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Viewing 1 to 30 of 8974
2017-06-05
Technical Paper
2017-01-1775
Mark A. Gehringer, Robert Considine, David Schankin
This paper describes recently developed test methods and instrumentation to address the specific noise and vibration measurement challenges posed by large diameter single-piece tubular aluminum propeller shafts with high modal density. The application described in this paper is a light duty truck, although the methods described are applicable to any rotating shaft with similar dynamic properties. To provide a practical example of the newly developed methods and instrumentation, rotating and non-rotating data were acquired in-situ for several propeller shafts of varying construction, including both lined and unlined shafts. Data were also acquired with and without a torsional tuned vibration absorber attached to the driveline. The example data exhibit features that are uniquely characteristic of large diameter single-piece tubular shafts with high modal density, including the particular effect of shaft rotation on the measurements.
2017-06-05
Technical Paper
2017-01-1820
Martin Sopouch, Josip Hozmec, Alessandro Cadario
This paper presents a simulation environment and methodology for noise and vibration analyses of a driven rear axle in a bus application, with particular focus on medium to high frequency range (400 Hz to 3 kHz). The workflow demonstrates structure borne noise and sound radiation analyses. The fully flexible Multi–Body Dynamics (MBD) model - serving to cover the actual mechanical excitation mechanisms and the structural domain – includes geometrical contacts of hypoid gear in the central gear and planetary gear integrated at hubs, considering non-linear meshing stiffness. Contribution of aforementioned gear stages, as well as the propeller shaft universal joint at the pinion axle, on overall axle noise levels is investigated by means of sensitivity analysis. Based on the surface velocities computed at the vibrating axle-housing structure the Wave Based Technique (WBT) is employed to solve the airborne noise problem and predict the radiated sound.
2017-06-05
Technical Paper
2017-01-1892
Yosuke Tanabe, Masanori Watanabe, Takafumi Hara, Katsuhiro Hoshino, Akira Inoue, Masaru Yamasaki
Predicting vibration of motor gearbox assembly driven by a PWM inverter in an early development stage is demanding, because the assembly is one of the dominant noise sources of electric vehicle (EV). In this paper, we propose a simulation model that can predict the transient vibration excited by gear meshing, reaction force from mount and electromagnetic forces including carrier frequency component of inverter up to 10 kHz. By employing the techniques of structural model reduction and state space modeling, the proposed model enables to predict the vibration of assembly in operating condition to simulate with a system level EV simulator. A verification test was conducted to compare the simulation result with running test result of EV. Although the absolute value of simulation is 10 dB different from test at most, we conclude that the model can well predict the trend of the dominant order vibration caused by the electromagnetic force of motor including the carrier frequency of inverter.
2017-06-05
Technical Paper
2017-01-1891
Todd Freeman, Kelby Weilnau
Similar to the automotive industry, the expectations from customers for the noise and vibration performance of personal vehicles such as golf carts, ATV’s, and side-by-side vehicles has continued to evolve. Not only do customers expect these types of vehicles to be more refined and to have acoustic signatures that match the overall performance capabilities of the vehicle, but marketing efforts continue to focus on product differentiators which can include the acoustic and vibration performance. Due to this increased demand for acoustic and vibration performance, additional NVH efforts are often required to meet these expectations. This paper provides a sample of some of the efforts that have occurred to further refine and develop the noise and vibration signature for golf carts.
2017-06-05
Technical Paper
2017-01-1847
Asif Basha Shaik Mohammad, Ravindran V, Nageshwara Rao P
The high noise and vibration levels, to which drivers of agricultural tractor are often exposed for long periods of time, have a significant part in the driver’s fatigue and may lead to substantial hearing impairment and health problems. For these reasons, the noise and vibration comfort has become an important criterion in the design of the driver’s cabin and a determining factor in the acceptance and sales potential of agricultural tractors. Therefore, it is essential for an optimal cabin design to have time and cost effective analysis tools for the assessment of the noise and vibration characteristics of various design alternatives at both the early design stages and the prototype testing phase. Airborne excitation and Structure Borne excitation are two types of dynamic cabin excitations mainly cause the interior noise in a driver’s cabin.
