Cooperative Vehicular Systems Research Articles

Road Incident Detection under Rate Adaptation-Based Congestion Control in Cooperative Vehicular Systems

Road Incident Detection under Rate Adaptation-Based Congestion Control in Cooperative Vehicular Systems

GeoSS: Geographic Segmentation Security Barriers for Virtual Emotion Detection With Discriminative Priorities in Intelligent Cooperative Vehicular System

A development of the integrated vehicular system through ground and aerial cooperation using intelligent mobile robots and smart UAVs is required to support various applications including intelligent transportation, secure service, surveillance reinforcement. Also, it is highly anticipated that the applicability of virtual emotion is expanded continuously in smart systems. In this paper, we introduce a geographic segmentation security barrier system for the purpose of secure surveillance through virtual emotion detection in intelligent cooperative vehicular area with mobile robots and UAVs. The proposed system is necessary to provide discriminative priorities in the requested cooperative vehicular area consisting of mobile robots and UAVs with rapid construction. Moreover, with ILP formulation, we formally defined a problem whose goal is to maximize a total number of geographic segmentation security barriers such that the completed establishment of those barriers is done by a specific group of mobile robots and UAVs within the requested various districts where they are divided according to differential security priorities. To solve the problem, we devise novel schemes to return the maximum number of geographic segmentation security barriers so that it pursues the maximization of system lifetime consequently. Then, the proposed approaches are implemented through expansive simulations and their performances based on numerical results are evaluated clearly.

Cooperative vehicular systems: crossroad management through visible light

Information and communication technologies enable optoelectronic cooperative vehicular systems with bi-directional communication, where vehicles communicate with other vehicles, road infrastructures, traffic lights, and vulnerable road users. We use the concept of request/response for the management of a trajectory in a two-way-two-way traffic lights controlled crossroad, using visible-light communication (VLC). The connected vehicles receive information from the network (Infrastructure to Vehicle, I2V), interact with each other (Vehicle to Vehicle, V2V) and with the infrastructure (Vehicle to Infrastructure, V2I), using a request distance and pose estimation concept. In parallel, an intersection manager (IM) coordinates the crossroad and interacts with the vehicles (I2V) using the response distance and the pose estimation concepts. The communication is performed through VLC using the street lamps and the traffic signaling, to broadcast the information. Data are encoded, modulated, and converted into light signals emitted by the transmitters. Tetra-chromatic white sources are used, providing a different data channel for each chip. As receivers and decoders, SiC wavelength division multiplexer (WDM) devices, with light filtering properties, are considered. A simulated vehicle-to-everything (V2X) traffic scenario is presented, and a generic model of cooperative transmission is established. The primary objective is to control the arrival of vehicles to the intersection and schedule them to cross over at time instants that minimize delays. A phasing traffic flow is developed as a proof of concept (PoC). The simulated/experimental results confirm the cooperative VLC architecture. Results show that the communication between connected cars is optimized using a request/response concept and that pose analysis is an important issue to control driver’s behavior in a crossroad. The block diagram conveys that the vehicle’s behavior (successive poses) is influenced by the maneuver permission, by the I2V messages and also by the intersection redesigned layout and presence of other vehicles. An increase in the traffic throughput with least dependency on infrastructure is achieved.

POSACC: Position-Accuracy Based Adaptive Beaconing Algorithm for Cooperative Vehicular Safety Systems

Cooperative vehicular safety systems are expected to revolutionize the driving experience by providing road safety applications based on incident detection. Two vital quality parameters for cooperative safety applications are the position accuracy and communication reliability of the status information. The receiver may take erroneous decisions if the received data does not correspond to the latest situation of the transmitter (e.g., position, velocity, and trajectory of the target vehicle). In this paper, we propose and evaluate a POSition-ACCuracy (POSACC) based adaptive beaconing algorithm for cooperative vehicular safety systems. POSACC integrates three different control mechanisms to guarantee specific performance metrics. It adopts the position accuracy and communication reliability as the highest priority metrics, due to their direct impact on the vehicle's systems capability to avoid potential traffic accidents in real-time. In addition, it guarantees the priority metrics, maintaining the vehicle's warning distance, channel load, and end-to-end latency into the operative range of cooperative safety applications. POSACC is compared with three different state-of-the-art adaptive beaconing algorithms; ETSI DMG, LIMERIC, and DC-BTR&P. Extensive evaluation results show that POSACC successfully controls the beacon rate, transmission power, and the size of the minimum contention window. Simulation results also demonstrate that POSACC is more effective than the benchmark algorithms by guaranteeing the operational requirements of cooperative safety applications in a wider range of traffic situations.

