Browsing by Subject "DSRC"

Now showing 1 - 5 of 5
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    Design and Development of a Visual Warning System for Worker Safety On Roadside Work zones
    (2016-09) Abbaszadeh Banaeiyan, Nazanin
    Growing traffic on US roadways and heavy construction machinery on road construction sites pose a critical safety threat to construction workers. This writing summarizes the design and development of a worker safety system using Dedicated Short Range Communication (DSRC) to specifically address the workers’ safety for the workers working around the heavy machinery. The proposed system has dual objectives. First objective is to improve workers’ safety by providing visual guidance to the operators of the construction vehicles about the workers’ presence in the vicinity. This visual guidance keeps the operators of the heavy machinery well informed about the whereabouts of the workers in close proximity while operating the heavy vehicle. The second objective of the proposed system is to improve the work-zone traffic mobility by dynamically posting suitable speed limits and other warning messages on the DSRC-equipped variable message signs (VMSs) depending on the workers’ presence in an active work-zone to appropriately warn the drivers of the passing-by vehicles. A prototype was developed and field tests were conducted to demonstrate and evaluate the performance of the proposed system. The evaluation test results show that the system can successfully identify the presence of workers around a construction vehicle on an Android tablet with acceptable distance (1.5 – 2 m) and direction (1-5 degrees) accuracies. Furthermore, the test results show that a DSRC equipped VMS can successfully post a suitable speed limit corresponding to the presence of workers in its vicinity.
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    Development and Demonstration of a In-Vehicle Lane Departure and Advanced Curve Speed Warning System
    (2018-03) Faizan, Muhammad
    A lane departure warning system (LDWS) and advance curve warning system (ACWS) are critical elements among several Advanced Driver-Assistance Systems (ADAS) functions, which has significant potential to reduce crashes. Generally, LDWS use different image processing or optical scanning techniques to detect a lane departure. In case of LDWS, these systems have some limitations such as harsh weather or irregular lane markings can influence their performance. Other LDWS use GPS receiver with access to lane-level resolution digital maps to system's efficiency but make the overall system more complex and expensive. On the other hand, ADWS use road-level information which includes road curvature, speed-limit, position. etc. of a given curve. In this report, a lane detection method is proposed which uses a standard GPS receiver to determines the lateral shift of a vehicle by comparing a vehicle’s trajectory to the reference road direction without any lane-level but a road-level information from a standard digital mapping database. Furthermore, system estimates the road curvature and provides advisory speed-limit of a given curve simultaneously. The field test results show that the proposed system can detect a true lane departure with an accuracy of almost 100%. Although no true lane departure was left undetected, occasional false lane departures were detected about 10% of the time when the vehicle did not actually depart its lane. Furthermore, system always issue the curve warning about an advisory speed limit well ahead of time at a safe distance.
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    Merge Assist System Using GPS and DSRC Based Vehicle-to-Vehicle Communication
    (2019-01) Hussain, Shah
    One potential area to improve driver safety and traffic mobility is around merge points of two roadways e.g., at a typical freeway entrance ramp. Due to poor visibility because of weather or complex road infrastructure, on many such entrance ramps, it may become difficult for the driver on the merging/entrance ramp to clearly see the vehicles travelling on the main freeway, making it difficult to merge. A fundamental requirement to facilitate many ADAS functions including a merge assist system is to accurately acquire vehicle positioning information. Accurate position information can be obtained using either sensor-based systems (camera-based, RADAR, LiDAR) or Global Navigation Satellite Systems (GPS, DGPS, RTK). For these systems to work well for practical road and weather conditions, advanced techniques and algorithms are needed which make the system complex and expensive to implement. In this report, the author proposes a merge assist system by acquiring the relative positioning of vehicles using standard GPS receivers and DSRC based V2V communication. The DSRC equipped vehicles travelling on the main freeway and on the entrance-ramp will periodically communicate their positioning information with each other. Using that information, the relative trajectories, relative lane and position of all DSRC equipped vehicles travelling on the main freeway, will be calculated and recorded in real time in the vehicle travelling on the entrance ramp. Finally, a merge time cushion will also be calculated which could potentially be used to assist the driver of the ramp vehicle to safely merge into the freeway.
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    On QoS provisioning for vehicular safety communication
    (2013-09) Sharafkandi, Sarah
    This dissertation studies the problem of safety communication in vehicular networks. Despite advances in automative safety during the past decades, still thousand of injuries and fatalities happen yearly in vehicle-related accidents. Dedicated Short Range Communication (DSRC) technology enables vehicles to communicate to each other through wireless medium, so they can inform each other of a potential danger on the road. Two important applications of vehicular network technology are collision avoidance and collecting traffic information. Collision avoidance relies on periodic sharing of safety messages to avoid accidents. Each vehicle that receives these safety messages from its neighbors, uses them to determine if any of the neighbors poses a collision threat. If a vehicle determines that this is the case, the onboard unit will warn the driver. For collision avoidance it is important that the status data of the vehicles be delivered on time and so the Medium Access Control (MAC) protocol design is very important. This dissertation studies two different approaches to the MAC design protocol: First, we use the QoS mechanism of IEEE 802.11 to reduce the collision rate among safety packets when IEEE 802.11p is used which is the likely scenario in United States. Then, we introduce a new contention-free TDMA-based MAC protocol tuned for vehicular communication which can guarantee an upper bound on the delivery delay of safety messages. Finally, we propose a strategy for collecting safety information of vehicles in a Road Side Units (RSU). This information can be used for analysis on the road traffic condition which can be then shared through a disseminating strategy with the vehicles on the road.
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    Traffic Information System To Deliver In-Vehicle Messages On Pre-Defined Routes Using Dsrc Based V2V Communication
    (2016-11) Zaman, Attiq Uz
    Today, US highways are at an age where they require more reconstruction and repair, resulting in more work zones. At the same time, highway traffic volumes are at an all-time high and will only keep rising in the foreseeable future. The growth in road miles is not in proportion to the demand, which is resulting in rapid deterioration of the nation’s roadways. Creating work zones on congested highways and in dense urban areas is the only solution for the transportation agencies to ensure that the roads remain usable. Every year there are several traffic incidents on the roads with work zones and studies have shown that most of these work zone crashes involve rear-ending the vehicle in front usually at the end of a traffic queue. This paper describes the architecture and functionality of a work zone traffic information system using Dedicated Short Range Communication (DSRC) based vehicle to vehicle communication and a newly designed hopping algorithm to resolve this problem. Our proposed hopping algorithm can deliver in-vehicle messages transmitted by a roadside unit installed at work zone site to far away vehicles travelling towards work zone on pre-defined routes. Our newly designed hopping algorithm uses rectangular regions to define a hopping route and can hop messages to vehicles on multiple routes at the same time without the risk of creating a broadcast storm. Although, the messages hopped by our proposed hopping algorithm will generally be applicable to the vehicles on only one side of the road (travelling towards work zone), the DSRC equipped vehicles present on both sides of the road will participate in hopping to maximize the number of available hopping nodes in situations with lighter traffic flow and/or low DSRC market penetration. Furthermore, our hopping algorithm increases message security by not requiring any hopping nodes (i.e., DSRC equipped vehicles) to modify the contents of the hopped message. We have also performed numerical simulations to evaluate the performance of our hopping algorithm. The simulation results show that the proposed hopping algorithm works as expected and successfully disseminate DSRC messages along a pre-defined route.