Browsing by Subject "Collision avoidance systems"
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Item Cooperative Intersection Collision Avoidance System – Stop Sign Assist: Experiments to Validate Use of an In-Vehicle Interface Design(Center for Transportation Studies, University of Minnesota, 2012-04) Becic, Ensar; Manser, Michael; Creaser, Janet; Donath, MaxThe three studies included in the current report examine the transition from an infrastructure-based rural intersection crossing assist system to one located inside a vehicle. The primary goals of the first study, conducted in a simulator, were to examine the effect of potentially confounding factors, such as the drivers’ familiarity with the assist system and the impact of cognitive load on the drivers’ performance. Next, we examined the efficacy of several different designs of such system to determine the optimal interface design to be used for the in-vehicle system. Finally, the optimal design of the system was examined in the third study, as a field test. The results showed that the use of the system under cognitively demanding conditions did not result in any adverse consequences, which suggested that the processing of the system required minimal cognitive resources. Additionally, the results showed that the benefits of the assist system, such as reduced probability of accepting a critical gap were exhibited under the limited visibility conditions when the perceptual task of determining an appropriate crossing gap became overly demanding. The results from the field study showed that the use of the assist system resulted in improved intersection crossing performance exhibited in increased likelihood of making a complete stop at the stop sign and showed a strong trend toward a decreased probability of accepting critical gaps. Additionally, the impact of the in-vehicle CICAS-SSA was equivalent for older and younger drivers; that is, both age groups benefited from the use of the system.Item Minnesota Department of Transportation Rural Intersection Conflict Warning System (RICWS) Reliability Evaluation(Center for Transportation Studies, University of Minnesota, 2014-06) Menon, Arvind; Donath, MaxThe Minnesota Department of Transportation (MnDOT) developed the Rural Intersection Conflict Warning System (RICWS) Deployment project to reduce crashes at stop-controlled intersections. It is a statewide, Intelligent Transportation Systems project that will deploy intersection conflict warning systems at up to 50 rural, stop-controlled intersections. These systems will address crashes at stop-controlled intersections by providing drivers - on both the major and minor road - with a dynamic warning of other vehicles approaching the intersection. The first RICWS site, Trunk Highway 7 and Carver County CSAH 33, was evaluated for a period of 34 days to demonstrate the reliability of the system. During this period, the RICWS signs, beacons, and any other displays were covered and unavailable for driver interaction. The University of Minnesota installed a portable Intersection Surveillance System (ISS) and collected data from the RICWS as well as from the ISS. The data collected from the RICWS was validated against data recorded by the ISS in order to determine the accuracy and reliability of the RICWS. The RICWS was determined to have an activation rate of 99.98%, and meets the MnDOT specification of 99.95% sign activation rate. Sign activations were also validated using video captured at the site and a sample of times for valid activations and valid periods when the sign was inactive were recorded.Item Ultra Reliable Detection of Imminent Collision for Enhanced Occupant Safety(Intelligent Transportation Systems Institute, Center for Transportation Studies, University of Minnesota, 2012-05) Taghvaeeyan, Saber; Sun, Zhen; Mott, Michael; Rajamani, RajeshThis project focuses on the use of anisotropic magnetoresisitve (AMR) sensors for detection of an imminent unavoidable collision. An analytical formulation is developed for the variation of the magnetic field around a car as a function of position. Based on magnetic field measurements using AMR sensors, the position and velocity of any other car can be estimated and an imminent collision detected just prior to collision. The developed AMR sensor system has very high refresh rates, works at very small distances down to zero meters and is highly inexpensive. A variety of experimental results are presented to demonstrate the performance of the system for both one-dimensional and two-dimensional relative motion between cars. The second part of the project conducts simulations to show the benefits of detecting an imminent collision using the developed AMR sensors. An occupant model is developed to analyze occupant motion inside a car during a frontal collision. Analytical formulations and simulations are used to show how occupant safety can be enhanced when knowledge of an imminent collision is available.