Showing papers by "Marco Zennaro published in 2004"

An overview of emerging results in cooperative UAV control

Abstract: Inexpensive fixed wing UAV are increasingly useful in remote sensing operations. They are a cheaper alternative to manned vehicles, and are ideally suited for dangerous or monotonous missions that would be inadvisable for a human pilot. Groups of UAV are of special interest for their abilities to coordinate simultaneous coverage of large areas, or cooperate to achieve goals such as mapping. Cooperation and coordination in UAV groups also allows increasingly large numbers of aircraft to be operated by a single user. Specific applications under consideration for groups of cooperating UAV are border patrol, search and rescue, surveillance, communications relaying, and mapping of hostile territory. The capabilities of small UAV continue to grow with advances in wireless communications and computing power. Accordingly, research topics in cooperative UAV control include efficient computer vision for real-time navigation and networked computing and communication strategies for distributed control, as well as traditional aircraft-related topics such as collision avoidance and formation flight. Emerging results in cooperative UAV control are presented via discussion of these topics, including particular requirements, challenges, and some promising strategies relating to each area. Case studies from a variety of programs highlight specific solutions and recent results, ranging from pure simulation to control of multiple UAV. This wide range of case studies serves as an overview of current problems of Interest, and does not present every relevant result.

Distributing synchronous systems with modular structure

Abstract: Synchronous programs were introduced to simplify the development of reactive systems hiding the complexity and indeterminism of the interleaving while taking full advantage of possible concurrency. The introduction of communication networks enabled the creation of distributed systems presenting the programmer with a new burden of interleaving and nondeterminism due to the asynchronous communication medium. Again this complexity should be hidden from the user while taking full advantage of the possible concurrency to improve performance. Many algorithms for the automatic distributions of synchronous programs have been proposed so far, but they are not suitable for large scale system because they do not preserve the compositionality of the original code: the modularity of the synchronous program is lost. As a result the subsystems are not re-usable and a small local change results in the recompilation and re-distribution of the overall system. This solution is cumbersome and unpractical in many real-world applications. In this paper we introduce an algorithm for the distribution of synchronous programs that preserves the modularity and allows separate compilation and subsystem re-use.