2017-06-05
Technical Paper
2017-01-1832
Giovanni Rinaldi, Jason Edgington, Brian Thom
Typical approaches to regulating sound performance of vehicles and products rely upon A-weighted sound pressure level or sound power level. It is well known that these parameters do not provide a complete picture of the customer’s perception of the product and may mislead engineering efforts for product improvement. A leading manufacturer of agricultural equipment set out to implement a process to include sound quality targets in its product engineering cycle. First, meaningful vehicle level targets were set for a tractor by conducting extensive jury evaluation testing and by using objective metrics that represent the customer’s subjective preference for sound. Sensitivity studies (“what-if” games) were then conducted, using the predicted sound quality (SQ) index as validation metric, to define the impact on the SQ performance of different noise components (frequency ranges, tones, transients).
2017-06-05
Technical Paper
2017-01-1839
Edward T. Lee
It is common for automotive manufacturers and off-highway machinery manufacturers to gain an insight of the system structural dynamics by evaluating the system inertance functions near the mount locations. The acoustic response at the operator’s ears is a function of the vibro-acoustic characteristics of the system structural dynamics interacting with the cavity, with the actual load applied at the mount locations. The overall vibro-acoustic characteristics can be influenced by the change in local stiffness. To analyze the response of a system, it is necessary to go beyond analyzing its transfer functions. The actual load needs to be understood and be applied towards the transfer function set. Finite element (FE) based analysis provides a good foundation for deterministic solutions. However finite element method suffers in accuracy as the frequency increases. Many NVH problems happen to be at the mid frequency range where solving the problem with the FE-only approach falls short.
2017-06-05
Technical Paper
2017-01-1858
James Haylett, Andrew Polte
Truck and construction seats offer a number of different challenges over automotive seats in the identification and characterization of Buzz, Squeak, and Rattle (BSR) noises. These seats typically have a separate air or mechanical suspension and usually have a larger number and variety of mechanical adjustments and isolators. Associated vibration excitation tend to have lower frequencies with larger amplitudes. In order to test these seats for both BSR and vibration isolation a low-noise shaker with the ability to test to low frequency, down to 1 Hz was used. Slowly swept sine excitation was particularly helpful in understanding the seat mode shapes and nonlinearities at low frequency which showed large displacements. A typical sample set of seat BSR sounds are described in terms their time and frequency characteristics and widely used sound quality metrics.
2017-06-05
Technical Paper
2017-01-1889
Todd Tousignant, Kiran Govindswamy, Georg Eisele, Christoph Steffens, Dean Tomazic
The automotive industry continues to develop new powertrain and vehicle technologies aimed at reducing overall vehicle level fuel consumption. Specifically, the use of electrified propulsion systems is expected to play an increasingly important role in helping OEM’s meet fleet CO2 re-duction targets for 2025 and beyond. Electric and hybrid electric vehicles do not typically utilize IC engines for low-speed operation. Under these low-speed operating conditions, the vehicles are much quieter than conventional IC engine-powered vehicles, making their approach difficult to detect by pedestrians. To mitigate this safety concern, many manufacturers have synthesized noise (using exterior speakers) to increase detection distance. Further, the US National Highway Traffic Safety Administration (NHTSA) has provided recommendations pursuant to the Pedestrian Safety Enhancement Act (PSEA) of 2010 for such exterior noise signatures to en-sure detectability.
2017-06-05
Technical Paper
2017-01-1764
Himanshu Amol Dande, Tongan Wang, John Maxon, Joffrey Bouriez
The demand for quieter interior cabin spaces among business jet customers has created an increased need for more accurate prediction tools. In this paper the authors will discuss a collaborative effort between Jet Aviation and Gulfstream Aerospace Corporation to develop a Statistical Energy Analysis (SEA) model of a large commercial business jet. To have an accurate prediction, it is critical to accurately model the structural and acoustic subsystems, critical noise transmission paths and dominant noise sources on the aircraft. The geometry in the SEA model was developed using 3D CAD models of major airframe and interior cabin components. The noise transmission path was characterized through extensive testing of various aircraft components in the Gulfstream Acoustic Test Facility. Material definitions developed from these tests became input parameters in the SEA model.
