited to watch the video and completed a self-designed survey questionnaire. The external factors affecting the driver's mood were explored by analyzing all these data.
2014-04-01
Technical Paper
2014-01-0462
Se Jin Park, Seung Nam Min, Murali Subramaniyam, Heeran Lee, Dong Gyun Kim, Cheol Pyo Hong
Abstract Vibration is both a source of discomfort and a possible risk to human health. There have been numerous studies and knowledge exists regarding the vibrational behavior of vehicle seats on adult human occupants. Children are more and more becoming regular passengers in the vehicle. However, very little knowledge available regarding the vibrational behavior of child safety seats for children. Therefore, the objective of this study was to measure the vibrations in three different baby car seats and to compare these to the vibrations at the interface between the driver and the automobile seat. The test was performed on the National road at the average speed of 70 km/h and acceleration levels were recorded for about 350 Sec (5.83 min). One male driver considered as an adult occupant and a dummy having a mass of 9 kg was representing one year old baby. Four accelerometers were used to measure the vibration. All measured accelerations were relative to the vertical direction.
2014-04-01
Technical Paper
2014-01-1694
Michael Delbaere, Didier Frachon, Gerald Masson
Abstract Many synchronous electric motors require a very accurate position sensor compatible with a sinusoidal control. The purpose of such a control is to enable an efficient and smooth operation enhancing the comfort by limiting vibrations. In some cases related to mechanical constraints, we have to deal with through-shaft design. One can quote for examples power drives for Electric or Hybrid Electric Vehicles as well as for Electric Power Steering motor. More generally, these sensors need to keep a simple and robust design and a restricted number of parts as they are submitted to high vibration levels, a wide temperature range and speeds of several krpm. In order to meet such requirements, MMT has developed a magnetic sensor principle offering a competitive alternative to the conventional inductive resolver type sensors. The basics of this solution is a through shaft angular position sensor using one or two Hall-effect probes.
2014-04-01
Technical Paper
2014-01-1700
Xiaobing Liu, Paul Nahra, Anna Strehlau
Abstract Engine stop/start systems are one technology being developed to meet ever tightening fuel economy regulations. Several production vehicles in the market have adopted stop/start systems with 12 volt batteries and enhanced starters. During engine autostart events (restart after autostop), the engine/vehicle vibration may be objectionable to customers. In this paper, the impact of extended range retarded intake cam phasing on first cycle combustion and vehicle vibration during engine autostart is provided. The engine intake cam phasers of a production vehicle were modified so the effective compression during autostart could be set as low as 3.5. Achieving these autostart conditions while maintaining typical cam timing positions under cold start conditions is achievable with an innovative dual park phaser. NVH measurements and engine speed traces indicate that this approach reduced vibration during engine autostart by a measurable amount.
2014-04-01
Technical Paper
2014-01-1708
Xiaoxun Chen, Yu Zhang, Yunqing Zhang, Ming Jiang
Abstract In the present study, the research of the exhaust system is performed in three steps. In the first step, the average driving degree of freedom displacement (ADDOFD) is calculated by the free modal analysis of the exhaust system. It is easy to find the reasonable location of the hanger according to the value of the ADDOFD, since it represents the relative size of some DOF's response displacement at excitation state. The second of which is to analyse the vibration isolation performance of the exhaust system based on the first step. The dynamic analysis of the exhaust system together with the powertrain is studied, by which way the unit sinusoidal excitation is applied at the powertrain's mass centre, so that the response force at the hanger can be obtained. Finally, the relationship between the constrained model of the exhaust system and the stiffness of the hanger is investigated, which is significant in engineering.
2014-04-01
Technical Paper
2014-01-1758
Zamir Zulkefli, Maurice Adams
Abstract Gears are used in numerous applications where mechanical power needs to be transmitted as in the powertrain of cars, buses and other vehicles. These gears can potentially be a significant source of high-frequency vibration and radiated noise in a vehicle, which can be both harmful and objectionable to any listeners in the vicinity. A proposed approach to addressing the gear mesh-frequency vibrations is to utilize the low pass filtering effect of a hydrostatic bearing in a gear mesh-frequency noise mitigation system. This paper describes an experimental investigation of the low pass filtering effect of a hydrostatic bearing using an experimental setup involving a widely available materials testing machine. By using the materials testing machine, appropriately sized hydrostatic bearing and externally pressurized fluid supply system, empirical data was collected that allowed the frequency response of the hydrostatic bearing to be determined.
2014-04-01
Technical Paper
2014-01-1757
Marco Mammetti, Marina Roche Arroyos
Abstract Over recent years IDIADA has developed several prototype electric vehicles as well as testing a number of electric powertrain configurations. Generally the electric motor output shaft delivers the torque to the transmission under a considerable level of high-frequency load variation and with noticeable torque irregularities that must be smoothed out in order to fulfill general NVH targets. This paper deals with the development phase of a prototype vehicle in which a specific testing activity was carried out to improve the overall NVH behavior of the powertrain. For this purpose, the mechanism of energy transference from the current to the motor and from the motor to the downstream driveline components was deeply characterized. The activity was aimed at smoothing the abrupt change in torque delivery and limiting the transfer of torque irregularities from the motor to the transmission.
2014-04-01
Technical Paper
2014-01-1756
Miguel De la Cruz, Stephanos Theodossiades
Abstract In this paper, a direct correlation between transmission gear rattle experiments and numerical models is presented, particularly focusing on the noise levels (dB) measured from a single gear pair test rig. The rig is placed in a semi-anechoic chamber environment to aid the noise measurements and instrumented with laser vibrometers, accelerometers and free field microphones. The input torsional velocity is provided by an electric motor, which is controlled by a signal generator, aiming to introduce an alternating component onto the otherwise nominal speed; thus, emulating the engine orders found in an internal combustion engine. These harmonic irregularities are conceived to be the triggering factor for gear rattle to occur. Hence, the rig is capable of running under rattling and non-rattling conditions. The numerical model used accounts for the gear pair's torsional dynamics, lubricated impacts between meshing teeth and bearing friction.
2014-04-01
Collection
This technical paper collection sets out to reflect the recent advances on the research, development and practices of Powertrain NVH treatment. The coverage includes: engine, engine subsystem and components noise and vibration; powertrain systems noise measurement and instrumentation; powertrain systems noise analysis.
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