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Technical Paper

Effects of Vehicle Windshield Defrosting and Demisting Process on Passenger Comfort

2001-05-15
2001-01-1729
This paper describes an investigation into the fluid flow and heat transfer on the windshield as well the effect of the air discharge from the defroster vents on passenger comfort. The investigation is both experimental and computational. Full-scale tests are conducted on a current vehicle model using non-intrusive diagnostic methods. The results presented are from numerical simulations validated by experimental measurements. The numerical predictions compare well with the experimental measurements. The locations of maximum velocity and pressure, as well as width and length of re-circulation regions, are correctly predicted.
Technical Paper

Forward Collision Warning: Preliminary Requirements for Crash Alert Timing

2001-03-05
2001-01-0462
Forward collision warning (FCW) systems are intended to provide drivers with crash alerts to help them avoid or mitigate rear-end crashes. To facilitate successful deployment of FCW systems, the Ford-GM Crash Avoidance Metrics Partnership (CAMP) developed preliminary minimum functional requirements for FCW systems implemented on light vehicles (passenger cars, light trucks, and vans). This paper summarizes one aspect of the CAMP results: minimum requirements and recommendations for when to present rear-end crash alerts to the driver. These requirements are valid over a set of kinematic conditions that are described, and assume successful tracking and identification of a legitimate crash threat. The results are based on extensive closed-course human factors testing that studied drivers' last-second braking preferences and capabilities. The paper reviews the human factors testing, modeling of results, and the computation of FCW crash alert timing requirements and recommendations.
Technical Paper

Child Injuries & Fatalities - Who is Behind the Wheel?

2001-03-05
2001-01-1305
Recent crash data was used to evaluate the safety performance of drivers who transport children. The age difference between drivers and children was found to be an important predictor of crash-related driving behavior and choices. Also, certain driver behaviors and choices when transporting children were identified as creating elevated risk. This study provides information that parents might use to reduce risk when their children are riding with other drivers. The results may also be of interest to professionals concerned with graduated licensing and the establishment and enforcement of laws relating to child endangerment such as drinking and driving with child passengers.
Technical Paper

Influence of Mount Stiffness on Body/Subframe Acoustic Sensitivities

2003-05-05
2003-01-1714
A comparison of acoustic sensitivities of the 2000 Ford Taurus and 1999 Toyota Camry identifies an interesting paradox: the Taurus has a competitive advantage over the Camry when comparing body-only transfer functions, but a handicap to the Camry when the subframe is included in the measurements. Further, the Taurus subframe/mount subsystem actually behaves as an amplifier rather than an isolator over most of the powertrain excited frequency range. This report attempts to explain the cause of these behaviors through a hybrid CAE/test method and recommends a design strategy to lower the Subframe to Driver's Right Ear sensitivities of the Taurus.
Technical Paper

Full- and Model-Scale Scrutiny of the Effects of Vehicle Windshield Defrosting and Demisting on Passenger Comfort and Safety

2003-03-03
2003-01-1082
Maintaining adequate visibility at all times, through a vehicle windshield, is critical to the safe usage of the vehicle. The ability of the windshield defrosting and demisting system to quickly and completely melt ice on the outer windshield surface and remove mist formed on the inner surface is therefore of paramount importance. The objectives of this paper are to investigate the fluid flow and heat transfer on the windshield as well the effect of the air discharge from the defroster vents on passenger comfort. The results presented are from numerical simulations validated by experimental measurements both carried out a model and full-scale. The numerical predictions compare well with the experimental measurements at both scales. The effects of the defrosting and demisting air on occupants' comfort and safety are examined.
Technical Paper

Simulation of Hybrid Electric Vehicles with Emphasis on Fuel Economy Estimation

1998-02-23
981132
This paper describes SHEV, a computer program created to simulate hybrid electric vehicles. SHEV employs the time-stepping technique in order to evaluate energy flow in series hybrids, and makes use of a unique method in order to speed up the fuel economy estimation. This estimation method is a refinement of the “state of charge matching” method and is explained in detail. The graphic user interfaces employed in SHEV make it easy to use and give it a look similar to regular Windows‚ applications. This paper also gives some examples of the screens created by the program, depicts its main flowchart, and describes a battery model optimized for this application.
Technical Paper

State of Knowledge and Current Challenges in Defrosting Automotive Windshields

1998-02-23
980293
Rapid and effective windshield defrosting has been the goal of various investigations by automotive engineers around the world. Car manufacturers have invested considerable resources to satisfy the thermal needs, safety requirements, and comfort demands of their customers. This paper addresses the climate control issues of defrosting automotive windshields. The paper summarizes the state of knowledge of the various approaches for improving defroster performance. Experimental as well as computational efforts, accompanied by heating techniques and heat boosters will be presented. The paper also features relevant measurement methods for airflow and thermal patterns, and discusses current challenges. Recommendations are made on where to focus engineering and design efforts given the state of present technologies.
Technical Paper