2017-06-05
Technical Paper
2017-01-1757
Matthew Maunder, Benjamin Munday
Excitement, image and emotion are key attributes for cars, particularly those with higher power ratings. Engine sound has traditionally acted as the car’s voice, conveying these attributes to the driver and passengers along with the brand image. Engine sound also underpins the dynamic driving experience by giving instant feedback about how a car is operating, enhancing the connection between driver and vehicle. For decades, the automotive industry has engineered engine sound to achieve these benefits, thereby defining the ‘language’ of car sound. Electric vehicles deliver strong and responsive performance but naturally lack the acoustic feedback that internal combustion engines provide. While this gives advantages in terms of comfort and environmental noise, the benefits of engine sound are lost. Carefully controlled acoustic feedback brings tangible and valuable benefits both for the dynamic driving experience and to convey the brand image.
2017-06-05
Technical Paper
2017-01-1755
Frank C. Valeri, James T. Lagodzinski, Scott M. Reilly, John P. Miller
Hybrid powertrain vehicles inherently create discontinuous sounds during operation. The discontinuous noise created from the electrical motors during transition states are undesirable since they can create tones that do not correlate with the dynamics of the vehicle. The audible level of these motor whines and discontinuous tones can be reduced via common noise abatement techniques or reducing the amount of regeneration braking. One electronic solution which does not affect mass or fuel economy is Masking Sound Enhancement (MSE). MSE is an algorithm that uses the infotainment system to mask the naturally occurring discontinuous hybrid drive unit and driveline tones. MSE enables a variety of benefits, such as more aggressive regenerative braking strategies which yield higher levels of fuel economy and an overall more pleasing interior vehicle powertrain sound. This paper will discuss the techniques and signals used to implement MSE in a hybrid powertrain equipped vehicle.
2017-06-05
Technical Paper
2017-01-1763
Lisa Steinbach, Ercan Altinsoy, Robert Rosenkranz
In today's urban environment inhabitants are permanently exposed to elevated noise levels, which are mostly dominated by traffic noise. The current electrification of vehicles might affect the traffic noise in city centers. The aim of this work was to determine the pedestrian reaction and the annoyance of more realistic traffic situations. For this purpose both combustion and electric vehicle noise situations and mixed scenarios of both concepts were generated. The differences in the perceived annoyance were investigated with perception studies. It was found that in some cases the order of the annoyance ratings will change: a single electric vehicle, which was perceived as least annoying, was evaluated as the most annoying noise by the increase to eight vehicles. The background noise also has an impact on the perception of annoyance and the warning effect.
2017-06-05
Technical Paper
2017-01-1834
Dirk von Werne, Prasanna Chaduvula, Patrick Stahl, Michael Jordan, Jamison Huber, Korcan Kucukcoskun, Mircea Niculescu
Fan noise can form a significant part of the vehicle noise signature and needs hence to be optimized in view of exterior noise and operator exposure. Putting together unsteady CFD simulation with acoustic FEM modeling, tonal and broadband fan noise can be accurately predicted, accounting for the sound propagation through engine compartment and vehicle frame structure. This paper focuses on method development and validation in view of the practical vehicle design process. In a step by-step approach, the model has been validated against a dedicated test-set-up, so that good accuracy of operational fan noise prediction could be achieved. Main focus was on the acoustic transfer through the engine compartment. The equivalent acoustic transfer through radiators/heat exchangers is modeled based on separate detailed acoustic models. The updating process revealed the sensitivity of various components in the engine compartment.
2017-06-05
Technical Paper
2017-01-1835
Nader Dolatabadi, Ramin Rahmani, Stephanos Theodossiades, Homer Rahnejat, Guy Blundell, Guillaume Bernard PhD
Clutches are commonly utilised in passenger type and off-road heavy-duty vehicles to disconnect the engine from the driveline and other parasitic loads. In off-road heavy-duty vehicles, fuel efficiency and start-up functionality at extended ambient conditions, such as cold start-up and low intake absolute pressure are crucial. Off-road vehicle manufacturers usually overcome the parasitic loads in these conditions by oversizing the engine. Caterpillar Inc. as the pioneer in the off-road technology has developed a novel clutch design to allow for engine downsizing while vehicle’s performance is not affected. The tribology behaviour of clutch will be crucial to start engagement in time and reach the maximum clutch capacity in the shortest possible time and the safest method in terms of dynamics. A multi-body dynamics model of the clutch system is developed in MSC ADAMS. Flywheel carries the same speed and torque as engine and represents the engine input to the clutch.
