Transports can be made safer, more secure and efficient by help of telemetry and tracking on-line in real time. T4 is a system architecture aimed to support the development of telematic services for transparent tracking and surveillance monitoring of goods transported by different means on a global scale. The main idea is to focus on the transported pallets or parcels instead of the vehicles moving them. To enable rapid response to new customer requirements and to support remote management of field equipment, software implemented services are designed, packaged, deployed and mediated using XML, Java and the OSGi software technology standards.
Vehicle-to-vehicle wireless communication is a key component of tomorrow's cooperative safety applications. However, the wireless link is susceptible to effects such as shadowing which can cause communication failures. Such failures may in turn lead to hazardous traffic situations when safety applications cease to function. By monitoring communication QoS and adapting to changes, effects of link failure may be mitigated, however this requires a specification of the application QoS requirements. In this paper we combine the T-Window reliability QoS metric with a spatial component, allowing us to capture the dependencies between VANET QoS requirements and road geometry. The proposed representation can be used both at design-time, to characterize applications, and at run-time for QoS monitoring and adaptation purposes.
Cooperative safety using vehicle-to-vehicle and vehicle-to-infrastructure communication enables warning systems to take into account more detailed and longer range information than previously possible. Due to the increased prediction horizon tactical concepts such as traffic rules and driver intentions must be modelled in addition to short term kinematics traditionally used in driver alert systems. We propose a cooperative warning system that models such concepts using artificial potential fields taking into account multiple route-choice hypotheses. The system is being implemented on the hardware and software platform of the European CVIS project and will be used to evaluate the feasibility of using the history of route-choice estimates as an indicator of unpredictable driver behaviour.
Proactive vehicle safety systems based on vehicle-to-vehicle and infrastructure-to-vehicle communication are promising new approaches to reducing the number of accidents on our roads. In-vehicle applications are envisaged to provide a variety of services to the driver including warning about potential collisions and other hazardous situations. For the safe operation of these applications it is important not only to efficiently model the environment but also to reason about, and predict, how reliable such a model is under various circumstances. In this paper we propose an approach to estimating the reliability and availability of the wireless medium at hazardous locations by cooperatively detecting communication disturbances in order to allow for more accurate decisions by in-vehicle applications.
Proactive vehicle alert systems that warn the driver about dangerous situations must be able to reason about, and predict, likely future states of the traffic environment. Our prediction method is based on a combination of a fuzzy logic model for intersection turning behavior and Gipps model for car following behavior. The stochastic models are used together with a particle filter to recursively approximate the state probability distribution as measurements are received over time. Estimates of the unobservable part of the state are used to predict path choice and thus driver intentions. The approach is evaluated on trajectory data gathered from video footage of an intersection, however it is also relevant for trajectories acquired through vehicle-to-vehicle communication.
Even though improvements in automotive safety have caused a significant decline in the number of traffic fatalities there is a strong need for further work. One important area is wireless communication from vehicle-to-vehicle and vehicle-to-infrastructure which enables a host of new cooperative traffic applications ranging from collision avoidance to intelligent cruise control. However, using cooperation between vehicles as an enabler for safety-related functionality raises new issues on system dependability. In this paper we characterize the domain of cooperating vehicles and cooperative situation awareness and suggest a system architecture that promotes independent development and verification of safety functions.
In this paper an analysis of a distributed control system based on Java is presented. A classical PID controlled system is implemented simulating each part of a real control system running in different computers connected to a local area network. The communication message time periods and their jitter are measured running the system in different computer environments and the results are presented and discussed at the end. Real time specification for Java is used in the implemented software and the results are compared to other implementations. © Springer-Verlag Berlin Heidelberg 2011.
Future transportation systems will be a heterogeneous mix of items with varying connectivity and interoperability. A mix of new technologies and legacy systems will co-exist to realize a variety of scenarios involving not only connected cars but also road infrastructures, pedestrians, cyclists, etc. Future transportation systems can be seen as a System of Systems (SoS), where each constituent system - one of the units that compose an SoS - can act as a standalone system, but the cooperation among the constituent systems enables new emerging and promising scenarios. In this paper we investigate how to architect cars so that they can be constituents of future transportation systems. This work is realized in the context of two Swedish projects coordinated by Volvo Cars and involving some universities and research centers in Sweden and many suppliers of the OEM, including Autoliv, Arccore, Combitech, Cybercom, Knowit, Prevas, ÅF-Technology, Semcom, and Qamcom. © 2016 Association for Computing Machinery. All rights reserved.
