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Technical Paper

Learning from Human Naturalistic Driving Behavior at Stop Signs for Autonomous Vehicles

2019-04-02
2019-01-1021
Despite public expectations that autonomous vehicles should be able to avoid most accidents, the existing fleet of autonomous test vehicles has demonstrated this is simply not the case. An explanation for some of these accidents has been that these vehicles do not drive like humans and therefore do not exhibit certain driving patterns expected by human drivers. With the high likelihood of a gradual integration of autonomous vehicles into our traffic system in the future, there will be a need for such vehicles to adapt to, and mimic, human driving. Although much work has been done to understand human behavior and performance in driving, it has been mostly geared towards defining human capabilities and limitations. Little work has been done on the interactions between human-driven and autonomous vehicles.
Technical Paper

Development of a Robust Database for Measuring Human Gaze Behavior and Performance during Naturalistic Driving

2017-03-28
2017-01-1369
Vision plays a key role in the safe and proper operation of vehicles. To safely navigate, drivers constantly scan their environments, which includes attending to the outside environment as well as the inside of the driver compartment. For example, a driver may monitor various instruments and road signage to ensure that they are traveling at an appropriate speed. Although there has been work done on naturalistic driver gaze behavior, little is known about what information drivers glean while driving. Here, we present a methodology that has been used to build a database that seeks to provide a framework to supply answers to various ongoing questions regarding gaze and driver behavior. We discuss the simultaneous recording of eye-tracking, head rotation kinematics, and vehicle dynamics during naturalistic driving in order to examine driver behavior with a particular focus on how this correlates with gaze behavior.
Technical Paper

Vehicle Fires Resulting from Hot Surface Ignition of Grass and Leaves

2017-03-28
2017-01-1354
One potential fire ignition source in a motor vehicle is the hot surfaces on the engine exhaust system. These hot surfaces can come into contact with combustible and flammable liquids (such as engine oil, transmission fluid, brake fluid, gasoline, or Diesel fuel) due to a fluid leak, or during a vehicle collision. If the surface temperature is higher than the hot surface ignition temperature of the combustible or flammable liquid in a given geometry, a fire can potentially ignite and propagate. In addition to automotive fluids, another potential fuel in post-collision vehicle fires is grass, leaves, or other vegetation. Studies of hot surface ignition of dried vegetation have found that ignition depends on the type of vegetation, surface temperature, duration of contact, and ambient conditions such as temperature and wind speed. Ignition can occur at surface temperatures as low as 300 °C, if the vegetation is in contact with the surface for 10 minutes or longer.
Technical Paper

Efficacy and Usage Patterns for Three Types of Rearview Camera Displays During Backing Up

2012-04-16
2012-01-0287
The usage of rearview camera displays and their effectiveness on drivers' capability to avoid unexpected obstacles during four common backing tasks (i.e., parallel parking, backing between two vehicles, backing down a driveway, backing out of a garage) was evaluated on a closed-course with stationary confederate vehicles, signage, and lane markings. The obstacle consisted of either a stationary or a moving target that appeared to the rear of the test vehicle. Eye movements and vehicle dynamics measurements (i.e., longitudinal acceleration, brake displacement) were recorded, in addition to obstacle hit/avoidance rates. Performance was assessed for four rearview camera (RVC) conditions: small center-stack display (SD), large center-stack display (i.e., navigation screen) (LD), in-mirror display (IMD), and no display (ND).
Technical Paper

Timing of Head-to-Vehicle Perimeter Contacts in Rollovers

2007-04-16
2007-01-0370
During a rollover accident the position of an occupant within a vehicle at the time of vehicle-to-ground contact affects the occupant's injury potential and injury mechanisms. During rollovers, the accelerations developed during the airborne phases cause an occupant to move away from the vehicle's center of mass towards the perimeter of the vehicle. The occupant is already in contact with vehicle structures during upper vehicle structure-to-ground impacts. The location and extent of the occupant-to-vehicle contacts and the times and locations at which the contacts occur depend upon a variety of factors including occupant size, initial position in the vehicle, restraint status, vehicle geometry, and rollover accident parameters. Onboard and offboard video of existing dolly rollover studies, specifically the “Malibu” studies, were examined to quantify the motion of the occupants' heads and determine the timing and locations of head contacts to the vehicle perimeter.
Technical Paper

An Evaluation of Laminated Side Window Glass Performance During Rollover

2007-04-16
2007-01-0367
In this study, the occupant containment characteristics of automotive laminated safety glass in side window applications was evaluated through two full-scale, full-vehicle dolly rollover crash tests. The dolly rollover crash tests were performed on sport utility vehicles equipped with heat-strengthened laminated safety glass in the side windows in order to: (1) evaluate the capacity of laminated side window safety glass to contain unrestrained occupants during rollover, (2) analyze the kinematics associated with unrestrained occupants during glazing interaction and ejection, and (3) to identify laminated side window safety glass failure modes. Dolly rollovers were performed on a 1998 Ford Expedition and a 2004 Volvo XC90 at a nominal speed of 43 mph, with unbelted Hybrid II Anthropomorphic Test Devices (ATDs) positioned in the outboard seating positions.
Technical Paper

Relationship Between Anti-Lock Tire Mark Length and Speed Change

2007-04-16
2007-01-0723
The relationship between pre-braking speed and the length of locked wheel skid marks has been explored in many publications. However, the existing literature does not address the effects of anti-lock braking on pre-braking speed calculations based on the length of tire marks. Anti-lock brake systems reduce the wheel slip and avoid wheel lock (100% slip) to enable a vehicle to achieve high deceleration rates under emergency braking while retaining steering control. Typically, during braking an ABS system will maintain 5-25% slip, and can sometimes leave faint and/or alternating tire marks as opposed to the dark skid marks created by a locked sliding wheel. Instrumented vehicle testing was conducted on a variety of vehicles to quantify the effects of pre-mark braking on overall speed change. From this data, the effective deceleration for the tested road surface was evaluated and compared to existing literature for locked wheel braking.
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