2017-06-05
Technical Paper
2017-01-1833
Bonan Qin, Jue Yang, Xinxin Zhao
Articulated engineering vehicle travels on complex road, its working condition is bad and because of the non-rigid connection between the front and rear body, additional degrees of freedom is brought in and the transverse stiffness is relatively weak. When the articulated vehicle run in a high speed along a straight line, it is easy to cause the transverse swing and the poor manipulation stability. If it is serious enough, it will lead to "snake shape" instability phenomena. This kind of instability will increase driving resistance and tire wear, the lateral dynamic load and aggravate the damage of the parts. When steering, the center of gravity will offset laterally which will lead a higher probability of rollover accident. A mathematical model for a 35t articulated dump truck with four motor-driven wheels is established in this paper, to study the condition for its stable driving and the effects of the vehicle structural parameters.
2017-06-05
Technical Paper
2017-01-1837
Paul R. Donavan, Carrie Janello
Acoustic beamforming was used to localize noise sources on heavy trucks operating on highways in California and North Carolina at a total of 20 sites. Over 1,200 trucks were measured under a variety of operating conditions including cruise on level highways, on upgrades, down degrades, low speed acceleration, and for various speeds and pavements. The contours produced by the beamforming measurements were used to identify specific source contributions under these conditions and for a variety of heavy trucks. Consistently, the highest noise levels were seen the tire-pavement interface with lessor additional noise radiated from the engine compartment. Noise from elevated exhaust stacks was only documented for less than 5% of the trucks measured. The results were further reduced to produce vertical profiles of noise levels versus height above the roadway. The profiles were normalized to the highest noise level at ground level.
2017-06-05
Technical Paper
2017-01-1890
Xingyu Zhang, Bo Yang, Manchuang Zhang, Sanbao Hu
H-Bahn ("hanging railway") refers to the suspended, unmanned urban railway transportation system. Through the reasonable platform layout, H-Bahn can be easily integrated into the existing urban transit system. With the development of urban roads, the associated rail facilities can be conveniently disassembled, moved and expanded. The track beam, circuits, communication equipment, and sound insulation screen are all installed in a box-type track beam so that the system can achieve a high level of integration and intelligence. The carriage of the modern H-banh vehicle is connected with the bogies by two hanging devices. The vehicle is always running in the box-type track beam; therefore there are less possibilities of derailment. Consequently, the key work focuses on the running stability evaluation and curve negotiation performance analysis.
2017-06-05
Technical Paper
2017-01-1855
Ramakanta Routaray
The basic function of a motorcycle frame is somewhat similar to that of the skeleton in the human body, i.e. to hold together the different parts in one rigid structure. One of the major benefits (for a motorcycle enthusiast) of using an advanced frame design lies in the sporty handling characteristics of the bike. A well designed frame can add to the joy of riding a motorcycle as the bike would feel more stable, effortless, and confident around corners, in straight lines and while braking. A well approved modeling techniques or adequate guide line principles have to be followed while designing the body and chassis in order to achieve the vibration within control. This paper depicts a methodological right approach to model the body and chassis of a two wheeler in order to control noise and vibration of the body and chassis.
2017-06-05
Technical Paper
2017-01-1762
Michael Roan, M. Lucas Neurauter, Douglas Moore, Dan Glaser
Hybrid and electric vehicles (HVs and EVs) have demonstrated low noise levels relative to their Internal Combustion Engine (ICE) counterparts, particularly at low speeds. As the number of HVs/EVs on the road increases, so does the need for data quantifying auditory detectability by pedestrians; in particular, those who are vision impaired. Manufacturers have begun to implement additive noise solutions designed to increase vehicle detectability while in electric mode and/or when traveling below a certain speed. A detailed description of the real-time acoustic measurement system, the corresponding vehicular data, development of an immersive noise field, and experimental methods pertaining to a recent evaluation of candidate vehicles is provided herein. Listener testing was completed by 24 legally blind test subjects for four vehicle types: an EV and HV with different additive noise approaches, an EV with no additive noise, and a traditional ICE vehicle.