Biofidelity of Anthropomorphic Test Devices for Rear Impact

1997-11-12
973342
This study examines the biofidelity, repeatability, and reproducibility of various anthropomorphic devices in rear impacts. The Hybrid III, the Hybrid III with the RID neck, and the TAD-50 were tested in a rigid bench condition in rear impacts with ΔVs of 16 and 24 kph. The results of the tests were then compared to the data of Mertz and Patrick[1]. At a AV of 16 kph, all three anthropomorphic devices showed general agreement with Mertz and Patrick's data [1]. At a AV of 24 kph, the RID neck tended to exhibit larger discrepancies than the other two anthropomorphic devices. Also, two different RID necks produced significantly different moments at the occipital condyles under similar test conditions. The Hybrid III and the Hybrid III with the RID neck were also tested on standard production seats in rear impacts for a AV of 8 kph. Both the kinematics and the occupant responses of the Hybrid III and the Hybrid III with the RID neck differed from each other.
Technical Paper

Driver Understanding and Recognition of Automotive ISO Symbols

1988-02-01
880056
This study assesses the understanding and recognition, by U.S. drivers, of the 25 automotive ISO symbols specified in SAE Standard J1048. A two-part survey was administered to 505 volunteers at a Secretary of State's office located in a Detroit suburb. Percentage results for symbol understanding indicated low levels of understanding for many symbols; percentage results for symbol recognition were generally much higher for all symbols. The effects of gender, age, and education level on the percentage results are summarized.
Technical Paper

World Radio Revisited: Still a Myth?

1990-02-01
900040
As in most industries, car radio designers have long envisioned a product which could be sold without modification throughout the world. However, local requirements, performance differences, and customer preferences have presented major obstacles to achieving this goal. Since publishing a previous paper on this subject in 1983, many changes have taken place in electronics and in car radio design. Some of these changes have reduced the barriers to producing a “World Radio” while others have presented new obstacles to be overcome. This paper addresses some of those changes and the current possibilities.
Technical Paper

Cylinder Head Gasket Fretting/Scrub Mechanism Investigation and Analysis Procedure Developments

2017-03-28
2017-01-1091
Typically, modern automotive engine designs include separate cylinder heads and cylinder blocks and utilize a multilayer steel head gasket to seal the resulting joint. Cylinder head bolts are used to hold the joint together and the non-linear properties of head gasket provide capability to seal the movement within the joint, which is essential for engine durability and performance. There are three major failure modes for head gasket joint: fluid or gas leakage due to low sealing pressure, head gasket bead cracking due to high gap alternation and scrubbing/fretting due to pressure and temperature fluctuations causing lateral movement in the joint. During engine operation, the head gasket design should be robust enough to prevent all three failure modes and the resulting design must consider all three major failure modes to provide acceptable performance.
Technical Paper

An Object-Oriented Approach to the Post-Processing of Cylinder Bore Distortion, Valve Seat Distortion, Valve Guide-to-Seat Misalignment and Cam Bore Misalignment

2017-03-28
2017-01-1075
In CAE analysis of cylinder bore distortion, valve seat distortion, valve guide-to-seat misalignment and cam bore misalignment, nodal displacements on the cylinder bore inner surface and on the gage lines of valve seats, valve guides and cam bores are typically output. Best fit cylinders, best fit circles and best fit lines are computed by utilizing the output displacements of the deformed configuration. Based on the information of the best fit geometry, distortions and misalignments are assessed. Some commercial and in-house software is available to compute the best fit cylinders, best fit circles and best fit lines. However, they suffer from the drawback that only one best-fit geometry can be computed at a time. Using this kind of software to assess distortions and misalignments of engine components would be tedious and prone to error, since data transfer as well as the intermediate computation has to be done by hand, and the process is not automatic.
Technical Paper

Considerations for Head-Injury Categorization via NASS Analysis

2017-03-28
2017-01-1430
The present study had three objectives: (1) define a reasonable number of categories to bin head injuries, (2) develop an overarching risk function to estimate head-injury probability based on injury probabilities pertaining to those subordinate categories, and (3) assess the fidelity of both the overarching function and approximations to it. To achieve these objectives, we used real-world data from the National Automotive Sampling System (NASS), pertaining to adult drivers in full-engagement frontal crashes. To provide practical value, we factored the proposed US New Car Assessment Program (US NCAP) and the corresponding Request for Comments from the government. Finally, the NASS data stratifications included three levels of injury (AIS1+, AIS2+, AIS3+), two levels of restraint (properly-belted, unbelted), and two eras based on driver-airbag fitment (Older Vehicles, Newer Vehicles).
Technical Paper

