Your Selections

Comfort
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

 
new

Assessment of Automotive Environmental Noise on Mobile Phone Hands-Free Call Quality

FEV North America, Inc.-Jeffrey Pruetz, Channing Watson, Todd Tousignant, Kiran Govindswamy
Published 2019-06-05 by SAE International in United States
Environmental noises such as wind, road, powertrain, and HVAC noise are important aspects to consider when implementing a hands-free terminal for mobile phone calling from within a car. Traditionally, these environmental noises have been exclusively considered for driver comfort; however, with the introduction of the hands-free terminals (HFT) and increasing consumer demand relative to mobile phone call quality, a broader implication of high background noise levels should be considered. HFT algorithm development and implementation can and does provide a high level of background noise suppression to mitigate these concerns, but this is often done at the expense of computational power and cumulative delay during a phone call. The more advantageous solution would be to address the problem from a source and path perspective with emphasis on reduction of noise in the frequency bands which most influence call quality performance. The assessments shown throughout this paper establish a sensitivity of HFT call quality to background noise levels based on industry-standard metrics, including those defined by International Telecommunication Union (ITU) standards. These assessments were established based on…
Datasets icon
Annotation icon
 
new

Fast Accurate Non-Destructive Measurement of Absorber Impedance and Absorption

3M Company-Jon Alexander
Bruel & Kjaer Sound and Vibration A/S-Jason Kunio, Flemming Larsen
Published 2019-06-05 by SAE International in United States
Cabin acoustic comfort is a major contributor to the potential sales success of new aircraft, cars, trucks, and trains. Recent design challenges have included the increased use of composites, and the switch to electrically powered vehicles, each of which change the interior noise spectral content and level. The role of acoustic absorption in cabins is key to the optimisation of cabin acoustic comfort for modern vehicles, with acoustic impedance data needed in order to assess and optimise the impact of each component of a given lay-up.Measurements of absorbing interior trim are traditionally performed using either sample holder tests in a static impedance tube (impedance and absorption), or through tests in reverberation rooms (absorption only). Both of these procedures present challenges. In-tube absorption and impedance measurements are destructive, requiring highly accurate sample cutting and sealing. Reverberation room absorption measurements are subject to the effects of varying room diffusion, along with the impact of edge diffraction, sample geometry, and location. Finally, while non-destructive methods using hand-held probes also measure absorption, they are not able to measure impedance…
Annotation icon
 
new

Experimental Investigation on Gear Rattle Noise Reduction in Passenger Car

Maruti Suzuki India Limited-Devendra Kumar Khare, Abhishek Lakhanlal Vaishya, Archan Sunibhai Pujara, Radhe Krishna, Kingshuk Satpathy, Ved Prakash Choudhary, Anant Pandey
Published 2019-06-05 by SAE International in United States
Gear rattle noise reduction inside the passenger cabin is one of the major challenges for customer comfort enhancement. Therefore, it becomes a prime target during transmission design and development. Gear rattle is generated due to meshing teeth collision of free gears, which is caused due to torsional vibration of engine transferred through clutch. Vibrations are generated due to free gears teeth impact and are transferred to shaft, bearings and transmission housing. The sound absorption and structural vibration of transmission housing was optimized by changing the geometrical features of the transmission housing that affects radiated noise.Experimental approach for gear rattle noise reduction through transmission housing modification is described in this paper. Moreover, CAE method is also incorporated with the experiments for optimization of future vehicle transmission system designs.
Datasets icon
Annotation icon
 
new

Numerical Methodology of Tuning a System to Target Frequencies by Adding Mass

Oakland University-Longhan Chen, Randy Gu
Published 2019-06-05 by SAE International in United States
To ensure ride comfort, the dynamic characteristics, such as natural frequencies, of a vehicle is often tuned to a specific value by managing the magnitude and location of some masses and/or configuration of stiffeners without sacrificing the structural strength and overall fuel performance of the vehicle. We first formulate the mathematical statement of the problem in a constrained eigenvalue form. Optimal solutions are sought using various finite element techniques. A novel methodology involving genetic algorithm and Newton’s iterative method is developed to solve the constrained eigenvalue problems. Several examples, including discrete and continuous systems, are presented to demonstrate the effectiveness and accuracy of the proposed methodology. The strategy of managing the mass location and distribution to target a preferred natural frequency or frequencies is given in the conclusion.
Annotation icon
 
new

Noise and Vibration Prediction and Validation for Off-Highway Vehicle Cab Using Hybrid FE-SEA Methodology