2017-06-05
Technical Paper
2017-01-1909
Joel Bruns, Jason Dreyer
The application of hydraulic body mounts between a pickup truck frame and cab to reduce freeway hop and smooth road shake has been documented in literature and realized in production vehicles. Previous studies have demonstrated the potential benefits of these devices, often through iterative prototype evaluation. Component dynamic characterization has also shown that these devices exhibit significant dependence on dynamic amplitude and preload; however, analysis of these devices has not fully addressed these dependences. This paper aims to understand the amplitude and preload dependence on the spectrally varying properties of a production hydraulic body mount. This double-pumping, three-spring mount construction has a shared compliant element between the two fluid-filled chambers. A reduced-order multi-physics model of the mount assembly is developed using parameters derived from bench testing of the different elastomeric components and the fluid system.
2017-05-18
Journal Article
2017-01-9678
G Agawane, Varun Jadon, Venkatesham Balide, R Banerjee
Abstract Liquid sloshing noise from an automotive fuel tank is becoming increasingly important during frequent accelerating/decelerating driving conditions. It is becoming more apparent due to significant decrease in other noise sources in a vehicle, particularly in hybrid vehicles. As a step toward understanding the dynamics of liquid sloshing and noise generation mechanism, an experimental study was performed in a partially filled rectangular tank. A systematic study was performed to understand the effects of critical parameters like fill level and acceleration/deceleration magnitude. Response parameters like dynamic pressure, dynamic force, dynamic acceleration and sound pressure levels along with high speed video images were recorded. The proposed experimental setup was able to demonstrate major events leading to sloshing noise generation. These events in the sloshing mechanism have been analysed from the dynamic sensor data and correlated with high speed video images.
2017-04-11
Journal Article
2017-01-9625
Souhir Tounsi
Abstract In this paper, we present a design and control methodology of an innovated structure of switching synchronous motor. This control strategy is based on the pulse width modulation technique imposing currents sum of a continuous value and a value having a shape varying in phase opposition with respect to the variation of the inductances. This control technology can greatly reduce vibration of the entire system due to the strong fluctuation of the torque developed by the engine, generally characterizing switching synchronous motors. A systemic design and modelling program is developed. This program is validated following the implementation and the simulation of the control model in the simulation environment Matlab-Simulink. Simulation results are with good scientific level and encourage subsequently the industrialization of the global system.
2017-04-11
Journal Article
2017-01-9176
Jitesh Shukla, A Grinspan, Jeyanthi subramanian
Abstract Lifting axles are auxiliary axles that provide increased load carrying capacity in heavy commercial vehicles. Lift axle gives better fuel efficiency as well as it reduces the operational costs by means of increasing the loading carrying capacity. These axles are raised when the vehicle is in unloaded condition, thus increasing the traction on remaining wheels and reducing the tire wear which in turn lower down the maintenance cost of the vehicle. Lifting height and force requires to lift the whole mechanism and are two main considerable factors to design the lifting axle mechanism. Although in India currently, the use of lift mechanism of single tire with continuous axle is more common. But in the case of pusher axle, continuous axle is unable to lift more after certain height because of the draft angle of the propeller shaft, and single tire axle which has less load carrying capacity up to 6T (Tons).
2017-04-11
Journal Article
2017-01-9178
Arash E. Risseh, Hans-Peter Nee, Olof Erlandsson, Klas Brinkfeldt, Arnaud Contet, Fabian Frobenius lng, Gerd Gaiser, Ali Saramat, Thomas Skare, Simon Nee, Jan Dellrud
The European Union’s 2020 target aims to be producing 20 % of its energy from renewable sources by 2020, to achieve a 20 % reduction in greenhouse gas emissions and a 20 % improvement in energy efficiency compared to 1990 levels. To reach these goals, the energy consumption has to decrease which results in reduction of the emissions. The transport sector is the second largest energy consumer in the EU, responsible for 25 % of the emissions of greenhouse gases caused by the low efficiency (<40 %) of combustion engines. Much work has been done to improve that efficiency but there is still a large amount of fuel energy that converts to heat and escapes to the ambient atmosphere through the exhaust system. Taking advantage of thermoelectricity, the heat can be recovered, improving the fuel economy.
