Valentin Iordache

Cooperative Communication Network for Adaptive Truck Platooning.

Truck platooning represents a solution to increase energy efficiency of the freight road transport. This method assumes very little distance between trucks so that overall aerodynamic quotient is improved. However, this requires a specific and dedicated infrastructure, due to the fact that the total length of the convoy may be considerable, which has a negative impact on the general traffic: other vehicles need a lot of space (and time) to overtake the platoon and this can only be done on highways with more than two lanes / direction. This means that in most cases (national roads and less wide highways) platoons cannot be formed and this method cannot be implemented. To resolve this situation, in this article we have proposed a solution for dynamic platoon formation, based on vehicle-to-vehicle communications, that will allow other vehicles to gradually overtake the vehicles forming the platoon. For this, a communication technology proposal has been made to ensure the identification of vehicles that are obstructed by the platoon. We have also made a series of laboratory measurements to test the validity of the proposed solution and, in the end, presented our

Use of Energy Efficient Sensor Networks to Enhance Dynamic Data Gathering Systems: A Comparative Study between Bluetooth and ZigBee

As road traffic conditions worsen due to the constantly increasing number of cars, traffic management systems are struggling to provide a suitable environment, by gathering all the relevant information from the road network. However, in most cases these are obtained via traffic detectors placed near road junctions, thus providing no information on the conditions in between. A large-scale sensor network using detectors on the majority of vehicles would certainly be capable of providing useful data, but has two major impediments: the equipment installed on the vehicles should be cheap enough (assuming the willingness of private car owners to be a part of the network) and be capable of transferring the required amount of data in due time, as the vehicle passes by the road side unit that acts as interface with the traffic management system. These restrictions reduce the number of technologies that can be used. In this article a series of comprehensive tests have been performed to evaluate the Bluetooth and ZigBee protocols for this purpose from many points of view: handshake time, static and dynamic data transfer (in laboratory conditions and in real traffic conditions). An assessment of the environmental conditions (during tests and probable to be encountered in real conditions) was also provided.

Bluetooth latency analysis for vehicular communications in a Wi-Fi noisy environment

Vehicular communications represent the novelty in road safety and improvement of traffic conditions, as they allow the exchange of appropriate data between vehicles or between vehicles and infrastructure (road side units). However, in such dynamic environment, a safe and reliable communication is very difficult to obtain. The most tested and appropriate technologies appear to be, in 2.4 GHz: Wi-Fi, Bluetooth and ZigBee, while in 5.8/5.9 GHz the FCC has allocated typical Dedicated Short Range Communication frequency band. However, for typical non-critical applications there is no need for expensive communications. There are several cheaper options, like ZigBee, Bluetooth or Wi-Fi. In this paper we have performed a series of analysis on Bluetooth technology, as the most common short distance communication and we have tested the possibility of transferring data in noisy Wi-Fi environment. The results obtained (in terms of handshake time) were assessed and conclusions regarding the possibility of implementing Bluetooth communications in vehicular environments have been formulated.

Analysis of handshake time for bluetooth communications to be implemented in vehicular environments

The key element in modern Intelligent Transport Systems is the communication between all the devices, as neither of them can run independently, but require interaction with other equipment. This is also true for vehicles: advances in autonomous vehicles field requires communications with other vehicles or infrastructure, in order for the vehicle to be aware of its environment. There are several technologies available for short/medium distance that are suitable for vehicular communications. The most used one for vehicle-to-vehicle is Dedicated Short Range Communication. However, in many applications this expensive technology is not necessary, especially when the key element is connection time, due to the reduced data quantity needed to be exchanged. In this paper we have performed analysis on Bluetooth, as the most common short distance communication technology, and we have tested the handshake time in noisy Wi-Fi environments.

Use of V2I communications to enhance accuracy of the estimated time of arrival in crowded transport environments

Traveller information systems are an important element in a modern urban traffic management concept. Much information may be provided that is addressed to different receptors (drivers, bikers, public transport users). For each of them different data sources are requires and, therefore, a unitary system is difficult to develop and implement. From all the components that can be put in place, we consider that one of the most important ones is the public transport user information. This concept has two reasons: first of all, a very good public transport may represent the solution for future urban travel, as roads are getting more and more crowded with private cars that can only transport an extremely reduced number of people (considering the space occupied in the road network) compared to the public transport. Second of all, in crowded road networks, the time a bus will arrive in a bus stop is very difficult to estimate. That is why, in this paper, we have described a system that is developed now only as a laboratory model, that aims to provide a good estimation even in congested situations.

Analysis of interferences in data transmission for wireless communications implemented in vehicular environments

This paper aims to provide an image on the usability of low power, short distance standard communications technologies for specific applications, like messaging, in cooperative collision avoidance or emergency vehicles guidance. Specific measurements regarding communications interferences and density have been performed in representative road junctions in Bucharest and the results were used to determine modalities for employing this type of communications for such applications.

Considerations for using ZigBee technology in vehicular non-critical applications

The paper presents results of ZigBee communication tests performed in a specifically set electromagnetic environment, with the purpose to determine the applicability of ZigBee technology in non-critical messaging for vehicular communications. Known for its low energy consumption, the ZigBee technology might be used in background messaging for cooperative driving, with the purpose to reduce the overload on the main channels used for emergency message warning, or other critical applications. In the paper are presented the test bed, results and solutions for new approaches with usability to vehicular communications.

The framework of using models for comparative assessment of traffic sensors

The intelligent transport systems (ITS) are now one of the most dynamic sector in terms of finding solutions for transport domain. These systems are applications of electronics, IT, computer science and other connected disciplines which are installed in terms of increasing the efficiency of the transport activities and decreasing the negative impact of them. ITS are mainly based on a sensor network which is able to collect data from transport processes. The paper is focused on elaboration of a common model for traffic sensor which is able to support comparative assessment of various traffic sensors (the example in the paper is based on inductive loops and virtual loops based on CCTV cameras). The framework and the models are created in LabVIEW and an example of using the model in comparative assessment is provided. The authors presented the methodology for the elaboration of the model as well as the recommendations for comparative assessment based on the proposed framework.