Sensor networks are being applied in several emerging sophisticated applications due to the use of powerful and high-quality sensor nodes, such as radars and visible light cameras. However, these nodes need additional features to optimally benefit from heterogeneous modern computing platforms. Therefore, reconfigurable computing is a potential paradigm for those scenarios as it can provide flexibility to explore the computational resources on that kind of high performance computing system. This paper presents a reconfigurable sensor node allocation support, based on application requirements, provided by a middleware focused on heterogeneous sensor networks. In order to address this concern, an aspect-orientation paradigm and intelligent agents approach is proposed followed by an UAV case study.
Many modern applications require high-performance platforms to deal with a variety of algorithms requiring massive calculations. Moreover, low-cost powerful hardware (e.g., GPU, PPU) and CPUs with multiple cores have become abundant, and can be combined in heterogeneous architectures. To cope with this, reconfigurable computing is a potential paradigm as it can provide flexibility to explore the computational resources on hybrid and multi-core desktop architectures. The workload can optimally be (re)distributed over heterogeneous cores along the lifecycle of an application, aiming for best performance. As the first step towards a run-time reconfigurable load-balancing framework, application requirements and crosscutting concerns related to timing play an important role for task allocation decisions. In this paper, we present the use of aspect-oriented paradigms to address non-functional application timing constraints in the design phase. The DERAF aspects’ framework is extended to support reconfiguration requirements; and a strategy for load-balancing is described. In addition, we present preliminary evaluation using an Unmanned Aerial Vehicle (UAV) based Surveillance System as case study.
Sensor networks are being used to implement different types of sophisticated emerging applications, such as those aimed at supporting ambient intelligence and surveillance systems. This usage is enhanced by employing sensors with different characteristics in terms of sensing, computing and mobility capabilities, working cooperatively in the network. However, the design and deployment of these heterogeneous systems present several issues that have to be handled in order to meet the user expectations. The main problems are related to the nodes' interoperability and the overall resource allocation, both inter and intra nodes. The first problem requires a common platform that abstracts the nodes' heterogeneity and provides a smooth communication, while the second is handled by cooperation mechanisms supported by the platform. Moreover, as the nodes are supposed to be heterogeneous, a customizable platform is required to support both resource rich and poorer nodes. This paper analyses surveillance systems based on a heterogeneous sensor network, which is composed by lowend ground sensor nodes and autonomous aerial robots, i.e. Unmanned Aerial Vehicles (UAVs), carrying different kinds of sensors. The approach proposed in this work tackles the two above mentioned problems by using a customizable hardware platform and a middleware to support interoperability. Experimental results are also provided.
Node failures in Wireless Sensor Networks composed by static sensor nodes are common due to the nature of the sensor devices and the usually harsh environments in which they are deployed. Node failures can diminish the performance of the network as a whole, thus affecting its functionality in delivering the desired services. For instance, significant regions can become uncovered due to failure of several nearby nodes. This paper reports a study about the use of mobile sensor nodes acting in cooperation with static ones in order to fill gaps created by faulty static nodes. The proposed fault handling mechanism presents alternative policies with pros and cons, depending on the user priorities imposed to the system and the occurrence of failures. A discussion about this topic is presented based on results obtained by simulation of the proposed mechanisms.
The emerging applications using sensor network technologies constitute a new trend requiring several different devices to work together and partly autonomously. However, the integration and coordination of heterogeneous sensors in these emerging systems is still a challenge, especially when the target application scenario is susceptible to constant changes. The setup and adaptation of these systems are challenging, considering that their nodes are distributed and must respect operational constraints, such as energy consumption. Due to the dynamicity of the scenarios in which they are deployed and the nature of their operations these systems require autonomous decisions that have to be taken without any human operator intervention. This paper presents a reflective middleware that supports heterogeneous sensor networks deployed in dynamic scenarios. This middleware presents specific handling of users’ requirements by representing them as missions that must be accomplished by the network. These missions are then translated to network parameters and activities that are distributed to network nodes by means of the autonomous reasoning that takes into account network nodes’ capabilities and environment conditions. A multi-agent framework is proposed to provide the necessary support for missions’ dissemination and for the required reasoning to allow autonomous behaviour related to mission allocation and network adaptation.