Stochastic Geometric Analysis in Cooperative Vehicular Networks Under Weibull Fading

We study the performance of a cooperative vehicular communication system in a highway traffic scenario, where the locations of co-channel interfering vehicles are modeled by a one-dimensional Poisson point process (PPP). Wireless channel modeling campaigns have shown that the statistical patterns of vehicle-to-vehicle (V2V) channels can often be modeled by the Weibull distribution. Due to the complex characteristics of random fading and interference, system performance analysis is involved. To address this issue, we establish a framework for performance analysis in vehicular networks under Weibull fading and one-dimensional Poisson field of interference, where the Weibull probability density function (PDF) is approximated by a finite exponential mixture. By this means, the approximation expressions of the successful/unsuccessful message transmission probabilities for both direct V2V communication and the three-node cooperative vehicular communication are derived through stochastic geometry. Monte-Carlo simulations verify the accuracy of our derivation, as well as the advantages of encouraging cooperation among vehicles. Our methods and results can potentially be used to facilitate stochastic geometric analysis in many other complex vehicular networks under Weibull fading.

Cooperative vehicular communication systems based on visible light communication

The use of visible light communication (VLC) in vehicular communication systems for vehicle safety applications is proposed. The system aims to ensure the communication between a LED-based VLC emitter and an on-vehicle VLC receiver. A traffic scenario is established. Vehicle-to-vehicle (V2V) and infrastructure-to-vehicle (I2V) communications are analyzed. For the V2V communication study, the emitter was developed based on the vehicle headlights, whereas for the study of I2V communication system, the emitter was built based on streetlights. The VLC receiver is based on amorphous SiC technology and enhances the conditioning of the signal enabling to decode the transmitted information. Receivers are located at the rooftop of the vehicle, for I2V communications, and at the tails for V2V reception. Clusters of emitters, in a square topology, are used in the I2V transmission. The information and the ID code of each emitter in the network are sent simultaneously by modulating the individual chips of the trichromatic white LED. Free space is the transmission medium. An on–off code is used to transmit data. An algorithm to decode the information at the receivers is set. The proposed system was tested. The experimental results confirmed that the proposed cooperative VLC architecture is suitable for the intended applications.

GNSS Multipath-Resistant Cooperative Navigation in Urban Vehicular Networks

Multipath delays and signal outages in urban environments have been the most difficult problems in Global Navigation Satellite System (GNSS)-based cooperative vehicular navigation systems. In this paper, we develop a non-line-of-sight (NLOS) GNSS signal detection algorithm and propose a multipath-resistant hybrid sum–product algorithm over a wireless network (MRH-SPAWN) and multipath-resistant hybrid cooperative extended Kalman filter (MR-hcEKF) techniques that significantly enhance multipath robustness in urban environments, compared with H-SPAWN and hcEKF, respectively. We provide theoretical derivation and realization of the proposed techniques and demonstrate the performance with numerous Monte Carlo simulations using field measurements of multipath delays. The proposed techniques significantly improve the positioning accuracy of all vehicles and outperform the conventional cooperative positioning (CP) technique in urban multipath environments.

GNSS, 비전 및 레이더를 이용한 H-SPAWN 알고리즘 기반 자동차 협력 항법시스템

In this paper, we propose a vehicular cooperative navigation system using GNSS, vision sensor and radar sensor that are frequently used in mass-produced cars. The proposed cooperative vehicular navigation system is a variant of the Hybrid-Sum Product Algorithm over Wireless Network (H-SPAWN), where we use vision and radar sensors instead of radio ranging(i.e.,UWB). The performance is compared and analyzed with respect to the sensors, especially the position estimation error decreased about fifty percent when using radar compared to vision and radio ranging. In conclusion, the proposed system with these popular sensors can improve position accuracy compared to conventional cooperative navigation system(i.e.,H-SPAWN) and decrease implementation costs.

Relay selection for DF-based cooperative vehicular systems

In this paper, error performance analysis of decode-and-forward (DF)-based cooperative vehicular networks with relay selection is investigated. All of the links in the system are modeled as cascaded Nakagami-m distributed random variables which provide a realistic description of an intervehicular channel. We employ virtual-noise (VN)-based demodulation, maximum likelihood (ML) demodulation, cooperative maximal ratio combining (C-MRC), and log-likelihood-ratio-based transmissions in mitigating error propagation effect encountered in DF cooperative networks. In order to obtain more effective solutions and improve the system performance, we introduce hybrid anti-error propagation approaches, namely VN-MRC, VN-ML, and VN-LLR in which relay selection criterion is derived by using conditional bit error rate (BER) expressions of VN technique while data detection is performed by utilizing maximal ratio combining (MRC), ML detection, C-MRC and LLR transmission methods. The performance analyses and the numerical results for cascaded Nakagami-m channels have shown that VN-LLR approach provides significant performance improvement with respect to the other considered techniques in DF cooperative vehicular systems with relay selection.

