56 research outputs found

    A Strategy for Emergency Vehicle Preemption and Route Selection

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    Emergency vehicle preemption (EVP) aims to give right of way to emergency vehicles (EV) heading toward the incident location through a network of signalized intersections by creating a green wave en-route. The design goals of EVP systems are two folds: first, to avoid any hindrance to the passage of EV along the road and at the intersections and second, to reduce the negative impact of preemption on general traffic. The negative impact of EVP on normal traffic can be minimized by selecting appropriate preemption strategy. The EVP schemes proposed earlier aim to minimize the travel time of the EV with no or little consideration to the negative impact of EVP on the normal traffic. In this study, a joint strategy for optimal path selection and EV preemption is developed. The proposed scheme selects the optimal path for the EV before it departs from its origin and then activates the preemption on each intersection en-route at the right time to clear the intersection before the EV reaches. The proposed EVP scheme also aims to minimize the impact of EVP over normal traffic at both stages (i.e., path selection phase and preemption phase). A major advantage of the proposed method is that once the optimal path is selected, the emergency information can be disseminated to other vehicles using vehicle-to-vehicle and vehicle-to-infrastructure communication in the EV path to clear the entire route or the approaching lane. The strategy was tested using a microscopic simulation environment for a real traffic network. The findings indicated a major reduction in the travel time of the EV while minimizing the impact of preemption on the normal traffic. The proposed strategy and evaluation procedure can be helpful for corresponding agencies and practitioners to assess the impact of implementing preemption on existing or proposed arterials. - 2019, The Author(s).Open access funding provided by the Qatar National Library.Scopu

    Designing Emergency Vehicle Detection System with Wireless Bluetooth Based on Arduino

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    Congestion is a problem that arises because of the many vehicles on the road. One of the bottlenecks that is often encountered is at a crossroads. From several vehicles, there are emergency vehicles that must be prioritized. Therefore, this research develops a system using Bluetooth technology that gives priority to emergency vehicles to cross the junction. This system works is the first Bluetooth module before the junction with a distance of 500 meters detecting it with autopairing and autoconnect on the Android Bluetooth that has been made. This system uses Arduino Mega as its data processor to make the traffic lights output freeze to the green light, then the traffic light will return to normal when the second Bluetooth module after the junction with a distance of 100 meters detects Android Bluetooth. The results of the study are very helpful when the lane is jammed, but for empty lines this system has a maximum limit at speeds not exceeding 81.43 km/h because the detection distance limit of the Bluetooth connection is only 50 meter

    A traffic signal control algorithm for emergency vehicles

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    Signal preemption disrupts normal traffic signal to allow emergency vehicles to pass through the intersection more safely and quickly. In medical emergency situations, EVP (Emergency Vehicle Preemption) offers a faster response to the sufferer which improves the chance of survival. Despite this lifesaving advantage, conventional preemption has some problems which need more attention. Two important issues are increased delay of overall traffic due to preemption and absence of prioritization of conflicting preemption requests. This thesis presents a traffic signal control algorithm that addresses the above. We have used TSP (Transit Signal Priority) techniques to improve the EVP system. TSP is a proven strategy to provide a better quality public transit operation in urban areas. Our proposed algorithm adjusts signal phases using TSP techniques to serve an emergency vehicle. We consider both single and multiple simultaneous emergency vehicle requests. TSP techniques help us to alleviate the impact on general traffic. For multiple emergency vehicle requests, a branch and bound algorithm is developed that prioritizes among conflicting requests. Experiments have been conducted using the VISSIM microscopic traffic simulator. Results show that the proposed traffic control algorithm reduces overall traffic delay by up to 8% compared to conventional EVP system

    Emergency vehicle lane pre-clearing: From microscopic cooperation to routing decision making

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    Emergency vehicles (EVs) play a crucial role in providing timely help for the general public in saving lives and avoiding property loss. However, very few efforts have been made for EV prioritization on normal road segments, such as the road section between intersections or highways between ramps. In this paper, we propose an EV lane pre-clearing strategy to prioritize EVs on such roads through cooperative driving with surrounding connected vehicles (CVs). The cooperative driving problem is formulated as a mixed-integer nonlinear programming (MINP) problem aiming at (i) guaranteeing the desired speed of EVs, and (ii) minimizing the disturbances on CVs. To tackle this NP-hard MINP problem, we formulate the model in a bi-level optimization manner to address these two objectives, respectively. In the lower-level problem, CVs in front of the emergency vehicle will be divided into several blocks. For each block, we developed an EV sorting algorithm to design optimal merging trajectories for CVs. With resultant sorting trajectories, a constrained optimization problem is solved in the upper-level to determine the initiation time/distance to conduct the sorting trajectories. Case studies show that with the proposed algorithm, emergency vehicles are able to drive at a desired speed while minimizing disturbances on normal traffic flows. We further reveal a linear relationship between the optimal solution and road density, which could help to improve EV routing decision makings when high-resolution data is not available