The use of mobile software agents is a promising approach to implement services and disseminate data over ad hoc networks. This paper presents an analysis of mobile autonomous agents with different levels of intelligence that allow them to make usage of the positioning information with different complexity in a mobile ad hoc network aiming at efficient data dissemination. This information considers the nodes current and future locations, as well as the route used to reach their destinations, depending on the agents' intelligence. Using this information, the agents decide their movement from node to node during opportunistic connections in order to accomplish their goals related to data dissemination and/or service provisioning. The analysis of this proposal is done in the context of a sensor network application, implemented by sensing services provided by mobile agents, which run on top of an infrastructure-less Vehicular Ad hoc Network (VANET). Simulation results are presented and discussed to support the proposed ideas. (C) 2013 Elsevier B.V. All rights reserved.
This paper presents a bio-inspired networking strategy to support the cooperation between static sensors on the ground and mobile sensors in the air to perform surveillance missions in large areas. The goal of the proposal is to provide a low overhead in the communication among sensor nodes, while allocating the mobile sensors to perform sensing activities requested by the static ones. Simulations have shown that the strategy is efficient in maintaining low overhead and achiving the desired coordination. © 2013 by the authors; licensee MDPI, Basel, Switzerland.
This paper explores geographical location awareness to support software agent mobility in ad hoc networks. The idea is to evaluate the concept of opportunistic communication to perform agent migration and mobility among nodes (handover), in an infrastructureless vehicular ad-hoc network (VANET). The application of this idea can support a number of applications, and one of particular interest is a “virtual sensor network” composed of software agents that implement missions in the form of sensing services, which use the available resources provided by the physical nodes, i.e. physical sensor devices, computing platforms and communication devices. A case study is presented together with simulations results to assess the efficiency of the proposed approach.
This paper presents middleware mechanisms to support real-time services in heterogeneous sensor networks, focusing on the evaluation of link metrics. Heterogeneous sensor networks require specific QoS (quality of service) guarantees in order to allow the coordination and cooperation among the different nodes that compose the system. In order to improve QoS, one of the first steps is to enhance the usage of the communication links, aiming at a more reliable and efficient message exchange. In this paper, key middleware features to address this concern are presented, in which a focus is given on the use of a link metric that, as part of a protocol, is used to optimize the message forwarding in relay communications across the network. Additionally, preliminary results are also presented.
The use of sensor networks in different kinds of sophisticated applications is emerging due to several advances in sensor technologies and embedded systems. However, the integration and coordination of heterogeneous sensors is still a challenge, especially when the target application environment is susceptible to changes that the system must track and adapt itself to in order to fulfil the users’ requirements. These changing scenarios require services being provided in different places during the system runtime, and to fulfil this, a support for adaptability is needed. In this paper we present some initial ideas to use multi-agents in a middleware that aims to provide the necessary support to sophisticated sensor network applications.
The use of sensor networks in different kinds of sophisticated applications is emerging due to several advances in sensor/embedded system technologies. However, the integration and coordination of heterogeneous sensors is still a challenge, especially when the target application environment is susceptible to changes. Such systems must adapt themselves in order to fulfil increasing requirements. Especially the handling of real-time requirements is a challenge in this context in which different technologies are applied to build the overall system. Moreover, these changing scenarios require services located at different places during the system runtime. Thus a support for adaptability is needed. Timing and precision requirements play an important role in such scenarios. Besides, QoS management must provide the necessary support to offer the flexibility demanded in such scenarios. In this paper we present the real-time perspective of a middleware that aims at providing the support required by sophisticated heterogeneous sensor network applications. We propose to address the real-time concerns by using the OMG Data Distribution Service for Real-time Systems approach, but with a more flexible approach that fits in the heterogeneous environment in which the proposed middleware is intended to be used. We also present a coordination protocol to support the proposed approach.
The use of sensor networks in sophisticated applications is emerging as a new trend. However, the integration and coordination of heterogeneous sensors is still a challenge, especially when the target application scenario is susceptible to constant changes. Such systems must adapt themselves in order to fulfill requirements that can also change during the system runtime. Moreover, the changes that occur in such scenarios require services located at different places during the system runtime. Due to the dynamicity of this context, system adaptations must take place very quickly, requiring that decisions for adaptation are taken autonomously by the system without waiting for human operator's directions. Thus a reflective behavior must be provided. This paper presents a reflective middleware that supports reflective behaviors to address adaptation needs of heterogeneous sensor networks deployed in dynamic scenarios. This middleware presents specific handling of concerns related to real-time, service adaptation and resource allocation through network reasoning. These concerns are addressed mainly by the use of mobile and multi-agents, and aspect-oriented concepts. The use of multi-agents represents the spreading of intelligence over the network, while the mobile-agents provide service adaptation by code mobility. In the same direction, aspects address behavioral adaptations related to crosscutting concerns.