John Deere C&F-Joseph Sullivan, Jinghao Liu, Sanghoon Suh
John Deere India Pvt., Ltd.-Parag Chaudhari
Published 2019-06-05 by SAE International in United States
Operator noise is an important aspect for noise and vibration of off-highway vehicles and a quieter cab is critical for the operator comfort. The noise level inside the cab is influenced by structural and acoustic transfer paths. In this paper, we used hybrid FE-SEA approach to consider both structural and acoustic transfer path as FEM and SEA methods individually face limitations in high and low frequencies respectively. A hybrid FE-SEA cab model was built to predict the structural and acoustic transfer functions. The analysis model was built with the systematic approach validated at each step with the laboratory test results. For the structural transfer function, structural excitations were applied at four cab mount locations and accelerations at various locations on the cab were validated. For the acoustic transfer function, the cab was excited with the volume velocity source inside the cab and sound power output of various panels were calculated and compared to the test results. Good agreement was observed between the simulation and the test results for both structural transfer path and acoustic transfer…
Annotation icon
 
new

A Control Strategy to Reduce Torque Oscillation of the Electric Power Steering System

Concordia University Montreal-Subhash Rakheja
South China University of Technology-Duo Fu, Wen-Jun Yan
Published 2019-06-05 by SAE International in United States
This paper proposes a new evaluation method of analyzing stability and design of a controller for an electric power steering (EPS) system. The main purpose of the EPS system’s control design is to ensure a comfortable driving experience of drivers, which mainly depends on the assist torque map. However, the high level of assist gain and its nonlinearity may cause oscillation, divergence and instability to the steering systems. Therefore, an EPS system needs to have an extra stability controller to eliminate the side effect of assist gain on system stability and attenuate the unpleasant vibration. In this paper, an accurate theoretical model is built and the method for evaluating system quality are suggested. The bench tests and vehicle experiments are carried out to verify the theoretical analysis. The evaluation method proposed in this paper can not only guide the design of controller parameters, but also evaluate the control effect while the performance of several controllers are all excellent.
Datasets icon
Annotation icon
 
new

Plastic Bearings Redefine the Wheelchair

  • Magazine Article
  • TBMG-34580
Published 2019-06-01 by Tech Briefs Media Group in United States

For wheelchair users, the feeling of uneven ground can seem all too familiar. Determined to make ride discomfort a thing of the past, Israel-based SoftWheel has completely reinvented the wheel for a float-like experience.

 
new

Flexible, Transparent, Wearable Bio-Patch

  • Magazine Article
  • TBMG-34639
Published 2019-06-01 by Tech Briefs Media Group in United States

Silicon nanoneedle patches are currently placed between skin, muscles, or tissues where they deliver exact doses of biomolecules. Commercially available silicon nanoneedle patches are usually constructed on a rigid and opaque silicon wafer. The rigidity can cause discomfort and cannot be left in the body very long.

 

New platform, chic sheetmetal for tech-centric 2020 Range Rover Evoque

Automotive Engineering: May 2019

Stuart Birch
  • Magazine Article
  • 19AUTP05_16
Published 2019-05-01 by SAE International in United States

The new-generation Range Rover Evoque is loaded with luxury and lots of electronic safety systems to bring comfort, in every sense, to its driver. But why does it still need the outlandish offroad prowess Jaguar Land Rover demonstrated at its media launch when most examples are likely to spend their working lives in the city or cruising freeways?

Annotation icon
 

The CAN Bus: Driving the Future of Autonomous Military Vehicles

  • Magazine Article
  • TBMG-34343
Published 2019-05-01 by Tech Briefs Media Group in United States

It’s a crisp November day in Michigan, and a convoy of British and American resupply vehicles are rumbling along at a comfortable 25 miles per hour. In the lead is a British Army Rheinmetall MAN Military Vehicles (RMMV) HX-60 truck, trailed closely by two U.S. Army Oshkosh Light Medium Tactical Vehicles (LMTVs). In total, there are zero humans operating this convoy.