2017-04-11
Journal Article
2017-01-9075
Rami Abousleiman, Osamah Rawashdeh, Romi Boimer
Abstract Growing concerns about the environment, energy dependency, and the unstable fuel prices have increased the sales of electric vehicles. Energy-efficient routing for electric vehicles requires novel algorithmic challenges because traditional routing algorithms are designed for fossil-fueled vehicles. Negative edge costs, battery power and capacity limits, vehicle parameters that are only available at query time, alongside the uncertainty make the task of electric vehicle routing a challenging problem. In this paper, we present a solution to the energy-efficient routing problem for electric vehicles using ant colony optimization. Simulation and real-world test results demonstrate savings in the energy consumption of electric vehicles when driven on the generated routes. Real-world test results revealed more than 9% improvements in the energy consumption of the electric vehicle when driven on the recommended route rather than the routes proposed by Google Maps and MapQuest.
2017-04-11
Journal Article
2017-01-9076
Ioannis Karakitsios, Evangelos Karfopoulos, Nikolay Madjarov, Aitor Bustillo, Marc Ponsar, Dionisio Del Pozo, Luca Marengo
Abstract The aim of this paper is to introduce a complete fast dynamic inductive charging infrastructure from the back-office system (EV management system) up to the Electric Vehicle (EV) (inductive power transfer module, positioning mechanism, electric vehicle modifications) and the EV user (User interface). Moreover, in order to assess the impact of the additional demand of inductive charging on the grid operation, an estimation of the 24-hour power profile of dynamic inductive charging is presented considering, apart from the road traffic, the probability of the need for fast charging, as well as the specifications of the proposed solution. In addition, an energy management system is presented enabling the management of the operation of the inductive charging infrastructure, the interaction with the EV users and the provision of demand response services to different stakeholders.
2017-03-28
Technical Paper
2017-01-1169
Ahmed M. Ali, Alhossein Mostafa Sharaf, Hesham Kamel, Shawky Hegazy
Abstract This paper presents an integrated experimental and simulation investigation which is conducted on a series hybrid electric vehicle. The mathematical model is simulated in two distinct environments; MATLAB/Simulink and GT-Suite. An experimental test rig is devised in order to measure the vehicle performance including wheeled-chassis dynamometer. Components consumed powers, vehicle speed, engine revolution, fuel consumption and consumed energies are all measured in real time and the results are used to verify the numerical modelling work. For optimizing the performance of the vehicle, a rule based control algorithm is proposed and applied to the model using Stateflow environment. Many sequential-decision logic-based rules are graphical coded to operate the internal combustions engine at its most fuel efficient modes.
2017-03-28
Technical Paper
2017-01-1174
Vincent Freyermuth, Aymeric Rousseau
Today’s value proposition of plug-in hybrid electric vehicles (PHEV) and battery electric vehicles (BEV) remain expensive. While the cost of lithium batteries has significantly decreased over the past few years, more improvement is necessary for PHEV and BEV to penetrate the mass market. However, the technology and cost improvements of the primary components used in electrified vehicles such as batteries, electric machines and power electronics have far exceeded the improvements in the main components used in conventional vehicles and this trend is expected to continue for the foreseeable future. Today’s weight and cost structures of electrified vehicles differ substantially from that of conventional vehicles but that difference will shrink over time. This paper highlights how the weight and cost structures, both in absolute terms and in terms of split between glider and powertrain, converge over time.
2017-03-28
Technical Paper
2017-01-1110
Muammer Yolga, Markus Bachinger
Abstract With the introduction of new regulations on emissions, fuel efficiency, driving cycles, etc. challenges for the powertrains are significantly increasing. In order to fulfil these regulations, hybrid-electric powertrains are an unquestioned option for short and long-term solutions. Hybridization however, is not only fulfilling these challenging efficiency or emission targets, but also allows numerous new possibilities on control strategies of different powertrain elements as well as new approaches of designing them. A good example is transmissions where, hybridization allows a new transmission type called Dedicated Hybrid Transmission (DHT), which enables to use novel control strategies bringing improved performance, driveability, durability and NVH behavior. This paper focuses on the novel shift strategy where friction clutches do not have to slip.
Viewing 1 to 30 of 8974