Embedded systems have several characteristics, such as application specific needs, real-time constraints and intrinsic embedded concerns (i.e. energy consumption), which hinder the reuse of previously developed components as well as their adaptation to provide variability in a software product line. As more applications require embedded system solutions, it is clear that if each time a new application is developed, it is not suitable to develop its supporting embedded system components from scratch. Resulting in an inability of the industry to follow the needs imposed by the market. To cope with this problem, the reuse of components within software product lines is a key issue. It seams to be easy task, but in fact it is not, due to increasing amount functionalities and crosscutting concerns present in those applications. In this paper we present an approach to handle components at a higher abstraction level, whose handling of crosscutting concerns is weaved by system level aspects, in order to address such complexity and also to make it easier the handling of variations in a software product line.
How to measure and maintain connectivity is an important issue in ad hoc networks. A special case of such network is Wireless Sensor Networks (WSN), which are often deployed in harsh environments and also susceptible to a number of problems that may negatively affect the connectivity among the nodes. An additional factor that increases the cost of connectivity maintenance in ad hoc networks is when the nodes can move. When it comes to the WSN domain, this aspect is still more problematic, as the often small sensor nodes have in general a limited energy budget, and then should not use too much energy in the management of their connectivity. The goal of this work is to choose a topology for mobile WSN and improve the network connectivity as a whole while considering and influencing the energy consumption among all the nodes in the network. Different network topologies are considered and discussed. After evaluation of the pros and cons of the estimation quality when applied to each studied topology, a clustered hierarchical algorithm was chosen for network deployment. By means of a link estimator and considering different variables, a metric have been defined to estimate the link reliability. As a result, improved network connectivity is reported.
Vehicular Ad hoc Networks (VANETs) is a technology to support communication among vehicles or between vehicles and infrastructure in order to exchange traffic information and avoid accidents. Many applications in VANETs need to transmit messages to vehicles within a specific geographic region. This behaviour is called Geocast. Several Geocast routing protocols have been proposed for VANETs. In this paper, some important and representative Geocast routing protocols are summarized and theoretically compared. In order to evaluate the performance of these protocols, the evaluation methods are also defined, which include both the Packet Delivery Ratio (PDR) and the Packet Delivery Time (PDT). Additionally, some important and new models, such as the influences of city lights, and the distance between buildings potentially acting as free line of sight obstacles, are proposed to create a more realistic city environment for Geocast routing simulation. © 2014 IEEE
This paper identifies the need for multiple clients to concurrently access a device community. A set of embed ded devices cooperate via one or more service discovery protocols, such as UPnP, Jini, HAVi or OSGi. We present an approach that encapsulates additional services into a Distributed Access Framework (DAF). The services in DAF are responsible for secure and coordinated access of the distributed devices in the community. The different services of DAF can optionally be implemented and executed on different devices. We specify the DAF and demonstrate an implementation where the devices are organized according to the OSGi specification.
A traffic situation estimator capable of analyzing driving behavior utilizing an image analysis-based tracking module is presented. The behavior is analyzed by using a state machine driven counter to estimate the traffic rhythm and determine if the detected vehicles are approaching, getting away, have been overtaken or have overtaken the ego-vehicle. Depending on the result, the traffic situation estimator suggest different reactions, either to drive faster, slower or optionally suggest to overtake vehicles ahead to help the driver to follow the traffic rhythm which in turn will improve safety and energy efficiency. The proposed approach is implemented in a smart-phone and has shown good performance while testing the application on a two-lane highway. © 2016 IEEE.
As one of the most important enablers of Intelligent Transportation System (ITS), Inter-Vehicle Communication (IVC) have been a hot research direction in nearly a decade. To improve vehicle safety and cooperative systems, most of ITS applications need efficient and stable Vehicular Ad hoc Networks (VANETs) among vehicles and infrastructures, which can be set up by Geocast routing protocols. Some of these applications require the protocols, known as region-based Geocast routing protocols, supporting to broadcast messages to vehicles within a specific geographic region. Since different protocols are appropriate for different purposes or occasions, it is significant to simulate protocols and evaluate their performances under a variety of scenarios. Therefore, this paper focuses on investigations of simulation environment configurations for some known Geocast routing protocols. According to the investigations, a region based Geocast routing simulator is designed and developed. To demonstrate the effectiveness and the reliability of this simulator, several protocols are simulated and the performances of them are presented. © 2014 IEEE