Browsing by Subject "Radar"

Now showing 1 - 5 of 5
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    I-94 Connected Vehicles Testbed Operations and Maintenance
    (Center for Transportation Studies, University of Minnesota, 2019-06) Duhn, Melissa; Parikh, Gordon; Hourdos, John
    In March 2017, the Connected Vehicle Testbed along I-94 went live. The original project was sponsored by the Roadway Safety Institute and built on the Minnesota Traffic Observatory's (MTO) existing field lab, also utilizing certain Minnesota Department of Transportation (MnDOT) infrastructure. The testbed originally consisted of seven stations, rooftop and roadside, capable of transmitting radar and video data collected from the roadway back to a database at the MTO for analysis, emulating what a future connected vehicle (CV) roadway will look like. This project funded maintenance and upgrades to the system, as well as movement of some stations due to construction on I-94. In addition, better visualization tools for reading the database were developed. The CV testbed is state-of-the-art, fully functional, and uniquely situated to attract freeway safety-oriented vehicle to infrastructure (V2I) and vehicle to vehicle (V2V) safety application development, implementation, and evaluation projects going forward.
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    Implementation of a V2I Highway Safety System and Connected Vehicle Testbed
    (Center for Transportation Studies, University of Minnesota, 2019-04) Hourdos, John; Parikh, Gordon; Dirks, Peter; Lehrke, Derek
    To better prepare for the Connected Vehicle (CV) roadway, RSI has established a CV testbed along a highly crashed section of I-94, building on the Minnesota Traffic Observatory’s existing field lab infrastructure. This real- world testbed was designed to implement and evaluate the next generation of vehicle-based freeway safety applications. The priority of this project was to establish the backbone of the sensor communication network and data collection system along the testbed length.
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    Implementation of High Accuracy Radar Detectors for Traffic Safety Countermeasure Evaluation
    (Center for Transportation Studies, University of Minnesota, 2014-06) Parikh, Gordon; Hourdos, John
    Rural roadways account for a significant portion of fatal crashes in the United States despite carrying lower total vehicle miles traveled than urban roads. An important contributor to this is excessive speeds at horizontal and vertical curves. While geometric design has established norms for handling these curves, the message is still often difficult to communicate to drivers. Recent technologies have been developed to enhance this communication on horizontal curves; however, treatments for vertical curves have not yet experienced similar advancements. A new approach, involving chevron signs, is being considered by Washington County, Minnesota. To accurately assess the impact of these signs on driver behavior, a before-after study must be implemented on one or more vertical curve locations. Given that such a study must reflect driver reactions to roadway messages, detailed vehicle trajectories must be collected. To capture speed trajectories of vehicles traversing vertical curves, the Minnesota Traffic Observatory developed radar-based, data-collection stations. These stations use automotive radar devices along with custom recording equipment and battery power mounted in weatherized cases to quickly and easily collect vehicle trajectory data for analysis. Through control-vehicle passes and instantaneous radar gun measurements, these stations have been shown to reliably measure the speed and position of vehicles traversing a vertical curve. With the two stations developed, a full field implementation could be developed to collect trajectories for analysis both before and after implementation of a new traffic-control device. For larger-scale implementations of these systems, the methodologies in this report could be used for capturing and post-processing of vehicle trajectories, although additional tools for cleaning and analyzing multiple simultaneous vehicle trajectories would be advised.
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    Intersection Decision Support Surveillance System: Design, Performance and Initial Driver Behavior Quantization
    (Minnesota Department of Transportation, 2007-08) Alexander, Lee; Cheng, Pi-Ming; Donath, Max; Gorjestani, Alec; Menon, Arvind; Shankwitz, Craig
    In rural Minnesota, approximately one-third of all crashes occur at intersections. Analysis of crash statistics and reports of crashes at rural expressway through-stop intersections shows that, for drivers who stop before entering the intersection, the majority of crashes involve an error in selecting a safe gap in traffic. The Intersection Decision Support system, developed at the University of Minnesota, is intended to reduce the number of driver errors by providing better information about oncoming traffic to drivers stopped at intersections. This report deals primarily with the surveillance technology which serves as the foundation upon which the IDS system will be built. Three components of the surveillance system are described in detail in the body of the report: 1) a Mainline Sensor subsystem; 2) a Minor Road Sensor subsystem; 3) a Median Sensor subsystem. These subsystems include radar units, laser-scanning sensors, and infrared cameras, integrated with a vehicle tracking and classification unit that estimates the states of all vehicles approaching the intersection. The design, installation, performance, and reliability of each of these three subsystems are documented in the report. The report concludes with an analysis of driver gap acceptance behavior at an instrumented intersection. Gap selection is examined as a function of time of day, traffic levels, weather conditions, maneuver, and other parameters. Log-normal distributions describe gaps acceptance behavior at rural, unsignalized expressway intersections.
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    The Virtual Bumper: A Control Based Collision Avoidance System For Highway Vehicles
    (Minnesota Department of Transportation, 1997-10) Schiller, William; Donath, Max
    This report summarizes research on a new collision avoidance strategy, the 'virtual bumper.' The research involves development and simulation testing of the virtual bumper, a two-dimensional control strategy that provides steering, throttle, and braking actuation to maneuver a vehicle in a dynamic environment with the goal of avoiding obstacles and other vehicles. The concept applies to both normal and emergency driving conditions. Under all circumstances, the virtual bumper incorporates vehicle dynamic limits to ensure that the control commands are within safe levels. The virtual bumper will attempt to avoid a collision and will, at least, minimize the magnitude of an unavoidable collision. To test the functionality of the virtual bumper, researchers evaluated several driving scenarios. The scenarios consider both normal driving situations and emergency driving conditions. The normal driving scenarios demonstrated that the control algorithm operates the vehicle similar to the way a human would. This is important because a comfortable and predictable (i.e., intuitive) system response is required for achieving driver acceptance. The emergency scenarios demonstrated that the strategy is capable of reacting appropriately while maintaining safe acceleration/deceleration levels for the vehicle. This evaluation showed that the virtual bumper can provide safe vehicle control for a broad range of driving situations.