    EMVLight: a Multi-agent Reinforcement Learning Framework for an Emergency Vehicle Decentralized Routing and Traffic Signal Control System

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    Emergency vehicles (EMVs) play a crucial role in responding to time-critical calls such as medical emergencies and fire outbreaks in urban areas. Existing methods for EMV dispatch typically optimize routes based on historical traffic-flow data and design traffic signal pre-emption accordingly; however, we still lack a systematic methodology to address the coupling between EMV routing and traffic signal control. In this paper, we propose EMVLight, a decentralized reinforcement learning (RL) framework for joint dynamic EMV routing and traffic signal pre-emption. We adopt the multi-agent advantage actor-critic method with policy sharing and spatial discounted factor. This framework addresses the coupling between EMV navigation and traffic signal control via an innovative design of multi-class RL agents and a novel pressure-based reward function. The proposed methodology enables EMVLight to learn network-level cooperative traffic signal phasing strategies that not only reduce EMV travel time but also shortens the travel time of non-EMVs. Simulation-based experiments indicate that EMVLight enables up to a 42.6%42.6\% reduction in EMV travel time as well as an 23.5%23.5\% shorter average travel time compared with existing approaches.Comment: 19 figures, 10 tables. Manuscript extended on previous work arXiv:2109.05429, arXiv:2111.0027

    Розробка алгоритмів ефективного управління діями пожежно-рятувальних підрозділів

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    The need of development of efficient algorithms for the integrated management of the fire rescue units’ activities from the moment of recieving the notice of the fire until return to the depot was substantiated. The need to assess the travel time of a fire extinguishing vehicle to the place of the call and fire area as key drivers of successful fire elimination was substantiated. We received a dependency that allows setting the value for the area of the fire depending on the duration of its free development and linear velocity of expansion. The analysis of this dependency shows that even a slight reduction in the duration of the free development of fire will significantly reduce the fire area and, accordingly, the amount of due losses. To design the algorithm of efficient management of the fire rescue units’ activities using the software package STATISTICA, dependencies were received allowing setting the values of travel time of a fire extinguishing vehicle to the place of the call and, as a consequence, the area of the fire, depending on the distance to the destination of the call and the time of day. On the basis of the received dependencies a block diagram was created of algorithm-simulation model of efficient management of the fire rescue units’ activities. The algorithm makes it possible to determine the optimal routes of fire rescue vehicles and calculate the area of a fire by proposed dependencies, as well as to choose the optimal technology for fire extinguishing. A computer software program, developed on the basis of this algorithm, will allow the head of fire extinguishing to facilitate the calculation of the parameters of development and elimination of fire, as well as the optimal quantity of capabilities for its elimination. A program to select the optimal technology of firefighting was also considered. The program for PC was written in the programming language С# for the Windows XP and Windows 7 operating systems. As a result of the program’s work for grade A and B fires, we receive the estimated quantity of forces and facilities for elimination of fire.Рассмотрено влияние основных факторов на параметры пожара. Получены зависимости, позволяющие определить значение продолжительности следования пожарного автомобиля к месту вызова и площади пожара. Обоснована необходимость и разработан алгоритм эффективного управления действиями пожарно-спасательных подразделений. Приведен пример и описана работа программного обеспечения для выбора оптимальной технологии пожаротушения.Розглянуто вплив основних чинників на параметри пожежі. Отримано залежності, що дають змогу визначити значення тривалості слідування пожежного автомобіля до місця виклику та площі пожежі. Обґрунтовано необхідність та розроблено алгоритм ефективного управління діями пожежно-рятувальних підрозділів. Наведено приклад та описано роботу програмного забезпечення для вибору оптимальної технології пожежогасіння

    Wireless networks for traffic light control on urban and aerotropolis roads

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    This paper presents a traffic lights system based on wireless communication, providing a support infrastructure for intelligent control in smart cities and aerotropolis scope. An aerotropolis is a metropolitan subregion which infrastructure is centered around an airport [1]. Traffic intensity is increasing all over the world. Intelligent dynamic traffic lights system control are sought for replacing classic conventional manual and time based systems. In this work a wireless sensors network is designed and implemented to feed real time data to the intelligent traffic lights systems control. A physical prototype is implemented for experimental validation outside laboratory environment. The physical prototype shows robustness against unexpected issues or local failures. Results are positive in the scope of the experiences made and promising in terms of extending the tests to larger areas
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