Browsing by Author "Bajikar, Sundeep"

Now showing 1 - 4 of 4
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    Analysis of a Differential Global Positioning System as a Sensor for Vehicle Guidance
    (Minnesota Department of Transportation, 1996-09) Bodor, Robert; Alexander, Lee; Liao, Chen-fu; Bajikar, Sundeep; Morellas, Vassilios; Donath, Max
    An ongoing research project examines guidance systems, which can take over control of a vehicle if the driver becomes incapacitated. Part of this project includes an evaluation of a Differential Global Positioning System (DGPS) for vehicle-based lane sensing. This report documents the results of tests of the 5 Hz NovAtel RT20 DGPS receiver. A series of 32 static tests found the overall mean and standard deviation for the offset errors within specifications. In a series of dynamic tests, in which the vehicle was driven around the track at speeds of 20-35 miles per hour, after removing the effect of the GPS receiver's latency, the DGPS determined position exhibited a mean offset error of -17.3 cm (-6.82 in) and a mean standard deviation of 25.5 cm (10.1 in) in the direction of vehicle motion. In the direction perpendicular to vehicle motion, the mean offset was 4.57 cm (1.8 in) with a mean standard deviation of 39.6 cm (15.6 in). With no overhead obstructions in these tests, continuous satellite lock was possible. Tests at higher speeds based on a more accurate methodology are planned for the future.
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    Evaluation of Radar for Snowplows: Initial Results
    (Minnesota Department of Transportation, 1998-04) Gorjestani, Alec; Pham, Thanh; Bajikar, Sundeep; Donath, Max
    Heavy or blowing snow often causes poor visibility for snowplows. This report presents the results of a one-year preliminary study to evaluate the performance of an off-the-shelf radar unit for improved detection of objects under snow and blizzard conditions. Researchers developed a geometrical computer model of radar range and closure rate measurement to provide a baseline for comparison with experimental results. They varied parameters such as radar orientation, location, and differential vehicle speed to determine their effect on radar performance. The radar's accuracy improves as the speed differential between vehicles increases, according to the research findings. Furthermore, slight deviations in orientation and location do not seem to greatly influence the radar's ability to detect other vehicles. The radar also was tested under falling snow conditions. The radar effectively detected target vehicles under 'light' and 'moderate' snow conditions with visibility down to less than one half mile. However, the very small number of snow events in the winter of 1997-98 limits the ability to make conclusions about the radar's performance under such conditions. Since the study began, commercially available radar technology has improved significantly, and researchers recommend testing the improved radar units in the future.
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    Magnetic Lateral Indication System Evaluation
    (Minnesota Department of Transportation, 1997-01) Bajikar, Sundeep; Morellas, Vassilios; Donath, Max
    This report summarizes conclusions and recommendations regarding the Magnetic Lateral Indication System. It analyzes results and conclusions that were derived by 3M and Honeywell, which conducted a feasibility study of a lateral position indication system for vehicles.
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    Safetruck: Sensing and Control to Enhance Vehicle Safety
    (Minnesota Department of Transportation, 1997-12) Alexander, Lee; Bajikar, Sundeep; Lim, Heon-Min; Morellas, Vassilios; Morris, Ted; Donath, Max
    This report summarizes the work performed during the 18-month period ending in December 1997. Researchers investigated the use of differential global positioning systems (GPS), inertial measurement, and other sensing technologies as the basis of a system that would prevent crashes. Such a system attempts to control the vehicle if it leaves the lane because the driver is incapacitated. The report includes in its appendices related work on driver fatigue and a bibliography on the effect of drugs and alcohol on driving behavior. The long-term goal of this research involves development of a "driver-centered" vehicle control system capable of providing lane-keeping feedback to the driver, and, ifnecessary, of imposing aggressive intervention strategies to take over control of the vehicle, steer it to a safe position on the shoulder, and stop it. This research also targets the development of "driver assistive" technologies--such as Heads Up Display and torque feedback supplied by the steering wheel--which provide information to the driver without necessarily requiring computer control of the vehicle. The highlight achievement during this funding period has been the successful demonstration of a GPS-based automated lane-keeping mode of a tractor-trailer on the Minnesota Road Research Project (Mn/ROAD) test track. The report concludes with a strategy for pursuing future deployment.