Heart-Rate Monitoring Using Single Camera

2017-03-28
2017-01-1434
Heart rate is one of the most important biological features for health information. Most of the state-of-the-art heart rate monitoring systems rely on contact technologies that require physical contact with the user. In this paper, we discuss a proof-of-concept of a non-contact technology based on a single camera to measure the user’s heart rate in real time. The algorithm estimates the heart rate based on facial color changes. The input is a series of video frames with the automatically detected face of the user. A Gaussian pyramid spatial filter is applied to the inputs to obtain a down-sampled high signal-to-noise ratio images. A temporal Fourier transform is applied to the video to get the signal spectrum. Next, a temporal band-pass filter is applied to the transformed signal in the frequency domain to extract the frequency band of heart beats. We then used the dominant frequency in the Fourier domain to find the heart rate.
Technical Paper

A Method for Vehicle Occupant Height Estimation

2017-03-28
2017-01-1440
Vehicle safety systems may use occupant physiological information, e.g., occupant heights and weights to further enhance occupant safety. Determining occupant physiological information in a vehicle, however, is a challenging problem due to variations in pose, lighting conditions and background complexity. In this paper, a novel occupant height estimation approach is presented. Depth information from a depth camera, e.g., Microsoft Kinect is used. In this 3D approach, first, human body and frontal face views (restricted by the Pitch and Roll values in the pose estimation) based on RGB and depth information are detected. Next, the eye location (2D coordinates) is detected from frontal facial views by Haar-cascade detectors. The eye-location co-ordinates are then transferred into vehicle co-ordinates, and seated occupant eye height is estimated according to similar triangles and fields of view of Kinect.
Technical Paper

An Indirect Occupancy Detection and Occupant Counting System Using Motion Sensors

2017-03-28
2017-01-1442
This paper proposes a low-cost but indirect method for occupancy detection and occupant counting purpose in current and future automotive systems. It can serve as either a way to determine the number of occupants riding inside a car or a way to complement the other devices in determining the occupancy. The proposed method is useful for various mobility applications including car rental, fleet management, taxi, car sharing, occupancy in autonomous vehicles, etc. It utilizes existing on-board motion sensor measurements, such as those used in the vehicle stability control function, together with door open and closed status. The vehicle’s motion signature in response to an occupant’s boarding and alighting is first extracted from the motion sensors that measure the responses of the vehicle body. Then the weights of the occupants are estimated by fitting the vehicle responses with a transient vehicle dynamics model.
Technical Paper

A Self-Adapting Passenger Airbag for the USNCAP

2017-03-28
2017-01-1446
A dual-chambered passenger airbag was developed for the 2011 USNCAP to minimize neck loading for the belted 5th female dummy while restraining the unbelted 50th dummy for FMVSS208. This unique, patented design adaptively controlled venting between chambers based on occupant stature. A patented pressure-responsive vent on the second chamber permitted aspiration into the second chamber before a delayed outflow to the environment. The delayed flow through the pressure-responsive vent from the second chamber acted like a pressure-limiting membrane vent to advantageously reduce the injury assessment values for the HIC and the Nij for the 5th female dummy.
Technical Paper

A System for Autonomous Braking of a Vehicle Following Collision

2017-03-28
2017-01-1581
This paper presents two brake control functions which are initiated when there is an impact force applied to a host vehicle. The impact force is generated due to the host vehicle being collided with or by another vehicle or object. The first function - called the post-impact braking assist - initiates emergency brake assistance if the driver is braking during or right after the collision. The second function - called the post-impact braking - initiates autonomous braking up to the level of the anti-lock-brake system if the driver is not braking during or right after the collision. Both functions intend to enhance the current driver assistance features such as emergency brake assistance, electronic stability control, anti-brake-lock system, collision mitigation system, etc.
Technical Paper

MyFord Dock Development

2017-03-28
2017-01-1694
Demand for enhanced infotainment systems with features like navigation, real-time traffic, music streaming service, mirroring and others is increasing, forcing automakers to develop solutions that fulfill customer needs. However, many of those systems are too expensive to be fitted to an entry-level vehicle leaving a gap in the market that fails customer’s expectation. This gap is usually filled by a smartphone which may have all the features the customer wants but in many cases it cannot be properly fitted in the vehicle due to lack of specific storage space. This paper describes how the engineering team developed an innovative, flexible and effective solution that holds a smartphone in an ergonomic location.
Technical Paper

An Indirect Tire Health Monitoring System Using On-board Motion Sensors

2017-03-28
2017-01-1626
This paper proposes a method to make diagnostic/prognostic judgment about the health of a tire, in term of its wear, using existing on-board sensor signals. The approach focuses on using an estimate of the effective rolling radius (ERR) for individual tires as one of the main diagnostic/prognostic means and it determines if a tire has significant wear and how long it can be safely driven before tire rotation or tire replacement are required. The ERR is determined from the combination of wheel speed sensor (WSS), Global Positioning sensor (GPS), the other motion sensor signals, together with the radius kinematic model of a rolling tire. The ERR estimation fits the relevant signals to a linear model and utilizes the relationship revealed in the magic formula tire model. The ERR can then be related to multiple sources of uncertainties such as the tire inflation pressure, tire loading changes, and tire wear.
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