Performance Analysis of Cooperative Vehicular Systems with Co-channel Interference Over Cascaded Nakagami-m Fading Channels

In this paper, we investigate a dual-hop decode-and-forward (DF) relaying vehicular system in the presence of co-channel interference, in which source, relay and destination terminals are composed ...

Fuzzy Logic Ticket Rate Predictor for Congestion Control in Vehicular Networks

Cooperative vehicular systems are currently being investigated to design innovative intelligent transportation systems (ITS) solutions for road traffic management and safety. This paper proposes a preventive congestion control mechanism applied at highway entrances and devised for ITS systems. Our mechanism integrates different types of vehicles and copes with vehicular traffic fluctuations due to an innovative fuzzy logic ticket rate predictor. The proposed mechanism efficiently detects road traffic congestion and provides valuable information for the vehicular admission control. When we apply an authentic enhanced mobility model, the results demonstrate the mechanism capability to accurately characterize road traffic congestion conditions, shape vehicular traffic and reduce travel time.

Vehicular Link Performance: From Real-World Experiments to Reliability Models and Performance Analysis

The enormous potential of cooperative vehicular systems to improve traffic safety and efficiency by wirelessly exchanging information among vehicles, as well as between vehicles and infrastructure, has been a research focus since the early 1990s. Significant evolution of this technology has prompted standardization bodies and automotive industry stakeholders worldwide to pay particular attention to its deployment and development, for which a deep understanding of the influence of every component and parameter is required.

Cooperative vehicle-to-vehicle active safety testing under challenging conditions

Cooperative vehicular communication systems are being developed to improve traffic safety and efficiency through the wireless exchange of information between vehicles and between vehicles and infrastructure units. The future deployment of cooperative active safety applications requires their prior extensive testing due to their critical nature and strict quality of service requirements. Such testing should consider challenging driving and communications conditions that could significantly impact the applications’ effectiveness. In this context, this paper presents a cooperative communications testing platform implemented to evaluate the operation and effectiveness of cooperative active safety applications under challenging driving and communications conditions. The paper also reports the results of an extensive testing campaign that reveals potential limitations of cooperative technologies and applications, and discusses possible countermeasures to overcome the applications’ effectiveness degradation under adverse operating conditions.

Traffic congestion detection in large-scale scenarios using vehicle-to-vehicle communications

Cooperative vehicular systems are currently being investigated to design innovative ITS (Intelligent Transportation Systems) solutions for road traffic management and safety. Through the wireless exchange of information between vehicles, and between vehicles and infrastructure nodes, cooperative systems can support novel decentralized strategies for ubiquitous and more cost-attractive traffic monitoring. In this context, this paper presents and evaluates CoTEC (COperative Traffic congestion detECtion), a novel cooperative technique based on Vehicle-to-Vehicle (V2V) communications designed to detect road traffic congestion. CoTEC is evaluated under large-scale highway scenarios using iTETRIS, a unique open source simulation platform created to investigate the impact of cooperative vehicular systems. The obtained results demonstrate CoTEC's capability to accurately detect and characterize road traffic congestion conditions under different traffic scenarios and V2V penetration rates. In particular, CoTEC results in congestion detection probabilities higher than 90%. These results are obtained without overloading the cooperative communications channel. In fact, CoTEC reduces the communications overhead needed to detect road traffic congestions compared to related techniques by 88%.

Congestion and Awareness Control in Cooperative Vehicular Systems

Cooperative vehicular systems have been identified as a promising solution to overcome the current and future needs for increasing traffic safety and efficiency, while providing infotainment and added-value services on the move. To achieve their objectives, cooperative vehicular systems will be based on wireless communications between vehicles and with other infrastructure nodes, and will have to deal with highly dynamic nodes, challenging propagation conditions, and stringent application requirements. By looking at cooperative applications and their data traffic, as well as the current and foreseen spectrum allocations for cooperative vehicular systems, there is a risk that the corresponding radio channels could easily be saturated if no control algorithms are used. The saturation of the radio channels would result in unstable vehicular communications, and thus in an inefficient operation of cooperative systems. As a prime example of upcoming ubiquitous networks contributing to the vision of “a thousand radios per person,” cooperative vehicular systems need to be designed to scale to high densities of radios without centralized coordination, while at the same time guaranteeing the requirements of the implemented applications and services, for example the stringent needs of active traffic safety applications. In this paper, we survey and classify various decentralized methods to control the load on the radio channels and to ensure each vehicle's capacity to detect and communicate with the relevant neighboring vehicles, with a particular focus on approaches based on transmit power and rate control. Finally, we discuss the open research challenges that are imposed by different application requirements and potential existing contradictions.